胆酸钠超分子水凝胶特殊温度响应性的机理研究.pdf

物理化学学报( Wuli Huaxue Xuebao)
2298
acta Phys.-Chim.、Sin.2012,28(10),2298-2304
October
doi:10.3866/PKU.WHXB201209112
www.whxb.pku.edu.cn
金属离子胆酸钠超分子水凝胶特殊温度响应性的机理硏究
蔡龙成王一杰2李娟'黄建滨12
(新疆大学化学化工学院,乌鲁木齐830046;2北京大学化学与分子工程学院,分子科学国家实验室,北京100871)
摘要:研究了胆酸钠溶液与金属离子溶液混合自组装而成的水凝胶随温度升高而机械强度增强的独特温度
响应性.利用透射电镜(TEM)和X射线衍射(XRD)仪表征了水凝胶中聚集体的微观形貌及分子排列方式.考察
了其流变学行为、荧光性质随温度的变化.结果表明,升温促进凝胶形成的速率,并提高凝胶的机械强度.随着
温度的升高,稀土离子的荧光强度显蓍增强.表面张力测量表明,胆酸钠溶液的临界胶束浓度随温度的升高而
略有降低.综合实验事实,我们提出随温度升高导致的凝胶强度増强行为是由胆酸钠分子在高温下聚集能力増
强的结果
关键词:水凝胶;胆酸钠;温度敏感;荧光性质;流变性质
中图分类号:O648
Investigation of the Mechanism of Temperature-responsiveness of
Metal-cholate Supramolecular Hydrogels
Collge) n CAL Long-cheng WANG Yi-jie LI Juan' HUANG Jian-bin
College of Chemistry and Chemical Engineering, Xinjiang University, Urumqi 830046,P R. China; Beijing National Laborator
for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Bejing 100871, P R. China
Abstract:
Temperature-promoted hydrogel formation was investigated in a mixed solution of sodium
cholate and metal ions. Transmission electron microscopy (TEM) was used to characterize the morphology
of the microstructures of the hydrogels, and nanofibers were observed. The arrangement of the cholate
and metal ions was proposed according o the X-ray difraction(XRD)measurements. Rheological
measurements revealed that the strength of the hydrogels increases with increasing temperature, while the
fluorescence of the gels increased as well. Increasing the temperature also increased the gel formation
rate. The critical micelle concentration of sodium cholate solution decreased slightly with increasing
temperature. On the basis of the experimental results, we propose that the increased hydrophobicity of
cholate ions with increasing temperature leads to stronger hydrogen bonding between cholate ions, which
accounts for the unique heating-enhanced gelation behavio
Key Words: Hydrogel; Sodium cholate; Temperature-sensitivity; Fluorescence; Rheological
behavior
中包含液体(水或其他溶剂)所形成的三维网络结
凝胶是由高分子结构相互交联和缠绕,在空隙构.其中,以水为溶剂的水凝胶凭偕优良的溶胀性、
Received: August 13, 2012; Revised: September 7, 2012; Published on Web: September 11, 2012
CorrespondingauthorsLIJuan,Email:ljpanpan(@163.com;TEL:+86-13201271692.HUANGjian-bin,Email:Jbhuang@pku,cdu.cn
Tel:+86-10-6275355
The project was supported by the Tianshan Scholars Program of Xinj ang University, hina(. 64.1)and National Natural Science Foundation of
新疆大学天山学者计划(03.064.12)及囻家自然科学基金(21073006)资助项目
C Editorial office of Acta Physico-chimica Sinica