【作者】 田佳；

【导师】 赵汉英；

【作者基本信息】 南开大学 ， 高分子化学与物理， 2012， 博士

【摘要】 金纳米粒子(AuNPs)是最稳定的金属纳米粒子，因其具有独特的光，电，磁，催化等性质而在生物，催化等领域得到广泛的应用。近年来含有AuNPs的高级杂化自组装结构的构筑引起了人们广泛的关注。柠檬酸钠稳定的AuNPs在油水界面上能够进一步被疏水性的带巯基的聚合物修饰，从而在界面上制备双亲性的AuNPs。在本研究中这些双亲性的AuNPs进一步组装可以得到功能性杂化乳胶粒子，胶束，囊泡和空心胶囊等结构：1.通过聚苯乙烯（PS）和双亲性AuNPs的自组装，成功地制备以PS为核，AuNPs为壳的乳胶粒子。带巯基的聚苯乙烯（PS-SH）溶解在甲苯中，柠檬酸钠稳定的AuNPs分散在水相中。把溶有PS的甲苯相和分散有AuNPs的水相混合并充分搅拌，在油水界面上PS-SH通过Au-S的作用接枝到AuNPs上，得到双亲性的AuNPs。这种双亲性AuNPs稳定地存在于液-液界面上，减小了界面张力，油滴尺寸变小并且尺寸分布较为均一。将乳液加入到过量的甲醇中，PS坍塌，得到以PS为核，AuNPs为壳的乳胶粒子。乳胶粒子的粒径随着PS-SH和AuNPs的质量比增加而增加。2.利用表面引发的可逆加成-断裂链转移自由基聚合（RAFT）在四氧化三铁纳米粒子（Fe3O4NPs）的表面制备PS分子刷，之后通过还原反应将PS末端的RAFT链转移试剂还原为巯基，制备得到HS-PS-Fe3O4NPs。亲水性的AuNPs分布在水里，HS-PS-Fe3O4NPs分布在甲苯，混合两种溶液，AuNPs通过Au-S作用接枝到疏水的Fe3O4NPs，这样双亲性的纳米粒子簇分布在液-液界面上，并起到稳定乳液的作用。将乳液加入到过量的甲醇中，制备得到以Fe3O4NPs为核，AuNPs为冠的核-壳结构。3.通过PS和AuNPs单体的液-液界面聚合制备侧链带有数个亲水性AuNPs的PS。这种杂化的双亲性的PS在水溶液中能够组装成特定的结构。杂化聚合物的亲水性对组装有重要的作用。亲水性的AuNPs的减少引起组装结构从胶束结构转变为囊泡结构。在聚合的AuNPs上接枝上亲水性的聚乙烯基吡咯烷酮（PVP），组装体从囊泡结构转变成核-壳-冠结构。杂化的带有AuNPs的PS与PS包裹的Fe3O4NPs能够组装成以PS和PS修饰的Fe3O4NPs为壁，AuNPs为冠的囊泡，囊泡的大小由AuNPs的数目决定。4.在油水界面制备表面带有双键的双亲性杂化AuNPs，并且以油滴为模板通过界面交联聚合（共聚）制备得到表面为AuNPs的（多组分）空心胶囊。这是一种简单的制备杂化纳米粒子空心胶囊的新方法。在液-液界面上亲水性的AuNPs和带有二硫键的疏水性的聚合物通过配体交换作用原位生成双亲性的AuNPs。油相甲苯与水的体积比对空心囊泡的尺寸有重要影响。囊泡的尺寸随着体积比增大而增大。利用透射电镜，扫描电镜和原子力显微镜等测试手段都被用来表征囊泡的结构。并且，通过甲基丙烯酰胺和杂化AuNPs的界面共聚可以得到多组分的空心囊泡。由于空心胶囊的亲水性的提高，在水溶液中多组分空心囊泡的尺寸比单组分的囊泡大。5.通过界面的配体交换制备双亲性带有蒽官能团的杂化的AuNPs，以油水乳液滴为模板，通过光二聚制备得到AuNPs空心胶囊。利用Misunobe反应制备带有蒽官能团的单体AnMA，用中间带二硫键的小分子引发剂ATRP聚合制备无规共聚物DS-PAnMA-co-PMMA。将DS-PAnMA-co-PMMA溶解在甲苯中，AuNPs分散在水中，在液-液界面上亲水性的AuNPs和带有二硫键的疏水性的聚合物通过配体交换作用原位生成双亲性反应性的AuNPs。蒽官能团被连接到AuNPs上，紫外光照射可以非常方便的得到表面为AuNPs的空心胶囊。利用透射电镜，荧光显微镜，原子力显微镜等测试手段表征空心胶囊的结构。以液-液界面为模板，利用Au-S作用在金表面部分接枝疏水的聚合物，可以制备得到功能性杂化乳胶粒子，胶束，囊泡和空心胶囊等组装结构，这是一种制备聚合物/无机纳米杂化材料的新颖，通用的方法。更多还原

