紫外光辐照法制备纳米Ag负载型高分子微球的研究

发布时间：2018-05-05 03:02

本文选题：光引发 + 分散聚合　；参考：《江南大学》2011年硕士论文

【摘要】：光引发聚合作为区别于热引发的一种聚合方法,具有设备简单、投资少、安全环保、容易实现工业化生产等优点,将在聚合物微球的制备中得到应用。本文首先以聚乙烯吡咯烷酮(PVP)为分散剂,2,2-二甲氧基-2-苯基苯乙酮(BDK)为光引发剂,在乙醇和水(V乙醇/V水=7/3)的混合介质中,由紫外(UV)光引发苯乙烯(St)和甲基丙烯酸甲酯(MMA)进行分散共聚,成功得到了P(St-co-MMA)聚合物微球。研究了影响聚合物微球收率及其粒径的因素。用傅立叶变换红外光谱(FTIR)、透射电子显微镜(TEM)、激光光散射(LLS)对微球的结构、形态和粒径分布进行表征,发现得到的P(St-co-MMA)聚合物微球的粒径均一,通过改变聚合反应条件可将微球粒径控制在500-800nm之间,在优化的聚合反应条件下,聚合物微球的收率可达到70%以上。为进一步研究光引发聚合,采用十二烷基硫酸钠(SDS)为乳化剂,BDK或2-羟基-4-(2-羟乙氧基)-2-甲基苯丙酮(Irgacure 2959)为光引发剂,在水中由UV光引发St、MMA和丙烯酸(AA)进行乳液聚合,成功得到了P(St-co-MMA-co-AA)聚合物微球。研究了引发剂种类、乳化剂用量等对反应收率和微球粒径的影响。采用扫描电子显微镜(SEM)、LLS对所得聚合物微球的粒径与粒径分布进行了表征,发现聚合物微球的粒径均一,改变聚合反应条件可将聚合物微球的粒径控制在70-180nm之间,聚合物微球的收率可达85%以上。进而以硝酸银(AgNO3)为金属源,制得的单分散聚合物微球为载体,利用微球表面的羰基基团络合吸附银离子(Ag+),在室温下通过硼氢化钠(NaBH4)或紫外光进行还原,制备出了负载有Ag纳米颗粒的聚合物复合微球。通过紫外-可见光分光光度计(UV-vis)、X-射线衍射(XRD)、TEM对复合微球的形态等进行表征,发现银纳米颗粒在聚合物微球表面实现了有效的分散;由NaBH4还原得到的Ag纳米颗粒粒径较小,小于10nm。通过抗菌实验发现复合微球对金色葡萄球菌具有良好的抗菌性;复合微球还具有催化性,其对亚甲基蓝(MB)的光催化降解率达到了97%。研究Ag纳米颗粒对表面吸附荧光素(FL)的荧光性能的影响,发现荧光增强效率随着Ag纳米颗粒浓度的增加而出现最大值。
[Abstract]:Photoinitiated polymerization, as a polymerization method different from thermal initiation, has the advantages of simple equipment, less investment, safety and environmental protection, easy to realize industrial production, and will be applied in the preparation of polymer microspheres. In this paper, polyvinylpyrrolidone (PVP) was first used as a dispersant, 2-dimethoxy-2-phenylacetophenone (BDK) as photoinitiator, in the mixture of ethanol and water / V ethanol / V water (7 / 3). The dispersion copolymerization of styrene (St) and methyl methacrylate (MMA) was carried out by UV photoinitiator UV) and the PnSt-co-MMA-polymer microspheres were successfully prepared. The factors affecting the yield and particle size of polymer microspheres were studied. The structure, morphology and particle size distribution of the microspheres were characterized by Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM) and laser light scattering (LLSs). By changing the polymerization conditions, the particle size of the microspheres can be controlled between 500-800nm and the yield of polymer microspheres can reach more than 70% under the optimized polymerization conditions. In order to further study the photoinitiation polymerization, the emulsion polymerization was carried out using SDS (sodium dodecyl sulfate) as emulsifier (BDK) or 2-hydroxy-4-oxy (2-hydroxyethoxy) -2-methylphenylethylacetone (Irgacure 2959) as photoinitiator in water. The polymer microspheres were successfully obtained. The effects of initiator and emulsifier amount on the yield and particle size of microspheres were studied. The particle size and distribution of polymer microspheres were characterized by scanning electron microscopy (SEM). It was found that the particle size of polymer microspheres was uniform, and the particle size of polymer microspheres could be controlled within the range of 70-180nm by changing the polymerization conditions. The yield of polymer microspheres is over 85%. Then the monodisperse polymer microspheres were prepared by using silver nitrate Agno _ 3 as the metal source and the carbonyl groups on the surface of the microspheres were used to adsorb Ag ~ (2 +) on the surface of the microspheres. At room temperature, the silver ions were reduced by sodium borohydride (NaBH4) or ultraviolet light. Polymer composite microspheres loaded with Ag nanoparticles were prepared. The morphology of the composite microspheres was characterized by UV-vis spectrophotometer (UV-Vis) X-ray diffraction (XRD) and TEM. It was found that the silver nanoparticles dispersed effectively on the surface of polymer microspheres, and the Ag nanoparticles reduced by NaBH4 were smaller in size than 10 nm. The antibacterial experiments showed that the composite microspheres had good antibacterial activity against Staphylococcus aureus and the composite microspheres had catalytic activity, and the photocatalytic degradation rate of the composite microspheres for methylene blue MBs reached 97%. The effect of Ag nanoparticles on the fluorescence properties of surface adsorbed fluorescein (FLL) was studied. It was found that the fluorescence enhancement efficiency of Ag nanoparticles increased with the increase of Ag nanoparticles concentration.
【学位授予单位】：江南大学
【学位级别】：硕士
【学位授予年份】：2011
【分类号】：TB383.1

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