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
Surface design and engineering is a critical tool to improve the interaction of materials with their surroundings. Immobilization of soft hydrogels is one of the attractive strategies to achieve surface modification. ...Surface design and engineering is a critical tool to improve the interaction of materials with their surroundings. Immobilization of soft hydrogels is one of the attractive strategies to achieve surface modification. The goal of this review is to provide a comprehensive overview of the different strategies used for surface tethering of hydrogel layers via crosslinking immobilization of pre-fabricated functional polymers. In this strategy, crosslinkable polymers are first prepared via various polymerization techniques or post-functionalization of polymers. Afterwards, the crosslinkable polymers are attached or tethered on the surfaces of substrates using a variety of approaches including photo-crosslinking, click reactions, reversible linkages, etc. For each case, the principles of hydrogel tethering have been explained in detail with representative examples.Moreover, the potential applications of the as-modified substrates in specific cases have also been addressed and overviewed.展开更多
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.
基金financially supported by Provincial Key Lab of Pulp and Paper Science and Technology and Joint International Research Lab of Lignocellulosic Functional Materials,Nanjing Forestry University,the National Nature Science Foundation of China(Nos.31730106 and 31770623)NSERC Canada。
文摘Surface design and engineering is a critical tool to improve the interaction of materials with their surroundings. Immobilization of soft hydrogels is one of the attractive strategies to achieve surface modification. The goal of this review is to provide a comprehensive overview of the different strategies used for surface tethering of hydrogel layers via crosslinking immobilization of pre-fabricated functional polymers. In this strategy, crosslinkable polymers are first prepared via various polymerization techniques or post-functionalization of polymers. Afterwards, the crosslinkable polymers are attached or tethered on the surfaces of substrates using a variety of approaches including photo-crosslinking, click reactions, reversible linkages, etc. For each case, the principles of hydrogel tethering have been explained in detail with representative examples.Moreover, the potential applications of the as-modified substrates in specific cases have also been addressed and overviewed.
