工艺参数对合成ZnO／Ag纳米复合抗菌剂产率的影响

通过正交实验，研究了反应温度、反应时间、反应物配比对ZnO／Ag纳米复合抗菌剂合成产率的影响规律。获得了高产率合成ZnO／Ag纳米复合抗菌剂的优选工艺条件：反应温度为10～25℃，ZnSO4与NH4HCO3的摩尔比为1：2-2．5，ZnSO4与NH4HCO3的反应时间为2．5～3h，AgNO3与NH4HCO3的摩尔比为1：1．5～2，反应时间为0．5h，ZnO／Ag的产率超过98％。XRD、TEM和SAED结果表明：ZnO／Ag纳米复合抗菌剂为具有纤锌矿结构的ZnO和立方结构的Ag组成。粒径为15～25nm，分散性较好。     

纳米沸石载Ag、Zn复合抗菌剂的分散性

对抗菌离子-纳米沸石为载体的复合抗菌剂进行了较系统的探讨。采用不同的工艺条件、不同的分散方法,使用透射电子显微镜对分散情况进行表征。实验表明,分散剂浓度、分散方法、分散剂种类都是影响纳米复合抗菌材料分散效果的重要因素,为纳米复合抗菌材料的研究和应用提供了可供参考的资料。     

脉冲电化学沉积法制备钛基HA/Ag复合涂层

采用脉冲电化学法在生物医用钛表面制备出纳米HA/Ag复合涂层。借助SEM、XRD等对复合涂层的形貌、成分进行表征。利用大肠杆菌和白色葡萄球菌两个菌种对该涂层抗菌性能进行分析研究。最后利用MC3T3-E1成骨细胞检测复合涂层的细胞相容性。结果表明：HA/Ag复合涂层呈纳米球状,由HA和Ag两相组成。Ag在HA涂层中分布均匀。复合涂层对两种细菌均有较好的抗菌效果,对大肠杆菌抗菌率达100%,对白色葡萄球菌的抗菌率接近100%,对大肠杆菌的抗菌能力高于白色葡萄球菌。细胞培养实验表明MC3T3-E1成骨细胞在HA/Ag复合涂层表面的黏附、铺展较好。综合可知,脉冲电化学沉积法制备的纳米HA/Ag复合涂层具有较好的抗菌性和细胞相容性     

壳聚糖改性及抗菌胶乳制备

采用氧化解聚法制备改性壳聚糖,并进行纳米化处理,得到纳米改性壳聚糖,将其作为抗菌剂,以天然胶乳为基材,采用共混法制得具有抗菌性能的医用抗菌胶乳。经扫描和透射电镜分析可知:壳聚糖微粒均匀分布在胶乳中,呈圆球状,粒径约为10nm,改性壳聚糖微粒均匀分散在胶乳中;以大肠杆菌作为试验菌,采用抑菌环试验对制得的抗菌胶乳进行抗菌性能的检测,结果表明:抑菌环直径大于抑菌标准规定的7 mm,表明该抗菌胶乳对大肠杆菌的抑菌效果良好。     

分散剂对陶瓷釉料中纳米氧化锌分散性的影响

采用沉降实验、粒度分析等手段对含纳米ZnO的水溶液、釉料和陶瓷成品进行了表征.研究了纳米Zno在水和釉料中的分散行为、纳米ZnO对陶瓷成品性能的影响.结果表明,纳米ZnO在水中最佳分散条件为0.8%(质量分数,下同)混合表面活性剂、2.0%纳米ZnO、pH 9;纳米znO在釉料中最佳分散条件为0.8%混合表面活性剂、4.0%纳米ZnO、pH9.陶瓷成品光泽度提高7.14%,烧成温度降低约15℃.     

