Zinc Oxide Nano Particles Integrated Kenaf/Unsaturated Polyester BioComposite

Increasing need for materials with special features have brought various new inventions,one of the most promising hope for new material with special features and functionalities is composites materials.Thus,this study report an integration of zinc nanoparticles into kenaf/polyester polymer composite to introduce new behavior to the composite.The composite behaviors were compared for mechanical,thermal,moisture absorption and biodegradability properties.Prepared Zinc Oxide nanoparticles entrenched in the kenaf/polyestaer composites net structure through chemical bonds between kenaf/ZnO/polyester resin,existence of ZnO significantly influence the mechanical and thermals properties of composites.Thermal analysis based on(TGA)response revealed the integration of ZnO nanoparticles improved the thermal stability when thermal decomposition temperature beyond 3650 C.The thermal cracking decreased with present of ZnO and increase with kenaf content(layers).The modulus,Tensile strength,break at elongation,flexural modulus,flexural strength and impact strength of the composites with higher content kenaf/ZnO nanoparticle are 560 MPa,58MPa,1.8%,1300 PMa,68 MPa and 31 MPa,respectively.Thus,addition of kenaf layers and ZnO results in larger mechanical properties enhancement,the results of the contact angle show improvement in wetting of the fibres with addition of ZnO nanoparticles.

Electrochemical and Photoelectrochemical Properties of Nano-Islands of Zinc and Niobium Oxides Deposited on Aluminum Thin Film by RF Magnetron Reactive Sputtering

Zinc oxide (ZnO) and niobium oxide (NbOx) with a nano-island structure were deposited by a sputtering method on Al-coated glass substrates. Cells with a (ZnO or NbOx)/Al/glass|KNO3aq.|Al/ glass structure were assembled, and electrochemical and photoelectrochemical properties were evaluated. The ZnO and NbOx electrodes had higher electrode potentials than the counter Al/glass electrode, and electron flows from the counter electrode to the ZnO and NbOx electrodes through the external circuit were commonly confirmed. In the ZnO-based cell, only faint photocurrent generation was seen, where Zn and Al elution from the ZnO electrode was found. In the NbOxbased cell, however, stable generation of electricity was successfully achieved, and electrode corrosion was not recognized even in microscopic observations. A photoelectrochemical conversion model was proposed based on potential-pH diagrams. In the case of nano-island structures formed at shorter NbOx deposition time, it was concluded that the photoelectrochemical reactions, which were proceeded in the immediate vicinity of the boundary among nano-islands, substrate, and electrolyte solution, were predominant for the photoelectrochemical conversion, and in the case of film structures with longer deposition time, the predominant reactions took place at the film surface.

Incorporation of Nano-Zinc Oxide in Lamellar Zirconium Phosphate: Synthesis and Characterization

In order to provide ultraviolet barrier, antifungal and antibacterial properties, nano-zinc oxide (ZnO) was added to lamellar zirconium phosphate (ZrP). The phosphate was synthesized via reaction of zirconium oxychloride octahydrate and phosphoric acid following its chemical modification with Jeffamine and nano-ZnO. Diffractometric, morphological, thermal, structural and relaxometric evaluations were conducted. Fourier transform infrared spectroscopy (FTIR) revealed increase of the area between 4000 - 3000 cm-1 due to the formation of ionic specie PO? +NH3-[C-(H)(CH3)-CH2-O-(C-(H)(CH3)-CH2-O)8-(CH2-CH2-O-CH3)] and nano-ZnO particles. Wide-angle X-ray diffraction indicated that intercalation of Jeffamine was successful. Thermogravimetry confirmed that nano-ZnO particle forced the expulsion of Jeffamine outside ZrP galleries. Scanning electron microscopy evidenced the Jeffamine intercalation and sample heterogeneity. Hydrogen molecular relaxation indicated the increase of molecular rigidity owing to the formation of ionic specie and the addition of nano-ZnO particles. It was postulated that a multifunctional and miscellaneous material constituted by as prepared ZrP, some delaminated ZrP platelets and nano-ZnO particles was achieved. The material has potential for usage as filler in polymeric composites.

