The temperature dependence of the specific refractive index increment d n /d c of aqueous poly( N isopropylacrylamide) solution in the range of 20 ℃ to 35 ℃ were determined by a differential refractometer. The measu...The temperature dependence of the specific refractive index increment d n /d c of aqueous poly( N isopropylacrylamide) solution in the range of 20 ℃ to 35 ℃ were determined by a differential refractometer. The measured d n /d c of the solution decreases regularly and smoothly with increasing temperature until to the specific coil globule transition temperature of PNIPAM (around 32 ℃) and afterwards it increases with increasing temperature on the contrary. This extraordinary phenomenon is successfully explained and treated by a quantitative theory in terms of accompanying solvation desolvation process in the course of coil globule transition of the polymer chain in solution.展开更多
用前端聚合法制备了聚(N-异丙基丙烯酰胺)/多壁碳纳米管(PNIPAM/MWCNTS)复合水凝胶,对产物的微观形貌、温敏性、力学性能和释药性能进行了研究。结果表明,PNIPAM/MWCNTS复合水凝胶具有温度敏感性,MWCNTS的加入不影响水凝胶的低临界转变...用前端聚合法制备了聚(N-异丙基丙烯酰胺)/多壁碳纳米管(PNIPAM/MWCNTS)复合水凝胶,对产物的微观形貌、温敏性、力学性能和释药性能进行了研究。结果表明,PNIPAM/MWCNTS复合水凝胶具有温度敏感性,MWCNTS的加入不影响水凝胶的低临界转变温度,随MWCNTS含量增加,水凝胶吸水能力降低,力学强度显著提高,当MWCNTS的含量由0%增至10%时,水凝胶的压缩强度从88 k Pa增加到666 k Pa。复合水凝胶具有良好的药物缓释性能。展开更多
文摘The temperature dependence of the specific refractive index increment d n /d c of aqueous poly( N isopropylacrylamide) solution in the range of 20 ℃ to 35 ℃ were determined by a differential refractometer. The measured d n /d c of the solution decreases regularly and smoothly with increasing temperature until to the specific coil globule transition temperature of PNIPAM (around 32 ℃) and afterwards it increases with increasing temperature on the contrary. This extraordinary phenomenon is successfully explained and treated by a quantitative theory in terms of accompanying solvation desolvation process in the course of coil globule transition of the polymer chain in solution.
文摘用前端聚合法制备了聚(N-异丙基丙烯酰胺)/多壁碳纳米管(PNIPAM/MWCNTS)复合水凝胶,对产物的微观形貌、温敏性、力学性能和释药性能进行了研究。结果表明,PNIPAM/MWCNTS复合水凝胶具有温度敏感性,MWCNTS的加入不影响水凝胶的低临界转变温度,随MWCNTS含量增加,水凝胶吸水能力降低,力学强度显著提高,当MWCNTS的含量由0%增至10%时,水凝胶的压缩强度从88 k Pa增加到666 k Pa。复合水凝胶具有良好的药物缓释性能。
