Asymmetric porous membranes from binary polymer solution by physical gelation induced phase separation

Polymer ◽  
2016 ◽  
Vol 87 ◽  
pp. 323-329 ◽  
Author(s):  
Hyoung-Ghi Park ◽  
Dahl-Young Khang
2021 ◽  
Author(s):  
Ehsan Hosseini

Polymer-dispersed liquid crystals (PDLCs) are a relatively new class of materials used for many applications ranging from switchable windows to projection displays. PDLSs are formed by spinodal decomposition induced by thermal quenching or polymerization. The objective of the present study is to introduce a new mechanism of phase separation in a binary polymer solution and develop a mathematical model and computer simulation to describe the phase separation during the early and intermediate stages of nucleation and growth and spinodal decomposition induced by thermal double quenching. The growth equilibrium limits of phase separation as well as phase transition are calculated by taking into consideration the Flory-Huggins theory for the free energy of mixing. A two step quench is modeled using Cahn-Hilliard theory for asymmetric binary polymer solution which is quenched from a stable state in the one-phase region to a metastable region where nucleation and growth occurs. The solution is allowed to coarsen for different time periods before a second quench was applied to a point further inside the phase diagram. The numerical results in two dimensions replicate the experimental and numerical work that has been recently done and published.


2021 ◽  
Author(s):  
Ehsan Hosseini

Polymer-dispersed liquid crystals (PDLCs) are a relatively new class of materials used for many applications ranging from switchable windows to projection displays. PDLSs are formed by spinodal decomposition induced by thermal quenching or polymerization. The objective of the present study is to introduce a new mechanism of phase separation in a binary polymer solution and develop a mathematical model and computer simulation to describe the phase separation during the early and intermediate stages of nucleation and growth and spinodal decomposition induced by thermal double quenching. The growth equilibrium limits of phase separation as well as phase transition are calculated by taking into consideration the Flory-Huggins theory for the free energy of mixing. A two step quench is modeled using Cahn-Hilliard theory for asymmetric binary polymer solution which is quenched from a stable state in the one-phase region to a metastable region where nucleation and growth occurs. The solution is allowed to coarsen for different time periods before a second quench was applied to a point further inside the phase diagram. The numerical results in two dimensions replicate the experimental and numerical work that has been recently done and published.


2014 ◽  
Vol 200 ◽  
pp. 2-6 ◽  
Author(s):  
Miho Yanagisawa ◽  
Yutaro Yamashita ◽  
Sada-atsu Mukai ◽  
Masahiko Annaka ◽  
Masayuki Tokita

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mayu Shono ◽  
Ritsuki Ito ◽  
Fumika Fujita ◽  
Hiroki Sakuta ◽  
Kenichi Yoshikawa

AbstractLiving cells maintain their lives through self-organization in an environment crowded with a rich variety of biological species. Recently, it was found that micro-droplets containing biomacromolecules, which vary widely in size, are generated accompanied by water/water phase-separation by simple mechanical mixing of an aqueous solution with binary polymers. Here, we report that cell-sized droplets of nearly the same size are generated as a linear array within a glass capillary upon the introduction of a binary polymer solution of polyethylene glycol (PEG) and dextran (DEX). Interestingly, when DNA molecules are added to the polymer solution, stable droplets entrapping DNA molecules are obtained. Similarly, living cells are entrapped spontaneously for the linearly-arranged cell-sized droplets. This simple method for generating micro-droplets entrapping DNA and also living cells is expected to stimulate further study on the self-construction of protocells and micro organoids.


2006 ◽  
Vol 110 (8) ◽  
pp. 3661-3665 ◽  
Author(s):  
Chris I. Addison ◽  
Pierre-Arnaud Artola ◽  
Jean-Pierre Hansen ◽  
Ard A. Louis

2017 ◽  
Vol 19 (36) ◽  
pp. 24961-24970 ◽  
Author(s):  
Binita Pathak ◽  
Goutam Prasanna Kar ◽  
Suryasarathi Bose ◽  
Saptarshi Basu

We propose a unique contact-free droplet based architecture to alter the phase separation behavior in binary polymer solution (PS/PVME in toluene) by tuning the external heating rate and concentration of added MWCNT particles.


2003 ◽  
Vol 58 (7-8) ◽  
pp. 392-396
Author(s):  
L.V. Govor ◽  
J. Parisi ◽  
G. H. Bauer

We report on the formation of self-assembled rings of CoPt3 nanoparticles in ultrathin polymer films (ring diameter about 1 μm, particle diameter 6 nm). The polymer thin film was formed by wetting a polymer solution on the surface of water. The process of self-assembling turns out to result from phase separation of the binary polymer solution film used, the subsequent dewetting of the top layer, and its decomposition into droplets on the surface of the bottom layer.


Sign in / Sign up

Export Citation Format

Share Document