电场诱导沉积方法制备PLZT基单层有序周期结构多孔薄膜

利用电泳组装聚苯乙烯微球单层模板为基础,以溶胶-凝胶方法制备含有纳米粒子的母液,通过电场诱导母液中纳米粒子填充模板孔隙,制备具有反演结构的PLZT有序多孔薄膜.通过SEM和XRD分析,分别给出通过电场诱导PLZT凝胶中纳米粒子沉积得到了单层有序周期结构的微观结构形貌及晶相组成.提供一种简单的制备而为铁电有序微结构的方法,可以用于功能陶瓷基光子带隙材料的研究.     

聚苯乙烯微球和无机多孔膜的制备

用分散聚合法合成单分散聚苯乙烯(PS)胶体球(粒径约300nm～1.6μm),用扫描电子显微镜(SEM)观测所得产物,研究了单体苯乙烯、分散稳定剂聚乙烯基吡咯烷酮(PVP)和引发剂偶氮二异丁腈(AIBN)用量的改变对胶体球粒径的影响,结果表明随着单体和引发剂用量的增加,PS微球的粒径增大;随着分散稳定剂用量的增加,PS微球的粒径减小.以所得PS球自聚集成的胶体晶体或薄膜为模板,在球间隙中渗入无机SiO2溶胶-凝胶,再除去PS球,得到多孔膜.     

单层氧化锌有序孔膜的制备与性质

采用电化学沉积方法,结合胶体晶体模板,通过循环伏安方法对体系的电化学特性进行研究,获得一种良好的低沉积速度的制备工艺,即通过合适的电位恒电势法,最终获得了单层二维的氧化锌有序孔膜结构.对应于不同的沉积厚度,所得有序孔的形貌也会有所不同.通过扫描电子显微镜对该氧化锌有序多孔膜结构进行了表征,并研究了相应的光致激发特性,二维氧化锌有序多孔膜在384 nm表现出明显光致激发峰,激发峰的位置没有因单层有序孔阵列结构存在而有明显改变.     

胶晶模板法合成三维有序大孔金属氧化物材料

以自然沉积组装的聚苯乙烯（Ps）微球为胶体模板,分别以浓度为50％的钛酸四丁酯醇溶液和锆酸四丁酯醇溶液为前驱体对模板进行填充,最后通过煅烧除去模板得到了三维有序大孔（3DOM）TiO2、ZrO2材料。从SEM照片可观察到,3DOMTiO2、ZrO2材料可以看成是PS模板的逆复制,孔径大小均匀,与PS模板相比具有一定的收缩。进一步通过TEM照片观察,3DOM材料整体上呈面心立方结构,孔壁完整致密。XRD显示,制备的3DOM的TiO2和ZrO2孔壁分别为锐钛矿型和单斜晶型。     

利用PS模板制备多孔SrFe12O19薄膜的研究

本文以提拉浸渍法使用聚苯乙烯(PS)球模板制备了有序多孔结构的锶铁氧体(SrFe12O19)薄膜。将微乳液聚合法合成的PS球,通过提拉浸渍法有序地组装在硅片基板上形成PS模板;使用溶胶-凝胶法制备SrFe12O19前驱体溶胶,再采用提拉浸渍法使SrFe12O19前驱体溶胶填充PS模板的空隙,在900 ℃保温2 h去除PS球后即制得多孔SrFe12O19薄膜。重点研究了聚乙烯吡咯烷酮(PVP)的含量对PS球微观形貌,浸渍时间对PS模板以及多孔SrFe12O19薄膜微观形貌的影响,并对多孔SrFe12O19薄膜的形成机理进行了讨论,建立了相应的模型。结果表明：添加0.2 g的PVP可得到粒径均匀的PS球,且微球之间空隙明显;将硅片在PS球乳液中浸渍10 s可得到单层有序的PS模板;当PS模板在SrFe12O19前驱体溶胶中浸渍10 s时可制备出孔径约200 nm的蜂窝状多孔结构的纯SrFe12O19相薄膜,其表现出优异的硬磁性能：饱和磁化强度为27.9 emu/g,剩磁为15.5 emu/g,矫顽力为2613.4 Oe。     

CO/Al2O3纳米线有序阵列的制备与磁性

用电化学法制备了高度有序的多孔氧化铝模板(AAO),用交流沉积法以硫酸盐为电解液在多孔氧化铝模板中还原生长了Co纳米线,制备了Co/Al2O3纳米线有序阵列.通过电化学脉冲剥离法去除了沉积在阵列表面的过剩金属钴和金属铝基底,提高了样品的磁垂直各向异性.分别用扫描电镜(SEM)、透射电镜(TEM)、X射线衍射仪(XRD)对多孔氧化铝模板和纳米线阵列的微观形貌和结构进行了分析,用振动样品磁强计(VSM)对样品的磁学性质进行了测试.分析了模板孔径、孔心距、长径比以及交流电化学沉积条件如pH值、温度等对纳米线结构和磁性能的影响.孔心距和长径比一定的条件下,孔径增大引起孔壁厚度降低会导致纵向矫顽力和剩磁比下降.纳米线中的晶粒在生长过程中(100),(002)择优取向.当外场垂直磁化时,磁滞回线有较高的矩形比(0.6～0.85)和矫顽力(80 000A/m～150 400A/m),具有明显的垂直膜面各向异性,矩形比和矫顽力都比一般的二维合金薄膜材料大得多.     

