Department of Physical Chemistry
Soft Matter Group
General Fields of Research Projects
Amphiphilic molecules may self-assemble, forming rich variety of structures. For fluid systems, a minor change of the environment may cause radical structural changes. Such soft mesoscale structures are found in many systems, including solutions of classical surfactants, block copolymer solutions and melts, biologic membranes, etc. Structural rearrangements often result in a crucial change of macroscopic properties (volume and elasticity of the sample, its viscosity, selectivity with respect to different solvents and salts, electric conductivity and so on). This can be used in the design of environmentally responsive smart materials whose behavior may be manipulated by external stimuli. The role of such materials is rapidly increasing in various applications. The major problem is to relate the macroscopic behavior of a complex fluid system with its molecular structure and to develop predictive models for engineering applications. We perform experimental studies and develop molecular-thermodynamic models for different types of complex fluids.
Self-Assembly of Soft Nanostructures in Solutions of Amphiphiles and Modulation of their Physico-Chemical Properties
The structure and properties of soft nanoscale assemblies such as surfactant micelles and physical polymer gels are sensitive to a change of conditions. The responsiveness of these structures has been used in various smart materials and devices, particularly for enhanced oil recovery, for reduction of drag in pipelines, in cosmetics, pharma, biomedicine, etc. The role of technologies that implement various "intelligent" materials and systems is expected to grow. Our goal is to advance in understanding of the behavior of soft mesostructured systems and to develop methods to control thermodynamic and structural properties of amphiphile-containing fluids by controlling self-assembly of nanoparticles. For predicting phase behavior and thermodynamic properties of classical fluids, molecular-thermodynamic methods are well-developed. Robust equations of state (e.g., SAFT) have been thoroughly tested, many parameters accumulated, and empirical correlations proposed. These EOS apply to spatially uniform bulk phases. However there have been no similar theoretical tools for fluid mixtures that contain soft nanostructures (wormlike micelles, microemulsion droplets, etc.) that have strong impact on physico-chemical properties of an amphiphile-containing solution. Our project is directed towards filling the existing gap by combining theoretical studies with experiment and computer simulation.
Molecular thermodynamic modeling of spatial networks in solutions of aggregating chainlike molecules
Reversible spatial networks (transient gels) are found in many systems, including solutions containing associating polymer chains or wormlike micelles. Formation of a network has strong impact on the rheologic and thermodynamic behavior. The reversibility of the network and controlled viscoelasticity make such systems very useful in a diversity of applications (drag reduction in heating systems, self-healing of coatings, drug delivery, enhanced oil recovery, etc.). Molecular theories of reversible networks are rapidly developing. In our work we combine mean-field approaches with computer simulation to study the association equilibrium and kinetics, the transition to the gel state and the topology of the gel. We focus on the relation between the molecular structure of the components and the structure of the spatial network formed in solution, the phase behavior of the system, the diffusion of sticky chains through the network and the viscoelasticity of the system.
Mesoscale Morphology and Macroscopic Behavior of Block Copolymer Gels
Block copolymer gels are widely used in various applications including drug-delivery systems, tissue implants, biosensors, separation membranes, nanoreactor engineering, etc. Their rich functionality complemented by rich morphological response to a mild variation of external conditions (pH, temperature and salinity) make them indispensable in the design of environmentally sensitive smart materials. The role of morphology in some cases can be dramatic. E.g., gyroid-like bicontinuous morphology of soft contact lenses provides excellent architecture for two counter-current flows (flow of tears from – and the opposite flow of oxygen towards – the eye cornea) that are crucial for high performance of a contact lens. Our goal is to derive molecular-thermodynamic models for engineering applications that would serve to predict structural and thermodynamic behavior of block copolymer gels taking into account the morphology of the gel. We consider microphase-segregated nonionic and ionic (both annealed and quenched) gels using analytical versions of self-consistent field theory.
Spatial Networks of Branched Wormlike Micelles
Many surfactants self-assemble into very long wormlike micelles. Solutions containing such aggregates show a number of interesting properties (e.g., viscoelasticity) and find numerous applications as commodity products, drag reducing agents, etc. Long wormlike micelles can entangle, branch and form three-dimensional networks (gels), or disassemble in response to variation of salinity, pH, composition of solvent, and temperature. Aggregation behavior of solution depends on the surfactant molecular architecture. We develop molecular-thermodynamic models that are aimed at predicting the aggregation behavior of surfactants in solution (the critical micelle concentration, the aggregate size and shape, the sphere-to-rod transition, the onset of branching, percolation, etc.) and the phase behavior, taking molecular characteristics of surfactant as a starting point. Special attention is paid to studying aggregate’s elasticity in ionic systems (e.g., the electrostatic contribution to the persistence length of a wormlike micelle).
