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Networks of Micellar Chains with Nanoplates

Networks of Micellar Chains with Nanoplates ISSN 1811-2382, Polymer Science, Series C, 2021, Vol. 63, No. 2, pp. 170–180. © The Author(s), 2021. This article is an open access publication. Russian Text © The Author(s), 2021, published in Vysokomolekulyarnye Soedineniya, Seriya C, 2021, Vol. 63, No. 2, pp. 159–170. REVIEWS a, b c,d V. S. Molchanov *, A. I. Kuklin , A. S. Orekhov , e f a N. A. Arkharova , E. S. Khudoleeva , and O. E. Philippova Department of Physics, Moscow State University, Moscow, 119991 Russia Joint Institute for Nuclear Research, Dubna, Moscow oblast, 141980 Russia Moscow Institute of Physics and Technology (National Research University), Dolgoprudny, Moscow oblast, 141701 Russia Kurchatov Institute National Research Center, Moscow, 123182 Russia Crystallography and Photonics Federal Scientific Research Center, Russian Academy of Sciences, Moscow, 119333 Russia OOO NPO NIIPAV, Volgodonsk, Rostov oblast, 347366 Russia *e-mail: molchan@polly.phys.msu.ru Received March 26, 2021; revised May 27, 2021; accepted June 16, 2021 Abstract—Nanocomposite networks of surfactant micellar chains and natural bentonite clay nanoplates are studied by rheometry, small-angle neutron scattering, and cryogenic transmission electron microscopy. It is shown that, in an aqueous medium in the presence of a small part of an anionic surfactant, sodium dodecyl sulfate, the molecules of a biodegradable zwitterionic surfactant, oleyl amidopropyl dimethyl carboxybetaine, form micron-length living micellar chains which entangle and form a network possessing well-def ined visco- elastic properties. It is found that addition of negatively charged clay nanoplates leads to an increase in vis- cosity and relaxation time by an order of magnitude. This is explained by the incorporation of the nanoplates into the network as physical multifunctional crosslinks. The incorporation occurs via the attachment of semi- spherical end-caps of the micelles to the surface of the particles covered with a surfactant layer, as visualized by cryogenic transmission electron microscopy. As the amount of nanoplates is increased, the rheological properties reach plateau; this is associated with the attachment of all end parts of micelles to nanoplates. The developed nanocomposite soft networks based on safe and eco-friendly components are promising for vari- ous practical applications. DOI: 10.1134/S1811238221020053 INTRODUCTION Wormlike surfactant micelles are widely used as thickening agents in the oil production [12, 13], cos- Modern technologies impose high requirements on metics, and household chemicals [14] and drag reduc- materials, especially in terms of ecology and safety for ing additives promoting the laminarity of a f low at its humans. Therefore, attempts are made to replace syn- high velocities [15]. Wormlike micelles replace poly- thetic polymers by natural polymers capable of bio- mers in many practical applications. However, a wider degradation accompanied by the formation of harm- use of micellar systems is prevented by relatively low less products [1]. An alternative approach can be the values of the viscosity and elastic modulus of surfac- use of supramolecular chains formed by the noncova- tant solutions. lent interactions of small molecules instead of polymer One of the most promising approaches to increase chains formed by covalent bonds. The simplest exam- the viscosity and elastic modulus of the networks pro- ple of such chains is the wormlike micelles of surfac- posed in recent years consists in the addition of inor- tants [2–7]. The contour length of the chains can ganic nanoparticles to wormlike surfactant micelles reach tens of micrometers [8], while their persistence [16]. Micellar chains can attach by their ends to the length is usually 15–40 nm [2] at a cross-section size surface of nanoparticles covered with a surfactant of 4–5 nm [3, 9]. They are similar to polymer chains, layer; as a result, the nanoparticles act as a crosslinking in particular, they can interlace and form a network of agent in the micellar network. It was shown that just topological entanglements which imparts viscoelastic end-caps of wormlike micelles participate in interac- properties to solutions. But, as opposed to polymer tion with the nanoparticles because they are the energy chains, living micellar chains constantly break up and unfavorable micelle regions. Surfactant molecules recombine [9, 10] and they can be easily destroyed, for have a spherical packing in them, as opposed to the example, by adding a small amount of nonpolar sub- cylindrical packing in the central part of a micelle stances [11]. which is optimum in the formation of wormlike 170 NETWORKS OF MICELLAR CHAINS WITH NANOPLATES 171 micelles. It was shown that the addition of nanoparti- The aim of this work is to study the effect of cles induces a significant increase in the viscosity of nanoparticles on the rheological properties and struc- surfactant solutions. The most substantial growth in ture of wormlike micelles based on a biodegradable zwitterionic surfactant with a long C18 tail, oleyl ami- viscosity (by orders of magnitude) is observed at the dopropyl dimethyl carboxybetaine (OAB), obtained concentration of surfactants in the vicinity of the over- from biorenewable resources, vegetable oils, with a lap concentration C* of micellar chains [17–19]. In small addition of an anionic surfactant, sodium this case, the introduction of nanoparticles leads to dodecyl sulfate (SDS). As opposed to the overwhelm- transition from a viscous f luid to a viscoelastic solu- ing majority of previous works on nanocomposite sys- tion. At a higher surfactant concentration when the tems based on wormlike surfactant micelles [17–23, micelles are already significantly entangled, the intro- 25], platelike nanoparticles with a high specif ic surface duction of nanoparticles increases viscosity moder- compared with commonly used spherical particles ately by 1.5–3 times [20–22]. were used as a filler. This provided a larger surface for Most studies of the effect of nanoparticles on the interaction with micellar chains. Moreover, the plate- rheological properties of the solutions of wormlike like nanoparticles of bentonite clay chosen for studies micelles were performed using cationic [17, 22] and are a nontoxic material of natural origin. It is shown in anionic surfactants [18, 20, 23] and their mixtures this work that the addition of bentonite nanoparticles [19]. At the same time, zwitterionic surfactants, which to the dense network of micellar chains increases the viscosity and relaxation time by an order of magni- are low-toxic, biodegradable, and safe even for the sen- tude. Therefore, the clay nanoparticles are an eff icient sitive child skin, are more promising in environmental and eco-friendly filler for micellar networks. terms [24]. However, just one work devoted to the effect of nanoparticles on the rheological properties of the solutions of zwitterionic surfactants has been published EXPERIMENTAL so far [25]. It was shown that the addition of negatively Materials charged silica nanoparticles (0.3–0.8 wt %) with a radius of 12 nm to a solution of the wormlike micelles of The anionic surfactant sodium dodecyl sulfate erucyl amidopropyl dimethyl betaine with a long C22 (SDS) (a molecular weight of 288 g/mol) (Helicon, tail increases the viscosity of the system twofold. Russia) (>97%) and sodium hydroxide (>85%) (Rie- At higher concentrations of the nanoparticles (above del-de Haën) were used without additional purifica- 1 wt %) a two-phase system is formed. No structural tion. The zwitterionic surfactant oleyl amidopropyl studies of these suspensions are available. dimethyl carboxybetaine (OAB) H C CH C N CH O O H was provided by OOO NPO NIIPAV (Russia) in the form of a solution containing 33 wt % OAB (including sodium and chloride ions), 0.5 wt % oleyl amidopropyl dimethyl amine (OA), 17.0 wt % isopropanol, and 49.5 wt % water. OAB was synthesized in two stages. Stage 1 OH CH 3 CH H N (CH ) N + 2 2 3 RC NH (CH ) N + H O 2 3 CH 3 CH O 3 Stage 2 O CH CH O RC NH (CH ) N 2 3 + ClCH COONa RC NH (CH ) N CH C 2 + NaCl 2 3 2 CH CH POLYMER SCIENCE, SERIES C Vol. 63 No. 2 2021 = 172 MOLCHANOV et al. Oleyl amidopropyl dimethyl amine was first obtained Research Methods from oleic acid and dimethylaminopropylamine (160°C, Rheometry. Rotational rheometry was used to under vacuum). Oleyl amidopropyl carboxybetaine was study the viscoelastic properties of the solutions and then synthesized from oleyl amidopropyl dimethyl amine suspensions. The measurements were performed on a and sodium monochloroacetate at 80°C. Sodium chlo- Physica MCR301 rheometer (Anton Paar, Austria). ride was the side reaction product. Shear stress was applied to the sample, and a change in the strain with time was measured. The viscosity of the To remove isopropanol the initial solution of the samples during f low was determined in the constant surfactant diluted fivefold with distilled water was fro- shear stress mode. In order to measure each point in zen in liquid nitrogen and lyophilized. The absence of 1 the graph of the dependence of viscosity on the shear isopropanol was conf irmed by H NMR spectroscopy. rate the shear stress was applied to the sample during In experiments, pH was maintained in the range of the time comparable to the inverse value of the corre- 11.0–11.2. Under these conditions, OA was not sponding shear rate. Frequency dependences of the charged and OAB was in the zwitterionic form (pK of viscous and elastic components of the complex elastic OAB is 2 [26]). modulus G*, the storage modulus G' and the loss modulus G", were obtained in the oscillatory shear Natural bentonite clay was purchased from Sigma- stress mode. The specified experiments were carried Aldrich. The size of clay nanoplates was in the range of out at low stress amplitudes after the preliminary 30–200 nm, and the average size was estimated as determination of the linear region of viscoelasticity. 