Polyacrylic acid particles in nano-scale were synthesized using an inverse (W/O) emulsion polymerization method. The particle size and size change of inverse micelles which solubilize a part of monomer solution was mo...Polyacrylic acid particles in nano-scale were synthesized using an inverse (W/O) emulsion polymerization method. The particle size and size change of inverse micelles which solubilize a part of monomer solution was monitored by PCS (photon correlation spectroscopy) and the particles of polyacrylic acid were viewed in scanning electron microscope for the first time. It was concluded that the inverse micelles were primarily the polymerization reaction sites.展开更多
Polyacrylamide/silica （PAM/SiO2） composite capsules were synthesized by inverse Pickering emulsion polymerization. Silica nanoparticles modified with methacryloxypropyltrimethoxysilane （MPS） were used as a stabili...Polyacrylamide/silica （PAM/SiO2） composite capsules were synthesized by inverse Pickering emulsion polymerization. Silica nanoparticles modified with methacryloxypropyltrimethoxysilane （MPS） were used as a stabilizer. Transmission electron microscopy （TEM）, scanning electron microscopy （SEM）. Fourier transform infrared （FTIR） spectroscopy, and thermal gravimetric analysis （TGA） were used to characterize the morphology and composition of the composite capsules. SEM and TEM images showed that capsules consisted of a particle shell and a polymer inner layer. The capsule size depends on the nanoparticle concentration in the continuous phase. The composite rigidity largely depends on the acrylamide concentration. FTIR and TGA results indicated the existence of polyacrylamide and SiO2 in the composite particles. Aqueous Hg（ll） removal testing by the PAM/SiO2 composite capsules indicated promising potential for removing heavy metal ions from wastewater.展开更多
Novel cellulose based flocculants C-g-P(DMC) with various chain architectures are synthesized through a situ graft copolymerization. The cationic ammonium chloride group(DMC) is grafted onto cellulose by two separate ...Novel cellulose based flocculants C-g-P(DMC) with various chain architectures are synthesized through a situ graft copolymerization. The cationic ammonium chloride group(DMC) is grafted onto cellulose by two separate inverse emulsion polymerization with γ-methacryloxypropyl trimethoxy silane(KH-570) and double bond addition reactions, which is a new and simple method to employ KH-570 as a bridge for the connection of cellulose matrix and DMC group. The effects of pH, flocculant dose, standing time on turbidity of kaolin suspensions and particle sizes have been studied systematically. In addition, the response surface methodology(RSM) study confirms that PAC and C-g-P(DMC)have synergy in turbidity removal with a higher removal efficiency of 98.32%. Moreover, C-g-P(DMC) 1 has higher removal efficiency with 96.5% at a low dosage of 0.6 mg L^(-1) and better floc properties than C-g-P(DMC) 2 and C-g-P(DMC) 3, suggesting that the length and quantity of cationic branch chains play a crucial role in Kaolin flocculation due to their dramatically enhanced bridging effects.展开更多
文摘Polyacrylic acid particles in nano-scale were synthesized using an inverse (W/O) emulsion polymerization method. The particle size and size change of inverse micelles which solubilize a part of monomer solution was monitored by PCS (photon correlation spectroscopy) and the particles of polyacrylic acid were viewed in scanning electron microscope for the first time. It was concluded that the inverse micelles were primarily the polymerization reaction sites.
文摘Polyacrylamide/silica （PAM/SiO2） composite capsules were synthesized by inverse Pickering emulsion polymerization. Silica nanoparticles modified with methacryloxypropyltrimethoxysilane （MPS） were used as a stabilizer. Transmission electron microscopy （TEM）, scanning electron microscopy （SEM）. Fourier transform infrared （FTIR） spectroscopy, and thermal gravimetric analysis （TGA） were used to characterize the morphology and composition of the composite capsules. SEM and TEM images showed that capsules consisted of a particle shell and a polymer inner layer. The capsule size depends on the nanoparticle concentration in the continuous phase. The composite rigidity largely depends on the acrylamide concentration. FTIR and TGA results indicated the existence of polyacrylamide and SiO2 in the composite particles. Aqueous Hg（ll） removal testing by the PAM/SiO2 composite capsules indicated promising potential for removing heavy metal ions from wastewater.
基金supported by the National Natural Science Foundation of China (51379077,21607044)the Fundamental Research Funds for the Central Universities (2016MS108)Natural Science Foundation of Hebei Province (B2017502069)
文摘Novel cellulose based flocculants C-g-P(DMC) with various chain architectures are synthesized through a situ graft copolymerization. The cationic ammonium chloride group(DMC) is grafted onto cellulose by two separate inverse emulsion polymerization with γ-methacryloxypropyl trimethoxy silane(KH-570) and double bond addition reactions, which is a new and simple method to employ KH-570 as a bridge for the connection of cellulose matrix and DMC group. The effects of pH, flocculant dose, standing time on turbidity of kaolin suspensions and particle sizes have been studied systematically. In addition, the response surface methodology(RSM) study confirms that PAC and C-g-P(DMC)have synergy in turbidity removal with a higher removal efficiency of 98.32%. Moreover, C-g-P(DMC) 1 has higher removal efficiency with 96.5% at a low dosage of 0.6 mg L^(-1) and better floc properties than C-g-P(DMC) 2 and C-g-P(DMC) 3, suggesting that the length and quantity of cationic branch chains play a crucial role in Kaolin flocculation due to their dramatically enhanced bridging effects.
