scholarly journals Water vapor induced self-assembly of islands/honeycomb structure by secondary phase separation in polystyrene solution with bimodal molecular weight distribution

2021 ◽  
Author(s):  
Maciej Łojkowski ◽  
Adrian Chlanda ◽  
Emilia Choińska ◽  
Wojciech Swieszkowski
Keyword(s):  
Molecular Weight ◽  
Phase Separation ◽  
Molecular Weight Distribution ◽  
Weight Distribution ◽  
Self Assembly ◽  
Secondary Phase ◽  
Honeycomb Structure ◽  
Polymer Chains ◽  
Molecular Weights ◽  
Secondary Phase Separation

<p>The formation of complex structures in thin films is of interest in many fields. Segregation of polymer chains of different molecular weights is a well-known process. However, here, polystyrene with bimodal molecular weight distribution, but no additional chemical modification was used. It was proven that at certain conditions, the phase separation occurred between two fractions of bimodal polystyrene/methyl ethyl ketone solution. The films were prepared by spin-coating, and the segregation between polystyrene phases was investigated by force spectroscopy. Next, water vapour induced secondary phase separation was investigated. The introduction of moist airflow induced the self-assembly of the lower molecular weight into islands and the heavier fraction into a honeycomb. As a result, an easy, fast, and effective method of obtaining island/honeycomb morphologies was demonstrated. The possible mechanisms of the formation of such structures were discussed.</p>

scholarly journals Water vapor induced self-assembly of islands/honeycomb structure by secondary phase separation in polystyrene solution with bimodal molecular weight distribution

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Maciej Łojkowski ◽  
Adrian Chlanda ◽  
Emilia Choińska ◽  
Wojciech Swieszkowski
Keyword(s):  
Molecular Weight ◽  
Phase Separation ◽  
Molecular Weight Distribution ◽  
Weight Distribution ◽  
Self Assembly ◽  
Secondary Phase ◽  
Honeycomb Structure ◽  
Polymer Chains ◽  
Molecular Weights ◽  
Secondary Phase Separation

AbstractThe formation of complex structures in thin films is of interest in many fields. Segregation of polymer chains of different molecular weights is a well-known process. However, here, polystyrene with bimodal molecular weight distribution, but no additional chemical modification was used. It was proven that at certain conditions, the phase separation occurred between two fractions of bimodal polystyrene/methyl ethyl ketone solution. The films were prepared by spin-coating, and the segregation between polystyrene phases was investigated by force spectroscopy. Next, water vapour induced secondary phase separation was investigated. The introduction of moist airflow induced the self-assembly of the lower molecular weight into islands and the heavier fraction into a honeycomb. As a result, an easy, fast, and effective method of obtaining island/honeycomb morphologies was demonstrated. The possible mechanisms of the formation of such structures were discussed.

scholarly journals The interplay between bi-modal molecular weight distribution in polystyrene and humidity induces self-assembly of biomimetic micropillars/honeycomb morphology in the thin polymer film

2021 ◽  
Author(s):  
Maciej Łojkowski ◽  
Adrian Chlanda ◽  
Emilia Choińska ◽  
Wojciech Swieszkowski
Keyword(s):  
Molecular Weight ◽  
Molecular Weight Distribution ◽  
Weight Distribution ◽  
Self Assembly ◽  
Phase Segregation ◽  
Polymer Chains ◽  
Thin Polymer Film ◽  
Chemical Compositions ◽  
Molecular Weights ◽  
The Right

<p>Segregation of polymer chains of different molecular weights is a well-known process. A traditional experimental approach of studying phase segregation in thin films composed of polymer blends with identical chemical compositions but different molecular weights was focused on functionalisation of chemical group or modification of end-group. In this study, however, a different approach was proposed. Polystyrene with bimodal molecular weight distribution, but no additional chemical modification was used. The films were prepared by spin-coating and the segregation between polystyrene phases was investigated by force spectroscopy. The solubility of bimodal polystyrene was explored. At the right molecular weight distribution and soluted in Methyl Ethyl Ketone, the phase segregation occurred. Introduction of moist airflow induced the separation of the lower molecular weight into micropillars and the heavier fraction self-organized into a honeycomb. As a result, an easy, fast, and effective method of obtaining micropillar/honeycomb morphologies was demonstrated. The mechanism of formation of such structures was explained. </p>

scholarly journals Exploiting the Interplay Between Bi-Modal Molecular Weight Distribution in Polystyrene and Humidity to Induce Self-Assembly of Biomimetic Micropillars/honeycomb Morphology in Thin Polymer Film

