Synergism of Zinc Oxide/Organoclay-Loaded Poly(lactic acid) Hybrid Nanocomposite Plasticized by Triacetin for Sustainable Active Food Packaging

The synergistic effect of organoclay(OC)and zinc oxide(ZnO)nanoparticles on the crucial properties of poly(lactic acid)(PLA)nanocompositefilms was systematically investigated herein.After their incorporation into PLA via the solvent casting technique,the water vapor barrier property of the PLA/OC/ZnOfilm improved by a maximum of 86%compared to the neat PLAfilm without the deterioration of Young’s modulus or the tensile strength.Moreover,thefilm’s self-antibacterial activity against foodborne pathogens,including gram-negative(Escherichia coli,E.coli)and gram-positive(Staphylococcus aureus,S.aureus)bacteria,was enhanced by a max-imum of approximately 98–99%compared to the neat PLAfilm.Furthermore,SEM images revealed the homo-geneous dispersion of both nano-fillers in the PLA matrix.However,the thermal stability of thefilm decreased slightly after the addition of the OC and ZnO.Thefilm exhibited notable light barrier properties in the UV-Vis range.Moreover,the incorporation of a suitable biodegradable plasticizer significantly decreased the Tg and notably enhanced theflexibility of the nanocompositefilm by increasing the elongation at break approxi-mately 1.5-fold compared to that of the neat PLAfilm.This contributes to its feasibility as an active food packa-ging material.

Improvement in the electrical performance and bias-stress stability of dual-active-layered silicon zinc oxide/zinc oxide thin-film transistor

Si-doped zinc oxide（SZO） thin films are deposited by using a co-sputtering method,and used as the channel active layers of ZnO-based TFTs with single and dual active layer structures.The effects of silicon content on the optical transmittance of the SZO thin film and electrical properties of the SZO TFT are investigated.Moreover,the electrical performances and bias-stress stabilities of the single- and dual-active-layer TFTs are investigated and compared to reveal the effects of the Si doping and dual-active-layer structure.The average transmittances of all the SZO films are about 90% in the visible light region of 400 nm-800 nm,and the optical band gap of the SZO film gradually increases with increasing Si content.The Si-doping can effectively suppress the grain growth of ZnO,revealed by atomic force microscope analysis.Compared with that of the undoped ZnO TFT,the off-state current of the SZO TFT is reduced by more than two orders of magnitude and it is 1.5 × 10^-12 A,and thus the on/off current ratio is increased by more than two orders of magnitude.In summary,the SZO/ZnO TFT with dual-active-layer structure exhibits a high on/off current ratio of 4.0 × 10^6 and superior stability under gate-bias and drain-bias stress.

Zinc oxide nanocomposites with antitumor activity

Zinc oxide nanocomposites in the form of coatings and composite films with antitumor activity were obtained by deposition of ZnO nanofilms on surfaces of ethyl ether Sali- cylidene DL-tyrosine (S1) and ethyl ether Sali- cylidene DL-tyrosine Cu (II) chelate (S2) by magnetron sputtering of Zn target. Ethyl ether salicylidene DL-tyrosine, Cu (II) chelate of ethyl ether salicylidene DL-tyrosine reveal some anticancer properties. Their zinc oxide nano- composites were obtained in the form of coat- ings (S1 + ZnO, S2 + ZnO) and composite films presenting a mixture of polyvinyl alcohol (PVA) with S1, S2 (S1 + PVA + ZnO, S2 + PVA + ZnO), for the purpose of increasing anticancer activity. Considerable increase in antitumor activity re- veal ZnO nanocomposites with salicylidene amino acid chelates (as distinct from their ethers) in the form of S2 + ZnO (47%) and S2 + PVA + ZnO (48%) in comparison with S2 (20%). Structural, spectral properties of the salicylidene amino acids and their ZnO nanocomposites were studied.

