To investigate the relationships between structures and toxicities of 13 quaternary ammonium compounds （QACs） to Chlorella pyrenoidosa, 2D- and 3D-QSAR models were built. The 2D-QSAR model included two parameters： ...To investigate the relationships between structures and toxicities of 13 quaternary ammonium compounds （QACs） to Chlorella pyrenoidosa, 2D- and 3D-QSAR models were built. The 2D-QSAR model included two parameters： averaged polarizability （a） and total connectivity （Tcon）. Furthermore, 3D-QSAR models were proposed by using comparative molecular field analysis （CoMFA） and molecular similarity index analysis （CoMSIA）. All these models were robust and predictive. To our interest, 3D-QSAR model suggested that the hydrophobieity of substituents was the dominating factor for the toxicities, electrostatic effect was the secondly important, and steric field gave the least contribution. Comparatively, the predictive ability of 3D-QSAR model is slightly more advantageous than that of 2D-QSAR. They can be used complementally in the toxicity description of this kind of compounds.展开更多
The performance of activated sludge in the removal of tetradecyl benzyl dimethyl ammonium chloride (C14BDMA) by adsorption from aqueous solution was investigated with different PH, contact time, ionic strength and tem...The performance of activated sludge in the removal of tetradecyl benzyl dimethyl ammonium chloride (C14BDMA) by adsorption from aqueous solution was investigated with different PH, contact time, ionic strength and temperature. Equilibrium was achieved within 2 h of contact time. The adsorption capacity increased largely with increasing solution pH and remained constant above pH 9. The ionic strength had a negative effect on C14BDMA removal. The adsorption isotherms were analyzed by Langmuir and Freundlich isotherm models, and equilibrium partitioning data was described well by both models. Kinetics data was best described by the pseudo second-order model. Experimental results indicated that the adsorption was favorable at lower temperatures. Thermodynamic parameters, including the Gibbs free energy (ΔG0), enthalpy (ΔH0), and entropy (ΔS0), were also calculated. These parameters indicated that adsorption of C14BDMA onto activated sludge was feasible, spontaneous and exothermic in the temperature range of 15-35℃. The activated sludge was shown to be an effective adsorbent for C14BDMA.展开更多
Quaternary ammonium compound are a class of broad-spectrum,high-efficiency and low-toxicity bactericide,which are widely used in daily life and industrial sterilization.Herein,the current state of domestic quaternary ...Quaternary ammonium compound are a class of broad-spectrum,high-efficiency and low-toxicity bactericide,which are widely used in daily life and industrial sterilization.Herein,the current state of domestic quaternary ammonium disinfectant products was summarized,as well as those new products developed and studied,and the development trend was also predicted.展开更多
Copolymers of quaternary ammonium monomer（QAM） and hydrophilic co-monomer were successfully synthesized by free radical polymerization. It was discovered that the hydrophilic co-monomers with poor antibac- terial ac...Copolymers of quaternary ammonium monomer（QAM） and hydrophilic co-monomer were successfully synthesized by free radical polymerization. It was discovered that the hydrophilic co-monomers with poor antibac- terial activity significantly enhanced the activity of QAM substituted with a long alkyl chain[i.e., N,N-dimethyl-N-dodecyl methacrylate ammonium bromide（DMAEMA-DB）]. When a suitable molar ratio of DMAEMA-DB to co-monomer was selected, the activity of the copolymers was up to 123 times that of the homopolymer of DMAEMA-DB against S. aureus, and 282 times that of it against E. colt. But unlike DMAEMA-DB, the co-monomers might weaken the activity of QAM substituted with a short alkyl chain[i.e., N,N-dimethyl-N-butyl methacrylate ammonium bromide（DMAEMA-BB）]. Moreover, it was found that copolymers of DMAEMA-DB were much more biocidal than those of DMAEMA-BB. Therefore, it could be speculated that the long alkyl chain plays an important role in the antibacterial activity, and that the hydrophilie co-monomers are beneficial to polymeric guaternary ammonium compounds（PQACs） to exert the positive effect of the long alkyl chain to the greatest degree.展开更多
A series of bis-quaternary ammonium compounds（bis-QACs） N,N＇-hevamethylenebis（1-alkyl-4-carbamoyl pyridinium bromide）（4BCAP-6,n）（alkyl chain length,n=8,10,12,14,16 and 18） were synthesized and characterized.T...A series of bis-quaternary ammonium compounds（bis-QACs） N,N＇-hevamethylenebis（1-alkyl-4-carbamoyl pyridinium bromide）（4BCAP-6,n）（alkyl chain length,n=8,10,12,14,16 and 18） were synthesized and characterized.Their surface tensions,critical micelle concentrations（CMC）,and antimicrobial activities were evaluated.4BCAP-6,10 exhibited the strongest antimicrobial activities except for that against Proteus vulgari.The activities of 4BCAP-6.n against Escherichia coli zk126 were not significantly influenced by temperature.pH and initial bacteria concentration.These results indicate that bis-QACs exhibit high antimicrobial activity regardless of the environmental conditions.展开更多
基金supported by the Environmental Science and Technology Innovation Team project of Jiangsu provincethe Natural Science Foundation of the Jiangsu Higher Education Institutions of China(No.13KJB150012)
文摘To investigate the relationships between structures and toxicities of 13 quaternary ammonium compounds （QACs） to Chlorella pyrenoidosa, 2D- and 3D-QSAR models were built. The 2D-QSAR model included two parameters： averaged polarizability （a） and total connectivity （Tcon）. Furthermore, 3D-QSAR models were proposed by using comparative molecular field analysis （CoMFA） and molecular similarity index analysis （CoMSIA）. All these models were robust and predictive. To our interest, 3D-QSAR model suggested that the hydrophobieity of substituents was the dominating factor for the toxicities, electrostatic effect was the secondly important, and steric field gave the least contribution. Comparatively, the predictive ability of 3D-QSAR model is slightly more advantageous than that of 2D-QSAR. They can be used complementally in the toxicity description of this kind of compounds.