抗菌PP/Rnano-ZnO复合材料的制备及性能研究

以棒状纳米氧化锌(Rnano-ZnO)为抗菌剂、聚丙烯(PP)为基材,采用熔融共混法在双螺杆挤出机中制备了抗菌PP/Rnano-ZnO复合材料。测试了复合材料的抗菌性能,通过DSC法研究了抗菌PP/Rnano-ZnO复合材料中Rnano-ZnO质量分数对结晶性能的影响,采用SEM分析了复合材料冲击断面的微观形貌,采用万能电子拉伸机测试了复合材料的力学性能。结果表明,抗菌PP/Rnano-ZnO复合材料中随着Rnano-ZnO的加入,结晶温度提高了1.81℃,相对结晶度提高了5.03%,冲击强度提高了47.83%,拉伸强度提高了20.96%和断裂伸长率提高了4790%;当抗菌PP/Rnano-ZnO复合材料中Rnano-ZnO质量分数为6.0%时,其力学性能、对大肠杆菌和金黄色葡萄球菌的抗菌效果最佳。

Spray Pyrolysis Deposition of Single and Mixed Oxide Thin Films

The influence of processing parameters is investigated on the structural characteristics of single and mixed oxides produced by spray pyrolysis technique. The films were synthesized by spraying precursor solutions through a noz-zle onto a heated alumina substrate. The precursor consisted separately of aqueous solutions of tin chloride for SnO2 and zinc chloride for ZnO for single oxide cases, and aqueous solutions of tin chloride and indium nitrate for SnO2 + In2O3 and zinc chloride and indium nitrate solutions for ZnO + In2O3 for mixed oxide cases. The substrate temperature was varied accordingly for each single and mixed case. The films produced were characterized by X-ray Photoelectron Spectroscopy and Scanning Electron Microscopy. The results indicate that a non-homogenous film is formed at low temperature for both single oxides considered. The temperature has significant effect on the composition of the synthesized films of both single oxides below 450℃. The results for mixed oxides show that the best homogeneous films are obtained for 80 wt% ZnO + 20 wt% In2O3, and 80 wt% SnO2 + 20 wt% In2O3.

Synthesis of Flower-like Zinc Oxalate Microspheres in Ether-water Bilayer Refluxing Systems and Their Conversion to Zinc Oxide Microspheres

Flower-like zinc oxalate with a mean diameter of 50 μm was synthesized via the reaction of zinc acetate and dimethyl oxalate in ether-water bilayer refluxing systems at low temperature.Flower-like zinc oxalate microspheres can be further transformed into the similar morphology to zinc oxide by the decomposition of zinc oxalate at 500℃.Scanning electron microscopy（SEM）,X-ray diffraction（XRD）,thermogravimetric analysisdifferential scanning calorimetric（TG-DSC）,energy dispersive X-ray spectrum（EDX） and Fourier transforminfrared spectroscopy（FT-IR） were used to characterize the structure features and chemical compositions of the as-synthesized products.The UV-Vis and photoluminescence spectrum of flower-like zinc oxide microspheres were studied.The experimental results showed that flower-like zinc oxalate microspheres may be self-assembled by the zinc oxalate flakes.The ether-water volume ratio of 4：1 and refluxing temperature of 40℃ were considered to favor the preparation of flower-like zinc oxalate microspheres.

IN-SITU POLYMERIZED SYNTHESIS AND PROPERTIES OF NANO-ZnO/PEG/PET COMPOSITE

Nano-ZnO particle （nZnOp） reinforced polyethylene glycol （PEG）/polyethylene terephthalate （PET） （nZnOp/PEG/PET） copolymeric composites with different mass fractions and molecular weights of PEG are synthesized via in-situ polymerization. The dispersion of nZnOp in copolymer matrixes and the effects of PEG and nZnOp particles on the crystallization behavior of the composites are studied by TEM, differential scanning calorimetry（DSC）, XRD and Fourier thansform infrared spectroscopy （FTIR ）. The results reveal that nZnOp particles are dispersed in the matrixes with nano-scale, and the addition of PEG induces more homogeneous dispersion of nZnOp. Simultaneously, these nanoparticles become nucleating centers during the crystallization of the matrixes. PEG segments can improve the flexibility of the PET molecular chain, resulting in the drop of the cold crystallization temperature and the rise of the crystallization rate of the composites. Furthermore, PEG （4 000） with the mass fraction of 10% can promote the crystallization rate of the composites. The mechanical properties show that the nano-particles strengthen and toughen the PET matrix, whereas PEG weakens these improve- ments.