100 nm [27]. The specific surface area of the nano- All the measurements were performed at 25°C in a plates was 63 m /g [28]. Al–OH, Mg–OH, and thermostatted cone–plate measurement cell with a Si‒OH functional groups were present on the surface cone diameter of 49.93 mm and an angle of 1°. [29], so that the nanoparticles had a negative charge in an alkaline medium [29]. Small-angle neutron scattering. Small-angle neu- tron scattering was used to study the structure of the Solutions were prepared using bidistilled deionized samples. The experiments were performed on a time- water obtained on a Milli-Q Millipore Waters unit of-f light YuMO spectrometer with a two-detector sys- (United States) as well as deuterated water (>99%) tem [31] of the IBR-2 reactor at the Frank Laboratory provided by Astrakhim (Russia). of Neutron Physics, Joint Institute of Nuclear Research (Dubna, Russia) in the dynamic range of −1 scattering vectors q = 0.006–0.7 Å in a thermostat- Preparation of Nanocomposite Networks ted cell at 25°C. D O was used as a solvent to obtain scattering from the entire structure, while a mixture of Clay nanoparticles were dispersed in an aqueous water and deuterated water (85%/15%), which makes medium using a SonoPuls ColePalmer 350 ultrasonic it possible to “hide” scattering from surfactant disperser with a power of 350 W for 30–60 min. The micelles, was used to obtain scattering only from clay time was increased with an increase in the amount of nanoplates in the nanocomposite network. The inten- the clay. Afterwards, the surfactants were added, and sity curves measured by small-angle neutron scatter- the resulting mixture was stirred for 1 day. The amount ing were normalized to a vanadium scatterer and cor- of surfactants (OAB, SDS) adsorbed on bentonite rected for sample transmission and thickness and nanoparticles was earlier determined by thermogravi- background scattering using the SAS program [32]. metry and elemental analysis. It is as low as 1 wt % in Cryogenic transmission electron microscopy (cryo- terms of the clay amount [27]. Since the amount of the TEM). Cryo-TEM was used to visualize the structure clay in the samples did not exceed 0.3 wt %, the of the networks. The sample was studied in the frozen amount of the adsorbed surfactant (up to 0.003 wt %) hydrated state. This is a direct method for visualizing was extremely small in comparison with the total objects of self-organizing systems in almost the same amount of the surfactant in the system under study form as that in which they exist in solution. The sam- (2.1 wt %). As was shown by transmission electron ples were studied on a Titan Krios 60-300 microscopy, elemental analysis, and X-ray diffraction TEM/STEM microscope (FEI, United States) with a [30], in the presence of OAB and SDS, bentonite spherical aberration corrector (Cs corrector), a direct mainly occurs in the form of tactoids consisting of f ive electron detector (DDE Falcon II), and a phase plate to ten plates and the interplanar distance insignifi- (Volta phase plates). TEM images were obtained at an cantly increases (by 5%). The small amount of the accelerating potential of 300 kV in the parallel beam adsorbed surfactant almost does not change the charge of the nanoplates, the zeta potential of which is mode; the radiation dose was no more than 100 e/Å . −27 mV, which is equal to the zeta potential of the ini- Images were processed using Digital Micrograph and tial nanoplates of −26 mV within the error of the mea- TIA programs. The samples for the cryo-TEM mea- surements [27]. The prepared suspensions were stable surements were prepared by applying the solution or and retained the initial viscoelastic properties for at suspension under study through the side port of Vitro- least 1 year. bot (Vitrobot Mark IV, FEI, United States) directly POLYMER SCIENCE, SERIES C Vol. 63 No. 2 2021 NETWORKS OF MICELLAR CHAINS WITH NANOPLATES 173 (а) (b) (c) Fig. 1. Photographic images of the viscoelastic samples containing 0.044 mol/L (1.93 vol %) OAB and 0.004 mol/L (0.1 vol %) SDS in (a) the absence and (b, c) presence of (b) 0.03 and (c) 0.1 vol % bentonite clay. Color drawings can be viewed in the elec- tronic version. onto a three-millimeter microscopic copper grid cov- topological entanglements of the micelles [2, 37]. The ered with a carbon layer [33]. After applying the sam- plateau of the storage modulus G is proportional to ple onto the grid, it was immersed into liquid ethane the amount of elastically active chains in the network for fast freezing. [10, 37]. Therefore, in the absence of the nanoparti- cles, the micellar chains entangle with each other and form a network structure exhibiting the viscoelastic RESULTS AND DISCUSSION behavior. Wormlike micelles of surfactants based on a mix- Figure 2 illustrates how the rheological properties ture of OAB and SDS at a total surfactant concentra- of the network of entangled surfactant micelles change tion of 0.048 mol/L (2.03 vol %) and a molar ratio of upon the addition of clay nanoparticles. It is seen that, OAB : SDS = 10 were used to prepare nanocomposite in the presence of the nanoplates, the zero-shear vis- networks. This ratio provides the formation of long cosity of the system η increases by an order of magni- wormlike surfactant micelles owing to the large size of tude and the frequency region of the elastic response the hydrophobic tail of OAB and the addition of the G ' > G " expands but the value of the storage modulus anionic surfactant [27, 34], which shields repulsion G ' remains almost unchanged. The observed changes between the cationic fragments of OAB. The concen- can be explained by the incorporation of the nano- tration of the filler, bentonite nanoplates (0– plates into the network of the interlaced surfactant 0.13 vol %), did not exceed the overlap concentration micellar chains as multifunctional physical crosslinks of bentonite plates (1 vol %) to ensure the predomi- between the micelles. This incorporation may occur nant interaction of the nanoparticles with the micelles by the attachment of energy unfavorable semispherical rather than with each other (Fig. 1). The overlap con- ends of wormlike micelles to the layer of surfactants on centration of the plates which corresponds to percola- the surface of the particles, as was shown in recent the- tion was experimentally determined. It was shown that oretical and experimental studies and computer simu- clay suspensions without surfactants exhibit the yield lation using particles of different nature [17, 19, 20, 27, point at concentrations above 1 vol % which is associ- 38–40]. The binding of the micelles with clay ated with formation of a three-dimensional structure nanoparticles slows down their reptation, which leads of clay nanoplates [35]. to an increase in the viscosity of the system during f low (Fig. 2b) and to a decrease of the nonelastic response (loss modulus) of the network under oscillatory shear Rheological Properties (Fig. 2a). It should be noted that at high shear rates (Fig. 2b) during the extension of chains along the direc- Figure 2 presents the viscosity curve and the fre- tion of deformation the value of viscosity does not quency dependences of the storage modulus G '(ω) depend on the presence of the particles. This can be and the loss modulus G "(ω) for the initial micellar explained by breakage of the bonds of micelles with par- network without nanoparticles. It is seen that, in the ticles under these conditions. A weak effect of the region of low shear rates, a Newtonian plateau is nanoparticles on the storage modulus of the system is observed in the f low curve which makes it possible to associated with a small number of new elastically active determine the viscosity at the zero shear rate η . The 2 entanglements formed by the nanoparticles in compar- value of the zero-shear viscosity η is 2 × 10 Pa s, ison with the total number of entanglements formed by which is by five orders of magnitude higher than the the interlaced chains, as was earlier demonstrated for viscosity of water. With an increase in the shear rate spherical nanoparticles [41]. viscosity decreases which is associated with the exten- sion of micelles along the shear direction [36]. A wide Therefore, it is shown that bentonite clay nano- elastic response region is seen in the frequency depen- plates can effectively increase viscosity and expand the dences of G '(ω) and G "(ω) in which G ' > G ". In addi- region of the elastic response of the network of entan- tion, there is a plateau in the dependence G '(ω) which gled micellar chains of surfactants. We assume that indicates formation of a network structure owing to this effect results from the binding of the ends of POLYMER SCIENCE, SERIES C Vol. 63 No. 2 2021 174 MOLCHANOV et al. wormlike micelles to the surface of the nanoplates G ', G '', Pа covered with the surfactant layer. (a) Structure The structure of the nanocomposite network was studied by small-angle neutron scattering. For the interpretation of the results, the scattering curves of the nanocomposite network were compared to the curves of scattering from the nanoparticles in the micellar network which were obtained by the contrast variation method and the scattering curves for the micellar network without the clay (Fig. 3). , 1 , 2 It follows from Fig. 3 that the curve of scattering , 3 −1 G '' from the bentonite clay nanoparticles in the region of min medium q has a slope of q which is characteristic for −2 −1 0 1 2 10 10 10 10 10 randomly orientated platelike objects [42]. In the ω, rad/s region of small q values, a small deviation from this Viscosity, Pа s slope can be observed which indicates the interaction of charged nanoplates with each other (a weak struc- (b) tural peak [42]). For the micellar network without the −1 clay the dependence of q traditional for cylindrical objects is observed in the region of small q values. There is no structural peak of electrostatic interaction which is associated with a relatively weak charge of OAB/SDS micellar chains [27] containing just 10% anionic surfactant. As for the curve of scattering from the nanocom- posite network in deuterated water, it is close to the scattering curve of the nanoplates in the region of −1 small q (which characterizes large scattering objects), while, in the region of large q (which characterizes −4 −3 −2 −1 0 1 2 small scattering objects), it agrees with the curve of 10 10 10 10 10 10 10 −1 scattering from the micellar network. Therefore, it can Shear rate, s be assumed that upon the addition of nanoparticles the micellar chains retain the local cylindrical struc- ture and the nanoparticles are uniformly distributed Fig. 2. (a) Frequency dependences of (closed symbols) the over the network; i.e., there is no additional structur- storage modulus and (open symbols) the loss modulus as well as (b) dependences of viscosity on the shear rate for ing or strong electrostatic interaction between the solutions of wormlike surfactant micelles containing nanoplates in the network. 