氧化锌纳米棒的水热法制备和抑菌性能的研究（英文）

采用水热法制备了ZnO纳米棒。采用琼脂稀释法研究商业纳米ZnO颗粒和水热法制备纳米ZnO棒对大肠杆菌抑菌作用的差异性。利用透射电镜、X射线衍射仪、比表面积测试仪、对大肠杆菌最小抑菌浓度进行表征。结果表明:ZnO纳米棒的粒径(约96 nm)比商业颗粒纳米ZnO(约185 nm)要小的多,ZnO纳米棒衍射峰宽值相对于商业ZnO纳米颗粒的要更宽,晶粒度更小(根据谢乐公式ZnO为98.203l nm,商业ZnO为189.3206,nm);.ZnO纳米棒(5.4759 m~2/m)的比表面积比商业ZnO纳米颗粒(3.6081 m~2/g)的更大,依据抗菌性原理,这两种指标皆表明ZnO纳米棒的抗菌性能相对较好,在最小抑菌浓度试验中,商业氧化锌纳米颗粒和水热法制备氧化锌纳米棒的最小抑菌浓度分别为0.22%和0.12%;ZnO纳米棒对大肠杆菌的抑制作用高于商业ZnO纳米颗粒对其的抑制作用。     

不同方法制备Ag/ZnO电接触材料研究（英文）

制备Ag/ZnO复合粉体作为增强相的4种方法分别为固相法、共沉淀法、银镜反应以及水热反应法。综合对比其相关性能,确立共沉淀方法为制备Ag/ZnO复合粉体的最佳方法。并对Ag同ZnO的复合比例进行研究。结果表明,当ZnO:Ag=1:0.1时,最终制备的粉体具有最优性能。通过机械合金化方法(PM)制备了Ag/ZnO电接触材料。通过XRD,扫描电子显微镜以及其他相关检测手段对2种不同的AgZnO电接触材料的机械以及电学性能进行表征。结果显示ZnO在2种不同的AgZnO电接触材料中,均呈现为ZnO增强相,均匀的分布在Ag基体中。其中采用共沉淀方法制备的AgZnO电接触材料具有较好的静态电学性能。     

Ag离子注入不锈钢分布状态与抗菌性能研究

抗菌性能的发挥取决与材料表面抗菌相的分布,采用MEVVA源高能离子注入机对A304不锈钢进行不同剂量Ag的注入,利用SEM、EDX对材料表面形貌和成分进行分析和通过后期的热处理和抗菌实验发现:样品对大肠杆菌、金霉球菌的抗菌效果达到96.6%和97.1%;过饱和注入的Ag出现Ag的团聚现象,不利于抗菌效果的发挥;非饱和往复注入通过热处理后出现含Ag弥散相。Ag的充分析出是材料发挥抗菌性能的所在,而饱和注入的不锈钢则出现大量银的团聚现象。     

纳米碳酸钙表面特性对PS/纳米CaCO3体系的影响

研究了偶联剂NDZ-101对纳米碳酸钙团聚体性能的影响.采用熔体剪切分散法制备了聚苯乙烯基纳米碳酸钙复合材料,利用粒度分析仪观察并分析了纳米碳酸钙团聚体的特征(包括团聚强度和内摩擦系数)对其在复合材料中分散程度的影响,并进一步研究了纳米碳酸钙表面性能对聚苯乙烯基纳米碳酸钙复合材料性能的影响.结果表明经1%(质量分数,下同)左右的NDZ-101处理的纳米碳酸钙在聚苯乙烯基体中的分散粒径最小,其特征粒径达196 nm.聚苯乙烯基纳米碳酸钙复合材料的玻璃化转变温度、熔体粘度和储能模量等性能都随偶联剂NDZ-101的增加呈先升后降的趋势.     

负载纳米CeO2的多孔银的制备、表征及SERS研究

采用NaOH溶液腐蚀Ag/CeO2/ZnO前驱体,制备出含有纳米CeO2微粒的多孔银复合材料。随着ZnO组元被溶解,CeO2微粒均匀分散到纳米多孔银的内表面。形貌表征表明,通过调节前驱体中ZnO的含量可细化纳米多孔AgCeO2复合材料的微观结构,当ZnO加入摩尔分数为70%时,CeO2微粒尺寸为6 nm。表面拉曼增强效应(SERS)测试表明,CeO2纳米微粒的形成和分散显著增强了多孔银的SERS性能;该复合材料在可见光条件下能够降解罗丹明(R6G)并有较好的自清洁性。     

