Effect of ph on silk fibroin gelation

Abstract

Aqueous silk fibroin gelled when it was kept for a required time under suitable conditions. The gelation time and the physical properties of fibroin gel could be controlled by adjusting pH and concentration of the silk fibroin solution. Gelation occurred when the electrostatic repulsion between the macromolecules was sufficiently reduced near and at the isoelectric point of silk fibroin (pI = 3.8-3.9). The strength of the gel at the isoelectric point was weak due to an insufficient formation of a network structure. Gel strength and gelling rate were greatly dependent on pH and concentration of the silk fibroin solution. The formation of network structure depended on the amount of a-structure developed in the gel. © 1992, The Society of Fiber Science and Technology, Japan. All rights reserved.