羧甲基壳聚糖/海藻酸钠水凝胶pH值对溶胀行为的影响

以CaCl2为交联剂制备了一系列羧甲基壳聚糖/海藻酸钠水凝胶。研究了羧甲基壳聚糖与海藻酸钠溶液的配比、交联剂的用量以及pH值对水凝胶溶胀率的影响,并分析了不同pH值时水凝胶的红外谱图。结果表明,pH=1.0、3.0时,水凝胶收缩,而pH=5.0、7.4、9.0、13.0时,水凝胶溶胀随pH值增高,其溶胀率增大。当两者配比为1:3,pH 9.0时溶涨率最大。同时,红外谱图证明,水凝胶的pH敏感行为是氨基和羧基基团结构的变化所引起的。

Effect of pH Value on Swelling Behavior of Carboxymethyl Chitosan and Sodium Alginate Hydrogels

A series of carboxymethyl chitosan/sodium alginate compound hydrogels are prepared with CaCl2 as the crosslinking agent. The effects of carboxymethyl chitosan and sodium alginate proportion, the amount of crosslinking agent used and the pH value on the swelling behavior are studied, and FT-IR spectra of different hydrogels are analyzed. The results indicate that the hydrogels contract at pH 1.0 and 3.0 respectively, while they swell at pH 5.0, 7.4, 9. 0 and 13.0 respectively. The biggest swelling capacity is achieved when the proportion of CMC/SAL is 1:3, and the pH value is 9. 0. Furthermore, FT-IR spectra of the hydrogels indicate that the difference in swelling behavior can be attributed to transformation of amino and carboxyl groups.