Self-assembled Vesicles As Templates For Preparing Hollow Nanomaterials

Nanosphere with inner empty?NIE?have received extensive attention in many fields ofelectrode materials,electronic components,sensors,optoelectronics and magnetic materials because of its unique advantages including internal cavity,large specific surface area,high stability,low density,good surface permeability and high porosity.However,so far,research reports on the preparation of hollow materials,especially the preparation of nano-hollow materials,have been reported few relatively,and the methods are still primitive.Advanced nano-functional materials,except the requiring of the morphology to be more easily shaped,the mechanical properties and thermal stability and the functional properties of the materials also require further research.The rapid expansion of the preparation of nano-hollow materials and the development of more kinds of hollow materials are two major research directions in the field of hollow nano-materials.For hollow materials,choosing a suitable precursor to synthesize a stable hollow nanostructure morphology while maintaining good properties is a very important strategy for material designing and tailoring.Based on the above research significance and purpose and the preliminary research of preparing silica vesicles,the hollow phenolic resin?RF?microspheres?Chapter 2?and hollow SiO₂/C microprisms?Chapter 3?are synthesized by using the water-soluble phenolic resin and a mixture of the water-soluble phenolic resin and TEOS as a precursor,and the vesicles of sodium dodecyl sulfate?SDS?and cetyltrimethylammonium bromide?CTAB?in the ammonia system as soft template.The obtained products were characterized by XRD,TEM,SEM,FTIR,BET,TGA and so on.In order to further study the relationship between reaction conditions and products,we also studied the structure,morphology and pore structure of the hollow RF microspheres and hollow SiO₂/C microprisms by changing the ratio of surfactant,temperature,time and stirring speed.The best reaction condition of the hollow materials were obtained.The formation mechanism of RF multilayer hollow microspheres and SiO₂/C single-layer hollow microprisms was discussed.The RF hollow microspheres synthesized in this study are multi-layered structures,which can have more high-activity reaction sites.They also have good periodicity,high sphericity,and controllable size from nanometer to micrometer.The method has the advantages of simpleness and high safety factor without any post-treatment such as calcinations.The phenolic resin can be degraded and discharged in the body,and solves the problem that the SiO₂ vesicles can form stones when they become the drug carrier.In this study,SiO₂/C hollow micro-prisms with single-layer with different morphologies and sizes were synthesized by vesicles and SDS recrystallization as a secondary template first time.The SiO₂/C hollow micro-columns have good mechanical properties,high load ratio and heat resistance.The hollow material has potential application value in the fields of battery electrodes,catalysis,photoelectric materials and the like.