2021 ◽  
Author(s):  
Maciej Łojkowski ◽  
Adrian Chlanda ◽  
Emilia Choińska ◽  
Wojciech Swieszkowski
Keyword(s):  
Molecular Weight ◽  
Molecular Weight Distribution ◽  
Weight Distribution ◽  
Self Assembly ◽  
Spin Coating ◽  
Phase Segregation ◽  
Polymer Chains ◽  
Thin Polymer Film ◽  
Chemical Compositions ◽  
Molecular Weights

<p>Segregation of polymer chains of different molecular weights is a well-known process. For many years, it was assumed that this process occurs over long-time intervals. On the contrary, solvent evaporation during spin-coating is very fast. A traditional experimental approach of studying phase segregation of thin films composed of polymer blends with identical chemical compositions but different molecular weights, was focused on functionalization of chemical group or modification of end-group. In this study however, a different approach was proposed, in which polystyrene with a bimodal molecular weight distribution but no additional chemical modification was implemented in order to examine and analyze its phase segregation. By doing this, we have presented an easy, fast, effective and fully controlled method of obtaining biomimetic micropillar/honeycomb morphologies. In addition, the evaporation rate during spin-coating and the viscosity of a solution with a bimodal molecular weight distribution was described.</p>

scholarly journals The interplay between bi-modal molecular weight distribution in polystyrene and humidity induces self-assembly of biomimetic micropillars/honeycomb morphology in the thin polymer film

2021 ◽  
Author(s):  
Maciej Łojkowski ◽  
Adrian Chlanda ◽  
Emilia Choińska ◽  
Wojciech Swieszkowski
Keyword(s):  
Molecular Weight ◽  
Molecular Weight Distribution ◽  
Weight Distribution ◽  
Self Assembly ◽  
Phase Segregation ◽  
Polymer Chains ◽  
Thin Polymer Film ◽  
Chemical Compositions ◽  
Molecular Weights ◽  
The Right

<p>Segregation of polymer chains of different molecular weights is a well-known process. A traditional experimental approach of studying phase segregation in thin films composed of polymer blends with identical chemical compositions but different molecular weights was focused on functionalisation of chemical group or modification of end-group. In this study, however, a different approach was proposed. Polystyrene with bimodal molecular weight distribution, but no additional chemical modification was used. The films were prepared by spin-coating and the segregation between polystyrene phases was investigated by force spectroscopy. The solubility of bimodal polystyrene was explored. At the right molecular weight distribution and soluted in Methyl Ethyl Ketone, the phase segregation occurred. Introduction of moist airflow induced the separation of the lower molecular weight into micropillars and the heavier fraction self-organized into a honeycomb. As a result, an easy, fast, and effective method of obtaining micropillar/honeycomb morphologies was demonstrated. The mechanism of formation of such structures was explained. </p>

scholarly journals Exploiting the Interplay Between Bi-Modal Molecular Weight Distribution in Polystyrene and Humidity to Induce Self-Assembly of Biomimetic Micropillars/honeycomb Morphology in Thin Polymer Film

2021 ◽  
Author(s):  
Maciej Łojkowski ◽  
Adrian Chlanda ◽  
Emilia Choińska ◽  
Wojciech Swieszkowski
Keyword(s):  
Molecular Weight ◽  
Molecular Weight Distribution ◽  
Weight Distribution ◽  
Self Assembly ◽  
Phase Segregation ◽  
Thin Polymer Film ◽  
Time Interval ◽  
Chemical Compositions ◽  
Short Time Interval ◽  
Molecular Weights

<p>Segregation of polymer chains of different molecular weights is a well-known process. A traditional experimental approach of studying phase segregation of thin films composed of polymer blends with identical chemical compositions but different molecular weights, was focused on functionalization of chemical group or modification of end-group. In this study however, a different approach was proposed, in which polystyrene with a bimodal molecular weight distribution but no additional chemical modification was implemented in order to examine and analyze its phase segregation. It was found that by choosing right molecular weight distribution it is possible to obtain controlled phase separation at short time interval and at microscale. By doing this, we have presented an easy, fast, effective and fully controlled method of obtaining biomimetic micropillar/honeycomb morphologies. In addition, the evaporation rate during spin-coating and the viscosity of a solution with a bimodal molecular weight distribution was studied.</p>

scholarly journals Exploiting the Interplay Between Bi-Modal Molecular Weight Distribution in Polystyrene and Humidity to Induce Self-Assembly of Biomimetic Micropillars/honeycomb Morphology in Thin Polymer Film

