摘要
为了得到具有高强度和高溶胀率的纳米水凝胶(NCgels),N-异丙基丙烯酰胺通过可逆加成断裂链转移(RAFT)聚合的方法,插层在含有质量分数为0.25%～15%的可扩展的有机化的蒙脱土(Clay-S)层间并交联。结果表明,与传统水凝胶相比,该水凝胶的强度和溶胀性能得到了很大提高,并且对温度的变化具有较快的响应速率。以质量分数为5%的蒙脱土,链转移剂的质量分数为0.5%制备的纳米水凝胶为例,该水凝胶在20℃的溶胀率为450,而传统水凝胶在相同温度时的溶胀率仅为20;该水凝胶在1min内失去75%的水,在4min内失去约90%的水,而传统水凝胶在15min内仅失去66%左右的水。
Nanocomposite hydrogels （NC gels） was prepared based on poly （N-isopropylacrylamide） （PNIPAM） containing 0. 25% - 15% of the expandable synthetic hectorite Laponite XLS （Clay -S） by reversible addition fragmentation chain transfer（RAFT） polymerization. The swelling behaviors were investigated and the hydrogels by RAFT polymerization （RAFT gels ） show accelerated shrinking kinetics and higher swelling ratio compared with conventional hydrogel（CGel）. It could be attributed to the presence of dangling chains mainly caused by chain transfer agent （ CTA）, which could retard the crosslinking reaction rate greatly. Taking hydrogel prepared with 5% clay and 0. 5% CTA as an example, the swelling ratio of the hydrogel was 450 at 20 ℃, whereas that of conventional hydrogel was 20 at the same temperature;the hydrogel lost 75% water within 1 min and about 90% water within 4 mins,whereas conventional hydrogel lost only about 66% water within 15 mins.
出处
《精细化工》
EI
CAS
CSCD
北大核心
2007年第12期1158-1162,共5页
Fine Chemicals
基金
中国科学院"百人计划"资助项目~~
