Modified Synthesis And Adsorption Simulation Of Styrene-Divinylbenzene Copolymer Hydrophobic Catalyst Carrier

At present,the treatment of tritium-containing wastewater in nuclear power plants is facing huge problems.The hydrogen-water liquid phase catalytic exchange（LPCE）technology using platinum/styrene-divinylbenzene copolymer（Pt/SDB）as a hydrophobic catalyst is expected to play an important role.However,the hydrophobic carrier SDB also has shortcomings such as fragility,reduced hydrophobicity in long-term use,and poor combination with catalyst Pt.Therefore,this article intends to use functional modification and hybrid modification to improve the performance of SDB carriers,and conduct structural characterization and performance evaluation of synthetic SDB and SDB modified carriers.Study on the preparation of functionalized modified SDB:SDB was synthesized through suspension polymerization with St and DVB under the initiation of benzoyl peroxide（BPO）.The SDB carrier was then swelled and heated by grafting chloromethyl and amino groups for functional modification;FT-IR test showed that the functional modification was successfully introduced into the above series of monomers;TGA test analysis showed that the heat stability of SDB-CH₂Cl and AEE-SDB were better than SDB;AEE-SDB has a static water contact angle of134.16°,showing good hydrophobic performance;the compressive strength of AEE-SDB is 32.14 N which is closed to SDB（32.10 N）.Research on the synthesis of inorganic nano-particles hybrid SDB:Firstly,the inorganic nano-SiO₂ and nano-TiO₂ are modified with silane coupling agent（KH570）and hydroxypropyl acrylate（HPMA）to get KH570-SiO₂,KH570-TiO₂ and HPMA-TiO₂ for the hydrophobic modification.The optimized modification conditions for KH570-SiO₂:set temperature at 65℃,adding 6wt%KH570 in toluene,and reacting at 100℃for 2h.The optimized modification conditions of KH570-TiO₂:the solvent consist of 93m L ethanol and 7m L water,adjusting the p H of the solution to 4.5,adding 25 wt%KH570,then reacting at 60℃for 8 hours;The optimized conditions for HPMA-TiO₂:the 5g HPMA and 0.1g initiator BPO were added to 100m L N,N-dimethylformamide at 70℃,then rising the temperature at 80℃reacted for 6 h after the reaction washing HPMA-TiO₂ with tetrahydrofuran.The ratio of KH570-SiO₂/SDB is St:DVB:KH570-SiO₂=10:10:1;For preparing KH570-SiO₂/GMA/SDB is St:DVB:KH570-SiO₂:GMA=10:10:1:2;For cooking the KH570-TiO₂/SDB is:St:DVB:KH570-TiO₂=10:10:1.2;For produing the HPMA-TiO₂/SDB is:St:DVB:HPMA-TiO₂=10:10:1.2;The test results of four hybrid modified carriers show that KH570-SiO₂/SDB:the hydrophobic angle:147.46°,compressive strength:107.21N,ratio Surface area:487.253m²/g;The KH570-SiO₂/GMA/SDB:hydrophobic angle:145.55°,compressive strength:115.34N,specific surface area:463.673m²/g;KH570-TiO₂/SDB carrier:hydrophobic angle:145.34°,compressive strength:108.28N,specific surface area:427.517m²/g;HPMA-TiO₂/SDB carrier:hydrophobic angle:152.17°,compressive strength:114.42N,specific surface area:434.548m²/g,which have a great improvement for SDB:hydrophobic angle:127.83°,compressive strength:32.10 N,specific surface area:397.48m²/g.Cobalt ferrite modified SDB research:The nano-Co Fe₂O₄ was successfully prepared by the low-heat solid-phase sol-gel method,its average particle size is about39.71 nm,then use stearic acid as an interface compatibilizer to treat the surface of Co Fe₂O₄.Co Fe₂O₄/SDB were synthesized through situ polymerization;the FT-IR test showed that it was successful to copolymerized St,DVB and Co Fe₂O₄;XRD test showed that the crystal form of Co Fe₂O₄ unchanged after hydrophobic modification with SA and the copolymerizing with SDB;The thermal decomposition temperature of the Co Fe2O4/SDB carrier has been greatly improved compared to the basic SDB carrier;The hydrophobic angle of Co Fe₂O₄/SDB reached 154.70°which is superhydrophobic;The pore structure data of Co Fe₂O₄/SDB were all decreased with the increase of the Co Fe₂O₄ doping amount;the compressive strength of Co Fe₂O₄/SDB increased with the increasement of Co Fe₂O₄ doping amount,and the compressive strength of Co Fe₂O₄/SDB reaches 221.91 N,which is 6.92 times than that of SDB.The nickel ion and cobalt ion solutions were used to simulate platinum ions for the adsorption characteristicsstudy of SDB and modified SDB carriers.Then study on SDB,KH570-SiO₂/SDB,HPMA-TiO₂/SDB,Co Fe₂O₄/SDB and AEE-SDB carriers adsorption performance for Ni（Ⅱ）and Co（Ⅱ）.The adsorption capacity of these modified carriers for nickel ions were compared.The results showed that the adsorption of KH570-SiO₂/SDB,HPMA-TiO₂/SDB,Co Fe₂O₄/SDB and AEE-SDB carriers have a greater adsorption rate than that of SDB,and AEE-SDB have the largest adsorption rate;The adsorption process of these five carriers conforms to the Lagrangian pseudo-second-order kinetic equation,which means the adsorption process is mainly chemical adsorption,with physical inter-particle adsorption and diffusion adsorption partly occured.The thermodynamic analysis shows that with the temperature rising during the adsorption of nickel（Ⅱ）on these carriers is beneficial to the adsorption reaction.The other four carriers are more in line with the Langmuir isotherm;The SDB carrier meets the Freundlich isotherm better;KH570-SiO₂/SDB in adsorption with nickel ions is non-preferential adsorption.Comparing the adsorption capacity of cobalt ions on various modified carriers,the results show that the adsorption rate of the four modified supports were greater than that of SDB,and AEE-SDB has the largest the adsorption rate.The adsorption process of these five carriers conforms to the Lagrangian pseudo-second-order kinetic equation,which means the adsorption process is mainly chemical adsorption,with physical adsorption and inter-particle adsorption partly occured.In the adsorption process of cobalt ions by the five carriers,the adsorption process is all endothermic,non-spontaneous and the orderliness of the system reduced.Adsorption isotherm analysis:HPMA-TiO₂/SDB,and AEE-SDB carrier were more in line with Langmuir isotherm,the adsorption process is main monolayer adsorption,and the other three carriers are more in line with Freundlich isotherm.In the adsorption process,the adsorption of nickel ions by the KH570-SiO₂/SDB and SDB carriers are preferential adsorption.This paper innovated the preparation of the three kinds of SDB modified carrier:through surface functionalization of SDB successfully synthesized by amination modification of SDB pellets;The nano inorganic oxide hybrid modification of SDB balls were successfully synthesized through ternary or quaternary copolymerization;Using cobalt ferrite composited with SDB to make the cobalt ferrite magnetic ball.Most of the prepared carriers improved its hydrophobic property,compressive strength,adsorption performance for cobalt and nickel ions;Based on the obtained adsorption characteristics between the carriers with Ni（Ⅱ）or Co（Ⅱ）,the adsorption kinetic equations,adsorption thermodynamic equations,and adsorption isotherm equations were used to evaluate the adsorption process,which is helpful to predict the interface adsorption mechanism between the active component and the carrier.