纳米氧化锌的分散及纳米整理剂的制备

研究了纳米氧化锌在水中的稳定分散介质及纳米整理剂的制备和应用。结果表明，对纳米氧化锌进行适当改性和乳化分散，有利于提高纳米水分散液的稳定性，自制水溶性聚氨酯起到良好的助分散作用；自制的纳米整理剂中纳米平均粒径97．01nm；纳米粒子为单核和多核的微囊式结构；纳米整理剂在纤维上呈非均匀浆膜分布；经纳米整理剂（含纳米ZnO10％）整理的纯棉织物，在10次水洗后的UPF等级达到50＋。     

Friction and wear behavior of hybrid glass/PTFE fabric composite reinforced with surface modified nanometer ZnO

Nano-ZnO was successfully grafted with 2,4-toluenediisocyanate (TDI) and β-aminoethyltrimethoxylsilane (OB551) to avoid the agglomeration of nano-ZnO in composite. The hybrid glass/PTFE fabric composites reinforced with the untreated, OB551 and TDI modified nano-ZnO, respectively, were prepared by dip-coating of the hybrid fabric in a phenolic adhesive resin containing the nanoparticles to be incorporated and the successive curing. The friction and wear behaviors of various nano-ZnO reinforced hybrid glass/PTFE fabric composites sliding against AISI-1045 steel in a pin-on-disk configuration were evaluated on a Xuanwu-III high-temperature friction and wear tester, with the unfilled one as a reference. The morphologies of the worn surfaces of the composites and of the counterpart pins were analyzed using scanning electron microscopy. In addition, FTIR spectrum was taken to characterize the untreated and treated nano-ZnO. It is found that the untreated and treated nano-ZnO reinforced hybrid glass/PTFE fabric composites exhibit improved wear resistance and friction-reduction in comparison with the unfilled one. The TDI modified nano-ZnO reinforced composite can obtain the best friction and wear performance under different applied load; followed by the OB551 modified nano-ZnO reinforced one. Sliding conditions, such as environmental temperature and lubricating condition, significantly affect the tribo-performances of the unfilled and filled hybrid glass/PTFE fabric composites.     

An evaluation of the corrosion resistance and adhesion properties of an epoxy-nanocomposite on a hot-dip galvanized steel (HDG) treated by different kinds of conversion coatings

Hot-dip galvanized steel (HDG) samples were chemically treated by Cr(III), Cr(VI), Cr(III)-Co(II) and Cr(III)-Ni(II) conversion coatings. Epoxy nanocomposites were prepared using 2 wt.%, 3.5 wt.%, 5 wt.% and 6.5 wt.% nano-ZnO. Electrochemical impedance spectroscopy (EIS), pull-off adhesion tester and scanning electron microscope (SEM) were utilized to evaluate epoxy coatings properties on the surface of pre-treated HDG samples. Results showed that addition of nano-ZnO particles (specially 3.5 wt.%) can significantly improve the corrosion resistance of the epoxy coating on HDG. Decrease of contact angle (φ) and increase of surface roughness (Ra) of the pre-treated HDG samples were obtained. Decrease of the value of φ was more pronounced when the Cr(III) pre-treated samples were post-treated by Cr(III)-Co(II) and Cr(III)-Ni(II) conversion coatings (CCs). The dry and wet adhesion strengths of the epoxy coating to HDG were significantly increased after the surface treatment of the samples. Increase of the adhesion strength and decrease of the adhesion loss were more pronounced on Cr(III)-Co(II) and Cr(III)-Ni(II) post-treated samples. The corrosion resistance of epoxy coating was also increased on the surface of pre-treated HDG samples. Increase of the corrosion resistance of the Cr(III) pre-treated HDG samples was more pronounced on the samples which were post-treated by Co(II) and Ni(II).     

Effect of ZnO particles on activated sludge: role of particle dissolution

The release of nanoparticles (NPs) into the environment, including wastewater treatment plants, is expected to increase in the future. Therefore, it is important to understand the potential effects of these NPs on activated sludge treatment processes. A pulse-flow respirometer was used to study the toxicity of nano-ZnO on activated sludge endogenous respiration, BOD biodegradation, and nitrification. In addition, toxicities of bulk ZnO particles and Zn ion (e.g. soluble Zn) were also studied. All three Zn forms were found to adversely impact the activity of activated sludge, with soluble Zn exhibited the greatest toxicity. The effects of nano-ZnO and bulk ZnO on activated sludge were caused by soluble Zn resulting from ZnO particle dissolution. The IC₅₀ values of soluble Zn on activated sludge endogenous respiration, BOD biodegradation, ammonia oxidation, and nitrite oxidation were 2.2, 1.3, 0.8, and 7.3 mg-Zn/L, respectively. Therefore, the first step of nitrification was most sensitive to Zn.     