0.044 mol/L OAB and 0.004 mol/L SDS (1)before and The micellar network before the addition of the (2, 3) after addition of (2) 0.07 and (3) 0.13 vol % dispersed clay. The dependences of the complex viscosity modulus nanoplates and the nanocomposite network were on frequency for solutions (opened triangles) without clay visualized by cryo-TEM. It follows from Figs. 4a and and (open circles) containing 0.07 vol % clay. The arrows 4b that, in both systems, the surfactant forms worm- in (a) indicate the values of the minimum of the loss mod- like micelles with a micron length which interlace and ulus G , and the solid lines in (b) refer to data approxi- '' min form a dense network of entanglements. mation by the Carreau model. Bentonite clay nanoplates with sizes of 100– 200 nm are observed in the cryo-TEM image of the nanocomposite network (Fig. 4b). Note that the net- the surfactant shell; this confirms the earlier pro- work of interlaced micelles is not deformed near the posed model for the interaction of wormlike micelles nanoparticles although the size of the latter is much with nanoparticles [17, 27, 40, 43]. To the best of our larger than the size of the unit cell of the network. knowledge, crosslinks between nanoparticles and This can be explained by the fact that owing the abil- micellar chains were earlier experimentally demon- ity for rearrangement and self-organization the net- strated only for the network filled with spherical sil- work of living micelles “adapts” to the nanoparticles. ica nanoparticles [19, 41]. This binding provides The image clearly shows points (denoted by the explanation for the increase in the zero-shear viscos- arrows in Fig. 4b), in which the micelles attach by the end parts to the surface of the nanoplates covered by ity, as shown above. POLYMER SCIENCE, SERIES C Vol. 63 No. 2 2021 NETWORKS OF MICELLAR CHAINS WITH NANOPLATES 175 I, сm 0.1 0.01 0.01 0.1 q, Å Fig. 3. (1, 2) Small-angle neutron scattering curves of the nanocomposite network of wormlike surfactant micelles containing 0.044 mol/L OAB, 0.004 mol/L SDS, and 0.04 vol % bentonite clay nanoplates in (1) D O and (2) D O/H O mixture (volume 2 2 2 parts, 15/85) which reveals scattering from clay nanoplates only as well as (3) the small-angle neutron scattering curve of the cor- responding micellar network of OAB/SDS without the clay in D O. Let us compare the size of the unit cell of the net- Figure 6b presents the dependence of the terminal work ξ from the rheological data and the results of relaxation time on the concentration of bentonite. To cryo-TEM studies. The value of ξ calculated from the estimate the terminal relaxation time in this system, 1/3 the inverse value of the shear rate, at which transition  kT from the plateau of viscosity to the drop region is elasticity modulus as ξ= [10] is 80 nm. The  G observed in the graph of the dependence of viscosity  density of the network in the cryo-TEM images seems on the shear rate, was calculated. It is known [46, 47] to be much higher than the calculated value (Fig. 5). that this transition occurs at the frequency that corre- This may be associated with the fact that we observe a sponds to the intersection of the frequency depen- two-dimensional picture from several layers of the dences of the storage modulus G ' and the loss modulus network which visually increases the density of the G " [48]. In our case, the corresponding shear rate was entanglement network. determined via approximation using the Carreau model (Fig. 2b) [44, 45]. This method for estimation Thus, the clay nanoplates are uniformly distributed of the terminal relaxation time is based on the fact that in the network and do not deform it owing to the rear- the Cox–Merz rule is fulfilled for the system under rangement of living micellar chains. The points of study like for most solutions of wormlike surfactant crosslinking of wormlike micelles and clay nanoplates micelles [46, 47]; i.e., the frequency dependence of the which provide the increase in the viscosity of the sys- complex viscosity modulus is in good agreement with tems under study are visualized. the dependence of viscosity on the shear rate (Fig. 2b). Therefore, estimation of the terminal relaxation time from the dependence of viscosity on the shear rate cor- Role of the Concentration of Nanoparticles responds to estimation of this relaxation time from the Let us consider how the rheological properties frequency dependence of the storage and loss moduli. change with increasing amount of the added nanoparti- It was shown (Fig. 6b) that the character of the cles. The value of the zero-shear viscosity was deter- dependence of the relaxation time on the concentra- mined through approximation of the dependences of tion of clay nanoparticles C generally repeats the viscosity on the shear rate using the Carreau model [44, character of the dependence of viscosity on C , which 45]. As is seen from Fig. 6a, with an increase in the con- n is consistent with the formula η = G τ [10] valid for centration of bentonite from 0 to 0.04 vol % the zero- shear viscosity first grows intensely and then the growth most viscoelastic solutions of wormlike surfactant noticeably weakens. Here, the value of the plateau stor- micelles. Thus, this ratio is also valid for the nanocom- age modulus remains almost unchanged (Fig. 6c). posite system. POLYMER SCIENCE, SERIES C Vol. 63 No. 2 2021 176 MOLCHANOV et al. 50 nm (а) 50 nm (b) (c) Fig. 4. Cryo-TEM images of (a) the micellar network without nanoparticles and (b) the corresponding nanocomposite network con- taining 0.044 mol/L OAB, 0.004 mol/L SDS, and 0.04 vol % bentonite clay nanoplates as well as (c) the schematic representation of nanocomposite network consisting of micellar chains and clay nanoplates and the schematic representation of attachment of a micelle to a particle (crosslink formation). The arrows in (b) indicate the regions of attachment of the micellar chains to the surface of the particles. Hence, the signif icant increase in viscosity which is At higher concentrations C the effect of the accompanied by an increase in the relaxation time can nanoparticles on the rheological parameters weakens be explained by the growth in the number of crosslinks noticeably. The attainment of saturation by the rheo- between the nanoplates and wormlike surfactant logical characteristics with an increase in the concen- micelles and slowdown of the reptation of the micelles tration of nanoparticles C was earlier predicted within at C from 0 to 0.0 4 vol %. the interaction model proposed by N.J. Wagner [17] POLYMER SCIENCE, SERIES C Vol. 63 No. 2 2021 NETWORKS OF MICELLAR CHAINS WITH NANOPLATES 177 Number of measurements, pcs 0 10 20 30 40 50 60 70 80 Cell size, nm Fig. 5. Size of the unit cell of the network ξ calculated from the cryo-TEM images of the nanocomposite network containing 0.044 mol/L OAB, 0.004 mol/L SDS, and 0.04 vol % bentonite clay nanoplates. and was experimentally observed upon adding silica where G is the plateau storage modulus, G '' is the min nanoparticles to the network of wormlike micelles of minimum loss modulus in the region of the plateau cationic [17] and anionic surfactants [20] as well as storage modulus (Fig. 2a), and l is the contour length upon adding submicron magnetite particles to the of the micelle between two entanglements. micellar network of the cationic surfactant [43]. In this work, this effect was first observed for a system with It is found that the average length of the micelles is nonspherical nanoparticles. The reason for this effect 2000 nm. Taking into account these data and knowing can be explained by the fact that, at a certain concentra- the weight of the surfactants in solution and the vol- tion of bentonite, all the end parts of the micelles are ume of one surfactant molecule, it is possible to esti- bound to the surface of the nanoparticles; as a result, mate the concentration of the micelles in the network further increase in the amount of the nanoparticles does as 3.5 × 10 1/L. Consequently, the concentration of not induce the formation of additional crosslinks but the end-caps will twice as much, 7 × 10 1/L. The leads to the redistribution of the end-caps of the amount of the clay nanoplates can be calculated micelles between the nanoparticles which weakly affects knowing the concentration of the nanoplates and their the viscosity and relaxation time. Note that, in this sys- average size (it is 100 nm according to [27]). The as- tem, saturation is attained at lower concentrations of calculated concentration of the nanoplates is 1.1 × clay nanoparticles in comparison with spherical silica 10 1/L. When the network is saturated with the nanoparticles [17, 20]. This makes it possible to assume nanoparticles about 60 ends of the micelles are that much more micellar chains attach to one nanoplate attached to each nanoplate. Note that in the case of than to a spherical nanoparticle. 