Photocatalytic and Antibacterial Activities of Ag/ZnO Nanocomposities Fabricated by Co-Precipitation Method

A Ag/ZnO nanocomposite has been synthesized and characterized for investigating its photocatalytic activity.The morphology and particle size of the Ag/ZnO was studied by scanning electron microscope(SEM) and the microstructure of the as-synthesized nanocomposite was confirmed by X-ray diffraction(XRD) analysis.The elemental composition of the metal oxide was determined by energy dispersion spectrometry(EDS).Diffuse reflectance spectra(DRS),Photoluminescence(PL) spectra,and Fourier transform infrared spectroscopy(FTIR) were also studied for characterizing the nanocomposite.The average particle size was found to be around 20–30 nm.Photocatalytic activity of Ag/ZnO has been investigated over methyl violet(6B) dye under UV and visible light irradiation.The degradation of methyl violet(6B)dye using ZnO and Ag/ZnO was compared and found that Ag/ZnO composite is more efficient than ZnO.The rate of disappearance of dye was monitored spectrophotometrically in the maximum visible absorption wavelength and the extent of degradation was discussed in terms of Langmuir–Hinshelwood model.The Ag/ZnO composite was found capable of degrading the industrial dye effluent.Effect of H2O2addition on dye degradation by the Ag/ZnO was investigated and Ag/ZnO was found to be an effective antimicrobial agent.Reusability of Ag/ZnO catalyst was also tested.     

Enhancement of Photocatalytic and Antibacterial Activities of ZnO:Ag Nanopowders Through the Addition of Bamboo Charcoal:An Efficient Natural Adsorbent

This research article explains the removal of methylene blue(MB)and malachite green(MG)from aqueous solution using adsorption/photodegradation activity of Zn O:Ag/bamboo charcoal(BC)nanocomposite.In addition,the antibacterial studies of the prepared samples were tested against Staphylococcus aureus(S.aureus)Gram-positive and Escherichia coli(E.coli)Gram-negative bacteria by the well diffusion method.The Zn O:Ag/BC nanocomposite exhibits superior photocatalytic activity compared with Zn O:Ag.Remarkable degradation efficiencies of 93.95%(MB)and 95.75%(MG)were recorded for Zn O:Ag/BC nanocomposite after 45 min.The degradation process follows a pseudo-first-order kinetics.The rate constant of Zn O:Ag/BC nanocomposite is two times greater than that of pristine Zn O nanopowder for the degradation of MB dye,while for MG dye degradation,it is three times.It is found that the Zn O:Ag/BC nanocomposite shows a higher rate of dye removal due to excellent adsorbing properties of bamboo charcoal(BC).The Zn O:Ag/BC nanocomposite showed better antibacterial properties compared to Zn O:Ag.In this study,the samples were prepared using a simple and low-cost soft chemical route and they were characterized by optical,structural,surface morphological,antibacterial and photocatalytic properties.These characterization studies substantiate the discussions on the photocatalytic and antibacterial activities of the synthesized samples.     

Enhancing the Antibacterial Efficiency of ZnO Nanopowders Synthesized by Combustion Method Through Ag + Fe Co-doping

(Ag + Fe)-doped ZnO nanopowders have been synthesized using combustion method. Ag doping level was kept as 2 at.%, and Fe doping level was varied from 3 to 6 at.%, and the structural, optical, surface morphological, and antibacterial properties have been investigated. The structural studies show that ZnO/(Ag + Fe) nanopowders have hexagonal wurtzite structure with a preferential orientation along the (101) plane. The FE-SEM images indicate that there is a gradual decrease in the grain size with the increase in the doping level of Fe, and the TEM images are correlated well with FE-SEM images. The XPS profile clearly confirms the presence of expected elemental composition. Photoluminescence studies reveal the presence of extrinsic defects in the material. Antibacterial activity of Ag- and Fe-doped ZnO nanopowders against Vibrio parahaemolyticus, Vibrio Cholerae, and Staphylococcus aureus bacteria was also investigated.     

