溶胶-凝胶法合成ZnO纳米材料及其抗菌性能研究

采用溶胶-凝胶法制备氧化锌纳米材料并考察了其抗菌性能.研究发现,通过调控醋酸锌-无水乙醇-氢氧化钠反应体系的反应温度、反应时间、反应物浓度以及反应体系中的水含量可以控制纳米ZnO的粒径分布;以金黄色葡萄球菌和大肠杆菌作为革兰氏阳性菌和革兰氏阴性菌的代表,用抑菌圈法考察了材料的抗菌性能,结果表明,溶胶-凝胶法合成的ZnO纳米材料抑菌效果明显优于相应的水热法产物和市售产品,且与其粒径分布密切相关;在实验条件下,ZnO材料对大肠杆菌和金黄色葡萄球菌的抑制性能随ZnO纳米材料的粒径增大在5nm左右出现一个极值,材料的粒径小于或大于5nm,其抗菌效果均变差.     

季铵盐壳聚糖抗菌纸的性能研究

以季铵盐壳聚糖为抗菌剂处理普通成纸,制备了包装用抗菌纸。采用抑菌圈法评价了该抗菌纸对大肠杆菌和金黄色葡萄球菌的抑制效果,研究了季铵盐壳聚糖的浓度对抗菌纸厚度、抗张强度、耐破度和抑菌性能的影响。结果表明,抗菌纸的抗张强度及耐破度均较原纸有所增加,厚度没有明显变化,能满足包装需求,且具有良好的抗菌性能,其抗菌效果随季铵盐壳聚糖浓度的增加而增强,并且相同季铵盐壳聚糖浓度下的抗菌纸对金黄色葡萄球菌的抑菌效果要好于大肠杆菌。     

聚乳酸/茶多酚复合纳米纤维膜抗菌机理

将茶多酚(TP)与聚乳酸(PLA)共混,采用静电纺丝方法制备PLA/TP复合纳米纤维膜。通过红外光谱(FT-IR)测试、抑菌圈法及流式细胞仪(FACS)对复合纳米纤维膜的成分、抗菌性能及抗菌机理进行研究。FT-IR测试结果验证了PLA/TP复合纳米纤维膜中通过价键的结合使两者复合在一起。抗菌测试结果显示:随着TP含量增加,复合纳米膜抗菌性能提高。对大肠杆菌和金黄色葡萄球菌的抑菌圈宽度分别从3.67cm和3.71cm增加到5.17cm和5.67cm。FACS结果表明:PLA/TP复合纳米纤维膜对比纯PLA纳米纤维膜对大肠杆菌和金黄色葡萄球菌的PI染色率明显增加,分别从0.78%和1.45%增加到6.47%和9.26%,揭示了PLA/TP复合纳米纤维膜能够破坏菌体细胞膜的完整性,最终导致其死亡。     

纳米ZnO/PVC保鲜膜抑菌性能及应用研究

研究了钠米ZnO/PVC膜对大肠杆菌和金黄色葡萄球菌的体外抑菌作用及对苹果切片防腐保鲜效果,以及纳米ZnO含量、溶液pH值、培养条件(无光和光照)等对纳米膜抑菌能力的影响。结果表明:添加纳米ZnO/PVC膜的菌悬液,光照振荡培养4h,大肠杆菌菌落总数减少大半;纳米膜中ZnO粒子含量越高,抑菌效果越好,且该膜对金黄色葡萄球菌的抑制作用高于大肠杆菌;纳米ZnO/PVC膜在不同酸碱度环境中抑菌性能稳定;纳米ZnO/PVC包装可以延缓苹果切片的褐变、腐烂,保持生理品质,常温贮藏3d,果实总酚含量高于对照组。     

TiO_2/ZnO粒子的制备及其抗菌性能

采用溶胶凝胶法制备了TiO2/ZnO复合粒子,通过XRD、SEM对所制备粉体颗粒的物相组成以及表面形貌进行表征,通过最小抑菌浓度法(MIC)研究了不同掺杂量的TiO2/ZnO复合粒子的抗菌性能。结果表明,掺杂TiO2的ZnO粒子显示优良的抗菌活性,对金黄色葡萄球菌(Staphylococcusaureus)的MIC≤62.5μg·mL-1。当TiO2的掺入量为20%,所得到的ZnO粒子的抗菌性能最佳,对绿脓杆菌、大肠杆菌、枯草芽孢杆菌、金黄色葡萄球菌四种菌的抑菌性能均有显著提高,并对其机理做了初步探讨。     

