共查询到20条相似文献,搜索用时 10 毫秒
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探讨了纳米氧化锌制备过程中的团聚问题及其抗菌性能。以三聚磷酸钠为表面活性剂,辅助沉淀法制备了纳米氧化锌粉体,用XRD,TEM,TG-DTA,BET等方法对产物进行了表征。结果表明:所得纳米氧化锌为高分散的球形颗粒,属于六方纤维矿的单晶结构,平均粒径为20 nm,比表面积可达70.478 1 m2/g。线性三聚磷酸钠与锌离子的络合作用,可以使前躯体均匀成核,并通过空间位阻抑制颗粒间的聚集,避免团聚的发生。采用杯碟法测试纳米氧化锌的抑菌活性。结果显示,纳米氧化锌对金黄色葡萄球菌、大肠埃希氏菌和沙门氏菌具有很好的抑菌活性,纳米氧化锌比表面积大小决定其抑菌活性。 相似文献
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In this work, the fabrication conditions of anodic aluminum oxide (AAO) templates with different pore size diameters were achieved using oxalic, tartaric, and phosphoric acidic electrolytes. Silver (Ag) nanostructures (NSs) were embedded in AAO template by simple hydrothermal and photoreduction methods. Moreover, titanium dioxide (TiO2) NSs (nanowires) was deposited into these porous templates by sol-gel method. FESEM results suggested that Ag nanofishstars, nanonecklaces (NNs), and TiO2 nanowires (NWs) like structures were grown in AAO pores with high-order and -aspect ratios. An anti-adhesive method was used to estimate the nano-size effect of the structures for enhancing antibacterial mechanism against Pseudomonas aeruginosa Gram-negative bacterium, and Staphylococcus aureus Gram-positive bacterium. In this study, the inhibition percentages of the Ag NNs/AAO membrane were 86.4, and 77.4%, respectively whereas that of the Ag film on glass substrate were 65, and 53.9%. Moreover, the inhibition percentages of the TiO2 NWs/AAO membrane were 85.9, and 70.1%, on the other hand, the TiO2 film on glass substrate were 60.3, and 45.2%. Results proved that the high porosity of the AAO template improved the contact-killing and release-killing actions of nanoparticles against biofilms. 相似文献
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Field experiments with wheat were conducted for two years on flood plain alluvial soils to study the effectiveness of soil application of zinc sulphate and zinc oxide at 0, 15, 45, 60, 75 and 90 days after sowing. Yield and zinc uptake of wheat increased significantly with the application of zinc. Delaying the application of both zinc sulphate and zinc oxide up to 45 days of sowing did not adversly affect the zinc nutrition of wheat. However, delaying the application for 75 or 90 days after sowing eliminated the response. Zinc sulphate, when applied within 60 days of sowing performed better than zinc oxide. In a laboratory study, zinc sulphate maintained a higher level of zinc in the soil solution than zinc oxide at least over a 3-week period. 相似文献
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Zinc oxide was electrodeposited from oxygenated aqueous solutions of zinc chloride at 80 C on tin oxide covered glass substrates. A new activation treatment for the substrate is established. This consists in the initial formation, in the deposition solution, of a thin metallic zinc layer (5–50 nm) converted to ZnO by in situ reoxidation. Variable densities of nucleation centers (with values approaching 1010 cm–2) are formed by this treatment. This allows control of the formation of a zinc oxide layer ranging from open deposits of isolated crystallites to compact and homogeneous layers. Compact layers have high specular transmission below the band gap value (3.5 eV), whereas open films exhibit extensive light scattering. The shapes of the current–time curves during deposition are discussed in terms of nucleation and structural effects. A possible influence of the semiconducting properties of the films is pointed out. 相似文献
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《Ceramics International》2020,46(9):13033-13039
The effect of rapid thermal annealing treatments on the microstructure, surface morphology, and optical characteristics of zinc tin oxide (ZTO) films produced by plasma-enhanced atomic layer deposition was investigated. The ZTO films were annealed in oxygen atmosphere for 2 min at four selected temperatures from 500 to 800 °C. The X-ray diffraction showed that the annealing temperature has a great influence on the crystalline characteristics of ZTO films. The film shows complete amorphous structure for as-deposited ZTO film. Meanwhile, the spinel zinc stannate Zn2SnO4 was obtained for the samples annealed from 500 to 800 °C, which shows polycrystalline nature. The X-ray photoelectron spectroscopy proved that the annealing process in oxygen gas can effectively can reduce the oxygen vacancy defects in the films. In addition, the photoluminescence spectroscopy manifests an ultraviolet emission with a broad peak range from 345 to 385 nm. Moreover, the ultraviolet luminescence intensity increases continuously with the increase of annealing temperature. Spectroscopic ellipsometry analyses demonstrate that the refractive index of annealed films increases as the increase of annealing temperature, while the extinction coefficient decreases gradually with the increase of annealing temperature in the visible light range. 相似文献
