Dynamics of Spinodal Decomposition in a Ternary Gelling System.

Yutaro Yamashita,Miho Yanagisawa,Masayuki Tokita

doi:10.3390/gels4020026

Abstract

The phase diagram and phase transitions of the ternary system of gelatin, water and poly(ethylene glycol) oligomers were studied as a function of the weight fraction of gelatin and the weight fraction and molecular weight of poly(ethylene glycol) oligomers. It was found that both phase separation and the sol-gel transition occur in this ternary system. The relative position of the phase separation line and the sol-gel transition line depends on the weight fraction and the molecular weight of the poly(ethylene glycol) oligomer that coexists in the solution. All aspects of the phase diagram are sensitive to the molecular weight of the poly(ethylene glycol) oligomer. Since the phase separation line crosses the sol-gel transition line in the phase space that is created by the temperature and the weight fraction of gelatin, the phase space is typically divided into four regions, where each region corresponds to a definite phase. The transitions between mutual phases were studied using the light-scattering technique.

Highlights

There are many water-soluble polymers distributed throughout the natural world
The results indicate that the phase diagram of the ternary system of gelatin, water and poly(ethylene glycol) (PEG) can be controlled by the appropriate choice of the molecular weight and the weight fraction of PEG oligomer
It was found from the phase diagrams that the two transitions of the phase separation and the sol-gel transition appear in the T − φg phase space in the ternary system of gelatin, water and PEG oligomer

Summary

Introduction

There are many water-soluble polymers distributed throughout the natural world. Some of these can be synthesized artificially, while others solely originate from biological systems. Since water-soluble polymers are environmentally sustainable, they are widely used in science, technology and even in our day-to-day lives. The phase behavior and the phase transition of polymer solution play important roles in the fabrication processes of polymeric materials. It may be important to obtain information on the phase structure of the water-soluble polymer in the solution state for the effective fabrication of many practical commodities. We report on the phase behaviors of gelatin, water and poly(ethylene glycol) (PEG) in a system

Results

Discussion

Conclusion