原位聚合制备PBT/nano-ZnO复合材料及其结晶性能研究

以精对苯二甲酸(PTA)和1,4-丁二醇(BDO)为基本原料,在5 L熔融缩聚反应釜中,采用原位聚合工艺,通过加入自制纳米氧化锌(nano-ZnO),制备得到聚对苯二甲酸丁二醇酯(PBT)/nano-ZnO复合材料。采用差示扫描量热仪对PBT/nano-ZnO复合材料的结晶性能进行测试,并研究了复合材料的非等温结晶行为。结果表明,加入nanoZnO后,不影响PBT的聚合工艺,nano-ZnO对PBT有异相成核作用;Jeziorny法可以很好地分析PBT及其复合材料的非等温结晶过程。

改性纳米氧化锌的制备及在环氧树脂中的应用

采用KBM-603型硅烷偶联剂作为改性剂,用蒸气法制备了改性纳米氧化锌。重点研究了改性前后纳米氧化锌的疏水性、微观形貌及粒径分布的变化。然后在环氧树脂中加入20%改性后的纳米氧化锌,考察了其添加前后力学性能及耐紫外性能的变化。研究结果表明:(1)通过对改性温度和改性时间的考察,纳米氧化锌的较佳改性工艺为:改性温度110℃,改性时间2 h。(2)通过对改性前后纳米氧化锌的接触角、透射电镜、粒径分布进行测定,发现KBM-603型硅烷偶联剂作为改性剂,可以使纳米氧化锌由亲水性粉体变为疏水性粉体,表面能降低,团聚被打开,这样更能发挥其对光线的吸收和反射作用。(3)在环氧树脂中加入20%的KBM-603型硅烷偶联剂改性纳米氧化锌,不仅能提高其力学性能,又能提升其耐紫外线老化的性能。

A Self-Powered Fast-Response Ultraviolet Detector of p–n Homojunction Assembled from Two ZnO-Based Nanowires

Nowadays, fabrication of micro/nano-scale electronic devices with bottom-up approach is paid much research attention. Here, we provide a novel micro/nano-assembling method, which is accurate and efficient, especially suitable for the fabrication of micro/nano-scale electronic devices. Using this method, a self-powered ZnO/Sb-doped ZnO nanowire p–n homojunction ultraviolet detector(UVD) was fabricated, and the detailed photoelectric properties were tested. At a reverse bias of -0.1 V under UV light illumination, the photoresponse sensitivity of the UVD was 26.5 and the rise/decay time of the UVD was as short as 30 ms. The micro/nano-assembling method has wide potential applications in the fabrication of specific micro/nano-scale electronic devices.

Nano-ZnO改性复合树脂抗菌性能的缓释性研究

目的:观察不同添加剂量的nano-ZnO改性复合树脂的锌离子释放规律及浸泡1个月后的抗菌活性。方法:制备不同添加剂量(1wt%,5wt%,10wt%)的nano-ZnO改性复合树脂试件,充分光固化后浸泡于无菌三蒸水中,分别于24h,1周,2周,1个月时使用锌(Zn)测定试剂盒对各组试件浸析液的锌离子含量进行测定,并对浸泡1个月的试件进行抗菌活性测定。结果:不同时间点检测的各组试件的锌离子释放量均随nano-ZnO添加剂量的增加而增加,10wt%的nano-ZnO添加组改性复合树脂在1个月时仍保持较高的锌离子释放水平,并且其同期抗菌活性也显著高于其他实验组(P<0.05)。结论:10wt.%的nano-ZnO添加组改性复合树脂可在一定时间内保持较高的锌离子释放水平,从而达到更加长效性的抗菌作用。

Nano-ZnO改性对光固化复合树脂机械性能影响的研究

目的研究nano-ZnO改性对复合树脂机械性能的影响。方法通过测定nano-ZnO改性复合树脂的挠曲强度,抗压强度及径向拉伸强度研究其对树脂机械强度的影响,并在电镜下观察复合树脂的显微形貌及其粘接界面。结果当nano-ZnO的添加量为1 wt.%、5 wt.%、10wt.%时,改性复合树脂的挠曲强度,抗压强度及径向拉伸强度与空白对照组之间无明显差别(P> 0. 05);当nano-ZnO的添加量达到15wt.%时,改性复合树脂的各项机械强度均明显降低(P <0. 05)。电镜结果显示nano-ZnO在不影响复合树脂机械性能的各组中均均匀分布,各组树脂-牙本质粘接界面混合层均匀连续,充填树脂与粘接剂间结合良好。结论添加量不超过10 wt.%时,nano-ZnO不会对复合树脂的机械性能造成负面影响,可以作为复合树脂抗菌改性的选择。

