KINETICS OF GROWTH OF LYZENGANG RING IN ELASTIC GELATIN GELS

Abstract

Gels are widely used in the food, pharmaceutical and cosmetic industries. Gels are also some household (liquid soap, detergent, gel balls for washing, gel nail polishes) and food (jelly, fruit jelly) substances that people use all the time. Examples of gels can be solidified solutions of gelatin, agar, pectin, silicic acid; celluloid, glue, textile fibers, etc. Gels are especially widely represented in plant and animal organisms, for example, muscle, nerve and connective tissue, the vitreous body of the eye, various types of biological membranes are examples of complex gels. Studying the physics and chemical properties of gels, the possibility of reactions in gels is an urgent task. The work investigates the kinetics of Lysengang ring growth in elastic gelatin gels. It is shown that one of the conditions for the formation of clear Lisengang rings in the gel is that the first electrolyte solution, which is mixed with the gelatin solution, should be of low concentration (up to 1%), and the second should be as high as possible (up to 90%). It was found that during the first day, 14 Lisengang rings were formed in the Ag2Cr2O7 gel, the distance between the rings was 0.1 cm, and the total diameter was 6-7 cm. During the following days, no changes were observed, except that the gel dried and became solid. Such a dry gel did not undergo any changes even for several months. It was shown that two rings of Cu(OH)2 were formed within 3-12 hours, however, unlike Ag2Cr2O7 rings, they were not clearly defined. During the day, the total diameter of the spot on the gel doubled, but the number of rings did not change. The only noticeable change that occurred after 5 days was that this dry gel in the Petri dish cracked and became brittle. This is possibly due to the formation of potassium salts with the hydrolyzate of gelatin protein molecules. It was determined that BaSO4 rings grew over the entire diameter of the Petri dish (12 cm) within eight hours, but a clear boundary between the rings could not be recorded. No changes were observed in this gel within 1 day. In 2-3 days, the gel began to dry, as the solvent began to evaporate. The process of formation of cracks was not observed. It is shown that the largest ring is formed from Ag2Cr2O7, and the least from BaSO4. This dependence can be explained by the different solubility of the formed salts in gels and their ability to influence the stability of the gel network in the gel volume.