【作者】 邹声文；

【导师】 王朝阳；

【作者基本信息】 华南理工大学 ， 材料学， 2014， 博士

【摘要】 多孔聚合物材料（如多孔聚合物微球和多孔整体柱材料）由于其独特的结构赋予了其特殊的物理化学性能和应用价值。因而，多孔聚合物材料一直是材料工作者研究和关注的焦点。本课题以Pickering乳液模板法为手段，以制备不同结构多孔或者多核聚合物微球以及多孔聚合物整体柱为主线，论文主要包含了以下六个部分。第一章为绪论，概述了Pickering乳液以及多孔聚合物材料的研究进展。第二章阐述两步法制备了多重Pickering乳液，并在此基础上聚合制备了结构可控的多孔微球。第三章探索一步法制备多重乳液，然后通过溶剂原位挥发制备多孔PLGA微球。第四章尝试用单重乳液模板聚合制备复杂结构微球。第五章采用粒子与表面活性剂为复合稳定剂，协同稳定制备高内相乳液。第六章研究了粒子与表面活性剂复合稳定的高内相乳液及其多孔材料的应用。本课题主要的研究内容和结果如下：1.首次通过简单地调控初乳水油比制备结构可控的多孔聚苯乙烯微球。采用疏水粒子和亲水粒子作为初乳油包水和复乳水包油的粒子乳化剂，采用两步法制备了稳定的水包油包水（W/O/W）的多重Pickering乳液。通过聚合油相中的苯乙烯单体得到了多孔聚苯乙烯微球。通过扫描电镜（SEM）及X射线能量分散谱（EDS）对微球的内部结构以及纳米粒子的位置进行了表征。结果表明聚合后粒子仍保留在微球的孔壁和外表面，构成杂化多孔微球。通过简单调节初乳水相和油相的体积比，其他条件不变，可以得到内部孔洞疏密程度不一的多孔微球，同时高的水油比还可以实现内部孔洞从闭孔结构向开孔结构的转变。2.首次一步法制备多重乳液及多孔PLGA微球。我们用自制的亲水SiO2纳米粒子作为水包油的稳定粒子，一步手摇制备了水包油包水的多重Pickering乳液，油相是PLGA的二氯甲烷溶液。通过对PLGA的分子结构、PLGA在油相中含量、SiO2纳米粒子在水相中的浓度以及油水比等因素的研究，发现只有上述影响因素在一定的范围内才能制备出多重乳液。通过油相二氯甲烷的挥发，我们制备了多孔的PLGA微球。乳液模板的类型直接影响挥发产物的形貌，只有多重乳液模板挥发后才能获得多孔微球。3.首次用单重Pickering乳液模板制备多核结构微球。以木质素胶体粒子作为水包油的稳定剂，制备了稳定的水包油单重Pickering乳液。油相为苯乙烯、二乙烯苯和十六烷的混合油相，另外再向混合油相中添加疏水纳米粒子作为成核剂。聚合反应开始后，聚苯乙烯分子由于不与十六烷互溶而发生相分离。此时，聚合物一方面在疏水粒子表面富集另一方面往乳滴的油水界面迁移。最后形成大空心球里面包裹很多小球的多核结构微球。疏水粒子和十六烷的含量对内部多核结构有重大的影响，而交联剂主要影响微球的机械性能。整个微球的尺寸则通过木质素粒子的浓度来调控。改变成核粒子的种类可以制备不同核心的多核微球，在油相中添加疏水四氧化三铁纳米粒子聚合制备了具有磁响应性的多核微球。4.首次利用粒子和表面活性剂作为复合稳定剂协同制备高内相乳液。采用疏水H30粒子和亲油的表面活性剂司班85作为复合稳定剂制备了不同油相的油包水高内相乳液。本工作选用的粒子和表面活性剂单独使用时均不能较好地制备油包水的高内相乳液，而粒子与表面活性剂的复合体系则能稳定体积分数高达98%的高内相乳液。通过对其乳液和聚合物形貌的分析得出，粒子稳定的大乳滴和表面活性剂稳定的小乳滴共存于整个乳液体系中。表面活性剂可能部分吸附到粒子表面而提高粒子的乳化能力。此外，粒子使连续相粘度增大促进乳化剂形成油包水的液滴。正是这种协同作用在高内相乳液的制备过程中起到了关键作用。通过对聚合物结构观察发现，使用这种粒子与表面活性剂的复合乳化剂能制备出不同孔结构的多孔材料。5.首次利用高内相乳液模板一步制备了多孔抗菌水凝胶。采用亲水N20纳米粒子和亲水的吐温80表面活性剂作为稳定剂制备水包油的高内相乳液。油相是抗菌性的易挥发的艾叶油，聚合水相单体一步制备多孔载油水凝胶，避免了油相的浪费。研究发现，粒子和表面活性剂在连续相中的质量分数不仅可以影响水凝胶的孔洞结构，而且显著影响了其力学性能。对载油水凝胶进行体外模拟释放和抗菌活性研究，结果发现其具有很好的缓释效果和非常优异的抗菌性能。更多还原