Asphaltene Drop-Out from Petroleum Fluids
Asphaltene drop-out causes troubles in production facilities and in pipelines transporting oil from oilfields. A major problem is to learn how to control the asphaltene drop-out by changing conditions/adding stabilizing agents. Prediction of the drop-out conditions is a very important task. Asphaltenes in crude oils are aggregated colloidal particles that together with resins are suspended in the oil before precipitation takes place. We develop molecular-thermodynamic aggregation models of asphaltene precipitation. We study the effects of many factors, including polydispersity of asphaltenes, resin molecular shape, crude oil composition and pressure.
Development of equations of state and phase equilibria calculations for engineering applications
Development of equations of state and phase equilibria calculations for engineering applications. One example is a group-contribution equation of state proposed in our lab (Hole Model) that generalizes a number of previously known lattice-fluid equations of state. HM has been tested for numerous fluid mixtures. Parameters of HM have been estimated for a large number of functional groups representing different classes of chemical compounds. This makes possible prediction of phase behavior for a large number of binary and multicomponent mixtures. Many applications of HM include prediction phase behavior of crude oils from various oilfields at natural conditions. Special modifications of HM have been proposed for aqueous solutions of weak electrolytes and for ionic liquids.
Thermodynamic Properties and Aggregation Behavior of Ionic Liquids
Ionic Liquids (ILs) are potentially perspective industrial solvents because they combine a number of properties for being environmentally harmless and recyclable reaction media in chemical processes. ILs are non-flammable, extremely low-volatile, show catalytic activity and can be tailored for numerous specific applications by modifying their functionality relatively easily. ILs are salts that remain liquid at ambient temperatures. In solutions, long chain ILs form micelles and other nanoscale structures. Despite rapidly growing literature on ILs there is a lack of understanding their basic properties. Our goal is to understand “how ILs work” by relating molecular characteristics of ILs to their macroscopic properties. Current research includes: - Application of variational-field theory to deduce the equation of state of ILs solution and study the effects of asymmetric charge distribution of the large organic cation; - Experimental study and molecular-thermodynamic modeling of aggregation phenomena in aqueous solutions of ILs; - Correlation and prediction of high-pressure phase diagrams in CO2+ILs with the aid of a group-contribution lattice-fluid EOS.
- Victorov Alexey I., professor, doctor of chemical Sciences, Head of Department of Physical Chemistry
- Gotlib Igor Yu, associate professor, PhD
- Safonova Evgenia A., associate professor, PhD
- Vanin Alexandr A. associate professor, PhD
- Voznesenskiy Mikhail A., associate professor, PhD
- Kopanichuk Ilia V. assistant professor
- Koneva Alina S. engineer
- Alopina Elena V. engineer, PhD
- Emelyanova Ksenia A, PhD student
- Korchak Peter, student
- Sorina Polina, student
- Victorov A., Self-Assembly into Branches and Networks, Chapter 2.,pp 41-76. In: Self -Assembly: From Surfactants to Nanoparticles, Ed. Nagarajan, Ramanathan,Wiley Series on Surface and Interfacial Chemistry (NY),1. Edition, 2019, 400 Pages, Hardcover, Wiley & Sons Ltd , ISBN: 978-1-119-00136-2
- Ksenia A. Emelyanova, Alexey I. Victorov. Molecular thermodynamic modeling of a bilayer perforation in mixed catanionic surfactant systems. Physical Chemistry Chemical Physics, 2018, 20, 27924 - 27929. C8CP04593C http://dx.doi.org/10.1039/C8CP04593C
- Elena A. Belyaeva, Aleksandr A. Vanin, Alexey Victorov. Distribution of Zwitter-Ionic Tryptophan between the Micelles of 1-Dodecyl-3-Methyl Imidazolium and Aqueous Medium from Molecular Dynamic Simulation Phys. Chem. Chem. Phys., 2018, 20, 23747-23753. http://dx.doi.org/10.1039/C8CP02488J
- I. Yu. Gotlib, A. I. Victorov. Association equilibrium and gelation in solutions of cross-associating chains containing inactive fragments. Polymer Science, Series C, 2018, December 2018, Volume 60, Supplement 1, pp 95–105
- A.S. Koneva, E.A. Safonova, P.S. Kondrakhina, M.A. Vovk, A.A. Lezov,Yu. S. Chernyshev, N.A. Smirnova Effect of water content on structural and phase behavior ofwater-in-oil (n-decane) microemulsion system stabilized by mixednonionic surfactants SPAN 80/TWEEN 80 // Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2017. — Vol. 518, — P. 273–282
- Elena V. Alopina, Evgenia A. Safonova, Igor B. Pukinsky, and Natalia A. Smirnova Liquid−Liquid Equilibria in Aqueous Mixtures of Alkylmethylimidazolium Glutamate with Potassium Carbonate and Some Physicochemical Properties of Aqueous [Cnmim][Glu] (n = 4, 6, 8) Solutions // Journal of Chemical and Engineering Data, 2016. — Vol. 61, — № 6. — P. 2013-2019
- Belyaeva E.A., Vanin A.A., Anufrikov Yu.A., Smirnova N.A. Molecular-dynamic simulation of aliphatic alcohols distribution between the micelle of 3-methyl-1-dodecylimidazolium bromide and their aqueous surrounding. COLLOIDS SURF. A, 2016, V. 508, PP. 93-100
- Igor Gotlib, Alexey Victorov. Effects of the linear chain structure on the cross-association equilibrium between chainlike molecules in a good solvent // Fluid Phase Equil. 2017. V. 454. P. 116–121. DOI: 10.1016/j.fluid.2017.09.015.
