PDF(Pubmed)
Abstract：
Chitosan, alginate, and chitosan-alginate (50:50) mixed hydrogels were prepared by freeze casting, freeze-drying, and subsequent physical cross-linking. Chitosan was cross-linked with citrate and alginate with calcium ions, while the mixed gels were cross-linked with both cross-linking agents. Both cryogels and xerogels were obtained by lyophilization and drying of the hydrogels. We investigated the effect of the chemical composition and the physical state of gels on the gel structure and sorption of model dyes. Alginate and mixed gels cross-linked with Ca2+ ions sorbed 80-95% of cationic dye from the solutions. The chitosan gels are primarily capable of adsorbing anionic dyes, but at near-neutral pH, their capacity is lower than that of alginate gels, showing 50-60% dye sorption. In the case of alginate gels, the dye sorption capacity of xerogels, cryogels, and hydrogels was the same, but for chitosan gels, the hydrogels adsorbed slightly less dye than the dried gels.
摘要：
壳聚糖,海藻酸盐,采用冷冻浇铸法制备壳聚糖-海藻酸盐(50:50)混合水凝胶,冷冻干燥,和随后的物理交联。壳聚糖与柠檬酸盐和藻酸盐与钙离子交联，而混合凝胶与两种交联剂交联。冷冻凝胶和干凝胶均通过水凝胶的冻干和干燥获得。我们研究了凝胶的化学成分和物理状态对模型染料的凝胶结构和吸附的影响。海藻酸盐和与Ca2离子交联的混合凝胶从溶液中吸附了80-95％的阳离子染料。壳聚糖凝胶主要能够吸附阴离子染料，但在接近中性的pH下,它们的容量低于藻酸盐凝胶，显示50-60%的染料吸附。在海藻酸盐凝胶的情况下，干凝胶的染料吸附能力，冷凝胶,水凝胶是一样的，但是对于壳聚糖凝胶，水凝胶吸附的染料比干燥的凝胶略少。