形貌和光照条件对ZnO抗菌性能的影响

检测了四针状氧化锌晶须、纳米氧化锌和普通工业级氧化锌的抗菌性能,比较了形貌和光照条件对ZnO抗菌性能的影响,并研究了ZnO对不同菌种的抗菌性能差异.结果表明,Zno形貌对其抗菌性能有较大影响,有光条件下ZnO抗菌性能大于无光条件下,3种ZnO对大肠杆菌的抗菌性能均比对金黄色葡萄球菌好.     

简单醇热法制备ZnO纳米棒及其抗菌性能研究

通过Zn(NO3)2.6H2O和NaOH的醇溶液制备ZnO,利用XRD和TEM对产物进行表征,产物为具有较高的结晶度和纯度的ZnO纳米棒,直径约为30nm,长度约为130～500nm。取市售ZnO和产物,采用抑菌圈法对3种常见致病菌作药物敏感试验,并测定了产物对金黄色葡萄球菌的最小杀菌浓度(MBC)。结果表明,产物与市售ZnO试剂均对大肠杆菌不敏感,对金黄色葡萄球菌和白色念珠菌有不同程度的敏感,且产物比市售试剂抑菌效果更为明显,产物对金黄色葡萄球菌的最小杀菌浓度(MBC)为1.5%。     

稀土铈掺杂纳米ZnO抗菌复合材料研究

采用纳米ZnO为载体,按照不同掺杂比例制备了复合无机抗菌剂 Ce4 /ZnO,采用抑菌圈实验和最小抑菌浓度实验来检测其抗菌性能。结果表明,掺杂稀土Ce4 明显提高了纳米 ZnO的抗菌性。通过对ZnO白样和Ce4 /ZnO试样的XRD测试, 结果表明 Ce4 已进入 ZnO晶格,同时对复合抗菌机理进行了探索研究。     

载银纳米纤维素/聚乙烯醇复合膜的制备及性能研究

目的制备一种具有良好力学性能和抑菌性能的新型抗菌聚乙烯醇复合膜。方法通过酸水解微晶纤维素制备纳米纤维素,经高碘酸钠氧化获得醛基纳米纤维素,加入银氨溶液原位合成载银纳米纤维素(Ag-DCNC)。以聚乙烯醇(PVA)为成膜基底,加入Ag-DCNC共混流延制备载银纳米纤维素/聚乙烯醇复合膜。结果 Ag-DCNC体积分数为3%时,复合膜的拉伸强度比纯PVA膜提高了8.8%。Ag-DCNC体积分数为5%的复合膜对大肠杆菌和金黄色葡萄球菌均具有较好的抑菌效果。结论载银纳米纤维素/聚乙烯醇复合膜具有较好的力学强度,对2种细菌均有良好的杀菌效果。该材料不但具有良好的性能,而且合成工艺简单,可以作为一种很有前途的抑菌膜用于包装行业。     

用电沉积法制备纳米氧化锌/海藻酸钠复合膜

以海藻酸钠为稳定剂用水热法合成纳米氧化锌,再用电沉积法制备了纳米氧化锌/海藻酸钠复合膜。测试纳米氧化锌的粒径和化学结构、观察了复合膜的形貌并测试其性能。结果表明,纳米氧化锌/海藻酸钠复合膜对大肠杆菌和金黄色葡萄球菌有良好的抗菌性能,对亚甲基蓝染料有良好的光催化降解效应。     

均匀沉淀法制备纳米氧化锌的研究

以硝酸锌、尿素为原料, 采用均匀沉淀法制备纳米氧化锌粉末. 以TEM和BET等方法对产物进行了表征, 发现可获得50nm左右的纳米氧化锌, 粒子 的比表面积为25.6m²/g; XRD分析表明, 产物为六方晶系; 通过XRD、IR和TG-DSC分析, 确定了纳米氧化锌的形成机理.     