30-nm silica nanoparticles no more than three end- Let us estimate the number of the end-caps of the caps of wormlike micelles are attached to one particle micelles attached to one nanoparticle in the network [41]. Therefore, the use of clay nanoplates with a large under saturation when all the ends of the micelles are surface area (the plate size is 30–200 nm) in compari- attached to clay nanoplates. The total number of the son with spherical silica nanoparticles (a diameter of end-caps of micellar chains can be calculated knowing 30 nm) makes it possible to increase the functionality of the concentration of micelles in the network. For this the crosslinks in the system by more than an order of purpose, let us determine the average length of the magnitude. Assuming that the clay is uniformly distrib- micelles L from the rheological data using the uted in the network the distance between the nanopar- Granek–Cates formula [37] ticles can be estimated as about 500 nm, which is several times shorter than the contour length of the micelles. This provides conditions for the attachment of all end- ≈ , e G '' caps of the micelles to the clay particles. min POLYMER SCIENCE, SERIES C Vol. 63 No. 2 2021 178 MOLCHANOV et al. In addition, the rheological data make it possible to Zero-shear viscosity, Pa s assess the characteristic breaking time of wormlike (a) micelles τ (the time between the successive chain br scission and recombination) from the frequency ω* of the minimum in the frequency dependence of the loss 10 modulus G '' as τ = 1/ω* [10, 36, 49]. The breaking br min time of the micelles τ characterizes the intensity of br renewal of the network owing to the reversible scission of living chains and determines the relaxation time of the system together with the reptation time of the micelles [2, 9]. Since the characteristic breaking time of wormlike micelles is usually 0.01–1 s [9, 27], the minimum of the loss modulus G '' often occurs in the min region of 1–100 rad/s in the frequency dependence. The breaking time is 0.8 s for the network of the sur- 0 0.03 0.06 0.09 0.12 0.15 factant micelles without nanoparticles under study Concentration of clay nanoparticles, vol % (Fig. 2a). Upon adding the clay the minimum of G '' min shifts to lower frequencies (Fig. 2a) which provides Relaxation time, s evidence for an increase in the breaking time. In the nanocomposite system, the renewal of the network (b) occurs not only owing to the reversible scission of the chains but also due to the reversible scission of the crosslinks. Therefore, the observed increase in the breaking time may be associated with the fact that the breaking time of crosslinks of the micelles with the nanoparticles is longer than the breaking time of the micelles. Figure 7 presents the dependence of breaking time on the amount of nanoplates in the network. It is seen that in the region of the intense increase in the relax- ation time (0–0.04 vol % clay), the breaking time increases in agreement with the increase in the num- ber of crosslinks in the network. Thus, the increase in 0 0.03 0.06 0.09 0.12 0.15 the relaxation time of the nanocomposite network can Concentration of clay nanoparticles, vol % be explained by the formation of crosslinks with the breaking time longer than the one of the micelles. As a G , Pа result, the micellar network strengthens. Note that if (c) the breaking time of the crosslinks was shorter than the breaking time of the micelles, the effect of the addition of the nanoparticles would be insignificant. Our assumption about the role of the breaking time of the crosslinks in comparison with the breaking time of the micelles was not earlier discussed in literature. It 6 can make a significant contribution to explanation of the effects of addition of nanoparticles to a micellar 4 network because regularities of the change in the properties of nanocomposite micellar networks avail- able in the literature cannot always be explained within the existing model [16]. 0 0.03 0.06 0.09 0.12 0.15 Thus, nanocomposite networks of OAB/SDS Concentration of clay nanoparticles, vol % micellar chains and natural bentonite clay nanoplates were created and studied in this work. It was shown that the nanoplates, acting as physical crosslinks, can Fig. 6. Dependence of (a) zero-shear viscosity, (b) termi- effectively increase the zero-shear viscosity and nal relaxation time, and (c) plateau storage modulus on expand the region of the elastic response of the net- the concentration of bentonite clay nanoparticles in net- work of the entangled micellar chains of surfactants. works containing 0.044 mol/L OAB and 0.004 mol/L SDS. Nanoplates of natural bentonite clay are a promising POLYMER SCIENCE, SERIES C Vol. 63 No. 2 2021 NETWORKS OF MICELLAR CHAINS WITH NANOPLATES 179 Breaking time, s 0 0.03 0.06 0.09 0.12 0.15 Concentration of clay nanoparticles, vol % Fig. 7. Dependence of breaking time characterizing the intensity of renewal of the network on the concentration of bentonite clay nanoparticles added to solution containing 0.044 mol/L OAB and 0.004 mol/L SDS. filler for the networks of living micellar chains of sur- REFERENCES factants, and the obtained nanocomposite networks 1. K. I. Lukanina, T. E. Grigoriev, S. V. Krasheninnikov, based on eco-friendly components show promise for V. G. Mamagulashvilli, R. A. Kamyshinsky, and practical application, in particular, in cosmetics and S. N. Chvalun, Carbohydr. Polym. 191, 119 (2018). oil production. 2. L. J. Magid, J. Phys. Chem. B 5647, 4064 (1998). 3. A. L. Kwiatkowski, V. S. Molchanov, and O. E. Philip- pova, Polym. Sci., Ser. A 61, 215 (2019). ACKNOWLEDGMENTS 4. B. A. Schubert, E. W. Kaler, and N. J. Wagner, Lang- The authors are grateful to E.E. Makhaeva (Moscow muir 19, 4079 (2003). State University) for fruitful discussion of the results. 5. Z. Chu, Y. Feng, X. Su, and Y. Han, Langmuir 26, 7783 (2010). 6. F. M. Kuni, A. K. Shchekin, A. I. Rusanov, and A. P. Gri- FUNDING nin, Colloid J. 66, 174 (200 4). This work was supported by the Russian Science Foun- 7. T. G. Movchan, I. V. Soboleva, E. V. Plotnikova, dation (project 17-13-01535). A part of work associated with A. K. Shchekin, and A. I. Rusanov, Colloid J. 74, 239 taking cryo-TEM images (A.S. Orekhov, N.A. Arkharova) (2012). was supported by the Ministry of Science and Higher Edu- 8. Z. Lin, Langmuir 12, 1729 (1996). cation of the Russian Federation. 9. M. S. Turner, C. Marques, and M. E. Cates, Langmuir 9, 695 (1993). 10. F. Kern, F. Lequeux, R. Zana, and S. J. Candau, Lang- OPEN ACCESS muir 10, 1714 (1994). This article is licensed under a Creative Commons Attri- 11. E. S. Boek, A. Jusufi, H. Lowen, and G. C. Maitland, J. Phys.: Condens. Matter 14, 9413 (2002). bution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or 12. G. A. Al-Muntasheri, F. Liang, and K. L. Hull, SPE format, as long as you give appropriate credit to the original Prod. Oper. 32, 186 (2017). author(s) and the source, provide a link to the Creative Com- 13. O. E. Philippova and A. R. Khokhlov, Pet. Chem. 50, mons license, and indicate if changes were made. The images 266 (2010). or other third party material in this article are included in the 14. K. D. Danov, S. D. Kralchevska, P. A. Kralchevsky, article’s Creative Commons license, unless indicated other- K. P. Ananthapadmanabhan, and A. Lips, Langmuir wise in a credit line to the material. If material is not included 20, 5445 (2004). in the article’s Creative Commons license and your intended 15. Y. Qi, E. Kesselman, D. J. Hart, Y. Talmon, A. Mateo, use is not permitted by statutory regulation or exceeds the and J. L. Zakin, J. Colloid Interface Sci. 354, 691 (2011). permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit 16. O. E. Philippova and V. S. Molchanov, Curr. Opin. http://creativecommons.org/licenses/by/4.0/. Colloid Interface Sci. 43, 52 (2019). POLYMER SCIENCE, SERIES C Vol. 63 No. 2 2021 180 MOLCHANOV et al. 17. F. Nettesheim, M. W. Liberatore, T. K. Hodgdon, Z. Yu, A. Briegel, L. Gan, Y. He, and G. J. Jensen, Nat. N. J. Wagner, E. W. Kaler, and M. Vethamuthu, Lang- Protoc. 1, 2813 (2007). muir 24, 7718 (2008). 34. N. C. Christov, N. D. Denkov, P. A. Kralchevsky, 18. M. Luo, Z. Jia, H. Sun, L. Liao, and Q. Wen, Colloids K. P. Ananthapadmanabhan, and A. Lips, Langmuir Surf., A 395, 267 (2012). 20, 565 (200 4). 19. Q. Fan, W. Li, Y. Zhang, W. Fan, X. Li, and J. Dong, 35. E. Paineau, L. J. Michot, I. Bihannic, and C. Baravian, Colloid Polym. Sci. 293, 2507 (2015). Langmuir 27, 7806 (2011). 20. I. F. Ismagilov, D. A. Kuryashov, A. R. Idrisov, 36. M. A. Calabrese, S. A. Rogers, R. P. Murphy, and N. Y. Bashkirtseva, L. Y. Zakharova, S. V. Zakharov, N. J. Wagner, J. Rheol. 59, 1299 (2015). M. R. Alieva, and N. E. Kashapova, Colloids Surf., A 37. R. Granek and M. E. Cates, J. Chem. Phys. 96, 4758 507, 255 (2016). (1992). 21. S. T. Adamy, J. Surfactants Deterg. 22 (5), 1189 (2019). 38. A. B. Jodar-Reyes and F. A. M. Leermakers, J. Phys. 22. M. Zhao, Y. Zhang, C. Zou, C. Dai, M. Gao, Y. Li, Chem. B 110, 18415 (2006). W. Lv, J. Jiang, and Y. Wu, Materials 10, 1096 (2017). 39. A. Sambasivam, A. V. Sangwai, and R. Sureshkumar, 23. G. Chauhan, K. Ojha, and A. Baruah, Braz. J. Chem. Langmuir 32, 1214 (2016). Eng. 34, 241 (2017). 40. W. Qin, L. Yue, G. Liang, G. Jiang, J. Yang, and Y. Liu, 24. G. W. FernLey, J. Am. Oil Chem. Soc. 55, 98 (1978). Chem. Eng. Res. Des. 123 (18), 14 (2017). 25. G. A. Gaynanova, A. R. Valiakhmetova, D. A. Kuryashov, 41. M. E. Helgeson, T. K. Hodgdon, E. W. Kaler, N. J. Wag- N. Y. Bashkirtseva, and L. Y. Zakharova, J. Surfactants ner, M. Vethamuthu, and K. P. Ananthapadmanabhan, Deterg. 18, 965 (2015). Langmuir 26, 8049 (2010). 26. J. G. Weers, J. F. Rathman, F. U. Axe, C. A. Crichlow, 42. J. D. F. Ramsay and P. Lindner, J. Chem. Soc., Fara- L. D. Foland, D. R. Scheuing, R. J. Wiersema, and day Trans. 89, 4207 (1993). A. G. Zielske, Langmuir 7, 854 (1991). 27. V. S. Molchanov, M. A. Efremova, A. S. Orekhov, 43. V. A. Pletneva, V. S. Molchanov, and O. E. Philippova, N. A. Arkharova, A. V. Rogachev, and O. E. Philippo- Langmuir 31, 110 (2015). va, J. Mol. Liq. 314, 113684 (2020). 44. A. L. Kwiatkowski, V. S. Molchanov, A. S. Orekhov, 28. R. Tayebee and V. Mazruy, J. Water Environ. Nano- A. L. Vasiliev, and O. E. Philippova, J. Phys. Chem. B technol. 3, 40 (2018). 120, 2547 (2016). 29. P. F. Luckham and S. Rossi, Adv. Colloid Interface Sci. 45. V. Croce, T. Cosgrove, A. Dreiss, S. King, G. Maitland, 82, 43 (1999). and T. Hughes, Langmuir 21, 6762 (2005). 30. V. S. Molchanov, M. A. Efremova, T. Y. Kiseleva, and 46. O. Manero, F. Bautista, J. F. A. Soltero, and J. E. Puig, O. E. Philippova, Nanosyst.: Phys., Chem. Math. 10, J. Non-Newtonian Fluid Mech. 106, 1 (2002). 76 (2019). 47. V. J. Anderson, J. R. Pearson, and E. S. Boek, in Rhe- 31. A. I. Kuklin, A. V. Rogachev, D. V. Soloviov, O. I. Ivan- ology Reviews, Ed. by D. M. Binding and K. Walters (Br. kov, Y. S. Kovalev, P. K. Utrobin, S. A. Kutuzov, Soc. Rheol., Aberystwyth, UK, 2006), pp. 217–253. A. G. Soloviev, M. I. Rulev, and V. I. Gordeliy, J. Phys.: 48. I. Couillet, T. Hughes, G. Maitland, and F. Candau, Conf. Ser. 848, 012010 (2017). Macromolecules 38, 5271 (2005). 32. A. S. Andreeva, O. E. Philippova, A. R. Khokhlov, 49. S. A. Rogers, M. A. Calabrese, and N. J. Wagner, Curr. A. K. Islamov, and A. I. Kuklin, Langmuir 21, 1216 Opin. Colloid Interface Sci. 19, 530 (2014). (2005). 33. C. V. Iancu, W. F. Tivol, J. B. Schooler, D. P. Dias, G. P. Henderson, G. E. Murphy, E. R. Wright, Z. Li, Translated by E. Boltukhina POLYMER SCIENCE, SERIES C Vol. 63 No. 2 2021 http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Polymer Science, Series C Springer Journals

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Copyright © The Author(s) 2021. ISSN 1811-2382, Polymer Science, Series C, 2021, Vol. 63, No. 2, pp. 170–180. © The Author(s), 2021. This article is an open access publication. Russian Text © The Author(s), 2021, published in Vysokomolekulyarnye Soedineniya, Seriya C, 2021, Vol. 63, No. 2, pp. 159–170.
