کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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5186329 | 1381101 | 2009 | 6 صفحه PDF | دانلود رایگان |
Ionic nanocomposite hydrogels cross-linked by hectorite Laponite XLS with high tensile strength and ultrahigh tensibility were successfully synthesized for the first time via in situ copolymerization of N-isopropylacrylamide (NIPAm) and sodium methacrylate (SMA). The pH and temperature response, transparency, and mechanical properties of the ionic hydrogels were investigated. The results showed that the addition of only 2Â mol% of SMA endowed the nanocomposite hydrogels with pH response, while the temperature response remained in the whole pH range. All the as-prepared hydrogels, even with 10Â mol% of SMA, demonstrated transparency higher than 75%. The tensile strength evidently decreased from 60Â kPa to 45Â kPa when the SMA content was higher than 6Â mol%. The elongation at break increased with increasing SMA content and 2800% was achieved for the sample containing 10Â mol% of SMA. The effective network chain density was estimated from the tensile stress at elongation of 200% and the equilibrium storage modulus. The low chain density was the intrinsic origin of the ultrahigh tensibility for these ionic NC gels. This work provides a new way to prepare dual responsive hydrogels with ultrahigh tensibility and high transparency.
Journal: Polymer - Volume 50, Issue 8, 9 April 2009, Pages 1933-1938