Effect of doping on structural and optical properties of ZnO nanoparticles: study of antibacterial properties

Sol-gel method was successfully used for synthesis of ZnO nanoparticles doped with 10 % Mg or Cu. The structure, morphology and optical properties of the prepared nanoparticles were studied as a function of doping content. The synthesized ZnO:(Mg/Cu) samples were characterized using XRD, TEM, FTIR and UV-Vis spectroscopy techniques. The samples show hexagonal wurtzite structure, and the phase segregation takes place for Cu doping. Optical studies revealed that Mg doping increases the energy band gap while Cu incorporation results in decrease of the band gap. The antibacterial activities of the nanoparticles were tested against Escherichia coli (Gram negative bacteria) cultures. It was found that both pure and doped ZnO nanosuspensions show good antibacterial activity which increases with copper doping, and slightly decreases with adding Mg.     

乙酸乙酯改性纳米氧化锌的制备及表征

利用乙酸乙酯作为改性剂,通过气相法对纳米氧化锌进行改性研究,用亲油化度考察改性效果;优化其改性工艺为:改性时间2h,改性温度120℃,改性剂的添加量为3.25%。通过透射电镜、激光粒度仪、接触角和沉降实验表明,改性后的纳米氧化锌颗粒均匀、团聚明显减弱、疏水性和分散性明显提高。     

几种纳米水性涂料的抗菌及抗病毒作用研究

为了观察几种纳米建筑涂料抗菌及抗副流感病毒的效果,将一定浓度的菌液或副流感病毒液与纳米材料作用一定时间,分别通过菌落计数及血凝试验检测菌量及病毒量的变化,并计算抑菌率和病毒吸附率、灭活率。结果表明,在几种纳米涂料中,以ZB-08-12的抗菌效果最好,其对金黄色葡萄球菌、大肠埃希菌、铜绿假单胞菌、枯草芽胞杆菌及白色念珠菌的抑制率分别为82.20%、87.86%、53.06%、63.20%、88.76%,对副流感病毒的平均吸附率及灭活率分别为87.50%、99.60%。     

Multifunctional ZnO/Nylon 6 nanofiber mats by an electrospinning–electrospraying hybrid process for use in protective applications

Abstract

ZnO/Nylon 6 nanofiber mats were prepared by an electrospinning–electrospraying hybrid process in which ZnO nanoparticles were dispersed on the surface of Nylon 6 nanofibers without becoming completely embedded. The prepared ZnO/Nylon 6 nanofiber mats were evaluated for their abilities to kill bacteria or inhibit their growth and to catalytically detoxify chemicals. Results showed that these ZnO/Nylon 6 nanofiber mats had excellent antibacterial efficiency (99.99%) against both the Gram-negative Escherichia coli and Gram-positive Bacillus cereus bacteria. In addition, they exhibited good detoxifying efficiency (95%) against paraoxon, a simulant of highly toxic chemicals. ZnO/Nylon 6 nanofiber mats were also deposited onto nylon/cotton woven fabrics and the nanofiber mats did not significantly affect the moisture vapor transmission rates and air permeability values of the fabrics. Therefore, ZnO/Nylon 6 nanofiber mats prepared by the electrospinning–electrospraying hybrid process are promising material candidates for protective applications.     

Multifunctional ZnO/Nylon 6 nanofiber mats by an electrospinning–electrospraying hybrid process for use in protective applications

ZnO/Nylon 6 nanofiber mats were prepared by an electrospinning–electrospraying hybrid process in which ZnO nanoparticles were dispersed on the surface of Nylon 6 nanofibers without becoming completely embedded. The prepared ZnO/Nylon 6 nanofiber mats were evaluated for their abilities to kill bacteria or inhibit their growth and to catalytically detoxify chemicals. Results showed that these ZnO/Nylon 6 nanofiber mats had excellent antibacterial efficiency (99.99%) against both the Gram-negative Escherichia coli and Gram-positive Bacillus cereus bacteria. In addition, they exhibited good detoxifying efficiency (95%) against paraoxon, a simulant of highly toxic chemicals. ZnO/Nylon 6 nanofiber mats were also deposited onto nylon/cotton woven fabrics and the nanofiber mats did not significantly affect the moisture vapor transmission rates and air permeability values of the fabrics. Therefore, ZnO/Nylon 6 nanofiber mats prepared by the electrospinning–electrospraying hybrid process are promising material candidates for protective applications.     