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ISSN 1811-2382, Polymer Science, Series C, 2021, Vol. 63, No. 2, pp. 170–180. © The Author(s), 2021. This article is an open access publication. Russian Text © The Author(s), 2021, published in Vysokomolekulyarnye Soedineniya, Seriya C, 2021, Vol. 63, No. 2, pp. 159–170. REVIEWS a, b c,d V. S. Molchanov *, A. I. Kuklin , A. S. Orekhov , e f a N. A. Arkharova , E. S. Khudoleeva , and O. E. Philippova Department of Physics, Moscow State University, Moscow, 119991 Russia Joint Institute for Nuclear Research, Dubna, Moscow oblast, 141980 Russia Moscow Institute of Physics and Technology (National Research University), Dolgoprudny, Moscow oblast, 141701 Russia Kurchatov Institute National Research Center, Moscow, 123182 Russia Crystallography and Photonics Federal Scientific Research Center, Russian Academy of Sciences, Moscow, 119333 Russia OOO NPO NIIPAV, Volgodonsk, Rostov oblast, 347366 Russia *e-mail: molchan@polly.phys.msu.ru Received March 26, 2021; revised May 27, 2021; accepted June 16, 2021 Abstract—Nanocomposite networks of surfactant micellar chains and natural bentonite clay nanoplates are studied by rheometry, small-angle neutron scattering, and cryogenic transmission electron microscopy. It is shown that, in an aqueous medium in the presence of a small part of an anionic surfactant, sodium dodecyl sulfate, the molecules of a biodegradable zwitterionic surfactant, oleyl amidopropyl dimethyl carboxybetaine, form micron-length living micellar chains which entangle and form a network possessing well-def ined visco- elastic properties. It is found that addition of negatively charged clay nanoplates leads to an increase in vis- cosity and relaxation time by an order of magnitude. This is explained by the incorporation of the nanoplates into the network as physical multifunctional crosslinks. The incorporation occurs via the attachment of semi- spherical end-caps of the micelles to the surface of the particles covered with a surfactant layer, as visualized by cryogenic transmission electron microscopy. As the amount of nanoplates is increased, the rheological properties reach plateau; this is associated with the attachment of all end parts of micelles to nanoplates. The developed nanocomposite soft networks based on safe and eco-friendly components are promising for vari- ous practical applications. DOI: 10.1134/S1811238221020053 INTRODUCTION Wormlike surfactant micelles are widely used as thickening agents in the oil production [12, 13], cos- Modern technologies impose high requirements on metics, and household chemicals [14] and drag reduc- materials, especially in terms of ecology and safety for ing additives promoting the laminarity of a f low at its humans. Therefore, attempts are made to replace syn- high velocities [15]. Wormlike micelles replace poly- thetic polymers by natural polymers capable of bio- mers in many practical applications. However, a wider degradation accompanied by the formation of harm- use of micellar systems is prevented by relatively low less products [1]. An alternative approach can be the values of the viscosity and elastic modulus of surfac- use of supramolecular chains formed by the noncova- tant solutions. lent interactions of small molecules instead of polymer One of the most promising approaches to increase chains formed by covalent bonds. The simplest exam- the viscosity and elastic modulus of the networks pro- ple of such chains is the wormlike micelles of surfac- posed in recent years consists in the addition of inor- tants [2–7]. The contour length of the chains can ganic nanoparticles to wormlike surfactant micelles reach tens of micrometers [8], while their persistence [16]. Micellar chains can attach by their ends to the length is usually 15–40 nm [2] at a cross-section size surface of nanoparticles covered with a surfactant of 4–5 nm [3, 9]. They are similar to polymer chains, layer; as a result, the nanoparticles act as a crosslinking in particular, they can interlace and form a network of agent in the micellar network. It was shown that just topological entanglements which imparts viscoelastic end-caps of wormlike micelles participate in interac- properties to solutions. But, as opposed to polymer tion with the nanoparticles because they are the energy chains, living micellar chains constantly break up and unfavorable micelle regions. Surfactant molecules recombine [9, 10] and they can be easily destroyed, for have a spherical packing in them, as opposed to the example, by adding a small amount of nonpolar sub- cylindrical packing in the central part of a micelle stances [11]. which is optimum in the formation of wormlike 170 NETWORKS OF MICELLAR CHAINS WITH NANOPLATES 171 micelles. It was shown that the addition of nanoparti- The aim of this work is to study the effect of cles induces a significant increase in the viscosity of nanoparticles on the rheological properties and struc- surfactant solutions. The most substantial growth in ture of wormlike micelles based on a biodegradable zwitterionic surfactant with a long C18 tail, oleyl ami- viscosity (by orders of magnitude) is observed at the dopropyl dimethyl carboxybetaine (OAB), obtained concentration of surfactants in the vicinity of the over- from biorenewable resources, vegetable oils, with a lap concentration C* of micellar chains [17–19]. In small addition of an anionic surfactant, sodium this case, the introduction of nanoparticles leads to dodecyl sulfate (SDS). As opposed to the overwhelm- transition from a viscous f luid to a viscoelastic solu- ing majority of previous works on nanocomposite sys- tion. At a higher surfactant concentration when the tems based on wormlike surfactant micelles [17–23, micelles are already significantly entangled, the intro- 25], platelike nanoparticles with a high specif ic surface duction of nanoparticles increases viscosity moder- compared with commonly used spherical particles ately by 1.5–3 times [20–22]. were used as a filler. This provided a larger surface for Most studies of the effect of nanoparticles on the interaction with micellar chains. Moreover, the plate- rheological properties of the solutions of wormlike like nanoparticles of bentonite clay chosen for studies micelles were performed using cationic [17, 22] and are a nontoxic material of natural origin. It is shown in anionic surfactants [18, 20, 23] and their mixtures this work that the addition of bentonite nanoparticles [19]. At the same time, zwitterionic surfactants, which to the dense network of micellar chains increases the viscosity and relaxation time by an order of magni- are low-toxic, biodegradable, and safe even for the sen- tude. Therefore, the clay nanoparticles are an eff icient sitive child skin, are more promising in environmental and eco-friendly filler for micellar networks. terms [24]. However, just one work devoted to the effect of nanoparticles on the rheological properties of the solutions of zwitterionic surfactants has been published EXPERIMENTAL so far [25]. It was shown that the addition of negatively Materials charged silica nanoparticles (0.3–0.8 wt %) with a radius of 12 nm to a solution of the wormlike micelles of The anionic surfactant sodium dodecyl sulfate erucyl amidopropyl dimethyl betaine with a long C22 (SDS) (a molecular weight of 288 g/mol) (Helicon, tail increases the viscosity of the system twofold. Russia) (>97%) and sodium hydroxide (>85%) (Rie- At higher concentrations of the nanoparticles (above del-de Haën) were used without additional purifica- 1 wt %) a two-phase system is formed. No structural tion. The zwitterionic surfactant oleyl amidopropyl studies of these suspensions are available. dimethyl carboxybetaine (OAB) H C CH C N CH O O H was provided by OOO NPO NIIPAV (Russia) in the form of a solution containing 33 wt % OAB (including sodium and chloride ions), 0.5 wt % oleyl amidopropyl dimethyl amine (OA), 17.0 wt % isopropanol, and 49.5 wt % water. OAB was synthesized in two stages. Stage 1 OH CH 3 CH H N (CH ) N + 2 2 3 RC NH (CH ) N + H O 2 3 CH 3 CH O 3 Stage 2 O CH CH O RC NH (CH ) N 2 3 + ClCH COONa RC NH (CH ) N CH C 2 + NaCl 2 3 2 CH CH POLYMER SCIENCE, SERIES C Vol. 63 No. 2 2021 = 172 MOLCHANOV et al. Oleyl amidopropyl dimethyl amine was first obtained Research Methods from oleic acid and dimethylaminopropylamine (160°C, Rheometry. Rotational rheometry was used to under vacuum). Oleyl amidopropyl carboxybetaine was study the viscoelastic properties of the solutions and then synthesized from oleyl amidopropyl dimethyl amine suspensions. The measurements were performed on a and sodium monochloroacetate at 80°C. Sodium chlo- Physica MCR301 rheometer (Anton Paar, Austria). ride was the side reaction product. Shear stress was applied to the sample, and a change in the strain with time was measured. The viscosity of the To remove isopropanol the initial solution of the samples during f low was determined in the constant surfactant diluted fivefold with distilled water was fro- shear stress mode. In order to measure each point in zen in liquid nitrogen and lyophilized. The absence of 1 the graph of the dependence of viscosity on the shear isopropanol was conf irmed by H NMR spectroscopy. rate the shear stress was applied to the sample during In experiments, pH was maintained in the range of the time comparable to the inverse value of the corre- 11.0–11.2. Under these conditions, OA was not sponding shear rate. Frequency dependences of the charged and OAB was in the zwitterionic form (pK of viscous and elastic components of the complex elastic OAB is 2 [26]). modulus G*, the storage modulus G' and the loss modulus G", were obtained in the oscillatory shear Natural bentonite clay was purchased from Sigma- stress mode. The specified experiments were carried Aldrich. The size of clay nanoplates was in the range of out at low stress amplitudes after the preliminary 30–200 nm, and the average size was estimated as determination of the linear region of viscoelasticity. 