【作者】 陈俊；

【导师】 邓涛； 陈焕春；

【作者基本信息】 上海交通大学 ， 材料工程（专业学位）， 2015， 硕士

【摘要】 环境敏感型微凝胶是微凝胶家族中的特殊群体,它们能对诸如光、热、PH值等环境因素的改变而快速反应,是一种智能聚合物材料。此类材料可以在诸如药物载体,对药物进行靶向释放,以及各种热、红外传感器探头等方面有广阔的应用前景。本文主要对红外温度敏感型微凝胶的合成及其特性进行研究。首先,采用微皂或者无皂乳液的自由基聚合法,以N-异丙基丙烯酰胺(NIPAM)为主链单体;配以2-丙烯酰胺-2-甲基丙磺酸(AMPS)等功能单体及N,N’-亚甲基双丙烯酰胺(BIS)等交联剂对微凝胶进行功能修饰及发生交联反应,以得到一种粒径大小均一,排布规整,对温度、红外敏感型微凝胶。并采用温度阶梯法对其吸收、透光率的变化进行研究,进而证明其温敏、光敏等特性。检测结果表明:合成得到了粒径大小均一、排布规整的微凝胶,其的低临界共溶温度约为31.5℃;其次,在合成PNIPAM微凝胶的基础上,在其主链中引入如丙烯酸(AA)等含羧基(-COOH)单体得到粒径梯度分布的丙烯酸共聚微凝胶。并对其透光率随温度变化进行检测,结果表明:粒径为120纳米的微凝胶颗粒的温敏值约29mk,说明较小粒径微凝胶颗粒的红外敏感特性要好于较大粒径的。同时在共聚微凝胶中引入羧基,并通过酰胺化反应得到含巯基微凝胶颗粒并通过锚接作用使得微凝胶能紧密结合在金膜表面形成均相PNIPAM单层膜。利用金膜所具有的表面等离子共振(Surface Plasmon Resonance,SPR)特性,将之与微凝胶结合后,随着温度的改变,它的SPR角会随随之发生红移现象,这种特性也能对微凝胶的红外温度敏感特性进行表征。通过对微凝胶-金膜结合体系的SPR检测结果表明:形成的PNIPAM-Au锚接分子结构既能发生一般金膜颗粒所具有的表面等离子共振现象,且在其LCST附近检测到的SPR角也会发生明显的入射角角度偏移。这也为该材料在药物光热控制释放、纳米开关以及红外传感器等诸多领域的应用开拓了新的思路。更多还原

【Abstract】 Environmental sensitive microgel is a special group in microgel family.Their state and performance can quick change or reaction with the change of temperature,light,PH value,and other environment factors.They are intelligent polymer materials.These materials can be used as the carrier of medicine for targeting release,or they can be used in the probe of various sensors.So,they have a broad prospect of application.This paper is focus on synthesis and characteristic research of these kinds microgels.First,a micro soap or soap free,free radical dispersion emulsion polymerization was used,and N-isopropyl acrylamide was used as main monomer,2-acrylamido-2-methyl-1-propanesulfonic acid was used as ionic comonomer,N,N’-methylene-bis-acrylamide as crosslinker to synthesize the microgel,in order to get a uniform size,regularly arrayed,temperature and infrared sensitive microgel.Test shows,the Low critical solution temperature was about 31.5℃.The paper also proved the temperature and light sensitivity of the microgel by using a temperature gradient method to test the absorption and photo permeability of light.Second,add carboxyl group contained group comonomer,like acrylic acid as the comonomer,in order to make controlled particle sized PNIPAM microgel.Test results showed a temperature sensitivity of ~ 29 mK was achieved through the use of the hydrogel copolymer NPs with size of 120-nm,which is higher than big ones’.It means Small NPs have better IR sensitivity than large NPs.At the same time,with the carboxyl group comonomer added into the molecular chiain of the PNIPAM,it can be close combined on Au foil surface and get a kind of Monolayer-protected clusters(MPC)through esterification or amidation reaction.Nano Au foil has the property of Surface Plasmon Resonance(SPR).When it combined with PNIPAM microgel,a red shift phenomenon will appear with the changing of temperature.This phenomenon can also represent the environmental sensitive of PNIPAM.Test results showed SPR could also be detected,and the red shift could be found in the LCST temperature range.更多还原