壳聚糖与聚乙烯醇磁性水凝胶的制备和性能研究

Preparation and Properties of Polyvinyl Alcohol(PVA)/Chitosan(CS) Magnet-Hydrogel

采用反复冷冻-融化技术(冻融)制备了Fe3O4/PVA/CS磁性水凝胶,并以相同方法制备了不交联、不掺磁的PVA/CS共混水凝胶和交联、不掺磁的PVA/CS交联水凝胶,研究对比了三类水凝胶的溶胀性能、再溶胀性能和力学性能随组分配比及冻融次数的变化行为,并研究了Fe3O4/PVA/CS磁性水凝胶的磁性能。结果表明:随着交联剂和Fe3O4的加入和冻融次数的增加,水凝胶的溶胀率减小,再溶胀速率减缓,但力学性能却呈现出增大趋势。Fe3O4/PVA/CS磁性水凝胶各个样品的磁滞回线皆剩磁很少,矫顽力很小,且剩磁和矫顽力的大小取决于Fe3O4掺量的大小,与冻融次数基本无关,随着Fe3O4掺量的增加剩磁和矫顽力都增大。

Magnetic hydrogels （ferrogels） were prepared by repeated freezing and thawing,and trimeric sodium phosphate （TPP） was added in as cross linker. The blending hydrogel based on PVA and CS without Fe3O4 micropartieles and TPP, the cross linking hydrogel based on PVA and CS with TPP but no Fe3O4 microparticles were prepared by the same method. Swelling rate,reswelling rate, tensile strength properties were measured for the samples with different compositions and number of freezing and thawing cycles. Magnetic characteristics of the Fe3O4/PVA/CS magnet-hydrogels were tested. It was turned out that swelling rate and reswelling rate decreased with the addition of TPP and Fe3O4 and the number of freezing and thawing cysles, but tensile strength increased. Fe3 O4/PVA/CS magnet-hydrogel had low remanence and coercive force. Remanence and coercive force were found to increase with the content of Fe2O4 ,but remained almost unchanged with the number of freezing and thawing cycles.