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Muhammad Ghozali Witta Kartika Restu Evi Triwulandari Muslih Anwar 《Polymer-Plastics Technology and Engineering》2020,59(12):1317-1325
ABSTRACTThis research was purposed at studying the effect of the addition of metal oxide (MO) as antibacterial agent on thermoplastic starch (TPS) properties. TPS/MO biocomposites with 0.1 until 2.0 phr of metal oxide were prepared. Antibacterial activity of TPS and TPS/MO biocomposites against bacteria was investigated. The inhibition zone of biocomposite films was dramatically increased along with the increasing of metal oxides contents. The addition of ZnO content resulted in an increase in inhibition zone for E. coli and S. aureus. The incorporation of MO into TPS/MO biocomposites tends to reduce mechanical properties, the mass loss and T50% of TPS/MO biocomposites. 相似文献
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《Ceramics International》2023,49(6):9657-9671
Photocatalytic degradation by visible light-driven generation of reactive oxygen species shows great promise for purification of environmental water. However, such degradation is limited by the low separation efficiency of photogenerated carriers and the poor adsorption capacity of the photocatalyst itself. To solve these problems, we successfully constructed and prepared a composite hydrogel (BV-GH) combining a three-dimensional network structure composed of graphene oxide and BiVO4 to achieve the synergistic effects of adsorption enrichment and photocatalytic degradation. The results show that the amount of methylene blue and methyl orange adsorbed by BV-GH is 258.78 mg g?1 and 217.16 mg g?1, respectively, which is much higher than that obtained for pure BiVO4. Due to the synergistic effect of adsorption enrichment and photocatalytic degradation, the degradation rate of the dye by BV-GH reaches 94.18% in 60 min, which is 6.98 times higher than that obtained for pure BiVO4. Electron spin-resonance (ESR) experiments confirm that the main factor affecting the dye degradation by BV-GH is the ability to produce more ·OH and ·O2?, which is an important reason for the excellent antibacterial performance of BV-GH against E. coli. This work can provide further inspiration for photocatalytic technology in water purification. 相似文献
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一种用初级氧化锌粉制备活性氧化锌工艺 总被引:2,自引:2,他引:2
研究了硫酸浸出初级氧化锌粉末制备活性氧化锌的工艺,讨论了浸出过程中液固质量比、硫酸质量分数对浸出率的影响。在硫酸锌溶液净化中,选择过硫酸铵除铁的方法。确定了活性氧化锌制备工艺参数,采用廉价的碳酸氢铵作为锌的沉淀剂制备前驱体,选择600℃煅烧前驱体4h。采用透射电镜和X衍射对产物活性氧化锌进行了表征。结果表明:活性氧化锌的粒度分布均匀,形貌为近似球形,其平均粒径为80nm,产品纯度高。采用化学法分析产物,其氧化锌质量分数为99.18%。 相似文献
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The galvanoluminescence (GL) properties of anodic oxide films formed in organic electrolytes were investigated at different aluminum annealing temperatures. The results of the spectral measurements showed two different types of GL sources: carboxylate ions incorporated in oxide films during the anodization and the molecules AlH, AlO, Al2, AlH2, also formed during anodization process and already recognized in the case of inorganic electrolytes. The latter was related to gamma alumina crystalline regions formed by annealing of the aluminum samples at temperatures above 500 °C. 相似文献
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Eight metal oxide sorbents including transition metal doped ZnO/SiO2 sorbents and ZnO/SiO2 were prepared by incipient wetness impregnation for regenerable desulfurization applications at low temperatures (i.e. room temperature). Among them, copper‐doped sorbent (Cu‐ZnO/SiO2) demonstrated the highest saturation sulfur capacity of 0.213 g sulfur/g ZnO (54% of the theoretical capacity), which is twice that of ZnO/SiO2 sorbent. Compared with ZnO/SiO2, Cu‐ZnO/SiO2 demonstrated superior desulfurization performance in a wide temperature range of 20–400°C. Due to the use of porous SiO2 support, Cu‐ZnO/SiO2 is highly regenerable. It can be easily regenerated in air at low temperatures, ca. 300–550°C, which are much lower than the typical regeneration temperatures of commercial ZnO sorbents. Cu‐ZnO/SiO2 maintained its sulfur capacity during 10 cycles of regeneration/sulfidation. © 2010 American Institute of Chemical Engineers AIChE J, 2010 相似文献