【Abstract】 Gold nanoparticle (AuNPs) is one of the most stable metal nanoparticles. It hasmany applications in biology and catalysis for its fanscinating size-related electronic,optic, magnetic, and catalytic properties. The structural arrangement of AuNPs playsa key role in device fabrication. In self-assembly process, designed AuNP buildingblocks spontaneously organize themselves into ordered structures througnnoncovalent interactions. Citrate-protected AuNPs allow further chemicalmodification by hydrophobic polymer chains, to obtain amphiphlic hybrid AuNPs.These amphiphlic hybrid AuNPs can segregate at the liquid-liquid interface, andassemble to colloid particles, micelles, vesicles, hollow capsules.1. Colloid particles with polystyrene (PS) cores and AuNPs coronae wereprepared based on self-assembly of AuNPs and PS. Citrate-stabilized AuNPs weredispersed in aqueous solution, and polystyrene with thiol terminal groups (PS-SH)was dissolved in toluene. A stable emulsion was obtained by mixing the twosolutions. Optical microscope images indicate that after grafting of PS-SH to thecitrate-stabilized AuNPs at liquid-liquid interface, the interfacial tension is reducedand the average size of toluene droplets in the emulsion decreases. Transmissionelectron microscope (TEM) results also prove the grafting of PS-SH to AuNPs andlocation of the hybrid nanoparticles at liquid-liquid interface. Colloid particles withPS cores and AuNPs coronae were prepared by addition of the emulsion into excessmethanol. The weight ratio of PS-SH to AuNPs exerts a significant effect on the sizeof colloid particles. TEM and dynamic light scattering results both indicate that thesize of colloid particles increases with the weight ratio. The application of thecore-shell structured colloid particles in protein separation was also investigated inthis research. Colloid particles with PS-coated magnetic nanoparticles in the corescan also be prepared by this strategy.2. PS brushes on Fe3O4nanoparticles were prepared by reversible additionfragmentation chain transfer (RAFT) polymerization, and after reduction reaction PS brushes with terminal thiol groups (HS-PS-Fe3O4NPs) were obtained.Citrate-stabilized AuNPs were dispersed in aqueous solution and HS-PS-Fe3O4NPswere dispersed in toluene. Upon mixing of the two solutions, a stable O/W emulsionwas prepared. Hydrophilic gold nanoparticles interacted with hydrophobic Fe3O4nanoparticles via Au-S interaction at liquid-liquid interface, and amphiphilicnanoparticle complexes were formed at the interface. In methanol, the nanoparticlecomplexes self-assembled into nanoparticles with Fe3O4-nanoparticle cores andgold-nanoparticle coronae. The core-shell structures were still remained in THF.3. PS with pendant hydrophilic AuNPs were synthesized by free radicalcopolymerization of styrene and AuNPs monomer at liquid-liquid interface. Thehybrid polymers can self-assemble into ordered structures in aqueous solutions. Thehydrophilicity of the hybrid polymers plays a key role in the self-assembly of thepolymers. A decrease in the number of hydrophilic AuNPs results in a transitionfrom micellar structure to vesicular structure. After grafting of hydrophilicpoly(N-vinyl pyrrolidone) chains to the pendant AuNPs, the self-assembly changesfrom vesilcular structure to core-shell-corona structure. The hybrid polymers andPS-coated Fe3O4nanoparticles can self-assemble into vesicles with PS andPS-coated Fe3O4nanoparticles in the walls and AuNPs in the coronae, and the sizeof vesicles is determined by the number of pendant AuNPs.4. Amphiphilic AuNPs were produced in situ at liquid-liquid interface via ligandexchange between hydrophilic AuNPs and disulfide-containing polymer chains. Byusing oil droplets as templates, hybrid hollow capsules with AuNPs on the surfaceswere obtained after interfacial cross-linking polymerization. The volume ratio oftoluene to water exerts an important effect on the size of capsules. The average size ofthe capsules increases with the volume ratio. TEM, scanning electron microscopy(SEM) and atomic force microscopy (AFM) were used to characterize the hollowstructures. In this research not only one-component but also multi-component hollowcapsules were prepared by copolymerization of acrylamide and hybrid AuNPs atliquid-liquid interface. Because of the improvement in hydrophilicity of the hollowcapsules, the average size of multi-component capsules is bigger than one-componentones in aqueous solution. 5. Amphiphilic AuNPs were produced in situ at liquid-liquid interface vialigand exchange between hydrophilic AuNPs and disulfide-containing polymerchains. By using oil droplets as templates, hybrid hollow capsules with AuNPs onthe surfaces were obtained after UV cross-linking dimerization. Monomer AnMAwas synthesized by Mitsunobe reaction, DS-PAnMA-co-PMMA was prepared byATRP and disulfide initiator. Citrate-stabilized AuNPs were dispersed in aqueoussolution and DS-PAnMA-co-PMMA was dissolved in toluene. Upon mixing of thetwo solutions, reactive amphiphilic AuNPs were obtained at the liquid-liduidinterface. Anthracene groups were tethered on thesurface of AuNPs, UV light easilycrosslink the reactive amphiphilic AuNPs at liquid-liquid interface to obtain hybridhollow capsules with AuNPs on the surfaces. TEM, fluorescence microscopy andAFM were used to characterize the hollow structures. The distances between AuNPscould be adjusted by changing dispersion medium of hollow capsules.更多还原