Konstantin Kolegov

Konstantin Kolegov
Astrakhan State University | aspu · Computer Science

PhD

About

39
Publications
3,536
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95
Citations
Citations since 2017
32 Research Items
91 Citations
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Introduction
Now I work at Astrakhan State University as a senior researcher at the laboratory of mathematical modeling. My interests include droplets and films, evaporative self-assembly, evaporative lithography, colloidal solutions, computational fluid dynamics, continuum and semi-discrete models.

Publications

Publications (39)
Preprint
Evaporating droplets and films are used in applications from different fields. Various methods of evaporative self-assembly are of particular interest. The paper describes a mathematical model of mass transfer in a droplet drying on a substrate based on the lubrication approximation. The model takes into account the transfer of a dissolved or suspe...
Article
We present a theoretical study and numerical simulation of Marangoni convection within ellipsoidal isotropic droplets embedded in free-standing smectic films (FSSFs). The thermocapillary flows are analyzed for both isotropic droplets spontaneously formed in FSSF overheated above the bulk smectic-isotropic transition and oil lenses deposited on the...
Preprint
We present theoretical study and numerical simulation of Marangoni convection within ellipsoidal isotropic droplets embedded in free standing smectic films (FSSF). The thermocapillary flows are analyzed for both isotropic droplets spontaneously formed in FSSF overheated above the bulk smectic-isotropic transition, and oil lenses deposited on the su...
Article
Full-text available
Colloidal droplets are used in a variety of practical applications. Some of these applications require particles of different sizes. These include medical diagnostic methods, the creation of photonic crystals, the formation of supraparticles, and the production of membranes for biotechnology. A series of earlier experiments had shown the possibilit...
Poster
Full-text available
Colloidal droplets are used in a variety of practical applications. Some applications require particles of different sizes. These include medical diagnostic methods, the creation of photonic crystals, the formation of supraparticles, and the production of membranes for biotechnology. Series of experiments have previously shown the possibility of pa...
Presentation
Full-text available
In the present work, we study the possibility of controlling the particle assembly during the evaporation of the liquid they are dispersed in, using a local heater mounted in the central part of the bottom of the open cell.
Preprint
Colloidal droplets are used in a variety of practical applications. Some applications require particles of different sizes. These include medical diagnostic methods, the creation of photonic crystals, the formation of supraparticles, and the production of membranes for biotechnology. Series of experiments have previously shown the possibility of pa...
Article
Full-text available
This work is devoted to a method to generate particle cluster assemblies and connected to evaporative lithography. Experiments are carried out using nonuniform evaporation of an isopropanol film containing polystyrene microspheres in a cylindrical cell. The local inhomogeneity of the vapor flux density is achieved by exploiting the temperature grad...
Poster
Full-text available
Evaporative lithography consists in creating conditions for nonuniform evaporation [1]. The compensatory flow occurs due to the nonuniform evaporation of the liquid and transfers the particles to the areas of intense evaporation. It is possible to control the vapor flux density along the free surface of the liquid layer in different ways. Sometimes...
Preprint
The work is devoted to one method of structured sediments formation connected to evaporative lithography. Experiments were carried out with nonuniform evaporation of an isopropanol film containing polystyrene microspheres in a cylindrical cell. The local inhomogeneity of the vapor flux density was achieved due to the temperature gradient. A copper...
Poster
Full-text available
Colloidal droplets are used in a variety of applications. Some of them require the presence of particles of different sizes. These include methods of medical diagnostics, the creation of photonic crystals, the formation of supraparticles, and the production of membranes for biotechnology. Some experiments have previously shown the possibility of pa...
Article
Full-text available
In this work, we continue to study the formation of particle chains (clusters) inside the annular sediment during the drying of a colloidal droplet on a substrate. The average value of the cluster size was determined after processing experimental data from other authors. We performed a series of calculations and found the value of the model paramet...
Preprint
Full-text available
In this work, we continue to study the formation of particle chains (clusters) inside the annular sediment during the drying of a colloidal droplet on a substrate. The average value of the cluster size was determined after processing experimental data from other authors. We performed a series of calculations and found the value of the model paramet...
Article
Full-text available
This review covers experimental results of evaporative lithography and analyzes existing mathematical models of this method. Evaporating droplets and films are used in different fields, such as cooling of heated surfaces of electronic devices, diagnostics in health care, creation of transparent conductive coatings on flexible substrates, and surfac...
Preprint
Full-text available
The review covers experimental results of evaporative lithography and analyzes existing mathematical models of this method. Evaporating droplets and films are applied in different fields, such as cooling of heated surfaces of electronic devices, diagnostics in health care, creation of transparent conductive coatings on flexible substrates, surface...
Data
Supplemental Material for one of the simulation videos [DOI: 10.1103/PhysRevE.100.033304]. The file "adv_dif_cap_t=1s.mp4" is a vidio of particle dynamics simulation when advection, diffusion and capillary attraction are taken into account for evaporation time t_max = 1 s.
Poster
Full-text available
A simplified model is developed, which allows us to perform computer simulations of the particles transport in an evaporating droplet with a contact line pinned to a hydrophylic substrate. The model accounts for advection in the droplet, diffusion and particle attraction by capillary forces. On the basis of the simulations, we analyse the physical...
Article
Full-text available
A simplified model is developed, which allows us to perform computer simulations of the particles transport in an evaporating droplet with a contact line pinned to a hydrophylic substrate. The model accounts for advection in the droplet, diffusion and particle attraction by capillary forces. On the basis of the simulations, we analyse the physical...
Article
Full-text available