Influence of Dispersion of Nano-ZnO Particles in Polymer Matrices on Properties of Relevant Nano Composite Fibers

The surface-passivated and non-surface-passivated zinc oxide nano-particles （marked as s-nanoZnO and ns-nanoZnO respectively） were evenly dispersed in polymer solutions with the aid of ultrasonic vibration to prepare nanocomposite film by free casting and to prepare nanocomposite fibers by wet spinning and to prepare nancomposites coating by surface smearing. The dispersion of s-nanoZnO and nsnanoZnO in PAN matrix were observed by transmittance electron microscopy, the mechanical properties of the relevant compesite samples were studied by INSRTON tensile strength tester. It was found that s-nanoZnO behaves a well-dispersed morphology in PAN films and fibers when its concentration was 2 wt% but ns-nanoZnO nano particles agglomerate into larger congeries in PAN films. It means that the surface-passivated process oft zinc oxide nano. particles was effective to disperse. The relative intensity and elonsation at break of s-nanoZnO-PAN composite fibers show maximum values with the increase of nano particle content in compesites （from 0 wt% to 2 wt% of s- nanoZnO）. The elasticity of the composite fibers increases whereas their modulus declines. Balanced the changes of the properties mentioned above, 2 wt% s-nanoZnO in PAN matrix is a proper content for the composite fibers spun by wet spinning. The result of surface smearing test means that the reactim between s-nanoZnO and polymer can be indicated by the color of nanocomposite surface coat on fibers.

Effect cf Nano-ZnO or Nano-Y_2O_3 on Sintering Property of Fused Quartz Ceramics

Fused quartz ceramic was prepared using high purity fused quartz powder as starting material,separately introducing 1%,2% and 3% （in mass,the same hereinafter） nano-ZnO or nano-Y203 as additive,molding at 50 MPa,firing in reduction atmosphere at 1 300,1 350 and 1 400 ℃ for 1 h,respectively.Apparent porosity and cold modulus of rupture were tested and fracture morphology was analyzed by SEM.The results show that adding nano-ZnO or nano-Y2O3 obviously improves sintering of fused quartz; adding nano-ZnO enhances modulus of rupture and decreases apparent porosity; the optimum addition of nano-Y2O3 as sintering aid of fused quartz is 2%.

推荐一个无机合成综合实验——基于废弃大豆油的微乳液法制备纳米氧化锌

纳米氧化锌是一类多功能纳米材料,由于其优秀的物理化学性质而被广泛应用于多个领域。传统的合成方法存在成本过高、过程复杂、产物不稳定等问题。微乳合成法具有操作简单,成本低廉,产物尺寸可控等优点,可以有效避免传统合成方法的缺陷。特别是将废弃大豆油合成的乳化剂应用在合成的过程中,可以实现废物的回收再利用,又能满足绿色化学和可持续发展的要求。使用X射线衍射(XRD)、扫描电镜(SEM)、化学分析等多种方法对产物纳米氧化锌的形貌和性质进行了表征,实现了无机合成-化学分析-仪器分析的综合偶联,从而达到提升大学生进行综合实验能力的目的。

High Alumina Fiber Composite SiO_2 Based Nanoporous Insulation Boards

The specimens were prepared with high alumina fiber accounting for 0. 5% , 10% or 15% by mass of the total amount of amorphous silica and high alumina fiber, using phenolic resin as binder, and extra-adding 0 or 0. 5% ZnO as sunscreen to cut the cost of SiO2 nanoporous insulation board. The hot volume stability and thermal conductivity （flat plate method ） of the specimens were tested and multi-Jimetion simulation equipment was used to study the thermal insulation performante. The results show that： （1） with high alumina fiber addition increasing, the linear shrinkage rate decreases, but thermal eonductivity changes a little; （2） adding ZnO can decrease thermal conductivity obviously; （3）for the specimen with ZnO and 15% of high alumina fiber, its cold face temperature hardly rises during the simulation experiment at 1 000 ℃ for 2 h, and the cold face temperature of the specimen with the smallest thickness of 2 cm doesn＇t exceed 180 ℃.