Zinc Oxide Composites of Doxorubicin in the Form of Coating, Composite Films and Gels with a High Antitumor Activity and Low Toxicity

This work is devoted to the formation doxorubicin (DOX) zinc oxide composites in the form of coating (DOX + ZnO), hydrogels and composite films of DOX with polyvinyl alcohol (DOX + PVA + ZnO) by DC-magnetron deposition of ZnO nanoscale particles (ZnO NPs) on their surfaces (DOX, DOX + PVA) with higher (two times and more) antitumor activity and considerable smaller toxicity at low doses of DOX in compositions compared to the initial drug. Using the methods of spectroscopy, atomic force microscopy (AFM), scanning electron microscopy (SEM) and X-ray Powder Diffraction (XRD), the role of ZnO NPs size on the antitumor activity of doxorubicin zinc oxide compositions is shown. AFM shows presence of many ZnO NPs on the surface DOX. A comparison of the FTIR spectra of DOX and its zinc oxide compositions has shown the presence of new bands of OH valence and deformation vibrations. It is possible to assume that interaction between ZnO and DOX takes place in the form of hydrogen bond, promoting the complexes formation. It is possible that both synergic and hydrogen-bonding ZnO with DOX increase the antitumor activity.

Influence of Tin Doping on the Photocatalytic Activity of Zinc Oxide Thin Films under UV Light

Pure ZnO and Sn-doped ZnO thin films were successfully prepared by the spray pyrolysis method onto glass substrates. The obtained films were characterized by XRD （X-ray diffraction）, SEM （scanning electron microscopy） and ultraviolet-visible spectroscopy. The XRD results showed that the FWHM of Sn-doped ZnO film increased due to the substitution of Sn for Zn, the tin doping within the film causes the ZnO crystallinity to deteriorate. The grains of the film doped with Sn using dibutyltin diacetate were found to be non-uniform distribution through the sample but those appeared to form ganglia-like hills in the case of pure ZnO film. Furthermore, the Sn-doped ZnO films were tested with respect to the photocatalysis in aqueous solutions of MG （malachite green） upon UV-light illumination and in darkness. It was found that Sn-doped ZnO films prepared under specific conditions showed a lower photocatalytic activity than that of pure ZnO films.

Electrochemical Synthesis and Photocatalytic Property of Zinc Oxide Nanoparticles

Zinc oxide(ZnO) nanoparticles of varying sizes(20, 44 and 73 nm) have been successfully synthesized by a hybrid electrochemical-thermal method using aqueous sodium bicarbonate electrolyte and sacrificial Zn anode and cathode in an undivided cell under galvanostatic mode at room temperature. The as-synthesized product was characterized by X-ray diffraction(XRD), X-ray photoelectron spectra(XPS), Scanning electron microscopy along with Energy dispersive analysis of X-ray(SEM/EDAX), Transmission electron microscopy(TEM), Ultra Violet- Diffuse reflectance spectroscopic methods(UV-DRS). and UV-DRS spectral methods.The as-synthesized compound were single-crystalline and Rietveld refinement of calcined samples exhibited hexagonal(Wurtzite) structure with space group of P63mc(No.186). The band gaps for synthesized ZnO nanoparticles were 3.07, 3.12 and 3.13 e V, respectively, based on the results of diffuse reflectance spectra(DRS). The electrochemically synthesized ZnO powder was used as photocatalysts for UV-induced degradation of Methylene blue(MB). Photodegradation was also found to be function of exposure time and dye solution p H. It has been found that as-synthesized powder has excellent photocatalytic activity with 92% degradation of MB, indicating ZnO nanoparticles can play an important role as a semiconductor photocatalyst.

Synthesis and Characterization of Zinc Oxide and Zinc Oxide Doped with Chlorine Nanoparticles as Novel <i>α</i>-Amylase Inhibitors

In this study we used a chemical solution method from oxalic acid (OX. acid) and zinc acetate (ZnAc) to prepare Zinc Oxide nanoparticles (ZnONPs) and Zinc Oxide nanoparticles doped with Chlorine (Cl:ZnONPs). The characterizations (FTIR, X-ray, SEM, TEM) of ZnONPs and Cl:ZnONPs were determined. Amylase inhibitors of ZnONPs and Cl:ZnONPs also were determined. SEM indicated that the ZnONPs and Cl:ZnONPs have an average particle size of 46.65 - 74.64 nm. TEM images of the ZnONPs and Cl:ZnONPs showed the round shaped. Compounds b, d and e exhibited significant inhibitory activity against amylase enzyme (from 69.21 ± 1.44 to 76.32 ± 0.78), respectively, and were comparable with that of acarbose (86.32 ± 0.63) at 1000 μg, thereby, projecting ZnONPs and Cl:ZnONPs as α-amylase inhibitors.