100 nm [27]. The specific surface area of the nano- All the measurements were performed at 25°C in a plates was 63 m /g [28]. Al–OH, Mg–OH, and thermostatted cone–plate measurement cell with a Si‒OH functional groups were present on the surface cone diameter of 49.93 mm and an angle of 1°. [29], so that the nanoparticles had a negative charge in an alkaline medium [29]. Small-angle neutron scattering. Small-angle neu- tron scattering was used to study the structure of the Solutions were prepared using bidistilled deionized samples. The experiments were performed on a time- water obtained on a Milli-Q Millipore Waters unit of-f light YuMO spectrometer with a two-detector sys- (United States) as well as deuterated water (>99%) tem [31] of the IBR-2 reactor at the Frank Laboratory provided by Astrakhim (Russia). of Neutron Physics, Joint Institute of Nuclear Research (Dubna, Russia) in the dynamic range of −1 scattering vectors q = 0.006–0.7 Å in a thermostat- Preparation of Nanocomposite Networks ted cell at 25°C. D O was used as a solvent to obtain scattering from the entire structure, while a mixture of Clay nanoparticles were dispersed in an aqueous water and deuterated water (85%/15%), which makes medium using a SonoPuls ColePalmer 350 ultrasonic it possible to “hide” scattering from surfactant disperser with a power of 350 W for 30–60 min. The micelles, was used to obtain scattering only from clay time was increased with an increase in the amount of nanoplates in the nanocomposite network. The inten- the clay. Afterwards, the surfactants were added, and sity curves measured by small-angle neutron scatter- the resulting mixture was stirred for 1 day. The amount ing were normalized to a vanadium scatterer and cor- of surfactants (OAB, SDS) adsorbed on bentonite rected for sample transmission and thickness and nanoparticles was earlier determined by thermogravi- background scattering using the SAS program [32]. metry and elemental analysis. It is as low as 1 wt % in Cryogenic transmission electron microscopy (cryo- terms of the clay amount [27]. Since the amount of the TEM). Cryo-TEM was used to visualize the structure clay in the samples did not exceed 0.3 wt %, the of the networks. The sample was studied in the frozen amount of the adsorbed surfactant (up to 0.003 wt %) hydrated state. This is a direct method for visualizing was extremely small in comparison with the total objects of self-organizing systems in almost the same amount of the surfactant in the system under study form as that in which they exist in solution. The sam- (2.1 wt %). As was shown by transmission electron ples were studied on a Titan Krios 60-300 microscopy, elemental analysis, and X-ray diffraction TEM/STEM microscope (FEI, United States) with a [30], in the presence of OAB and SDS, bentonite spherical aberration corrector (Cs corrector), a direct mainly occurs in the form of tactoids consisting of f ive electron detector (DDE Falcon II), and a phase plate to ten plates and the interplanar distance insignifi- (Volta phase plates). TEM images were obtained at an cantly increases (by 5%). The small amount of the accelerating potential of 300 kV in the parallel beam adsorbed surfactant almost does not change the charge of the nanoplates, the zeta potential of which is mode; the radiation dose was no more than 100 e/Å . −27 mV, which is equal to the zeta potential of the ini- Images were processed using Digital Micrograph and tial nanoplates of −26 mV within the error of the mea- TIA programs. The samples for the cryo-TEM mea- surements [27]. The prepared suspensions were stable surements were prepared by applying the solution or and retained the initial viscoelastic properties for at suspension under study through the side port of Vitro- least 1 year. bot (Vitrobot Mark IV, FEI, United States) directly POLYMER SCIENCE, SERIES C Vol. 63 No. 2 2021 NETWORKS OF MICELLAR CHAINS WITH NANOPLATES 173 (а) (b) (c) Fig. 1. Photographic images of the viscoelastic samples containing 0.044 mol/L (1.93 vol %) OAB and 0.004 mol/L (0.1 vol %) SDS in (a) the absence and (b, c) presence of (b) 0.03 and (c) 0.1 vol % bentonite clay. Color drawings can be viewed in the elec- tronic version. onto a three-millimeter microscopic copper grid cov- topological entanglements of the micelles [2, 37]. The ered with a carbon layer [33]. After applying the sam- plateau of the storage modulus G is proportional to ple onto the grid, it was immersed into liquid ethane the amount of elastically active chains in the network for fast freezing. [10, 37]. Therefore, in the absence of the nanoparti- cles, the micellar chains entangle with each other and form a network structure exhibiting the viscoelastic RESULTS AND DISCUSSION behavior. Wormlike micelles of surfactants based on a mix- Figure 2 illustrates how the rheological properties ture of OAB and SDS at a total surfactant concentra- of the network of entangled surfactant micelles change tion of 0.048 mol/L (2.03 vol %) and a molar ratio of upon the addition of clay nanoparticles. It is seen that, OAB : SDS = 10 were used to prepare nanocomposite in the presence of the nanoplates, the zero-shear vis- networks. This ratio provides the formation of long cosity of the system η increases by an order of magni- wormlike surfactant micelles owing to the large size of tude and the frequency region of the elastic response the hydrophobic tail of OAB and the addition of the G ' > G " expands but the value of the storage modulus anionic surfactant [27, 34], which shields repulsion G ' remains almost unchanged. The observed changes between the cationic fragments of OAB. The concen- can be explained by the incorporation of the nano- tration of the filler, bentonite nanoplates (0– plates into the network of the interlaced surfactant 0.13 vol %), did not exceed the overlap concentration micellar chains as multifunctional physical crosslinks of bentonite plates (1 vol %) to ensure the predomi- between the micelles. This incorporation may occur nant interaction of the nanoparticles with the micelles by the attachment of energy unfavorable semispherical rather than with each other (Fig. 1). The overlap con- ends of wormlike micelles to the layer of surfactants on centration of the plates which corresponds to percola- the surface of the particles, as was shown in recent the- tion was experimentally determined. It was shown that oretical and experimental studies and computer simu- clay suspensions without surfactants exhibit the yield lation using particles of different nature [17, 19, 20, 27, point at concentrations above 1 vol % which is associ- 38–40]. The binding of the micelles with clay ated with formation of a three-dimensional structure nanoparticles slows down their reptation, which leads of clay nanoplates [35]. to an increase in the viscosity of the system during f low (Fig. 2b) and to a decrease of the nonelastic response (loss modulus) of the network under oscillatory shear Rheological Properties (Fig. 2a). It should be noted that at high shear rates (Fig. 2b) during the extension of chains along the direc- Figure 2 presents the viscosity curve and the fre- tion of deformation the value of viscosity does not quency dependences of the storage modulus G '(ω) depend on the presence of the particles. This can be and the loss modulus G "(ω) for the initial micellar explained by breakage of the bonds of micelles with par- network without nanoparticles. It is seen that, in the ticles under these conditions. A weak effect of the region of low shear rates, a Newtonian plateau is nanoparticles on the storage modulus of the system is observed in the f low curve which makes it possible to associated with a small number of new elastically active determine the viscosity at the zero shear rate η . The 2 entanglements formed by the nanoparticles in compar- value of the zero-shear viscosity η is 2 × 10 Pa s, ison with the total number of entanglements formed by which is by five orders of magnitude higher than the the interlaced chains, as was earlier demonstrated for viscosity of water. With an increase in the shear rate spherical nanoparticles [41]. viscosity decreases which is associated with the exten- sion of micelles along the shear direction [36]. A wide Therefore, it is shown that bentonite clay nano- elastic response region is seen in the frequency depen- plates can effectively increase viscosity and expand the dences of G '(ω) and G "(ω) in which G ' > G ". In addi- region of the elastic response of the network of entan- tion, there is a plateau in the dependence G '(ω) which gled micellar chains of surfactants. We assume that indicates formation of a network structure owing to this effect results from the binding of the ends of POLYMER SCIENCE, SERIES C Vol. 63 No. 2 2021 174 MOLCHANOV et al. wormlike micelles to the surface of the nanoplates G ', G '', Pа covered with the surfactant layer. (a) Structure The structure of the nanocomposite network was studied by small-angle neutron scattering. For the interpretation of the results, the scattering curves of the nanocomposite network were compared to the curves of scattering from the nanoparticles in the micellar network which were obtained by the contrast variation method and the scattering curves for the micellar network without the clay (Fig. 3). , 1 , 2 It follows from Fig. 3 that the curve of scattering , 3 −1 G '' from the bentonite clay nanoparticles in the region of min medium q has a slope of q which is characteristic for −2 −1 0 1 2 10 10 10 10 10 randomly orientated platelike objects [42]. In the ω, rad/s region of small q values, a small deviation from this Viscosity, Pа s slope can be observed which indicates the interaction of charged nanoplates with each other (a weak struc- (b) tural peak [42]). For the micellar network without the −1 clay the dependence of q traditional for cylindrical objects is observed in the region of small q values. There is no structural peak of electrostatic interaction which is associated with a relatively weak charge of OAB/SDS micellar chains [27] containing just 10% anionic surfactant. As for the curve of scattering from the nanocom- posite network in deuterated water, it is close to the scattering curve of the nanoplates in the region of −1 small q (which characterizes large scattering objects), while, in the region of large q (which characterizes −4 −3 −2 −1 0 1 2 small scattering objects), it agrees with the curve of 10 10 10 10 10 10 10 −1 scattering from the micellar network. Therefore, it can Shear rate, s be assumed that upon the addition of nanoparticles the micellar chains retain the local cylindrical struc- ture and the nanoparticles are uniformly distributed Fig. 2. (a) Frequency dependences of (closed symbols) the over the network; i.e., there is no additional structur- storage modulus and (open symbols) the loss modulus as well as (b) dependences of viscosity on the shear rate for ing or strong electrostatic interaction between the solutions of wormlike surfactant micelles containing nanoplates in the network. 