Multifunction Integrated Polymer Capsules Based On Confined Self-assembly Strategy

In recent years, polymer capsules have attracted great attentions, owing totheir potential applications in controlled delivery systems, artificial cells,nanoreactors, etc. Many approaches to prepare polymer capsules have beendeveloped, nevertheless there still exist some barriers and shortcomings forthese approaches, such as the rare possibility of multifunctionalization ofcapsules and the inefficient control of their structure, composite, andpermeability. We developed a “confined self-assembly” strategy with sol-gelprocess, which succeeds in producing size and structure controllable polymercapsules by polymerizing ionic liquid surfactants bearing monomer unit insidetemplate channels. After template removal, polymer capsules containing ionicliquid moiety are obtained, which prove to possess functiona and passagecontrollability. This work concludes four parts as follows:Firstly, three pyrrole-containing imidazolium ionic liquid geminisurfactants were synthesized, whose behaviors in sol-gel self-assembly processto fabricate mesoporous silica as confined templates were examined. Byadjusting the surfactant concentration and its counter anions, all three types ofM41S family, especially a high quality MCM-48structure, was obtained wasprepared.Secondly, by altering the cation structures of imidazolium ionic liquidsurfactants, several types of mesoporous silica and organosilica spheres atdifferent diameters were fabricated, which would serve as multi-scale templateduring confined self-assembly process. To get more information on the self-assembly process, polymerization of monomers in the confined mesoporoussilica templates was also characterized.In the third part, base on the ordered confined self-assembly template andthe polymerization inside the confined space, a strategy has been developed tofabricate polymer capsules of high controllability on structure parameters,composites, passage and functions. The key point of this strategy is the application of the ionic liquid (IL) surfactant introducing both polymerizablepyrrole and imidazolium terminuses into the confined mesoporous silicatemplates simultaneously with the their formation. Through diffusion-controlledsurface polymerization, hollow capsules with different shell thicknesses andsizes were obtained. They were made of a mesoporous polymer-network shellbearing pendant IL moieties, which endowed the capsules with ability ofpermeability control and functionalization by exchanging specificcounter-anions.On the basis of highly controllable capsules, multifunction integration ofpolymer capsules was achieved by expanding the confined self-assemblystrategy to different templates in size, composite and structure. By largerspherical periodic mesoporous organosilica,10μm-scale polymer capsules withanalogous well controllability afore was obtained. By forming templates withmixed surfactants, glucose pendant was introduced on the wall, which gave thecapsules recognition capability with specific lectins. And the catalytic specieswas brought into the hollow cavity of capsule due tothe formation of core-shellconfined template, which provides the core as the medium to the inside ofcapsules. And the reactivity of this center was tuned by the permeability controlof capsules. By manipulating the confined self-assembly in multiple dimensions,we develop a strategy towards highly controllable, multifunction integratedpolymer capsules.In conclusion, by manipulating the proposed confined self-assemblyprocess in multiple dimensions, we develop a strategy towards highlycontrollable, integrated multifunctional polymer capsules.