摘要
以双官能团聚乙二醇(Br-PEO-Br)为引发剂,利用原子转移自由基聚合(ATRP)制得了含偶氮苯(AZO)和N-异丙基丙烯酰胺(NIPAM)的两亲性三嵌段共聚物P(AZO9-co-NIPAM9)-b-PEO48-b-P(AZO9-co-NIPAM9),并通过核磁共振(1HNMR)和凝胶渗透色谱(GPC)对产物进行了表征.该共聚物能够在溶液中自组装形成纳米胶束,运用透射电子显微镜(TEM)、荧光探针技术和动态光散射(DLS)研究了胶束的形貌、粒径及其在光或温度刺激下的响应行为.结果表明,该三嵌段共聚物胶束显现出我们以往报道的二嵌段共聚物所不具有的光释放行为:包覆有尼罗红的胶束在多次紫外-可见光循环照射之后,荧光强度和初始状态相比下降了大约40%,说明尼罗红在此过程中逐渐被释放.胶束的尺寸随着温度的升高而逐渐缩小.
A novel triblock copolymer containing azobenzene （AZO） and N-isopropylacrylamide （NIPAM） was synthesized by atom transfer radical polymerization （ATRP） using a poly（ethylene oxide） bifunctional macroinitiator （Br-PEO-Br）. The triblock copolymer was characterized by 1H NMR and gel permeation chromatography （GPC）. Uniformly distributed poly- meric micelles were obtained in aqueous solution by self-assembly method. Transmission electron microscope （TEM）, fluo- rescence spectroscopy and dynamic light scattering （DLS） were used for the investigation of the self-assemblies and their stimuli-responsive behavior. Photoinduced release behavior was achieved with the as-prepared triblock copolymer micelles, which has not been observed in our previously-reported diblock copolymer micelles： the fluorescence intensity of Nile Red trapped in the triblock copolymer micelles dropped by approximately 40% after UV and Vis light alternative irradiation, in- dicating that a portion of the Nile Red was released to the aqueous media. Besides, the micelles shrank during the heating process.
出处
《化学学报》
SCIE
CAS
CSCD
北大核心
2013年第5期733-738,共6页
Acta Chimica Sinica
基金
国家自然科学基金(Nos.21134003
21273048
51225304
51203023)
高等学校博士学科点专项科研基金(No.20100071110014)
上海市青年科技启明星跟踪计划(No.11QH1400400)资助~~