0.044 mol/L OAB and 0.004 mol/L SDS (1)before and The micellar network before the addition of the (2, 3) after addition of (2) 0.07 and (3) 0.13 vol % dispersed clay. The dependences of the complex viscosity modulus nanoplates and the nanocomposite network were on frequency for solutions (opened triangles) without clay visualized by cryo-TEM. It follows from Figs. 4a and and (open circles) containing 0.07 vol % clay. The arrows 4b that, in both systems, the surfactant forms worm- in (a) indicate the values of the minimum of the loss mod- like micelles with a micron length which interlace and ulus G , and the solid lines in (b) refer to data approxi- '' min form a dense network of entanglements. mation by the Carreau model. Bentonite clay nanoplates with sizes of 100– 200 nm are observed in the cryo-TEM image of the nanocomposite network (Fig. 4b). Note that the net- the surfactant shell; this confirms the earlier pro- work of interlaced micelles is not deformed near the posed model for the interaction of wormlike micelles nanoparticles although the size of the latter is much with nanoparticles [17, 27, 40, 43]. To the best of our larger than the size of the unit cell of the network. knowledge, crosslinks between nanoparticles and This can be explained by the fact that owing the abil- micellar chains were earlier experimentally demon- ity for rearrangement and self-organization the net- strated only for the network filled with spherical sil- work of living micelles “adapts” to the nanoparticles. ica nanoparticles [19, 41]. This binding provides The image clearly shows points (denoted by the explanation for the increase in the zero-shear viscos- arrows in Fig. 4b), in which the micelles attach by the end parts to the surface of the nanoplates covered by ity, as shown above. POLYMER SCIENCE, SERIES C Vol. 63 No. 2 2021 NETWORKS OF MICELLAR CHAINS WITH NANOPLATES 175 I, сm 0.1 0.01 0.01 0.1 q, Å Fig. 3. (1, 2) Small-angle neutron scattering curves of the nanocomposite network of wormlike surfactant micelles containing 0.044 mol/L OAB, 0.004 mol/L SDS, and 0.04 vol % bentonite clay nanoplates in (1) D O and (2) D O/H O mixture (volume 2 2 2 parts, 15/85) which reveals scattering from clay nanoplates only as well as (3) the small-angle neutron scattering curve of the cor- responding micellar network of OAB/SDS without the clay in D O. Let us compare the size of the unit cell of the net- Figure 6b presents the dependence of the terminal work ξ from the rheological data and the results of relaxation time on the concentration of bentonite. To cryo-TEM studies. The value of ξ calculated from the estimate the terminal relaxation time in this system, 1/3 the inverse value of the shear rate, at which transition  kT from the plateau of viscosity to the drop region is elasticity modulus as ξ= [10] is 80 nm. The  G observed in the graph of the dependence of viscosity  density of the network in the cryo-TEM images seems on the shear rate, was calculated. It is known [46, 47] to be much higher than the calculated value (Fig. 5). that this transition occurs at the frequency that corre- This may be associated with the fact that we observe a sponds to the intersection of the frequency depen- two-dimensional picture from several layers of the dences of the storage modulus G ' and the loss modulus network which visually increases the density of the G " [48]. In our case, the corresponding shear rate was entanglement network. determined via approximation using the Carreau model (Fig. 2b) [44, 45]. This method for estimation Thus, the clay nanoplates are uniformly distributed of the terminal relaxation time is based on the fact that in the network and do not deform it owing to the rear- the Cox–Merz rule is fulfilled for the system under rangement of living micellar chains. The points of study like for most solutions of wormlike surfactant crosslinking of wormlike micelles and clay nanoplates micelles [46, 47]; i.e., the frequency dependence of the which provide the increase in the viscosity of the sys- complex viscosity modulus is in good agreement with tems under study are visualized. the dependence of viscosity on the shear rate (Fig. 2b). Therefore, estimation of the terminal relaxation time from the dependence of viscosity on the shear rate cor- Role of the Concentration of Nanoparticles responds to estimation of this relaxation time from the Let us consider how the rheological properties frequency dependence of the storage and loss moduli. change with increasing amount of the added nanoparti- It was shown (Fig. 6b) that the character of the cles. The value of the zero-shear viscosity was deter- dependence of the relaxation time on the concentra- mined through approximation of the dependences of tion of clay nanoparticles C generally repeats the viscosity on the shear rate using the Carreau model [44, character of the dependence of viscosity on C , which 45]. As is seen from Fig. 6a, with an increase in the con- n is consistent with the formula η = G τ [10] valid for centration of bentonite from 0 to 0.04 vol % the zero- shear viscosity first grows intensely and then the growth most viscoelastic solutions of wormlike surfactant noticeably weakens. Here, the value of the plateau stor- micelles. Thus, this ratio is also valid for the nanocom- age modulus remains almost unchanged (Fig. 6c). posite system. POLYMER SCIENCE, SERIES C Vol. 63 No. 2 2021 176 MOLCHANOV et al. 50 nm (а) 50 nm (b) (c) Fig. 4. Cryo-TEM images of (a) the micellar network without nanoparticles and (b) the corresponding nanocomposite network con- taining 0.044 mol/L OAB, 0.004 mol/L SDS, and 0.04 vol % bentonite clay nanoplates as well as (c) the schematic representation of nanocomposite network consisting of micellar chains and clay nanoplates and the schematic representation of attachment of a micelle to a particle (crosslink formation). The arrows in (b) indicate the regions of attachment of the micellar chains to the surface of the particles. Hence, the signif icant increase in viscosity which is At higher concentrations C the effect of the accompanied by an increase in the relaxation time can nanoparticles on the rheological parameters weakens be explained by the growth in the number of crosslinks noticeably. The attainment of saturation by the rheo- between the nanoplates and wormlike surfactant logical characteristics with an increase in the concen- micelles and slowdown of the reptation of the micelles tration of nanoparticles C was earlier predicted within at C from 0 to 0.0 4 vol %. the interaction model proposed by N.J. Wagner [17] POLYMER SCIENCE, SERIES C Vol. 63 No. 2 2021 NETWORKS OF MICELLAR CHAINS WITH NANOPLATES 177 Number of measurements, pcs 0 10 20 30 40 50 60 70 80 Cell size, nm Fig. 5. Size of the unit cell of the network ξ calculated from the cryo-TEM images of the nanocomposite network containing 0.044 mol/L OAB, 0.004 mol/L SDS, and 0.04 vol % bentonite clay nanoplates. and was experimentally observed upon adding silica where G is the plateau storage modulus, G '' is the min nanoparticles to the network of wormlike micelles of minimum loss modulus in the region of the plateau cationic [17] and anionic surfactants [20] as well as storage modulus (Fig. 2a), and l is the contour length upon adding submicron magnetite particles to the of the micelle between two entanglements. micellar network of the cationic surfactant [43]. In this work, this effect was first observed for a system with It is found that the average length of the micelles is nonspherical nanoparticles. The reason for this effect 2000 nm. Taking into account these data and knowing can be explained by the fact that, at a certain concentra- the weight of the surfactants in solution and the vol- tion of bentonite, all the end parts of the micelles are ume of one surfactant molecule, it is possible to esti- bound to the surface of the nanoparticles; as a result, mate the concentration of the micelles in the network further increase in the amount of the nanoparticles does as 3.5 × 10 1/L. Consequently, the concentration of not induce the formation of additional crosslinks but the end-caps will twice as much, 7 × 10 1/L. The leads to the redistribution of the end-caps of the amount of the clay nanoplates can be calculated micelles between the nanoparticles which weakly affects knowing the concentration of the nanoplates and their the viscosity and relaxation time. Note that, in this sys- average size (it is 100 nm according to [27]). The as- tem, saturation is attained at lower concentrations of calculated concentration of the nanoplates is 1.1 × clay nanoparticles in comparison with spherical silica 10 1/L. When the network is saturated with the nanoparticles [17, 20]. This makes it possible to assume nanoparticles about 60 ends of the micelles are that much more micellar chains attach to one nanoplate attached to each nanoplate. Note that in the case of than to a spherical nanoparticle. 