The work is devoted to particles dynamics simulation in a colloidal drop, when it dries on a substrate and the triple-phase boundary is fixed. Experimental observations [Deegan R. D. et. al., 2000] show a ring deposition on a solid substrate after full droplet desiccation. This phenomenon of macrolevel is known as coffee ring effect. There are othe...
Preprint
Full-text available
A simplified model is developed, which allows us to perform computer simulations of the particles transport in an evaporating droplet with a contact line pinned to a hydrophylic substrate. The model accounts for advection in the droplet, diffusion and particle attraction by capillary forces. On the basis of the simulations, we analyse the physical...
Preprint
Full-text available
The work is devoted to particles dynamics simulation in a colloidal drop, when it dries on a substrate and the triple-phase boundary is fixed. Experimental observations [Deegan R. D. et. al., 2000] show a ring deposition on a solid substrate after full droplet desiccation. This phenomenon of macrolevel is known as coffee ring effect. There are othe...
Conference Paper
Full-text available
В работе теоретически изучается метод испарительной литографии в сочетании с внешним ИК-нагревом. Этот способ позволяет формировать твердые микроструктуры необходимой рельефной формы в результате испарения жидкой пленки коллоидного раствора под маской. Нагрев частиц способствует их спеканию, поэтому получаемая структура не содержит трещин в отличие...
Poster
Full-text available
Mass transfer in drying drops and films is interesting with practical point of view, since it is used in problems of evaporative lithography. Compensatory flows arise when conditions of nonuniform evaporation from the surface of the liquid layer are created and move colloidal particles in the region of fast evaporation. This makes it possible to ob...
Preprint
Full-text available
Mass transfer in drying drops and films is interesting with practical point of view, since it is used in problems of evaporative lithography. Compensatory flows arise when conditions of nonuniform evaporation from the surface of the liquid layer are created. Its move colloidal particles in the region of fast evaporation. This makes it possible to o...
Thesis
Full-text available
Построена нестационарная математическая модель, описывающая массоперенос в испаряющейся капле или пленке, в которой учтены вязкие, капиллярные и гравитационные силы, а также скорость и неравномерность испарения под маской. Предложена и реализована регуляризованная Theta-схема, являющаяся модификацией параметрической двухслойной шеститочечной разнос...
Article
Full-text available
Mass transfer in drying drops and films is interesting with practical point of view, since it is used in problems of evaporative lithography. Compensatory flows arise when conditions of nonuniform evaporation from the surface of the liquid layer are created and move colloidal particles in the region of fast evaporation. This makes it possible to ob...
Article
Full-text available
The paper theoretically studies the method of evaporative lithography in combination with external infrared heating. This method makes it possible to form solid microstructures of the required relief shape as a result of evaporation of the liquid film of the colloidal solution under the mask. The heated particles are sintered easier, so there are n...
Article
Full-text available
В работе теоретически исследуется модификация метода испарительной литографии, когда в систему добавлен ИК-излучатель. Полимерные покрытия с периодической структурой, повторяющей шаблон с точностью до миллиметрового размера, формируются поперечными потоками в жидких растворах коллоидных частиц. Течение возникает из-за неравномерного испарения с пов...
Article
Full-text available
This work is devoted to a theoretical studying of IR radiation-assisted evaporative lithography. Polymer coatings with periodic topographic patterns, repeating over millimeter length scales, are created from lateral flows in an aqueous dispersion of colloidal particles. The flow is driven by differences in evaporation rate across the wet film surfa...
Article
Full-text available
Applicability limits of a quasisteady approach to modelling the fluid dynamics in evaporated drop on a substrate (with constant contact area) and in circular well are defined in this paper. A nonsteady model is considered for comparison. Quasisteady and nonsteady (with the full-form equation of motion) sets of equations have been solved numerically...
Article
Full-text available
The author offers a method of formation of concentric ring structures out of microand nanoparticles on impermeable surfaces as a result of evaporation of the film of colloidal solution under a special mold. The above mentioned method is studied theoretically. A mathematical model of initial stage of process is solved numerically. The model includes...
Article
Full-text available
An one-dimensional mathematical model described evolution of drop shape and viscous fluid dynamics (vertically averaged radial flow of the liquid) as the result of evaporation from impermeable horizontal surface is presented in this work. The model considers the influence of volume and capillary forces. Non-steady-state approach has been used to de...
Article
Full-text available
The work aims to study the admissibility of the quasi-steady approach application in fluid flow modeling inside of evaporating drops placed on a solid horizontal substrate. Non-steady model has been developed to compare results with a quasi-steady model. For the first time one-dimensional motion equation of fluid in a drop is proposed from a moment...
Article
Full-text available
Выведены основные уравнения нестационарной математической модели одномерных (осредненных по высоте капли) течений в высыхающей капле, покоящейся на твердом основании. В результате численных расчетов показано, что процессы в капле определяются законом испарения и значением капиллярного числа. При малых значениях капиллярного числа результаты, получе...

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Projects

Projects (3)
Project
The scientific problem is to establish a connection between a number of effects related to phase transitions and to heat and mass transfer, with key parameters for controlling processes in evaporative lithography when obtaining micro- and nanoscale structured precipitation and solid relief coatings, which will improve the geometric and physico-chemical characteristics of the resulting patterns and will be taken into account when developing new modifications of the method under study for further implementation in technological production aimed at solving various applied problems.
Project
A. Computer simulation of the formation of particle depositions during evaporation of droplets of colloidal solutions B. Studying Marangoni convection in evaporating droplets of liquids and colloidal solutions, depending on the parameters of the problem C. Studying hydrothermal waves in an evaporating sessile drop by computer simulation
Archived project
Simulation of self-organization processes in drying drops and films