中文摘要：

通过醚化反应,将疏水性试剂异丙基缩水甘油醚（IPGE）,接枝到以羟乙基纤维素为亲水性骨架的主链上,合成了具有温度响应性的2-羟基-3-异丙氧基丙基羟乙基纤维素（HIPEC）,运用核磁共振（^1H NMR、^13C NMR、2D HSQC NMR）对HIPEC进行结构表征,其最低临界溶解温度（LCST）可通过改变疏水侧链的摩尔取代度（MS）和盐浓度来调节.通过荧光光谱仪、动态光散射（DLS）、共聚焦荧光显微镜（CLSM）研究了HIPEC在水溶液中自组装行为及Nile Red在HIPEC胶束中的增溶行为和温度控制释放行为,结果表明,HIPEC在溶液中自组装形成胶束,并且胶束粒径随着温度的升高而增大;在温度高于LCST时,Nile Red从HIPEC胶束中缓慢释放,并且可通过改变温度控制Nile Red的释放过程.

英文摘要：

Responsive polymers have attracted great interests in many application fields. Thermoresponsive polymers are especially appealing, and have been applied in biomedical and biotechnological fields. A thermoresponsive polymer, 2-hydroxy-3-isopropoxypropyl hydroxyethyl cellulose（HIPEC）, was prepared by etherification reaction, which grafted isopropyl glycidyl ether（IPGE） onto hydroxyethyl cellulose（HEC）. The HIPEC was characterized by ^1H NMR, ^13C NMR, and 2D HSQC NMR, and the molar substitution（MS） of HIPEC was determined by 1H NMR. The lower critical solution temperature（LCST） of HIPEC can be tuned from 17.0-43.0 ℃ by changing MS of hydrophobic groups from 1.21-2.88. The salt concentration has a significant influence on LCST, the experiment results indicated that the LCST of HIPEC decreased with increasing Na Cl concentration. Amphiphilic, thermoresponsive polymers can form micelles in aqueous solution and encapsulate guest molecules. Fluorescence spectroscopy and dynamic light scattering（DLS） showed that HIPEC can assemble into micelles, and micelles diameter significantly increase with increasing temperature. It is indicated that the morphologies of the HIPEC micelles can be varied by changing temperature. The critical micelle concentrations（CMC） of HIPEC which were measured by fluorescence spectroscopy decreased with increasing of the MS of hydrophobic groups. Additionally, using Nile Red as a probe, fluorescence spectroscopy and confocal laser scan microscope（CLSM） were applied to the HIPEC aqueous solution to examine the encapsulation of Nile Red aqueous solutions of the HIPEC. The research results show that Nile Red can be encapsulated and stabilized in the hydrophobic core of HIPEC micelles. The fluorescence intensity of Nile Red increased with increasing of HIPEC concentration, and there is a sharp increase in the number of HIPEC micelles above CMC. Because the morphologies of HIPEC micelles were disrupted when the temperature reached the LCST, the Nile Red which was capsu