纳米材料在食品包装中的应用研究进展

介绍了纳米材料在食品包装中的应用,指出了与传统的食品包装材料相比,纳米材料在保鲜效果、抗菌能力以及阻隔性能方面更加优越,应用前景广阔。     

用于合成纳米苯丙乳液的纳米TiO2表面改性及表征

研究了利用硅烷偶联剂改性纳米TiO2的方法,并通过FTIR、TEM等手段表征化学改性产物的结构和改性后纳米二氧化钛的分散性,结果表明偶联剂与二氧化钛表面发生化学偶联反应,使二氧化钛表面被偶联剂包覆,从而使二氧化钛改性产物在有机物中具有良好的分散性能.通过TEM分析用改性后的纳米TiO2原位合成的纳米TiO2/苯丙乳液复合体系具有以纳米TiO2粒子为核,以聚合物为壳的核壳结构,该乳液涂膜的耐水性达120h不泛白,硬度为H级,明显优于非纳米苯丙乳液,且具有很好的抑菌作用,可用于制备纳米水性涂料.     

In vitro antibacterial activity of ceftazidime,unlike ciprofloxacin,improves in the presence of ZnO nanofluids under acidic conditions

The development of antibiotic resistance among hospital pathogens has provided a great need for new antimicrobial agents. Zinc oxide nanoparticles (ZnO NPs) in combination with various antibiotics can act as a reducing agent for antibiotic resistance. The aim of this study was to investigate the influence and the mechanism of ZnO NPs on the antimicrobial activity of ciprofloxacin (CP) and ceftazidime (CAZ) against Enterococcus faecalis (E. faecalis) and Acinetobacter baumannii (A. baumannii) bacteria in acidic conditions (pH 5.5). ZnO NPs were synthesised using the solvothermal method and characterised. The MIC90 value of ZnO NPs against A. baumannii was 0.25 mg ml⁻¹ and its highest growth‐inhibitory activity was observed at 0.125 mg ml⁻¹ for E. faecalis. The Fourier transform infrared spectroscopy spectra of ZnO NPs treated with antibiotics showed the interaction between ZnO NPs and each of the two antibiotics. ZnO NPs at a sub‐inhibitory concentration had no effect on the antibacterial activity of CP and CAZ against E. faecalis and CP against A. baumannii. The action mechanism of ZnO NPs for enhancing the antibacterial efficacy of CAZ against A. baumannii was evaluated. ZnO NPs caused to increase in the antibacterial activity of CAZ against A. baumannii, possibly through the release of Zn²⁺ and increasing of membrane permeability.Inspec keywords: nanofluidics, antibacterial activity, drugs, nanoparticles, nanomedicine, microorganisms, pH, zinc compounds, II‐VI semiconductors, wide band gap semiconductors, semiconductor growth, X‐ray diffraction, light scattering, scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectra, ultraviolet spectra, visible spectra, DNA, molecular biophysics, biochemistry, atomic absorption spectroscopy, membranes, permeability, nanofabricationOther keywords: in vitro antibacterial activity, ceftazidime, nanofluids, acidic conditions, antibiotic resistance, hospital pathogens, antimicrobial agents, zinc oxide nanoparticles, reducing agent, antimicrobial activity, ciprofloxacin, Enterococcus faecalis bacteria, Acinetobacter baumannii bacteria, pH, solvothermal method, X‐ray diffraction, dynamic light scattering, ultraviolet‐visible spectrum, scanning electron microscopy, transmission electron microscopy, MIC90 value, growth‐inhibitory activity, Fourier transform infrared spectroscopy, subinhibitory concentration, reactive oxygen species measurement, DNA fragmentation, atomic absorption spectroscopy, SEM, membrane permeability, glycerol‐ammonium citrate. mixture, ZnO