30-nm silica nanoparticles no more than three end- Let us estimate the number of the end-caps of the caps of wormlike micelles are attached to one particle micelles attached to one nanoparticle in the network [41]. Therefore, the use of clay nanoplates with a large under saturation when all the ends of the micelles are surface area (the plate size is 30–200 nm) in compari- attached to clay nanoplates. The total number of the son with spherical silica nanoparticles (a diameter of end-caps of micellar chains can be calculated knowing 30 nm) makes it possible to increase the functionality of the concentration of micelles in the network. For this the crosslinks in the system by more than an order of purpose, let us determine the average length of the magnitude. Assuming that the clay is uniformly distrib- micelles L from the rheological data using the uted in the network the distance between the nanopar- Granek–Cates formula [37] ticles can be estimated as about 500 nm, which is several times shorter than the contour length of the micelles. This provides conditions for the attachment of all end- ≈ , e G '' caps of the micelles to the clay particles. min POLYMER SCIENCE, SERIES C Vol. 63 No. 2 2021 178 MOLCHANOV et al. In addition, the rheological data make it possible to Zero-shear viscosity, Pa s assess the characteristic breaking time of wormlike (a) micelles τ (the time between the successive chain br scission and recombination) from the frequency ω* of the minimum in the frequency dependence of the loss 10 modulus G '' as τ = 1/ω* [10, 36, 49]. The breaking br min time of the micelles τ characterizes the intensity of br renewal of the network owing to the reversible scission of living chains and determines the relaxation time of the system together with the reptation time of the micelles [2, 9]. Since the characteristic breaking time of wormlike micelles is usually 0.01–1 s [9, 27], the minimum of the loss modulus G '' often occurs in the min region of 1–100 rad/s in the frequency dependence. The breaking time is 0.8 s for the network of the sur- 0 0.03 0.06 0.09 0.12 0.15 factant micelles without nanoparticles under study Concentration of clay nanoparticles, vol % (Fig. 2a). Upon adding the clay the minimum of G '' min shifts to lower frequencies (Fig. 2a) which provides Relaxation time, s evidence for an increase in the breaking time. In the nanocomposite system, the renewal of the network (b) occurs not only owing to the reversible scission of the chains but also due to the reversible scission of the crosslinks. Therefore, the observed increase in the breaking time may be associated with the fact that the breaking time of crosslinks of the micelles with the nanoparticles is longer than the breaking time of the micelles. Figure 7 presents the dependence of breaking time on the amount of nanoplates in the network. It is seen that in the region of the intense increase in the relax- ation time (0–0.04 vol % clay), the breaking time increases in agreement with the increase in the num- ber of crosslinks in the network. Thus, the increase in 0 0.03 0.06 0.09 0.12 0.15 the relaxation time of the nanocomposite network can Concentration of clay nanoparticles, vol % be explained by the formation of crosslinks with the breaking time longer than the one of the micelles. As a G , Pа result, the micellar network strengthens. Note that if (c) the breaking time of the crosslinks was shorter than the breaking time of the micelles, the effect of the addition of the nanoparticles would be insignificant. Our assumption about the role of the breaking time of the crosslinks in comparison with the breaking time of the micelles was not earlier discussed in literature. It 6 can make a significant contribution to explanation of the effects of addition of nanoparticles to a micellar 4 network because regularities of the change in the properties of nanocomposite micellar networks avail- able in the literature cannot always be explained within the existing model [16]. 0 0.03 0.06 0.09 0.12 0.15 Thus, nanocomposite networks of OAB/SDS Concentration of clay nanoparticles, vol % micellar chains and natural bentonite clay nanoplates were created and studied in this work. It was shown that the nanoplates, acting as physical crosslinks, can Fig. 6. Dependence of (a) zero-shear viscosity, (b) termi- effectively increase the zero-shear viscosity and nal relaxation time, and (c) plateau storage modulus on expand the region of the elastic response of the net- the concentration of bentonite clay nanoparticles in net- work of the entangled micellar chains of surfactants. works containing 0.044 mol/L OAB and 0.004 mol/L SDS. Nanoplates of natural bentonite clay are a promising POLYMER SCIENCE, SERIES C Vol. 63 No. 2 2021 NETWORKS OF MICELLAR CHAINS WITH NANOPLATES 179 Breaking time, s 0 0.03 0.06 0.09 0.12 0.15 Concentration of clay nanoparticles, vol % Fig. 7. Dependence of breaking time characterizing the intensity of renewal of the network on the concentration of bentonite clay nanoparticles added to solution containing 0.044 mol/L OAB and 0.004 mol/L SDS. filler for the networks of living micellar chains of sur- REFERENCES factants, and the obtained nanocomposite networks 1. K. I. Lukanina, T. E. Grigoriev, S. V. Krasheninnikov, based on eco-friendly components show promise for V. G. Mamagulashvilli, R. A. Kamyshinsky, and practical application, in particular, in cosmetics and S. N. Chvalun, Carbohydr. Polym. 191, 119 (2018). oil production. 2. L. J. Magid, J. Phys. Chem. B 5647, 4064 (1998). 3. A. L. Kwiatkowski, V. S. Molchanov, and O. E. Philip- pova, Polym. Sci., Ser. A 61, 215 (2019). ACKNOWLEDGMENTS 4. B. A. Schubert, E. W. Kaler, and N. J. Wagner, Lang- The authors are grateful to E.E. Makhaeva (Moscow muir 19, 4079 (2003). State University) for fruitful discussion of the results. 5. Z. Chu, Y. Feng, X. Su, and Y. Han, Langmuir 26, 7783 (2010). 6. F. M. Kuni, A. K. Shchekin, A. I. Rusanov, and A. P. Gri- FUNDING nin, Colloid J. 66, 174 (200 4). This work was supported by the Russian Science Foun- 7. T. G. Movchan, I. V. Soboleva, E. V. Plotnikova, dation (project 17-13-01535). A part of work associated with A. K. Shchekin, and A. I. Rusanov, Colloid J. 74, 239 taking cryo-TEM images (A.S. Orekhov, N.A. Arkharova) (2012). was supported by the Ministry of Science and Higher Edu- 8. Z. Lin, Langmuir 12, 1729 (1996). cation of the Russian Federation. 9. M. S. Turner, C. Marques, and M. E. Cates, Langmuir 9, 695 (1993). 10. F. Kern, F. Lequeux, R. Zana, and S. J. Candau, Lang- OPEN ACCESS muir 10, 1714 (1994). This article is licensed under a Creative Commons Attri- 11. E. S. Boek, A. Jusufi, H. Lowen, and G. C. Maitland, J. Phys.: Condens. Matter 14, 9413 (2002). bution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or 12. G. A. Al-Muntasheri, F. Liang, and K. L. Hull, SPE format, as long as you give appropriate credit to the original Prod. Oper. 32, 186 (2017). author(s) and the source, provide a link to the Creative Com- 13. O. E. Philippova and A. R. Khokhlov, Pet. Chem. 50, mons license, and indicate if changes were made. The images 266 (2010). or other third party material in this article are included in the 14. K. D. Danov, S. D. Kralchevska, P. A. Kralchevsky, article’s Creative Commons license, unless indicated other- K. P. Ananthapadmanabhan, and A. Lips, Langmuir wise in a credit line to the material. If material is not included 20, 5445 (2004). in the article’s Creative Commons license and your intended 15. Y. Qi, E. Kesselman, D. J. Hart, Y. Talmon, A. Mateo, use is not permitted by statutory regulation or exceeds the and J. L. Zakin, J. Colloid Interface Sci. 354, 691 (2011). permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit 16. O. E. Philippova and V. S. Molchanov, Curr. Opin. http://creativecommons.org/licenses/by/4.0/. Colloid Interface Sci. 43, 52 (2019). POLYMER SCIENCE, SERIES C Vol. 63 No. 2 2021 180 MOLCHANOV et al. 17. F. Nettesheim, M. W. Liberatore, T. K. Hodgdon, Z. Yu, A. Briegel, L. Gan, Y. He, and G. J. Jensen, Nat. N. J. Wagner, E. W. Kaler, and M. Vethamuthu, Lang- Protoc. 1, 2813 (2007). muir 24, 7718 (2008). 34. N. C. Christov, N. D. Denkov, P. A. Kralchevsky, 18. M. Luo, Z. Jia, H. Sun, L. Liao, and Q. Wen, Colloids K. P. Ananthapadmanabhan, and A. Lips, Langmuir Surf., A 395, 267 (2012). 20, 565 (200 4). 19. Q. Fan, W. Li, Y. Zhang, W. Fan, X. Li, and J. Dong, 35. E. Paineau, L. J. Michot, I. Bihannic, and C. Baravian, Colloid Polym. Sci. 293, 2507 (2015). Langmuir 27, 7806 (2011). 20. I. F. Ismagilov, D. A. Kuryashov, A. R. Idrisov, 36. M. A. Calabrese, S. A. Rogers, R. P. Murphy, and N. Y. Bashkirtseva, L. Y. Zakharova, S. V. Zakharov, N. J. Wagner, J. Rheol. 59, 1299 (2015). M. R. Alieva, and N. E. Kashapova, Colloids Surf., A 37. R. Granek and M. E. Cates, J. Chem. Phys. 96, 4758 507, 255 (2016). (1992). 21. S. T. Adamy, J. Surfactants Deterg. 22 (5), 1189 (2019). 38. A. B. Jodar-Reyes and F. A. M. Leermakers, J. Phys. 22. M. Zhao, Y. Zhang, C. Zou, C. Dai, M. Gao, Y. Li, Chem. B 110, 18415 (2006). W. Lv, J. Jiang, and Y. Wu, Materials 10, 1096 (2017). 39. A. Sambasivam, A. V. Sangwai, and R. Sureshkumar, 23. G. Chauhan, K. Ojha, and A. Baruah, Braz. J. Chem. Langmuir 32, 1214 (2016). Eng. 34, 241 (2017). 40. W. Qin, L. Yue, G. Liang, G. Jiang, J. Yang, and Y. Liu, 24. G. W. FernLey, J. Am. Oil Chem. Soc. 55, 98 (1978). Chem. Eng. Res. Des. 123 (18), 14 (2017). 25. G. A. Gaynanova, A. R. Valiakhmetova, D. A. Kuryashov, 41. M. E. Helgeson, T. K. Hodgdon, E. W. Kaler, N. J. Wag- N. Y. Bashkirtseva, and L. Y. Zakharova, J. Surfactants ner, M. Vethamuthu, and K. P. Ananthapadmanabhan, Deterg. 18, 965 (2015). Langmuir 26, 8049 (2010). 26. J. G. Weers, J. F. Rathman, F. U. Axe, C. A. Crichlow, 42. J. D. F. Ramsay and P. Lindner, J. Chem. Soc., Fara- L. D. Foland, D. R. Scheuing, R. J. Wiersema, and day Trans. 89, 4207 (1993). A. G. Zielske, Langmuir 7, 854 (1991). 27. V. S. Molchanov, M. A. Efremova, A. S. Orekhov, 43. V. A. Pletneva, V. S. Molchanov, and O. E. Philippova, N. A. Arkharova, A. V. Rogachev, and O. E. Philippo- Langmuir 31, 110 (2015). va, J. Mol. Liq. 314, 113684 (2020). 44. A. L. Kwiatkowski, V. S. Molchanov, A. S. Orekhov, 28. R. Tayebee and V. Mazruy, J. Water Environ. Nano- A. L. Vasiliev, and O. E. Philippova, J. Phys. Chem. B technol. 3, 40 (2018). 120, 2547 (2016). 29. P. F. Luckham and S. Rossi, Adv. Colloid Interface Sci. 45. V. Croce, T. Cosgrove, A. Dreiss, S. King, G. Maitland, 82, 43 (1999). and T. Hughes, Langmuir 21, 6762 (2005). 30. V. S. Molchanov, M. A. Efremova, T. Y. Kiseleva, and 46. O. Manero, F. Bautista, J. F. A. Soltero, and J. E. Puig, O. E. Philippova, Nanosyst.: Phys., Chem. Math. 10, J. Non-Newtonian Fluid Mech. 106, 1 (2002). 76 (2019). 47. V. J. Anderson, J. R. Pearson, and E. S. Boek, in Rhe- 31. A. I. Kuklin, A. V. Rogachev, D. V. Soloviov, O. I. Ivan- ology Reviews, Ed. by D. M. Binding and K. Walters (Br. kov, Y. S. Kovalev, P. K. Utrobin, S. A. Kutuzov, Soc. Rheol., Aberystwyth, UK, 2006), pp. 217–253. A. G. Soloviev, M. I. Rulev, and V. I. Gordeliy, J. Phys.: 48. I. Couillet, T. Hughes, G. Maitland, and F. Candau, Conf. Ser. 848, 012010 (2017). Macromolecules 38, 5271 (2005). 32. A. S. Andreeva, O. E. Philippova, A. R. Khokhlov, 49. S. A. Rogers, M. A. Calabrese, and N. J. Wagner, Curr. A. K. Islamov, and A. I. Kuklin, Langmuir 21, 1216 Opin. Colloid Interface Sci. 19, 530 (2014). (2005). 33. C. V. Iancu, W. F. Tivol, J. B. Schooler, D. P. Dias, G. P. Henderson, G. E. Murphy, E. R. Wright, Z. Li, Translated by E. Boltukhina POLYMER SCIENCE, SERIES C Vol. 63 No. 2 2021

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