Synthesis Of AgCl Nanoparticles In W/O Microemulsion And Study Of AgCl/PMMA-F127 Organic/Inorganic Hybrid Membranes For Pervaporation Of Benzene/Cyclohexane Mixtures

AgCl nanoparticles were first synthesized in water-in-oil microemulsion using poly (ethylene oxide)-poly (propylene oxide)-poly (ethylene oxide) block copolymers (F127) as a surfactant and polymerizable methyl methacrylate (MMA) as oil phase. Then AgCl/PMMA-F127 inorganic-organic hybrid membranes were prepared by situ-polymerization. Pervaporation performances of hybrid membrane were tested for separation of benzene/cyclohexane mixtures. The research content in this paper included three sections.1. Study of the stability and the maximum water solubilization capacity (ωmax) of F127/MMA/(H2O+NaCl) and F127/MMA/(H2O+AgNO3) microemulsionThe stability of microemulsion was analyzed via the measurement of conductivity. (1) F127/MMA/(H2O+NaCl) and F127/MMA/(H2O+AgNO3) microemulsion could only form reverse micriemulsion when F127 was used as surfactant. (2) The concentration of F127 had little effect on theωmax; (3) The concentration of NaCl influenced slightly on theωmax of F127/MMA/(H2O+NaCl) reverse microemulsion, whereas the concentration of AgNO3 had obviously impact on the F127/MMA/(H2O+AgNO3) reverse microemulsion.2. Characterization of the formation and morphology of AgCl nanoparticles in reverse microemulsion Several important factors affected the numbers and the size of AgCl nanoparticles in synetheis of AgCl nanoparticles via reverse microemulsion, such as molar ratio of water to surfactant (water solubilitation,ω), the concentration of salt and surfactant. The formation and morphology of AgCl nanoparticles were analyzed by ultraviolet-visible (UV-vis) spectrum and transmission electron microscopy (TEM). (1) The formation of AgCl nanoparticles in F127 microemulsion spent more time than those in microemulsion using AOT as surfactant. The sizes of all particles were less than 10 nm and its distribution was narrow. (2) The size of AgCl nanoparticles increased first withωincrease then decreased slightly after theωreached 18. The numbers of AgCl nanoparticles decreased withωincrease. (3) More AgCl nanoparticles with smaller size would be formed with increase of NaCl (AgNO3) concentration. However, there were Ag particles appeared simultaneously at high concentration of reactant salt, with the formation of AgCl nanoparticles. (4) The size and the numbers of AgCl nanoparticle increased as the F127 concentration increased.3. Study on AgCl/PMMA-F127 hybrid membranes for pervaporation of benzene/cyclohexane mixturesThe AgCl/PMMA-F127 homogeneous membranes and composite membranes were prepared by microemulsion polymerization. (1) The structure of hybrid membrane were analyzed by scanning electron microscope (SEM), and the resultes indicated that the AgCl nanoparticles in spherical shape were well dispersedand and did not aggregated obviously in the hybrid membrane. The hybrid membrane was dense membrane. (2) The performance of composite membranes was tested by pervaporation experiment of benzene/cyclohexane mixtures. The flux and selectivity of the membrane increased and then decreased with the increase ofω. The flux and selectivity of the membranes first increased and then decreased with the increase of concentration of salt and F127.In conclusion, there were many important factors influences on the size and numbers of AgCl nanoparticles, incldingω, the concentration of salt and surfactant. Then the AgCl-PMMA/F127 membranes were regulated by changing of these factors.