Abstract:

Using polyaspartic acid (PASP) and polyacrylamide (PAM) as raw materials, magnetic PASP/PAM semi-interpenetrating (semi-IPN) hydrogels loaded with nano Fe₃O₄ particles were prepared by in-situ coprecipitation and semi-interpenetrating technology. The hydrogels were characterized by FTIR, TG, SEM, TEM and EDS. The magnetic properties, swelling properties and temperature sensitivity of the hydrogels were tested. The results showed that the prepared magnetic hydrogel had excellent thermal stability, and the nano Fe₃O₄ particles were spherical with a particle size of about 18nm and evenly dispersed. The hysteresis loop was “S” shaped, the maximum saturated magnetic intensity was 0.35emu/g, and it had superparamagnetic. The magnetic response time showed that the appropriate concentration of Fe₃O₄ was 1.0mol/L. When the concentration of nano Fe₃O₄ was 1.5mol/L and 0.5mol/L, the equilibrium swelling rate was 38g/g and 47g/g, respectively, and when the temperature was lower than 45℃, the swelling rate of hydrogels showed temperature sensitive and positive characteristics.

Key words: magnetism, polyaspartic acid, semi-interpenetrating, hydrogel

摘要：

以聚天冬氨酸（PASP）和聚丙烯酰胺（PAM）为原料，利用原位共沉淀法并结合半互穿技术在水凝胶上负载纳米Fe₃O₄粒子，制备磁性 PASP/PAM 半互穿水凝胶，采用红外光谱（FTIR）、热重分析（TG）、扫描电镜（SEM）、透射电镜（TEM）、能谱仪（EDS）等对水凝胶进行表征，并测试了水凝胶的磁学性能、磁响应时间、溶胀性能及温度敏感性。结果表明：所制备的磁性PASP/PAM水凝胶具有优异的热稳定性，纳米Fe₃O₄粒子呈现球状，粒径约18nm，且分散得比较均匀。磁滞回线整体呈“S”形，最大饱和磁强度为0.35emu/g（1emu/g=1A·m²/kg），且具有超顺磁性，磁响应时间表明Fe₃O₄的浓度以1.0mol/L为宜。纳米Fe₃O₄浓度1.5mol/L和0.5mol/L时平衡溶胀率分别为38g/g和47g/g，且温度低于45℃时，磁性水凝胶的溶胀率会出现温度敏感性和正向的特征。

关键词: 磁性, 聚天冬氨酸, 半互穿, 水凝胶