Effect of Ultra-Turrax on Nanocellulose Produced by Acid Hydrolysis and Modified by Nano ZnO by Sol-Gel Method

Cellulose nanocrystals (NCC) and cellulose nanofibrils (CNF) were obtained by a single step process, with synergy between 64% sulfuric acid hydrolysis and high shear from ultra-turrax stirring, which is an advantageous process for disintegrating cellulose microcrystalline and also may improve the hydrolysis process. The surface modification on the cellulose was performed by the sol-gel process, in which the sulfate groups from hydrolysis were replaced by nanoparticles of zinc oxide, which led to the increase of up to 54&deg;C Tonset, according to thermogravimetric analysis (TGA) results. The morphology and crystallinity degree were characterized by Helium Ion Microscopy (HIM), atomic force microscopy (AFM) and X-ray diffraction. In addition, the ZnO band was observed in Fourier transform infrared spectroscopy, furthermore, the change in the zeta potential confirmed the cellulose modification. The changes in the values of proton spin-spin relaxation time for the systems showing the confined hydrogen in the rigid domains, confirmed the results observed with the aforementioned techniques, for both cellulose after hydrolysis and ZnO modified cellulose, suggesting that ZnO disrupted crystal formation in cellulose.

一种车用纳米改性橡胶密封材料制备及性能研究

为提高橡胶密封材料的耐磨性能,以丁腈橡胶(NBR)为主要材料,纳米氧化锌为补强填料,制备一种密封材料,对其力学性能和摩擦磨损性能进行研究。结果表明,与普通氧化锌相比,含有纳米氧化锌的密封材料力学性能和耐磨性能更好,硬度为77.2 HA,压缩永久变形率为21.2%,拉伸强度和拉伸断裂伸长率分别是13.26 MPa、198.8%,撕裂强度为52.38 kN/m。在干摩擦磨损试验中,含有纳米氧化锌的密封材料平均摩擦系数为0.817,磨损量降低38.0%。在油润滑摩擦磨损试验中,含有纳米氧化锌的密封材料摩擦系数最后稳定在0.08。添加纳米氧化锌的密封材料综合性能良好,可作为汽车轴承等钢结构密封材料应用。

锌灰资源化回收及超临界水热合成纳米氧化锌系统工艺

为了对锌灰进行资源化回收及对其经济性进行分析,将湿法回收工艺和超临界水热合成技术相结合,将锌灰生成价值较高的纳米氧化锌产品,采用Aspen Plus软件平台,建立了完整的系统工艺,并分析了系统运行过程中的物料成本及能耗成本。在硫酸浓度为2 mol·L^(-1)、固液比为1∶8、浸出温度为50℃、浸出时间为2 h、搅拌器转速为300 r·min^(-1)的条件下,锌灰中锌的浸出率达到了95%以上。除杂过程除去了Fe、Al、Ni、Cu等杂质,除杂后的溶液中锌的质量分数达到了97%。利用锌灰浸出液在400℃和25 MPa的超临界条件下,合成了平均粒径为26 nm的纳米氧化锌,晶体结晶度良好,纯度较高。通过与纯物料所合成的纳米氧化锌进行对比,验证了该技术的可行性,显著提升了系统运行的经济性。

焦磷酸哌嗪/纳米阻燃剂协效阻燃PBS

以焦磷酸哌嗪(PAPP)为阻燃剂,选用氧化石墨烯(GO)、纳米蒙脱土(DK2)、硼酸锌(ZnB)作为协效剂与PAPP分别构成二元阻燃体系和三元阻燃体系。二元阻燃体系包括PAPP与DK2、PAPP与ZnB、PAPP与GO;三元阻燃体系包括PAPP、GO和ZnB及PAPP、DK2和ZnB。分别将上述二元阻燃体系及三元阻燃体系与聚丁二酸丁二醇酯(PBS)熔融共混制备PBS阻燃复合材料,研究不同复配体系阻燃剂的加入对PBS阻燃性能和力学性能的影响。结果表明,当PAPP含量为16.5%、DK2含量为1.5%、ZnB含量为2%时,PBS复合材料通过了UL94垂直燃烧测试,达到了V-0级,极限氧指数(LOI)达到32.4%,最大热释放速率峰值(PHRR)和总烟释放率(TSP)分别为227kW/m^(2)和3.4m^(2),与加入20%PAPP(FRPBS)相比,分别降低了50%和69%,残炭率达到13.8%,此外,拉伸强度为13.5 MPa,断裂伸长率为613.8%,冲击强度为8.0kJ/m^(2),与FRPBS相比,分别提升了9.1%、17.2%和40.3%。结果表明,三元阻燃体系能够同时提升PBS复合材料的阻燃性能力学性能。