Molecular Characteristics of Poly(N-isopropylacrylamide) Separated from Nanocomposite Gels by Removal of Clay from the Polymer/Clay Network
✍ Scribed by Kazutoshi Haraguchi; Yingjia Xu; Guang Li
- Publisher
- John Wiley and Sons
- Year
- 2010
- Tongue
- English
- Weight
- 572 KB
- Volume
- 31
- Category
- Article
- ISSN
- 1022-1336
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✦ Synopsis
Abstract
The extraordinary mechanical and swelling/deswelling properties of nanocomposite (NC) gels are attributed to their unique organic (polymer)/inorganic (clay) network structure. In this study, poly(N‐isopropylacrylamide) (PNIPA) was successfully separated from an NC gel network by decomposing the clay (hectorite) using hydrofluoric acid (HF). A very low HF concentration (0.2 wt.‐%) was adequate for the decomposition of the clay without causing any damage to PNIPA. The separated PNIPA had a high $\overline M _{\rm w}$ (=5.5 × 10^6^ g · mol^−1^). Also, $\overline M _{\rm w}$ was almost constant regardless of the clay concentration (C~clay~ = 1–25 × 10^−2^ mol · l^−1^), even though the properties of the NC gel varied widely over this C~clay~ range. Comparisons of NC gels, PNIPA, and SiO~2~‐NC gels indicated that the clay platelets specifically play an important role in NC gels.
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