【Abstract】 Porous polymer materials (such as multihollow polymer microspheres and porousmonoliths) have attracted more and more attention because of their special physical andchemical properties and applications endowed by their unique structure. This thesis describedthe development of new strategies for the preparation of different structure of porous ormulticore polymer microspheres and the porous polymer monoliths based on the Pickeringemulsion templates. The paper mainly includes the following six parts. The first chapter is theintroduction, summarizes the Pickering emulsion and the research progress of porous polymermaterials. The second chapter focuses on the fabrication of controllable multihollowmicrospheres based on the two-step multiple Pickering emulsion templates. The third chapterexplores one step method to prepare multiple emulsions and the fabrication of porous PLGAmicrospheres. The fourth chapter tries to use single emulsion template to manufacturepolymer microspheres with complex multicore structure. The fifth investigates usingcostabilizer of particles and surfactant to synergistically stabilize high internal phase emulsion.The last studies the costabilizer of particles and surfactant stablilized high internal phaseemulsion and the application of the emulsion-templated porous materials.The main research contents and results of this thesis are as follows:1. Fabrication of controllable multihollow polystyrene microspheres by simply adjustingthe volume ratios of inner water phase to oil phase. Hydrophobic and hydrophilic particleswere employed as emulsifiers for the primary W1/O and outer O/W2emulsion, respectively.Stable water-in-oil-in-water (W/O/W) multiple emulsions were prepared by two-step method.Multihollow polystyrene microspheres were obtained by polymering the styrene monomer inoil phase based on the multiple Pickering emulsion templates. The internal structure of themicrospheres and the location of the nanoparticles have been characterized by scanningelectron microscopy (SEM) and X-ray energy dispersive spectrum (EDS). The results showedthat the nanoparticles mainly located on the inner void wall and the outer surface of themicrospheres. By simple adjustment of volume ratios of internal water phase to oil phase, thenumber of voids in porous microspheres can be controlled. Moreover, high ratio of W1:O canalso make the internal pores change from the closed structure to interconnected pore structure.2. One step preparation of multiple emulsion and porous PLGA microspheres. We usesynthetic hydrophilic SiO2nanoparticles as stabilizer of oil-in-water emulsions, and PLGAsolution of methylene chloride as oil phase. W/O/W Pickering emulsion was one stepprepared by hand shaking the water and oil phase. We systematically investigated the influences of molecular structure of the PLGA, PLGA content in the oil phase, SiO2nanoparticles concentration in water phase and volume ratio of water to oil on the doubleemulsion formation and consequently on the structure of the PLGA microspheres. Opticalmicroscope and scanning electron microscope (SEM) were adopted to survey themicrospheres prepared under different conditions. The results showed that the multipleemulsions can only be obtained under proper conditions. Moreover, the emulsion templatesdirectly affect the morphology of the volatile products. Porous microspheres can be attainedonly after the volatilization of multiple emulsion templates.3. Fabrication of multi-core microspheres based on single Pickering emulsionpolymerization combining phase separation and nanoparticle nucleation. In this study,rattle-like polymer microspheres with multicores encapsulated in hollow spheres are facilelyfabricated via oil-in-water Pickering emulsion polymerization for the first time. Pickeringemulsions were stabilized by hydrophilic lignin nanoparticles. The oil phase containshydrophobic nanoparticles dispersed in polymerizable monomer, styrene and unpolymerizablesolvent, hexadecane. The multicore rattle-like microspheres are directly produced after thepolymerization of monomers in the oil droplets. The key point of this one-pot method for therattle-like microspheres lies in the nucleation of hydrophobic nanoparticles and the phaseseparation between the resulting polystyrene and hexadecane. We have systematicallyinvestigated the influences of the contents of hydrophobic nanoparticles, hexadecane,cross-linker and lignin particles on the structure and morphology of rattle-like microspheres.It is proven that the number and size of core, the shell thickness, size of rattle-likemicrosphere can be easily controlled by adjusting the various parameters. Moreover, specialfunctionalization of the rattle-like microspheres can be developed easily by adding differenthydrophobic nanoparticles in the oil phase. This work opens up a new route to fabricatemulti-level capsules or spheres.4. Fabrication of Pickering high internal phase emulsions (HIPEs) with ultrahigh internalphase fraction by using hydrophobic silica nanoparticles (H30) and nonionic surfactant ofSpan85as a dual emulsifier system. Water-in-hexane (W/O) HIPEs stabilized by a mixture ofH30and Span85were investigated. Increasing Span85concentration in mixture would resultin the appearance of smaller droplets of several to tens of micrometers in the HIPEs while apopulation of large droplets of hundreds of micrometers would appear with increasing H30concentration. Furthermore, the influences of Span85and H30on the formation of HIPEswere investigated from the polymerized HIPEs (polyHIPEs) synthesized through these HIPEstemplates using styrene as the oil phase. The synergism between particles and surfactant exists and plays a crucial role in the stability of HIPEs. This research opens up a new insight into thefabrication of Pickering HIPEs with an ultrahigh internal phase fraction. Moreover, porousmonoliths with different pore structure can be obtained from the co-emulsifier stabilizedHIPEs.5. One-pot prepared Artemisia argyi oil (AAO)-loaded macroporous antibacterialhydrogels through polymerizing oil-in-water Pickering high internal phase emulsions (HIPEs).The HIPEs were stabilized by hydrophilic silica nanoparticles (N20) with adding surfactantTween80. The void interconnectivity and pore size of the hydrogels could be tailored readilyby varying the N20nanoparticle and Tween80concentrations. The mechanical property ofthe porous hydrogels was related to the pore structure of the materials. The in vitro release ofthe AAO-loaded hydrogels with different inner morphologies was evaluated and showedcontrolled release activity. The antibacterial activity of the AAO-loaded hydrogel wasevaluated and exhibited excellent and long-term antibacterial activity.更多还原