纳米ZnO的表面改性研究

对比研究了γ-甲基丙烯酰氧基丙基三甲氧基硅烷（MPTMS）与纳米ZnO的不同表面反应方法,制备了表面负载有活性基团-乙烯基的纳米ZnO,初步探讨了表面反应机理。试验表明：以水为分教利的反应方法在环保、节能方面具有不可替代的优越性。     

纳米氧化锌的杀菌性能

以自制的纳米氧化锌为原料,对其悬浮液和聚氨酯板进行了大肠杆菌和金黄色葡萄球菌的杀菌试验。试验表明,纳米氧化锌具有明显的杀菌效果,随着处理时间的延长,杀菌率逐渐提高;随着氧化锌悬浮液浓度的提高或聚氨酯板中氧化锌添加量的增加,杀菌率也逐渐提高;对金黄色葡萄球菌的杀菌效果好于大肠杆菌。纳米氧化锌悬浮液的杀菌效果好于添加有纳米氧化锌的聚氨酯板,并对其杀菌机理给出了初步解释。     

Colloidal dispersion of nano-scale ZnO powders using amphibious and anionic polyelectrolytes

This article describes the dispersion of aqueous suspensions containing nano-scale ZnO powder by utilizing a hybrid of chemical dispersant and mechanical mixing/grinding process. The chemical dispersants included anionic or amphibious polyelectrolytes, i.e., sodium salt of polymethylacrylic acid (PMAA-Na) or polyacrylamide/(α-N, N-dimethyl-N-acryloyloxyethyl) ammonium ethanate (PDAAE). The optimum critical concentrations for each dispersants to achieve the lowest viscosity, smallest final sediment volume and particle size (d₅₀) for the nano-ZnO suspensions, 3 wt.% for PMAA-Na and 5 wt.% for PDAAE, were identified. The finely dispersed nano-ZnO powders were transferred to prepare sputtering target. The root-mean-square roughness (R_RMS) of thin films deposited by utilizing such a target was found to be 2.05 nm, which was lower than the R_RMS of the film (≈27.57 nm) deposited by using a commercial ZnO target comprised of micro-scale granules.     

纳米氧化锌/PP复合材料抗菌性能的研究

研究了PP/纳米ZnO复合材料抗菌性能 ,同时研究了光照时间和偶联剂对抗菌性能的影响。结果表明 :在光照的条件下 ,具有较好的抗菌性能 ,偶联剂的加入会提高复合材料的抗菌性能。纳米ZnO对大肠杆菌的抗菌效果要优于金黄色葡萄球菌     

纳米氧化锌强化糖汁石灰法澄清脱色工艺研究

以赤砂糖回溶糖浆为研究对象,探讨纳米氧化锌强化石灰法澄清脱色工艺的可行性。以脱色率与除浊率为指标,考察了纳米氧化锌用量、预灰p H值、预灰时间、预灰温度等4个因素对赤砂糖回溶糖浆脱色率和除浊率的影响。通过正交试验,优化工艺条件脱色最佳工艺为:纳米Zn O用量125 mg/kg、预灰温度40℃、预灰时间20 min、预灰p H值7.00,其脱色率可达9.9%;除浊最佳工艺为:预灰温度40℃、纳米Zn O用量125 mg/kg、预灰时间20 min、预灰p H值7.00,其除浊率可达96.0%。结果表明纳米氧化锌强化赤砂糖回溶糖浆石灰法澄清脱色的工艺具可行性。     

CTAB对溶胶-凝胶法制备纳米ZnO形貌的影响

以醋酸锌、草酸为主要原料,采用溶胶-凝胶法制备纳米ZnO。在反应体系中加入表面活性剂十六烷基三甲基溴化铵(CTAB),成功制得短柱状及棒状结构的纳米ZnO。借助XRD和TEM对产物的结构和形貌进行了表征。结果表明,产物属于纤锌矿结构的六方相ZnO,并且,在棒状结构纳米ZnO的形成过程中CTAB起关键作用,改变反应体系中CTAB的加入量,可以实现纳米ZnO的形貌控制合成。讨论了棒状纳米ZnO可能的形成机理。