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以七水硫酸锌、碳酸氢铵为原料,通过液相沉淀法合成纳米氧化锌前体,并焙烧获得纳米氧化锌。本文采用XRD、TG-DSC、TEM、BET等测试手段对纳米氧化锌及其前体进行表征,研究了焙烧温度对所制备氧化锌形貌、晶型及脱硫活性的影响,结果表明:所获得的碱式碳酸锌为不规则纳米晶,晶粒尺寸约为2~10nm;在不同的焙烧温度下所获得的纳米氧化锌的综合性能存在较大差异,其中在焙烧温度300℃处理所得纳米氧化锌综合性能较高,其晶粒尺寸为5~10nm之间,结晶度较完整,比表面积为41.41m2/g,在220℃脱硫活性较高,穿透硫容>25%;随着焙烧温度的提高,纳米氧化锌的晶化程度加大,表面性质被破坏,比表面积急剧下降,颗粒团聚严重;焙烧温度太低,则纳米氧化锌前体分解不完全,影响其纯度。 相似文献
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Abbas Sadeghzadeh-Attar Mohammad Reza Bafandeh 《International Journal of Applied Ceramic Technology》2019,16(6):2429-2440
In this work, anatase and rutile TiO2 nanorods were fabricated using one-step liquid phase deposition process, followed by heat treatment in the range 300-800°C. The direct and indirect band gap of the TiO2 nanorods was estimated form optical absorption data which illustrated a red shift at higher temperatures owing to the different nature of excitons in anatase and rutile phases. The photoluminescence (PL) spectra revealed the presence of two main emission bands consisting of four peaks. It was found that two high-energy peaks located at 2.95-3.30 eV could be generated from exciton transitions from the conduction band to the valence band of TiO2 nanorods, while two low-energy peaks located at 2.43-2.64 eV may arise from surface state transitions. The PL intensity firstly increased with temperature and at 500°C reached a maximum value, then decreased through increasing temperature up to 800°C. These variations in the intensity of PL emission could be explained in terms of changes in phase structure, crystallinity, and amount of the oxygen vacancies, which are all dependent to the annealing temperature based on X-ray diffractometer and X-ray photoelectron spectrometer studies. These results indicated that annealing temperature allows to manipulate the properties of TiO2 nanorods for opto-electronic applications. 相似文献
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Ko-Ying Pan Chia-Hung Chien Ying-Chih Pu Chia-Ming Liu Yung-Jung Hsu Jien-Wei Yeh Han C Shih 《Nanoscale research letters》2014,9(1):307
Substantial silver-embedded aluminum/silica nanospheres with uniform diameter and morphology were successfully synthesized by sol-gel technique. After various annealing temperatures, the surface mechanisms of each sample were analyzed using scanning electron microscope, transmission electron microscope, and X-ray photoelectron spectroscopy. The chemical durability examinations and antibacterial tests of each sample were also carried out for the confirmation of its practical usage. Based on the result of the above analyses, the silver-embedded aluminum/silica nanospheres are eligible for fabricating antibacterial utensils. 相似文献
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室温下采用氨浸出锌灰制得碱式碳酸锌,再经煅烧制得超细氧化锌。研究了在合成碱式碳酸锌过程中表面活性剂对碱式碳酸锌和氧化锌颗粒尺寸与形貌的影响。结果表明,聚乙二醇(PEG20000)和聚乙烯吡咯烷酮(PVP-K30)这两种表面活性剂对颗粒的分散效果最好,制得的碱式碳酸锌颗粒为无定形片状且分散均匀,平均粒径为1 μm,煅烧后的氧化锌颗粒为六方晶系纤锌矿结构,粒径约为0.7 μm。添加PVP-K30比添加PEG20000的碱式碳酸锌热分解温度高。添加PEG和PVP的碱式碳酸锌反应活化能分别为139.9 kJ/mol和146.8 kJ/mol。 相似文献
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《Ceramics International》2022,48(17):24935-24942
Methods of preparation and application of zinc oxide nanoparticles doped with Mn(II) and Co(II) ions are presented and discussed in the paper. Part one shows the results of the solvothermal synthesis of zinc oxide nanoparticles doped with Mn(II) and Co(II) ions. The effect of process parameters on the properties of doped nano zinc oxide has been identified. We also examined the impact of annealing in argon atmosphere of doped zinc oxide nanoparticles on physicochemical properties. Morphology analysis was performed using scanning microscopy and molecular analysis was performed using by inductively coupled plasma - optical emission spectrometry. The zeta potential was measured for samples annealed in argon atmosphere and for samples not annealed. Phase analysis was performed by x-ray diffraction. Based on this analysis, the lattice parameters were determined. 相似文献