文摘The performance of activated sludge in the removal of tetradecyl benzyl dimethyl ammonium chloride (C14BDMA) by adsorption from aqueous solution was investigated with different PH, contact time, ionic strength and temperature. Equilibrium was achieved within 2 h of contact time. The adsorption capacity increased largely with increasing solution pH and remained constant above pH 9. The ionic strength had a negative effect on C14BDMA removal. The adsorption isotherms were analyzed by Langmuir and Freundlich isotherm models, and equilibrium partitioning data was described well by both models. Kinetics data was best described by the pseudo second-order model. Experimental results indicated that the adsorption was favorable at lower temperatures. Thermodynamic parameters, including the Gibbs free energy (ΔG0), enthalpy (ΔH0), and entropy (ΔS0), were also calculated. These parameters indicated that adsorption of C14BDMA onto activated sludge was feasible, spontaneous and exothermic in the temperature range of 15-35℃. The activated sludge was shown to be an effective adsorbent for C14BDMA.
文摘Quaternary ammonium compound are a class of broad-spectrum,high-efficiency and low-toxicity bactericide,which are widely used in daily life and industrial sterilization.Herein,the current state of domestic quaternary ammonium disinfectant products was summarized,as well as those new products developed and studied,and the development trend was also predicted.
基金Supported by the National Natural Science Foundation of China（No.50673101）, the Scientific Foundation of Guangdong Province of China（Nos.0711020600015, 2004A30404001）, the Natural Science Foundation of Guangxi Zhuang Autonomous Region of China（Nos.2013GXNSFBA019040, 2013GXNSFBA019036）, the Projcet of Department of Education of Guangxi Zhuang Autonomous Region, China（No.2013YB171） and the Foundation of Guangxi University of Science and Technology, China.
文摘Copolymers of quaternary ammonium monomer（QAM） and hydrophilic co-monomer were successfully synthesized by free radical polymerization. It was discovered that the hydrophilic co-monomers with poor antibac- terial activity significantly enhanced the activity of QAM substituted with a long alkyl chain[i.e., N,N-dimethyl-N-dodecyl methacrylate ammonium bromide（DMAEMA-DB）]. When a suitable molar ratio of DMAEMA-DB to co-monomer was selected, the activity of the copolymers was up to 123 times that of the homopolymer of DMAEMA-DB against S. aureus, and 282 times that of it against E. colt. But unlike DMAEMA-DB, the co-monomers might weaken the activity of QAM substituted with a short alkyl chain[i.e., N,N-dimethyl-N-butyl methacrylate ammonium bromide（DMAEMA-BB）]. Moreover, it was found that copolymers of DMAEMA-DB were much more biocidal than those of DMAEMA-BB. Therefore, it could be speculated that the long alkyl chain plays an important role in the antibacterial activity, and that the hydrophilie co-monomers are beneficial to polymeric guaternary ammonium compounds（PQACs） to exert the positive effect of the long alkyl chain to the greatest degree.
基金supported by the National Natural Science Foundation of China(No.20972120)Doctor Fund of Henan University of Technology(No.150392)
文摘A series of bis-quaternary ammonium compounds（bis-QACs） N,N＇-hevamethylenebis（1-alkyl-4-carbamoyl pyridinium bromide）（4BCAP-6,n）（alkyl chain length,n=8,10,12,14,16 and 18） were synthesized and characterized.Their surface tensions,critical micelle concentrations（CMC）,and antimicrobial activities were evaluated.4BCAP-6,10 exhibited the strongest antimicrobial activities except for that against Proteus vulgari.The activities of 4BCAP-6.n against Escherichia coli zk126 were not significantly influenced by temperature.pH and initial bacteria concentration.These results indicate that bis-QACs exhibit high antimicrobial activity regardless of the environmental conditions.
