Preparation And Characterization Of RF Aerogel On UV Irradiation Method

Resorcinol formaldehyde (RF) aerogel is a kind of nanoscale amorphous solid materials. It possess many excellent properitise including large specific surface area. After carbonization, it has high porosity and electrical conductivity. RF aerogel has attracted much attention in the field of energy industry, catalysis, building industry, information industry, electrode materials, semiconductor materials and magnetic materials and so on. In the study of laser fusion, RF is often in the form of empty core ball as pellet material as ICF gas containers of alternative materials, because the RF aerogel has pore structure of 0.1 um, well transparency-available for optical method to DT frozen state and the roughness of the DT inner ice, only have hydrocarbon and so on. For a target with the empty core sphere, it requires well degress (more than 98%), wall thickness uniformity and high yield. The RF empty core ball is synthesized by microfluid injection molding technology, curing is divided into acid catalysis, heat curing and light curing, etc. Few people research the light curing which is a kind of new curing method, contrast to the RF prepared by Sol-gel method, photo-initiator 659 generators free radicals under UV light which causes the reaction of polymer monomer polymerase. This article is using water soluble, neutral photo-initiator 659 firstly, using UV irradiation method to synthesis RF block and RF sphere. In the paper, the research content including:(1) Water-soluble, neuter photo-initiator was used to synthesis RF aerogel by using UV irradiation method. The results will be discussed that gelation time of RF aerogel depend on the polymerization time, initiators quantities and curing quantities. Using NMR method, IR spectrum, scanning electron microscopy(SEM), N2 adsorplion/desorption to study characyerization and the diffience between the RF aerogel developed for UV irradiation method and Sol-gel method.(2) Using a mixture of industrial white oil, tetrachloroethylene and Span 80 as the oil phase, RF solution and photo-initiator 659 as aqueous phase. Conside oil matched and emulsifier content from match of surface tension and density. The RF empty core ball is synthesized by microfluid injection molding technology, discussed that call curing depend on different rate and different collection bottle shape. And curing spheres using optical method preliminary, made a exploration of this method for preparation of spheres.The following conclusion may be fromed by the analysis of experimental research above:(l)Water soluble, neutral photo-initiator 659 was wsed to synthesize RF aerogel by using free radical UV initiator, discussed the gelation time and the miscostructure of RF aerogel depend on the polymerization time, initiators quantities and curing quantities, discussed the difference of RF aerogel developed for UV irradiation method and Sol-gel method. The result is as following:the decrease in gelation time after polymerization time increase; a remarkable decrease in adding irradiation quantities, then the increase in gelation time after irradiation quantities was increase. Theory density is 5%, R:C in a 200:1 molar ratio, adding 10wt% photo-initiator 659, the perform for 40min, need the shortest gel time for 15min. the perform for 50min, the amount of initiator is 6wt%, need the shortest gel time for 15min. In the influence on pore structure, the structure, degree of fulcrum increased and specific surface area and pore structure has changed with the increase of performed time. With a certain performed time, adding 6% initiator has a low degree of fulcrum contrast of adding 10% initiator. The RF aerogel made by UV irradiation method still maintain a high pore structure, light initiator does not play any role in the formation of aerogel skeleton; the RF aerogel prepared by UV irradiation is crosslink with methylene bond not with methylene ether bridge bond.(2)Industrial oil:tetrachloroethylene in a 1:4.5 volumn, the quantities of span 80 is the sum of both quantities, solution can be good into sphere and suspended in the oil phase. Sphere is synthesized by microfluid injection molding, under the conduction of invariable in the oil phase, As the increase of water, the sphere size show the trend of increase, the size in the sphere after the carbide descease, the sphere curried by the spherical bottle has a large yield than the columnar bottle curing. RF prepared by UV method, sphere led to the layer eventually. Put forward a method by rotary evaporation apparatus and strong UV light to curing sphere, made a exploration of this method for preparation of sphere.