含Ag硬质涂层的结构及其摩擦腐蚀与抗菌特性的研究进展

从含Ag元素的硬质涂层入手,综述了二元含Ag的Ag-DLC涂层到三元含Ag的CrN/Ag、TiN/Ag、ZrN/Ag涂层,再到多元含Ag的CrSiN/Ag、TiCN/Ag、ZrCN/Ag等涂层的研究进展,分析了不同制备技术和参数、不同元素添加等手段对涂层结构、摩擦腐蚀及抗菌特性的影响.在含Ag硬质涂层从二元到多元的研究过程中,发现元素的含量和制备参数会对涂层的微观组织结构产生重要的影响,并且Ag元素的含量极大地影响着硬质涂层的摩擦学特性、耐腐蚀性能和抗菌性.已有研究表明:低剪切强度的软质Ag相的添加往往能提高涂层的耐磨特性,故将具有高热化学稳定性的Ag固体润滑剂与高耐磨性的硬质涂层相结合,可以改善硬质涂层的摩擦学特性;少量的Ag元素添加可以保持或略微改善涂层的耐腐蚀性能,但是掺杂较高含量的Ag会使硬质涂层的耐腐蚀性能降低;同时,Ag元素对能够引起金属腐蚀的细菌有很好的抗菌效果,且是对环境和人体安全性好的金属元素.若能在金属部件表面沉积含Ag的纳米复合涂层,可以满足水润滑部件耐磨和防污的使用要求.研究在水环境中具有耐磨、抗生物腐蚀的含Ag纳米复合涂层,有利于对机械工程设备中关键零部件的保护,对于海洋开发和社会发展具有重大意义.     

Growth and photocatalytic activity of ZnO nanosheets stabilized by Ag nanoparticles

The Ag nanoparticles-stabilized ZnO nanosheets were prepared using a liquid-liquid two-phase method with (n-Dodecyl)trimethylammonium bromide (DTAB) as a phase transfer agent at the room temperature. The silver nanoparticles which are conductors with the character of attracting energy can make the ZnO sheets stabilize under the higher energy electrons. The samples are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV-vis spectroscopy and fluorescence. The results demonstrate that the silver nanoparticles load on the surface of ZnO sheets and make the ZnO sheets stabilize. Furthermore, the formation mechanism of ZnO sheets stabilized by silver nanoparticles was also proposed and discussed in detail. Moreover, the photocatalysis test shows that the ZnO sheets stabilized by silver nanoparticles exhibit a higher photocatalytic activity than the pure ZnO nanosheets, thereby implying that the Ag/ZnO interfaces promote the separation of photogenerated electron-hole pairs and enhance the photocatalytic activity.     

磁性Fe3O4/Ag复合纳米粒子制备与抗菌性能

采用箔-纤维-箔法和1150℃/150 MPa/30 min的真空热压工艺成功制备了SiCf/Ti-43Al-9V复合材料,并使用金相显微镜、X射线衍射仪、扫描电镜及能谱仪对该复合材料微观组织的形成进行了研究.结果表明,制备过程中SiC纤维与TiAl基体合金发生反应,并形成一定厚度的反应层;基体组织为等轴晶,粒径约为8 μm,与原始合金组织相比明显细化;从反应层到远处的TiAl基体合金,基体合金的组织由全γ相转变为α2/γ片层组织、γ晶粒和晶间B2相的混合组织.其中全γ相区域的厚度为2～4 μm,并围绕纤维分布.根据Ti-Al-V相图、C原子和V原子的扩散,分析了这两个基体区域的形成机理,并结合热压成形过程中的塑性变形和变形储存能,解释了基体合金晶粒大小的变化.     

