期刊
POLYMER
卷 50, 期 11, 页码 2516-2525出版社
ELSEVIER SCI LTD
DOI: 10.1016/j.polymer.2009.03.044
关键词
Cationic hydrogels; Rapid response; pH/temperature sensitivity
资金
- National Natural Science Foundation of China [20674054]
- Key Project of the Ministry of Education of China [106131]
- Sichuan Youth Science and Technology Foundation for Distinguished Young Scholars [08ZQ026-042]
Dual temperature- and pH-sensitive comb-type grafted cationic hydrogels are successfully synthesized by grafting polymeric chains with freely mobile ends, which are composed of both N-isopropylacrylamide (NIPAM) segments and N,N-dimethylamino ethyl methacrylate (DMAEMA) segments, onto the backbone of crosslinked poly(NIPAM-co-DMAEMA) networks. Equilibrium and dynamic swelling/deswelling properties of the prepared hydrogels responding to pH and/or temperature are investigated. The prepared hydrogels demonstrate a lower critical solution temperature (LCST) at about 34 degrees C and a pK(a) value at about pH 7.3. At lower pH and lower temperature, both the swelling degree and the swelling rate of the comb-type grafted hydrogel are larger than those of the normal-type crosslinked hydrogel. The comb-type grafted poly(NIPAM-co-DMAEMA) hydrogel exhibits a more rapid deswelling rate than that of the normal-type hydrogel in response to a pH jump from 2.0 to 11.0 at a fixed temperature. The volume changes of the poly(NIPAM-co-DMAEMA) hydrogels are acute in a series of fixed buffer solutions with an abrupt increase of environmental temperature from 18 degrees C to a temperature higher than the LCST. The comb-type grafted poly(NIPAM-co-DMAEMA) hydrogels show quite fast shrinking behaviors in response to simultaneous dual temperature and pH stimuli. Drug-release in vitro from the prepared poly(NIPAM-co-DMAEMA) hydrogels is carried out when the environmental temperature and pH are changed synchronously. The results show that the model drug Vitamin B-12 is released much more rapidly from the comb-type grafted hydrogel than that from the normal-type hydrogel. The proposed dual temperature/pH-sensitive comb-type grafted cationic poly(NIPAM-co-DMAEMA) hydrogel in this study may find various potential applications, e.g., for fabricating rapid-response smart sensors, actuators, and chemical/drug carriers and so on. (C) 2009 Elsevier Ltd. All rights reserved.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据