Sesearch On Polymer Nanometer Microspheres Synthesized By The RAFT Polymerization

Phenolic compounds are important industrial chemicals and additives widely used in agricultural chemicals,petrochemical industry and synthetic rubbers.Phenolic compounds are enriched in aquatic environment due to dissolvability and stability,which not only endanger the survival and propagate of aquatiles,but also harm people’s health.Adsorption stripping by high efficiency and economic efficiency is widely applied in processing sewage water containing phenolic compounds.In consideration of environmental protection and recirculation of resource,seeking a more stable,higher absorption efficiency and costless absorbent is of great importance and owning a wide application background.In this paper,inorganic polyhedral oligomeric sesquioxane(POSS)was introduced into the chain transfer agent of trithiocarbonate,a novel organic-inorganic hybrid macromolecular chain transfer agent POSS-CTA and functional monomer N-(S)-(1-carboxy-1-phenyl)-meth-acrylamide(S-CBM)were designed and synthesized.The S-CBM nanospheres were prepared by RAFT polymerization.The effects of monomer concentration,crosslinker content and chain transfer agent content on particle size,particle size distribution and yield of S-CBM nanospheres were investigated systematically.The uniform and regular S-CBM microspheres with a diameter of 218nm,the particle size distribution index of 0.157 were prepared by RAFT polymerization.The inorganic POSS molecules in microspheres played a skeleton supporting role,making microspheres have a larger specific surface area and porosity.The specific surface area of S-CBM was 187 m~2/g and the pore volume of S-CBM microspheres was 0.57 cm~3/g.In cooperation of phenyl,POSS and micro-nanostructure of microspheres,the S-CBM appeared well hydrophobic,the static water contact angle was 142°,and the S-CBM microspheres have good thermal stability.The effects of S-CBM nanospheres adsorption capacity of(2,4-DCP),4-chlorophenol(4-CP)and pyrocatechol(PCC)were investigated by static adsorption method.The adsorption experiments were analyzed by isothermal adsorption model,adsorption kinetics and thermodynamic model.The properties of the adsorption process and the thermodynamic behavior were discussed,and desorption performance of S-CBM microspheres was investigated.The optimum adsorption conditions were pH=5,the concentrations of 2,4-DCP,4-CP and PCC were 100 mg/L,135 mg/L and 170 mg/L respectively,the adsorption time was6h,shaker speed was 120 r/min.Under the optimum conditions,the maximum adsorption capacity of S-CBM microspheres to 2,4-DCP,4-CP and PCC were 21.05 mg/g,34.28 mg/g and 40.16 mg/g,respectively.The isothermal adsorption processes of the three phenolic molecules followed the Langmuir model,that is,monomolecular adsorption,and were favorable adsorption.The adsorption data of the adsorption equilibrium process were fitted by the quasi-second order kinetic equation,it was chemically adsorbed.The results of thermodynamic analysis confirmed that the adsorption was spontaneous and exothermic.In addition,the microspheres have a stable and uniform rigid structure and good regeneration performance,which after recycling 5 times after the regeneration efficiency is still higher than80%.