The Preparation Of Mesoporous SBA-15/Hyperbranched Poly (Sulfone-Amine) Hybrid And Its Dye Adsorption Capacity

From 1990s,organic-inorganic hybrid materials have long attracted considerable interest in chemistry and material science.Especially,the hybridization of organic phase and mesoporous materials has become the focus of attention in recent years.Due to their uniform pore size,large pore volume and specific area,mesoporous materials have potential application in catalysis,separation,biological sensing and so on. Unfortunately,low chemical activity as a main shortcoming limits their further development.Hybridization can improve surface reactive ability of mesoporous material effectively.However,the study of mesoporous silica/hyper-branched polymer hybrids has barely been reported.In the thesis,mesoporous silica SBA-15 was synthesized by the template of amphiphilic tirblock copolymers(Pluronic P123).SBA-15 was modified by aminopropyl,then grafted by poly(sulfone-amine) with "one spot" strategy.Many methods,including SEM,TEM,XRD, Nitrogen adsorption,FTIR,NMR,EA,TGA,were used to characterize the surface topography,structure and chemical constitution of the hybrids obtained.The results show that hyperbranched poly(sulfone-amine) has been successfully grafted onto the surface of mesoporous silica SBA-15 and organic load was about 29wt%.The introduction of hyperbranched poly(sulfone-amine) doesn't destroy the intrinsic structure of mesoporous SBA-15,and hybrids still kept high ordered hexagonal mesostructure with the decrease of pore volume,pore diameter and surface area to a certain extent.Chemical reaction activity of mesoporous SBA-15 was effectively increased by grafting rich end amino group,and it was expected that the application could be broaded consequently.Mesoporous SBA-15/ hyperbranched poly(sulfone-amine) hybrids were used as adsorption medium for acid dye Sandolan-Red.On the basis of ultraviolet-vis spectroscopy,the hybrids have excellent adsorption ability with the maximum adsorption capacity of 585mg/g.The hybrids have rather better adsorption ability than SBA-15,aminopropyl modified SBA-15 and active carbon.Especially,the adsorption capacity of hybrids was 2-3 times more than that of active carbon.Many factors,such as times,temperatures and pH value can play effective roles to dye adsorption.It was found by dynamic adsorption that the hybrids could reach an adsorption balance in 10 hours.The optimum adsorption capacity would be achieved in weak acidic situation and temperature of 35℃.Langmuir and Freundlich models were applied to fit and describe the adsorption behavior.It's found by Langmuir model that mono-molecular layer adsorption dominated the whole adsorption process.Rate determining step was confirmed by simulating hybrids' adsorption behavior of dye with the help of first and second order dynamic equations.The results showed that the adsorption speed could be determined by both liquid membrane diffusion and grain diffusion in low concentration while liquid membrane diffusion in high concentration.