Preparation and Properties of Ultra-fine Chromium Carbonization of High Performance Mechanical Activation

The preparation of hydroxyl chromium oxide by hydrogen reduction of disodium chromate and particulate hydroxyl mechanical activation features were studied. Then with self-made hydroxyl chromium as the raw material, a direct reduction and carburization process was used to prepare ultra-fine chromium carbonization. Through SEM and XRD, the high performance mechanical activation, key coefficients, microstructure, hardness and wear-resisting property were investigated. The results reveal that suitable mechanical activation and carbon reducing carbonization temperature, carbonization time, carbon content are beneficial to obtaining ultra-fine chromium carbonization. Typically, when the time of high performance grinding is 5 min, the carbon reducing temperature is 1100 ℃, the carbon reducing time is 1h, the carbon content is 28%, and finally the particle size of chromium carbide powder is 1 μm. Under this condition of preparation of ultra-fine chromium carbide, both the hardness and wear resistance are better than those in the industrialization of chromium carbide coating.

New Constraints on the Environmental Impact of Iron Oxides and Lead-Zinc Mines in Red Sea Hills,Egypt

Iron oxides and lead-zinc deposits in host rocks located in ten drainage basins in the coastal plain of the Red Sea,Egypt,have been subjected to important mining activities.The drainage basins were analyzed to estimate the transportations of these minerals. Fourteen soil samples and fifteen plant samples were collected from sites located in the basin and also in neighboring area and chemically analyzed.In

机械力化学浸出法从氧化锌矿中高效浸出锌

以篮式研磨机为机械力化学活化设备对我国兰坪地区低品位氧化铅锌矿进行研究,提出将研磨与NaOH溶液浸出过程相结合浸出锌的机械力化学浸出(MCL)工艺。研究浸出温度、NaOH浓度、浸出时间、液固比和搅拌速度对锌浸出率的影响。实验结果表明,在最佳浸出条件下,采用MCL工艺锌的浸出率达到92.3%,比常规搅拌浸出(CSL)工艺的高7.2%,且两种工艺的能耗相差不大,证明了MCL工艺的优越性。通过对原矿进行锌物相分析以及对最佳条件下不同工艺浸出渣进行XRD、SEM-EDS、EPMA和粒度等分析,研究机械力化学活化的强化机理。

MEL-A-ZnONPs的制备、表征及抗菌活性研究

为提高纳米氧化锌(zinc oxide nanoparticles,ZnONPs)的分散性和抗菌活性,该研究将绿色、无毒的A型甘露糖赤藓糖醇脂(mannosylerythritol lipids-A,MEL-A)用于ZnONPs的制备和修饰,并利用紫外可见光谱、X射线衍射、傅里叶红外光谱、纳米粒度、Zeta电位和透射电镜-能谱等方法进行表征。结果表明,MEL-A添加浓度为0.250 mmol/L时,制备出的0.250MEL-A-ZnONPs平均粒径及多分散系数(polydispersity index,PDI)值最小,分别为(78.25±27.26)nm和0.155,Zeta电位的绝对值达到最大,为-22.89 mV,且透射电镜形貌及分散性最好,显著优于未修饰的对照组(N-ZnONPs)。利用最小抑菌浓度(minimum inhibitory concentration,MIC)、最小杀菌浓度(minimum bactericidal concentration,MBC)、生长曲线、抑菌圈等实验评价ZnONPs的抗菌性能,发现N-ZnONPs和0.250MEL-A-ZnONPs对金黄色葡萄球菌的MIC均为12.0 mg/L,MBC分别为24.0 mg/L和16.0 mg/L,对大肠杆菌的MIC分别为24.0 mg/L和20.0 mg/L,MBC分别为32.0 mg/L和24.0 mg/L,表明MEL-A-ZnONPs对金黄色葡萄球菌具有更好的抗菌效果。

