Croitoru Catalin, Pop Mihai Alin, Bedo Tibor, Cosnita Mihaela, Roata Ionut Claudiu, Hulka Iosif
Materials Engineering and Welding Department, Transilvania University of Brasov, Eroilor 29 Str, Brasov, Romania.
Materials Science Department, Transilvania University of Brasov, Eroilor 29 Str, 500036 Brasov, Romania.
Polymers (Basel). 2020 Mar 3;12(3):560. doi: 10.3390/polym12030560.
This paper discusses the structure morphology and the thermal and swelling behavior of physically crosslinked hydrogels, obtained from applying four successive freezing-thawing cycles to poly (vinyl alcohol) blended with various amounts of κ-carrageenan. The addition of carrageenan in a weight ratio of 0.5 determines a twofold increase in the swelling degree and the early diffusion coefficients of the hydrogels when immersed in distilled water, due to a decrease in the crystallinity of the polymer matrix. The diffusion of water into the polymer matrix could be considered as a relaxation-controlled transport (anomalous diffusion). The presence of the sulfate groups determines an increased affinity of the hydrogels towards crystal violet cationic dye. A maximum physisorption capacity of up to 121.4 mg/g for this dye was attained at equilibrium.
本文讨论了通过对与不同含量κ-卡拉胶共混的聚乙烯醇进行四个连续冻融循环而获得的物理交联水凝胶的结构形态、热行为和溶胀行为。当以0.5的重量比添加卡拉胶时，由于聚合物基质结晶度的降低，水凝胶在浸入蒸馏水中时的溶胀度和早期扩散系数增加了两倍。水向聚合物基质中的扩散可被视为一种弛豫控制的传输（反常扩散）。硫酸根基团的存在决定了水凝胶对结晶紫阳离子染料的亲和力增加。在平衡时，该染料的最大物理吸附容量达到121.4 mg/g。
