摘要
本文将具有光-温度双重响应特性的共聚物——聚7-(4-乙烯基苯氧基)-4-甲基香豆素-co-N-乙烯基己内酰胺-co-三乙二醇甲基醚甲基丙烯酸酯(PVNM)接枝到经多巴胺修饰的介孔二氧化硅(MSNs)表面,从而合成了聚合物刷MSNs-g-PVNM。利用傅里叶红外光谱、扫描电镜、热重分析和X射线光电子能谱等手段对其结构进行了表征,并系统地研究了其在不同刺激条件下的响应行为,探讨了聚合物刷对模型药物吡虫啉的负载和控释能力。结果表明,聚合物刷MSNs-g-PVNM对吡虫啉的负载率和负载效率分别可以达到9.2%和40.6%,释放率分别在20℃,365 nm和50℃,254 nm两个条件下达到最低(5.4%)和最高(52.4%)。叶片浸出实验可以证实,应用聚合物刷可以将三次淋洗后叶片上吡虫啉的损失率从25.2%降低到8.4%。因此,本聚合物刷可以通过改变光照、温度等外界条件调控吡虫啉的释放过程。
A light and temperature dual responsive copolymer,poly(7-(4-vinylbenzy-loxyl)-4-methylcoumarin-co-N vinyl caprolactam-co-tri(ethylene glycol)methyl ether methacrylate)(PVNM),was grafted on the surface of dopamine based mesoporous silica nanoparticles(MSNs).The resulting polymer brush,MSNs-g-PVNM,was characterized by FT-IR,TEM,TGA and XPS.The dual responsive behaviors of MSNs-g-PVNM were systematically studied.With imidacloprid as the model guest pesticide,the loading percentage and loading efficiency of the polymer brush were determined as 9.2%and 40.6%,respectively.The release efficiency of imidacloprid in MSNs-g-PVNM was the lowest value of 5.4%at 20℃ and 365 nm,and it reached the highest value of 52.4%at 50℃ and 254 nm.The loss percentage of imidacloprid on the leaves contained imidacloprid-loaded MSNs-g-PVNM(8.4%)was much less than that contained only imidacloprid(25.2%)after three rinses.It was confirmed that the release process of imidacloprid was well regulated through changing external conditions such as light and temperature.
作者
徐文双
杨周晓爽
张光阳
刘辉
XUWen-shuang;YANG Zhou-xiao-shuang;ZHANG Guang-yang;LIU Hui(Hunan Provincial Key Laboratory of Efficient and Clean Utilization of Manganese Resources,College of Chemistry and Chemical Engineering,Central South University,Changsha 410083,China;Yongzhou Vocational Technical College,Yongzhou 425100,China)
基金
Project(21376271)supported by the National Natural Science Foundation of China
Project(2016TP1007)supported by the Hunan Provincial Science and Technology Plan Project,China
Projects(201810533078,S2020105330395)supported by the Undergraduates Innovative Training Foundation of Central South University,China。