کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5182008 | 1380977 | 2013 | 7 صفحه PDF | دانلود رایگان |
Poly(N-isopropylacrylamide) (PNIPAm)-hectorite clay nanocomposite cryogels (NC-C gels) were prepared by freezing polymerization at â18 °C of NIPAm monomer in the aqueous hectorite clay suspensions. The clay concentration CxLS was found to be a key factor determining the characters of the NC-C gels, because the average interparticle distance became smaller than the clay diameter when CxLS > 6 w/v%. The NC-C gels of CxLS â¤Â 6.0 w/v% were heterogeneous at the nascent state and became homogeneous after 24 h thawing, which endowed the cryogels self-improved mechanical strength and elongation up to 900%. On the contrary, for the NC-C gels of CxLS > 6.0 w/v%, the extensibility was about half of the corresponding normal NC gels, suggesting that the heterogeneity cannot be homogenized after 24 h thawing. The deswelling and reswelling rate of the NC-C gels of CxLS > 6 w/v% was significantly accelerated due to the micropore structure formed by the molten ice crystals. The micro-pores were observed with SEM and CLSM from the cryogels with the clay content higher than 6 w/v%. The extensibility of the NC-C gels was much higher than other cryogels with high deswelling rate, promising some possible applications.
Journal: Polymer - Volume 54, Issue 7, 22 March 2013, Pages 1846-1852