Study On Preparation Of Hybrid Macro-Porous Materials With Bridged Silsesquioxane And Modification Of Its Hole-Wall By Sulfhydryl Grafting

In this study, a crack-free macro-porous monolith xerogel material was prepared via Sol-Gel process, by ambient pressure drying and using TEOS or bridged silsesquioxane (designed and prepared by our team, called"Q series") as a precursor. The colloidal crystal templating method and the pore-forming agent formation method were used to synthesize this material.Different preparation factors (such as amount of water and kind of catalyst) and precursors, which effect Sol-Gel process, were discussed and optimized completely. Both drying control chemical additives and exchanging solvent were used to reduce the crack in ambient pressure drying process of alcogel. We discussed different kinds of pore-forming agent effect multi-porous material on the pore structural characteristics. And the related factors of colloidal crystal templating method which affect the three-dimensional ordered macro-porous (3DOM) material on pore structural characteristics were researched.Moreover, the mercapto functional group was grafted onto the Q series (Q-ethylene glycol) bridged silsesquioxane. Then the hole-wall mercapto modified functional hybrid 3DOM material was prepared with it by colloidal crystal templating method, base on Sol-Gel process. Meanwhile, we also carry out initial research on this material for use as heavy metal ion adsorbent.The FT-IR was used to investigate the chemistry structural characteristics of bridged silsesquioxane which designed and prepared by our team and mercapto modified bridged silsesquioxane. The Laser Particle Size Analyzer was used to investigate the colloidal particle size and its distribution in the PS emulsion which contained colloidal particles, The SEM was used to investigate the morphology of colloidal crystal template which close-packed by PS colloidal particles. For multi-porous material we prepared respectively, a specific surface area and pore size distribution analyzer was employed to determine the N2 adsorption-desorption at 77K for meso-porous and micro-porous, the BET equation and BJH method were used to estimate the specific surface area and pore size distribution; the Mercury Porosimetry method was used to estimate the porosity and pore size for macro-porous. The Atomic Absorption Spectrophotometer was employed to investigate the adsorption behavior of hole-wall mercapto modified functional hybrid 3DOM material.The results show that we had synthesized bridged silsesquioxane as our designed successfully; and we can reduce the crack in ambient pressure drying process of alcogel by using DMF as DCCAs and Hexane as exchanging solvent.The 3DOM multi-porous material we prepared by colloidal crystal templating method have developed and uniform pore structure, the pore size is 300nm and its distribution is narrow. The multi-porous material prepared by pore-forming agent formation method reveals worse pore structure properties, but it greatly improved by adding bridged silsesquioxane Q2000, the pore size is 50~200nm, the porosity is 70.2% and the specific surface area is 473 m2/g.The hole-wall mercapto modified functional hybrid 3-DOM material reveals well adsorption effect to Pb2+,Cu2+,Cd2+ and Hg2+ ion. The adsorption capacity and adsorption rate for Hg2+ ion were found to be 3.53 mmol/g and 71.59%.