【摘要】 背景:课题组已经对季铵盐蒙脱土抗菌剂进行了系统的研究,但具有耐热性不足的缺点。季鏻盐是新一代高效、广谱、低毒杀菌剂,与对应的结构相似的季铵盐比较,季鏻盐的热稳定性更好。目的:观察新型有机蒙脱土抗菌剂结构、表面性能和抗菌活性。设计、时间及地点:体外观察实验,于2008-09/12在暨南大学化学系科研实验室完成。材料:将十二烷基三甲基季鏻阳离子插入蒙脱土层间制备新型有机蒙脱土抗菌剂。方法:反应体系中按季鏻阳离子与钠基蒙脱土的阳离子交换容量的摩尔比分别为0.5︰1,1︰1和1.5︰1加料,采用离子交换法制备了3种不同季鏻阳离子含量的有机蒙脱土抗菌剂。主要观察指标:分别通过热分析仪,X射线衍射仪,zeta电位仪,比表面积和孔隙度分析仪测定样品的季鏻阳离子含量和热稳定性、层间距的变化、zeta电位、比表面积。采用二倍稀释法测定样品对大肠杆菌和金黄色葡萄球菌的最低抑菌浓度。结果:有机蒙脱土抗菌剂中季鏻阳离子的热分解起始温度都大于300℃,具有良好的热稳定性。而且随着季鏻阳离子含量的增加,有机蒙脱土抗菌剂的层间距增大,zeta电位越正,比表面积越低,抗菌活性越好,但是当季鏻阳离子的添加量超过其阳离子交换容量时,对应有机蒙脱土抗菌剂中的季鏻阳离子含量增加不大。因此实验中季鏻阳离子与钠基蒙脱土的阳离子交换容量的合适摩尔比为1︰1,对应的有机蒙脱土抗菌剂中的季鏻阳离子含量为21.93%,zeta电位为-19.75mV,比表面积为47.36m2/g,对大肠杆菌和金黄色葡萄球菌的最低抑菌浓度分别为250和120mg/L。结论:季鏻阳离子含量为21.93%的有机蒙脱土抗菌剂的热稳定性好、抗菌活性高。更多还原

【Abstract】 BACKGROUND:Ammonium montmorillonite antibacterial agents have been systemically investigated now,but the applications in engineering plastics are limited owing to the low heat resistance. Quaternary phosphonium salts that are high-effective,broad-spectrum and low-toxic bactericidal agents have great heat resistance compared to quaternary ammonium salts. OBJECTIVE:To explore the structure,surface properties and antibacterial activity of organo-montmorillonite antibacterial agents. DESIGN,TIME AND SETTING:An in vitro observational experiment was performed at Research Laboratory of Department of Chemistry,Jinan University from September to December 2008. MATERIALS:Organo-montmorillonite antibacterial agents were prepared by introducing trimethyldodecyl phosphonium cations into montmorillonite. METHODS:The mol ratios of quaternary phosphonium cations to cation exchange capacity of sodium montmorillonite in reaction solutions were 0.5:1,1:1 and 1.5:1,respectively,and three kinds of organo-montmorillonite antibacterial agents containing different contents of trimethyldodecyl phosphonium cations were prepared through an ion-exchange method. MAIN OUTCOME MEASURES:The content of quaternary phosphonium cations and heat resistance,the change of interlayer spacing,the zeta potential and the special surface area of samples were measured by using a thermal analyzer,a X-ray diffractometer,a zeta potential analyzer,a specific surface area and porosimetry analyzer,respectively. The minimum inhibitory concentration(MIC) of the samples against Escherichia coli(E. coli) and Staphylococci aureus(S. aureus) was estimated by a two-fold diluting method. RESULTS:The onset temperatures of the decomposition for quaternary phosphonium cations in organo-montmorillonite antibacterial agents were all higher than 300 ℃,and they were preferable thermal stability. The interlayer spacing became broader,the zeta potential was more positive,the surface area was lower,and the antibacterial activity was higher when the content of quaternary phosphonium cations increased in organo-montmorillonite antibacterial agents. For the organo-montmorillonite antibacterial agents containing 21.93 wt% of quaternary phosphonium cations,the zeta potential was-19.75 mV,the specific surface area was 47.36 m2/g,and the MIC values against E. coli and S. aureus were 250 and 120 mg/L,respectively. CONCLUSION:The organo-montmorillonite antibacterial agents containing 21.93 wt% of quaternary phosphonium cations possesses good heat resistance and high antibacterial activity.更多还原