Thermal stability and long-acting antibacterial activity of phosphonium montmorillonites

Na-montruorillonite (Na-MMT) was exchanged with three quaternary alkylphosphonium salts:decyl tributylphosphonium bromide (DTBPBr), dodecyl tributylphosphonium bromide (DDTBPBr) and hexadecyl tributylphosphonium bromide (HDTBPBr), to investigate the effects of phosphonium salts species and relative molecular mass on the characteristics, morphology, thermal stability and long-acting antibacterial property of phosphonium montmorillonites. The resulting modified montmorillonites were characterized by the FTIR, XRD, TEM, and TG/DTG techniques. And minimum inhibitory concentration (MIC) was used to investigate antibacterial activity. The results show that the phosphonium salts are intercalated into Na-MMT, and the basal spacing of P-MMTs is enlarged with the increase of phosphonium salt content or the growth of alkyl chain length. DDTBP-MMT-3 with 19.83% (mass fraction) of dodecyl tributylphosphonium salts, displays excellent thermal stability and long-acting antibacterial activity.     

Structure and antibacterial activity of new layered perovskite compounds

New layered perovskite compounds, AgxNa（2-x）La2Ti3O10（x=0.2, 0.3 and 0.5） were synthesized by an ion-exchange reaction of Na2La2Ti3O10 with AgNO3 solution and characterized by energy dispersive X-ray analysis（EDX）, X-ray diffractometly（XRD）, scanning electron microscopy（SEM） and X-ray photoelectron spectroscopy（XPS）. The ion-exchange processes were optimized, and the antibacterial activity, light permanency and water-resistance were evaluated. Surprisedly, no significant changes in crystal structure of Na2La2Ti3O10 are found by the exchange of silver ions. The Ago.3Na1.7La2Ti3O10 particles conglomerate obviously with irregular shape and size. Ago.3Na1.7La2Ti3O10, possessing the minimum inhibitory concentrations（MICs） against Escherichia coli （E. coli）, Staphylococcus aureus （S. aureus） of 180 mg/L and 240 mg/L, has high antibacterial activity, good light permanency and water-resistance. The ionic state silver in AgxNa（2-x）La2Ti3O10 is the antibacterial active component.     

有机-无机复合抗菌剂的制备及抗菌性能

依次将无机抗菌离子(锌离子)和有机抗菌离子(十四烷基三丁基季鏻盐)插入到蒙脱土中制备出有机-无机复合抗菌剂,其中锌和季鏻盐的含量分别为2.60%(质量分数)和22.31%(质量分数)。热重(TG)、X-射线衍射(XRD)分析结果表明,锌离子和季鏻盐确实交换到蒙脱土中,并且复合抗菌剂中有机物的热分解起始温度为220℃左右,具有较好的热稳定性。抗菌试验的结果表明,复合抗菌剂具有较好的抗菌性能,对S.aereus和E.coli的最小抑菌浓度(MIC)分别为100μg.mL-1和300μg.mL-1。将100mg复合抗菌剂在100mL蒸馏水中浸20d后,季鏻盐阳离子和Zn2 的释放量均很小,分别为4.831mg.L-1和1.896mg.L-1,表明复合抗菌剂具有良好的耐水性。     

季铵盐改性蒙脱土的制备与表征

采用离子交换法将不同的季铵盐交换到蒙脱土的层间得到改性蒙脱土。以十二烷基二甲基苄基氯(1227)为例,研究了季铵盐离子交换反应的最佳反应条件为:当温度为60℃,时间为6h,1227/CEC的摩尔比为1.5∶1.0时,1227的交换率为82.65%。在相同的条件下,其它的单季铵盐的交换率也均大于80%。其中1431的交换率达到99.75%。热重分析(TG)、X-射线衍射(XRD)、红外光谱(FT-IR)的结果表明季铵盐已经插入蒙脱土的层间,且季铵盐的热稳定性明显提高。     

膨胀型阻燃剂/有机蒙脱土/聚丙烯复合材料的制备及性能研究

采用9,10-二氢-9-氧杂-10-氧化物(DOPO)为原料制备了膨胀型阻燃剂6H-二苯并[C,E][1,2]氧代磷酸甘油酯-6-丙酸,α-甲基-,甲酯,6-氧化物(DOPPMO),采用熔融插层法将有机阳离子插层进蒙脱土中制备了有机蒙脱土(OMMT),再将DOPPMO和OMMT与聚丙烯共混制备了复合阻燃材料。通过XRD、TEM和SEM表征了复合阻燃材料的微观结构;通过极限氧指数、垂直燃烧和热失重分析方法研究了复合阻燃材料的阻燃性能;通过拉伸和冲击实验研究了复合材料的力学性能。结果显示DOPPMO与OMMT表现出良好的协同阻燃效应,且添加阻燃材料的聚丙烯力学性能基本保持不变。     

聚丙烯纤维与4-乙烯基吡啶辐射接枝研究

采用~(60)Coν射线共辐照接枝法,研究了聚丙烯(PP)纤维与4-乙烯基吡啶(4-VP)在甲醇中的接枝共聚反应。讨论了剂量率、辐照时间、单体浓度、阻聚剂以及无机酸对接枝反应的影响。实验获得的接枝共聚物,其亲水性和染色性有明显的改善。