响应曲面法优化超声协同活化剂浸出高硅低锗氧化锌烟尘研究

为了最大化高硅低锗氧化锌烟尘(ZOD)中锌、锗提取效率,研究了采用响应曲面法(RSM)构建并优化了十二烷基硫酸钠(C_(12)H_(25)SO_(3)Na)辅助下的超声强化浸出过程,并建立了锌、锗浸出率的精确预测模型。结果表明:在单因素试验基础上,运用RSM确定的最优浸出条件为浸出温度70℃,液固体积质量比8 mL/1 g,初始酸质量浓度160 g/L,该条件下的锌浸出率达96.94%,锗浸出率为85.41%;C_(12)H_(25)SO_(3)Na在浸出过程中发挥了关键的硅胶抑制剂作用,有效阻止了硅离子聚合成硅胶,这一效果在超声波的协同作用下更为显著,体现了温度、超声波与C_(12)H_(25)SO_(3)Na三者之间的显著协同效应。研究结果能为高硅低锗氧化锌烟尘的资源化利用提供高效的回收策略,并为其他高硅废弃物的回收提供技术参考。

氧化锌在橡胶生产中的应用综述

氧化锌是橡胶工业重要的添加剂之一。综述了氧化锌作为硫化剂、活化剂、交联剂、抗老化剂、热稳定剂和着色剂等在橡胶生产中的作用机制,列举了氧化锌橡胶在轮胎和密封件等方向的具体应用,分析了其在橡胶工业领域的研究现状和不足,并对应用前景予以展望。

日粮添加不同水平的氧化锌对波尔山羊卵巢活动和繁殖性能的影响

本试验将不同水平的氧化锌添加到波尔山羊的日常饲养中,研究其对卵泡活动和繁殖性能的影响。试验将60只山羊平均分为4组,每组3个重复,每个重复5只羊。分别为对照组、试验I组(日粮+300mg/kg氧化锌)、试验Ⅱ组(日粮+500mg/kg氧化锌)和试验Ⅲ组(日粮+700mg/kg氧化锌)。试验为期40d,试验结束后测定其卵泡活动、繁殖激素和繁殖性能等指标。结果发现,与对照组相比,在日粮中添加不同水平的氧化锌对波尔山羊的促性腺激素释放激素(GnRH)、促卵泡成熟激素(FSH)、促黄体生成激素(LH)均有显著影响(P <0.05),其中添加500mg/kg氧化锌对提升波尔山羊的卵泡活动效果最显著(P <0.05),GnRH、FSH和LH比对照组分别提高18.17%、29.34%和27.14%;其次,在日粮中添加不同水平的氧化锌对波尔山羊血清中的雌二醇(E2)、孕酮(P4)等繁殖激素指标也有显著影响(P <0.05),其中试验Ⅱ组的繁殖激素指标与对照组相比差异显著(P <0.05),E2、P4分别提高11.56%和27.93%。最后,在日粮中添加不同水平的氧化锌对波尔山羊的繁殖性能也有显著影响(P <0.05),其中500mg/kg氧化锌试验组羊受胎率、产羔率及双羔率与对照组相比差异显著(P <0.05),受胎率、产羔率及双羔率分别比对照组提高30.8%、33.3%和33.3%。研究结果表明,在日粮中添加500mg/kg的氧化锌,对波尔山羊的卵泡活动和繁殖性能的促进效果最显著。

高分散性活性剂SA-800在胎面胶中的应用

研究高分散性活性剂SA-800(简称SA-800)等氧化锌含量(简称等锌)或减氧化锌含量(简称减锌)替代普通氧化锌在胎面胶中的应用。结果表明:SA-800等锌替代普通氧化锌时,胎面胶的焦烧时间和正硫化时间延长,加工安全性好,其他性能基本相当,可在丁苯橡胶/顺丁橡胶/白炭黑胎面胶和天然橡胶/炭黑胎面胶中替代普通氧化锌;SA-800减锌替代普通氧化锌时,胎面胶的焦烧时间和正硫化时间与等锌替代时相比略有缩短,仍长于普通氧化锌胎面胶,其他性能变化不大,且与普通氧化锌胎面胶基本相当。使用SA-800可实现锌减量的目的。

氧化锌的微观形貌调控及其光催化性能研究

为研究氧化锌的微观形貌对光催化性能的影响,研究了以硝酸锌为锌源,氢氧化钠为沉淀剂,采用直接沉淀法制备的不同微观形貌的氧化锌。通过X射线衍射仪(XRD)对氧化锌的物相结构进行分析,表明该方法可成功制备出氧化锌;采用扫描电镜(SEM)对制备出的氧化锌粉体微观形貌进行表征,结果表明随着氢氧化钠与硝酸锌摩尔比的增加,氧化锌粉体分别呈现出球状、花状和棒状构型。随后开展了氧化锌光催化降解柠檬黄效果实验,降解实验表明,氢氧化钠与硝酸锌的摩尔比为4时,制备的氧化锌粉体具有最好的光催化性能,当pH为6,氧化锌质量浓度为0.15 g/L时,在50 min内柠檬黄降解效率可达到99.47%。