- Ksenia Emelyanova, Igor Gotlib, Anna Shishkina, Michail Voznesenskiy, and Alexey Victorov Molecular Thermodynamic Modeling of Self-Assembly into Branches and Spatial Networks in Solution, Journal of Chemical & Engineering Data (2016), 61, (12), 4013−4022, DOI: 10.1021/acs.jced.6b00531
- Igor Yu. Gotlib, Ivan K. Malov, Alexey I. Victorov and Mikhail A. Voznesenskiy. Association Equilibrium for Cross-Associating Chains in a Good Solvent: Crowding and other Non-ideality Effects, J Phys Chem B, 2016, 120, 7234−7243, DOI: 10.1021/acs.jpcb.5b12530
- Ilia V. Kopanichuk, Alexandr A. Vanin, Igor Yu. Gotlib and Alexey I. Victorov Steric Asymmetry vs Charge Asymmetry in Dilute Solution Containing Large Weakly Charged Ions, Fluid Phase Equilibria, 2016, 428, 203-211 http://dx.doi.org/10.1016/j.fluid.2016.06.008
- A I Victorov, M A Voznesenskiy, E A Safonova, "Spatial networks in solutions of worm-like aggregates: universal behaviour and molecular portraits", RUSS CHEM REV, 2015, 84 (7), 693–711, DOI: 10.1070/RCR4524
- A. Victorov. Molecular Thermodynamics of Soft Self-Assembling Structures for Engineering Applications. J Chem Technol Biotechnol. (2015) 90 (8), 1357-1363, DOI: 10.1002/jctb.4693,
- S. V. Koroleva and A. I. Victorov. The strong specific effect of coions on micellar growth from molecular-thermodynamic theory. Phys.Chem.Chem.Phys.(2014) 16, 17422-17425. DOI: 10.1039/c4cp02178a
- Alexey I. Victorov. Modeling of Micelle-Solution Equilibria for Mixed Nonionic Micelles with Strong Specific Interactions in Coronae: Group-Contribution Approach. Journal of Chemical & Engineering Data (2014) 59, 2995−3002. DOI: 10.1021/je500103h
- Sofia V. Koroleva and Alexey Victorov. Modeling of the Effects of Ion Specificity on the Onset and Growth of Ionic Micelles in a Solution of Simple Salts. Langmuir (2014), 30, N 12, 3387−3396. DOI: 10.1021/la404845y
- S.Tcyrulnikov, A. I. Victorov. Molecular Thermodynamic Modeling of Gelation and Demixing in Solution of Cross-Associating Chains, Macromolecules, (2013) 46, N11, 4706–4715, DOI: 10.1021/ma400425h
- A.I. Victorov. Curvature elasticity of a weak polyelectrolyte brush and shape transitions in assemblies of amphiphilic diblock copolymers, Soft Matter, 8, N20, 5513–5524 (2012) DOI:10.1039/C2SM25079A
- N.A.Smirnova, A.I.Victorov “Quasilattice equations of state for molecular fluids” In: Equations of state for fluids and fluid mixtures, IUPAC, Experimental Thermodynamics, Vol.5, Eds. Sengers J.V., Kaiser R.F., Peters C.J., White H., Elsevier, 2000, Pt.I, pp.255-288, doi:10.1016/S1874-5644(00)80018-1
- Victorov A.I. Hole quasichemical model, its group-contribution version. In: Liquid-vapor equilibrium thermodynamics. Ed. A.G.Morachevsky, Leningrad, Khimia, 344 p., 1989 (in Russian).