- - Preparation of silica-chitosan composite materials by sol-gel techniques

摘要

PURPOSE: Provided is a method of preparing silica-chitosan composite material by the sol-gel method which is used in making glasses and ceramics at the low temperature. As raw materials, chitosan is a biopolymer from the shrimp and crab shell, and the silica is the porous inorganic material. The composite is used in treating the waste water by absorbing heavy metals, radio active materials, in recovering precious metals, in eliminating metals in the potable water cleaner, in controlling trace metals for plant growth and in carrying catalyst or fixed enzymes. CONSTITUTION: The preparation method comprises: a step of making mixed sol by slowly adding a chitosan solution to the diluted solution of 100wt.% of tetraethoxysilane in 100-500wt.% of ethanol, wherein the chitosan solution is made by dissolving 100wt.% of chitosan to 500- 5000 wt.% of 10-50% acetic acid; a step of using 0.001-10wt.% of hydrochloric acid as hydrolysis catalyst, and hydrolyzing and gelling the solution at 30-50deg.C in the oven and drying it at 100-120degC.