Antibacterial Activity of Cu^(2+)-ZnO-modified 13X Zeolite against E.coli and S.aureus

A new type of zeolite composite antibacterial agents was prepared by introducing zinc oxide and copper ions into 13 X zeolite through the coprecipitation and ion-exchange methods. The structural properties of the tested antibacterial material were characterized and the antibacterial activity was evaluated. In Cu^(2+)/ZnO-13 X(CZ-13), zinc oxide and copper ions were either embedded in the interlayer space or dispersed on surface of 13 X zeolite. Excellent antimicrobial activity of CZ-13 was observed on Escherichia coli(E. coli) and Staphylococcus aureus(S.aureus). In the case of Cu^(2+)/ZnO-13 X, both MIC and MBC against E.coli were 0.2 mg/mL and 0.8 mg/mL. For S.aureus, CZ-13 also showed similar antibacterial properties. The bacterial cells turned from normal rod-shape into irregular shapes after treatment with the tested CZ-13. An increase of the intracellular enzyme activity after CZ-13 addition suggested that the permeability of the cell membrane increased and bacteria were damaged.

Evaluation of antibacterial activity of zinc oxide nanoparticles synthesized using phycobilins of Anabaena variabilis NTSS17

Objective:To evaluate the antibacterial activity of zinc oxide nanoparticles synthesized using phycobilins of Anabaena variabilis NTSS17.Methods:The cyanobacterial isolate was collected from paddy field and morphologically identified as Anabaena variabilis NTSS17,that produces a pigment i.e.phycobiliproteins.The biosynthesized zinc nanoparticles were characterized by different spectroscopic and analytical techniques such as UV-visible spectrophotometer,Fourier transform infrared spectroscopy and X-ray diffraction which confirmed the formation of zinc nanoparticles.Results:Antibacterial activity of zinc oxide nanoparticles was examined against Escherichia coli,Rhodococcus rhodochrous and Pseudomonas aeruginosa.The maximum zone of inhibition occurred at 5 mg/1000 mL concentration of zinc oxide nanoparticles.Conclusions:Due to potent antimicrobial and intrinsic properties of zinc oxide,it can be actively used for biomedical applications.

湿法炼锌溶液中臭氧氧化除铁工艺及动力学研究

以臭氧为强氧化剂、ZnO为中和剂进行湿法炼锌溶液中Fe^(2+)脱除的试验及动力学研究。考察初始Fe^(2+)浓度、溶液pH、反应温度和O_(3)流量等因素对除铁效果的影响。结果表明:增大pH、温度和O_(3)流量可以显著增加除铁效率,而增加初始Fe^(2+)浓度会降低除铁效率。宏观动力学研究表明,对比常用的拟一级、拟二级、Higbie和Avrami等动力学方程,臭氧氧化—沉淀除铁符合拟一级反应特征,受扩散控制,反应表观活化能为28.57 kJ mol,动力学方程为rFe^(2+)=8.22[Fe^(2+)]0^(-0.74)[H^(+)]^(-0.51)Qo^(1.89)_(3) exp(-3436 T)。

低锌活性剂SA-1替代氧化锌在丁苯橡胶胶料中的应用

采用低锌活性剂SA-1作为丁苯橡胶(SBR)胶料的硫化活性剂,研究其用量对SBR硫化胶物理性能、耐热空气老化性能和动态力学性能的影响,同时与普通氧化锌997进行对比。结果表明:活性剂SA-1在SBR基体中的分散性优于氧化锌997;活性剂用量较大(3~5份)时,采用活性剂SA-1的SBR硫化胶具有较出色的物理性能和耐热空气老化性能;随着活性剂SA-1和氧化锌997用量的减小,SBR硫化胶的物理性能和耐热空气老化性能均有下降,与氧化锌997相比,活性剂SA-1可以在用量更小时保持SBR硫化胶的物理性能;采用活性剂SA-1的SBR硫化胶具有更好的抗湿滑性能,同时滚动阻力无明显增大。