钛合金表面GO/纳米ZnO复合涂层的制备及性能

为了有效解决生物医用钛合金长期植入人体后,易发生细菌感染和面临有害金属离子释放的问题,采用水热反应和涂覆方法,分别在聚多巴胺(PDA)预处理的Ti6Al4V合金表面制备了氧化石墨烯涂层(GP/T)和氧化石墨烯/纳米氧化锌复合涂层(GZP/T)。系统分析了2种涂层的物相结构、微观形貌及其在林格氏液中的耐腐蚀性能和在大肠杆菌环境中的抗菌性能。结果表明:聚多巴胺发挥“双面胶”桥接作用,有效增强了涂层与基底间的化学键合;GP/T涂层抗菌率随着GO浓度增大而增大;GZP/T纳米复合涂层相较Ti6Al4V基材具有优异的耐蚀性,该复合涂层中ZnO起主要抗菌作用。     

Enhanced photocatalytic activity of new photocatalyst Ag/AgCl/ZnO

A new composite photocatalyst Ag/AgCl/ZnO was fabricated by a two-step synthesis method under the hydrothermal condition. The sample was characterized by XRD, TG-DSC, SEM, TEM, DRS and XPS. The results showed that the samples were composed of Ag, AgCl and ZnO, and the particle size was in the range of 100 nm-1 μm. Methyl orange (MO) was used as a representative dye pollutant to evaluate the photocatalytic activity of Ag/AgCl/ZnO. The photocatalytic activity of Ag/AgCl/ZnO catalyst was higher than that of the pure ZnO catalyst. It was found that the Ag/AgCl/ZnO structure changed to Ag/ZnO gradually after several repeated experiments. However, the photocatalytic ability of the sample was not reduced. Finally, a possible photocatalytic mechanism was proposed.     

Effects of Oxide-Modified Spherical ZnO on Electrical Properties of Ag/ZnO Electrical Contact Material

Silver-zinc oxide (Ag/ZnO) electrical contact material is widely used as contacts of the medium duty switching devices. Effects of modified ZnO on properties of Ag/ZnO electrical contact material were investigated in this work. NiO and CuO were introduced to modify spherical ZnO by a chemical solution nano-coating method. Ag/ZnO contacts prepared using the modified spherical ZnO were produced by powder metallurgy (PM) method in a muffle furnace in temperature ranges from 750 to 900 °C. Results show that electrical conductivity, stability of relative density, and Vickers’ hardness of Ag/ZnO electrical contact material can be improved by the addition of NiO because of the formation of NiO solid solution Zn_0.2Ni_0.8O. The addition of CuO to Ag/ZnO electrical contact material makes arcing energy and mass loss lower. Since this is attractive for a longer service life, using NiO and CuO co-modified ZnO as a second phase may be a promising way to improve properties of Ag/ZnO electrical contact material. Hence, the presented results could also be useful for the design of a new Ag/ZnO electrical contact material.     

Morphology controlled synthesis of ZnO nanoparticles for in-vitro evaluation of antibacterial activity

Novel hierarchical flower- and nanorod-shaped ZnO nanoparticles with uniform morphological features were successfully synthesized through controlled precipitation method in aqueous media without using any surfactant or template. To elucidate the growth mechanism of the synthesized nanoparticles, the effects of pH, reaction time and temperature were studied systematically. Selected ZnO samples were then subjected to SEM, FT-IR and XRD analysis. XRD patterns confirmed well crystalline nature of the as-synthesized powders. Furthermore, synthesized nanoparticles (hierarchical flowers as ZnO-1 and nanorods as ZnO-2), as well as commercial ZnO (ZnO-Com), were then investigated for in-vitro evaluation of antibacterial activity against various bacterial strains of clinical importance. Results showed that ZnO-2 exhibited higher antibacterial activity to all tested strains than ZnO-1, while ZnO-Com showed no antibacterial response in the applied experimental conditions. In addition, ZnO concentration-dependent antibacterial study unfolded that size of inhibition zones increased significantly from ~30 to 33 mm against Streptococcus mutans and from ~28 to 30 mm against Escherichia coli with increasing ZnO-2 concentration from 0.25 to 0.75 µg/µL. The present study, therefore, suggests that the application of synthesized ZnO nanoparticles as the antibacterial agent may be effective for inhibiting certain pathogenic bacteria in biomedical sides.