Preparation And Properties Of Superhydrophobic And High Strength SDB Catalyst Carrier

The treatment of tritium-containing wastewater is the bottleneck in the development of nuclear power in China.To remove tritium,liquid phase catalytic exchange?LPCE?technology depending on platinum/styrene-divinylbenzene copolymer?Pt/SDB?has attracted more and more attention of every country.However,the currently used SDB carrier also has disadvantages such as weak hydrophobicity,low strength,poor dispersion of Pt.Preparation of SDB possessing super-hydrophobicity?static hydrophobic angle?150°?,high strength?compressive strength?100N?and high specific surface area?300⁸00 m²/g?is the main target,currently.In view of this,the paper is going to improve the hydrophobicity and strength of SDB by studying the synthesis process of SDB,and studying the synthesis of the nanoparticle-modified and carbon materials enhanced SDB;to explore the adsorption mechanism of the metal particles on the carrier by using cheap metals such as nickel to simulate the adsorption process of noble metal Pt at the solid-liquid interface,and provide theoretical support for loading Pt on the surface of SDB.Preparation and polymerization process of binary copolymerization of SDB:styrene?St?,divinylbenzene?DVB?were used as monomers,SDB was synthesized by suspension polymerization under the initiation of benzoyl peroxide?BPO?.The effects of dispersing agents,cross-linking agents,heating rates and other experimental conditions were studied.The optimized conditions for preparation of SDB were:the ratio of DVB to St monomer is1:1,the amount of BPO is 0.3 g,the amount of composite dispersant PVA and CE is 3.5 g and 0.5 g,respectively.The prepared SDB carrier show hydrophobicity that the static water contact angle was 132.81°?higher than our previously reported of 130.01°?.The compressive strength of the prepared SDB carrier was 32.07 N?higher than our previously reported of 27.13 N?,and the specific surface area of the prepared SDB carrier was 408.78m²/g.However,there is still a big gap between the results and the research goals of super-hydrophobic and high-strength.Research on synthesis of inorganic nano-oxide modified SDB:KH570 modified SiO₂?K-SiO₂?and stearic acid modified CeO₂?Y-CeO₂?were added to prepare inorganic nanoparticles hybrid modified K-SiO₂/SDB and Y-CeO₂ carriers.The optimized condition for preparation of K-SiO₂ were:in the case of toluene as solvent,the amount of KH570 is5%of SiO₂,and the kept the reaction at 110°C for 2 h.The optimized condition for preparation of Y-CeO₂ were:in the case of ethanol as solvent,the amount of stearic acid was6%of CeO₂,and kept the reaction at 80°C for 1.5 h.For preparation of K-SiO₂/SDB,the optimized amount of reactor was:St:DVB:K-SiO₂=10:10:1?mass ratio?,For preparation of Y-CeO₂/SDB,the optimized amount of reactor was:St:DVB:Y-CeO₂=10:10:0.8?mass ratio?.The results show that the K-SiO₂/SDB and Y-CeO₂/SDB carriers were successfully prepared,and the hydrophobicity of K-SiO₂/SDB and Y-CeO₂/SDB carriers reached 141.22°and 149.78°,respectively,which are close to superhydrophobic.The compressive strength of K-SiO₂/SDB and Y-CeO₂/SDB carriers was as high as 113.54 N and 107.11 N,respectively.The specific surface area of K-SiO₂/SDB was 435.56 m²/g,which is much higher than that of Y-CeO₂/SDB?421.34m²/g?.These performances are much better than those of SDB.Research on carbon material modified SDB:KH570 modified nano-graphite powders?MGC?were employed to prepare graphite carbon modified SDB?MGC/SDB?carrier.In addition,sucrose was used as a carbon source to achieve carbon coating modification of the SDB carrier at a high temperature?SDB/C?,and MS/SDB carrier as a control was prepared.The optimized condition for preparation of MGC were:in the case of ethanol as solvent,the amount of KH570 accounted for 10%of nano-graphite powder,kept reaction at 30°C for 2 h.The optimized amount of MGC in MGC/SDB is:DVB:St:MGC=10:10:0.8?mass ratio?.The optimized condition for preparation of SDB/C were:M_sucrose:M_SDB=1:1?mass ratio?,the reaction system was heated to 320°C for 1 h and holding for 2 h.The results show that the MGC/SDB,MS/SDB and SDB/C carriers were successfully prepared.The hydrophobicity of SDB/C was about 152.47°,which achieved superhydrophobicity.The hydrophobicity of MGC/SDB and MS/SDB was 146.51°and 136.70°,respectively.MS/SDB had the highest compressive strength of 145.60 N,and the compressive strength of MGC/SDB and SDB/C were 105.72 N and 81.19 N,respectively,all of them showed outstanding compressive capacity.The specific surface area of SDB/C was 59.63 m²/g,while the specific surface areas of MGC/SDB and MS/SDB were 413.14 m²/g and 379.67 m²/g,respectively.Study on the adsorption characteristics of carrier using nickel ion instead of platinum ions:The Ni²⁺adsorption performance simulation test was carried out to various carriers such as SDB,K-SiO₂/SDB,Y-CeO₂/SDB,MGC/SDB,MS/SDB and SDB/C.The results show that the adsorption rate of nickel ions by MGC/SDB,MS/SDB and SDB/C carriers was higher than that of SDB?0.1300%?,and the adsorption rate of MGC/SDB was the highest,reaching0.3165%,while the adsorption rates of K-SiO₂/SDB and Y-CeO₂/SDB are 0.1015%and0.0620%,respectively.The adsorption kinetics of SDB,Y-CeO₂/SDB,MGC/SDB carrier show that the adsorption reaction arrived in equilibrium after about 2.5 h.The average adsorption capacity of MGC/SDB is the largest,while the SDB is the lowest,and when the input quality of the carrier increases,the adsorption amount per unit mass decreases.The adsorption of Ni²⁺on Y-CeO₂/SDB and MGC/SDB carriers mainly belong to a chemical process agreeing well with the Lagrangian pseudo second-order kinetic equation.The pseudo-first-order/second-order kinetic fitting results of the SDB carrier are similar,and there may be uniform physical adsorption and chemical adsorption.During the adsorption of Ni²⁺by MGC/SDB,Y-CeO₂/SDB and SDB carriers,?H⁰<0,indicating that it is an endothermic process.?G⁰>0,and decreases with increasing temperature,indicating that the reaction is a non-spontaneous process at these temperatures.Increasing the temperature contributes to the spontaneous reaction.?S⁰>0,indicating that the order of the system is reduced during the dynamic process of adsorption.In this paper,the hydrophobicity and compressive properties of SDB carriers were significantly improved by adding nano-inorganic oxides and carbon materials into the reactio system,through the related synthesis study.In addition,the adsorption characteristics of nickel ions are studied by the related carriers,and the adsorption process between the carrier and nickel ions are described by kinetic equation and thermodynamic equation.This work can help to deeply analyze the interface adsorption mechanism between Pt and its carriers.