2021 ◽  
Author(s):  
Maciej Łojkowski ◽  
Adrian Chlanda ◽  
Emilia Choińska ◽  
Wojciech Swieszkowski
Keyword(s):  
Molecular Weight ◽  
Molecular Weight Distribution ◽  
Weight Distribution ◽  
Self Assembly ◽  
Phase Segregation ◽  
Thin Polymer Film ◽  
Time Interval ◽  
Chemical Compositions ◽  
Short Time Interval ◽  
Molecular Weights

<p>Segregation of polymer chains of different molecular weights is a well-known process. A traditional experimental approach of studying phase segregation of thin films composed of polymer blends with identical chemical compositions but different molecular weights, was focused on functionalization of chemical group or modification of end-group. In this study however, a different approach was proposed, in which polystyrene with a bimodal molecular weight distribution but no additional chemical modification was implemented in order to examine and analyze its phase segregation. It was found that by choosing right molecular weight distribution it is possible to obtain controlled phase separation at short time interval and at microscale. By doing this, we have presented an easy, fast, effective and fully controlled method of obtaining biomimetic micropillar/honeycomb morphologies. In addition, the evaporation rate during spin-coating and the viscosity of a solution with a bimodal molecular weight distribution was studied.</p>

scholarly journals Exploiting the Interplay Between Bi-Modal Molecular Weight Distribution in Polystyrene and Humidity to Induce Self-Assembly of Biomimetic Micropillars/honeycomb Morphology in Thin Polymer Film

2021 ◽  
Author(s):  
Maciej Łojkowski ◽  
Adrian Chlanda ◽  
Emilia Choińska ◽  
Wojciech Swieszkowski
Keyword(s):  
Molecular Weight ◽  
Molecular Weight Distribution ◽  
Weight Distribution ◽  
Self Assembly ◽  
Phase Segregation ◽  
Thin Polymer Film ◽  
Time Interval ◽  
Chemical Compositions ◽  
Short Time Interval ◽  
Molecular Weights

<p>Segregation of polymer chains of different molecular weights is a well-known process. A traditional experimental approach of studying phase segregation of thin films composed of polymer blends with identical chemical compositions but different molecular weights, was focused on functionalization of chemical group or modification of end-group. In this study however, a different approach was proposed, in which polystyrene with a bimodal molecular weight distribution but no additional chemical modification was implemented in order to examine and analyze its phase segregation. It was found that by choosing right molecular weight distribution it is possible to obtain controlled phase separation at short time interval and at microscale. By doing this, we have presented an easy, fast, effective and fully controlled method of obtaining biomimetic micropillar/honeycomb morphologies. In addition, the evaporation rate during spin-coating and the viscosity of a solution with a bimodal molecular weight distribution was studied.</p>

scholarly journals Matrix-graph model of the polymer materials destruction process

2018 ◽  
Vol 80 (3) ◽  
pp. 50-55
Author(s):  
A. A. Khvostov ◽  
S. G. Tikhomirov ◽  
I. A. Khaustov ◽  
A. A. Zhuravlev ◽  
A. V. Karmanov
Keyword(s):  
Mathematical Model ◽  
Molecular Weight ◽  
Molecular Weight Distribution ◽  
Weight Distribution ◽  
Graph Model ◽  
Polymer Materials ◽  
Simulation Environment ◽  
Destruction Process ◽  
Molecular Weights ◽  
The Mathematical Model

The paper deals with the problem of mathematical modeling of the process of thermochemical destruction using the theory of graphs. To synthesize a mathematical model, the Markov chain is used. For the formalization of the model a matrix-graph method of coding is used. It is proposed to consider the process of destruction as a random process, under which the state of the system changes, characterized by the proportion of macromolecules in each fraction of the molecular mass distribution. The intensities of transitions from state to state characterize the corresponding rates of destruction processes for each fraction of the molecular weight distribution (MWD). The processes of crosslinking and polymerization in this work have been neglected, and it is accepted that there is a probability of transition from any state with a lower order index (corresponding to fractions with higher molecular weights) to any state with a higher index (corresponding fractions with lower molecular weights). A computational formula is presented for estimating the number of arcs and model parameters from a given number of fractions of the molecular weight distribution of the polymer. An example of coding in a matrix form of a graph model of the process of degradation of polybutadiene in solution for the case of six fractions of the molecular weight distribution is shown. As the simulation environment, the interactive graphical simulation environment of MathWorks Simulink is used. To evaluate the parameters of the mathematical model, experimental studies of the degradation of polybutadiene in solution were carried out. The chromatography of the polybutadiene solution was used as the initial data for the estimation of the MWD polymer. The considered matrix-graph representation of the structure of the mathematical model of the polymer destruction process makes it possible to simplify the compilation of the model and its software implementation in the case of a large number of vertices of the graph describing the process of destruction

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