有序多孔氧化铝模板及 ZnO 沉积膜的制备与表征

采用二次阳极氧化法制备有序多孔氧化铝模板(AAO),探讨了氧化时间、磷酸溶液浸泡后处理对氧化铝表面形貌的影响。以AAO为模板沉积ZnO薄膜,通过SEM,XRD,EDS,AFM等技术对氧化铝模板及ZnO薄膜进行表征,结果表明,有序多孔层为非晶态氧化铝。研究了以AAO为模板沉积ZnO薄膜作光阳极的染料敏化太阳电池的光电转换性能,得出其转换效率为0.34%。     

电泳沉积ZnO薄膜的制备和表征（英文）

采用电泳沉积,在ITO玻璃基片上制备了多孔纳米晶片组成的网状ZnO薄膜。研究了工艺参数如电流密度和沉积时间对ZnC)前躯体薄膜的表面形貌和相组成的影响。结果表明,纳米片在低电流密度下水平覆盖在基片上,而在高电流密度下则垂直于基片排列形成均匀分布的网状膜。基于纳米片表面上电荷的分布提出了可能的形成机理。由于一些纳米片的聚集,增加沉积时间有助于花状微米球的形成。从胶体悬浮液中所沉积的薄膜主要由ZnO和Zn_4C3(OH)_6H_2O相组成,热处理后薄膜中的Zn_4C3(OH)_6H_2O相完全转变成ZnO。多孔纳米片的形成是由于Zn_4C3(OH)_6H_2O相分解释放了水和CO_2。热处理加强了ZnO薄膜的微纳米层级结构。     

高度有序多孔氧化铝模板影响因素的研究

在酸性电解液中,用阳极氧化法制备得到了多孔阳极氧化铝(anodic aluminum oxide,AAO) 模板.用金相显微镜观察了铝片表面上的晶界,并结合扫描电镜对多孔氧化铝薄膜进行了观察和表征.研究了影响多孔氧化铝模板孔洞有序性的关键性因素.实验结果表明,多孔阳极氧化铝膜的有序度依赖于铝箔预处理、电极材料、氧化电压和电解液类型及温度等因素.     

微/纳米多孔氧化锌薄膜的电化学制备及其光催化性能

在高度阴极极化条件下,以析氢气泡为动态模板,电沉积制备微/纳米多孔锌薄膜,经加热氧化制备得到微/纳米多孔氧化锌薄膜.研究电流密度、镀液组成和温度对多孔金属锌薄膜孔径大小和孔壁形貌的影响.结果表明:通过改变电流密度、镀液组成和温度,可调控孔径大小和孔壁结构;在30 ℃的0.05 mol/L ZnSO4和2 mol/L NH4Cl溶液中,电流密度为0.3～0.8 A/cm2时,可得到主孔径约为50～100 μm的多孔锌薄膜,形成孔壁的枝晶由大小为100～300 nm的颗粒构成;在空气气氛下经350 ℃加热1 h、450 ℃加热2 h氧化处理后,多孔锌薄膜转变为具有相似微/纳米多孔结构的氧化锌薄膜,并显示出优异的光催化降解罗丹明B的性能.     

Layer-by-layer assembly of nanocomposite films with thickness up to hundreds of nanometers

1 Introduction In 1991, DECHER and his co-worker extended ILER’s pioneering work on fabrication of inorganic colloidal particle-based layer-by-layer assembled films to the preparation of polyelectrolyte-based layer-by-layer assembled films[1?3]. Now the…     

硅溶胶改性有机-无机杂化纳米薄膜的制备及性能测试

采用溶胶-凝胶法,以甲基三乙氧基硅烷(MTEOS)和正硅酸乙酯(TEOS)为原料,制备有机-无机杂化薄膜,又采用纳米硅溶胶对有机-无机杂化薄膜进行改性。硅溶胶改性后有机-无机杂化纳米薄膜透明而且光滑,大大提高了薄膜的临界厚度。以热失重(DTA/TG)、傅立叶红外光谱(FTIR)手段研究了薄膜材料的结构及性能随温度的变化,并对涂覆于不锈钢表面上的硅溶胶改性后有机-无机杂化薄膜的防腐蚀性能进行了实验检测。结果表明,硅溶胶改性后有机-无机杂化薄膜的热稳定性能明显提高,并具有优良的抗腐蚀性能。     

Platinum colloid catalyzed etchingless gold electroless plating with strong adhesion to polymers

Echingless electroless plating (ELP) process that can produce gold thin film with strong adhesion to various polymer films has been developed. We have found that platinum (Pt) colloidal nanoparticles have excellent catalytic activity for ELP. The Pt colloidal nanoparticles can be immobilized via electrostatic interactions on a substrate simply by dipping it into a Pt colloid. Owing to the excellent catalytic property of the Pt nanoparticles, continuous gold thin films can be produced at room temperature using a simple cyanide-free gold electroless plating solution composed of chloroauric acid and hydrogen peroxide. The process requires no surface modifications for the immobilization of the catalyst, and by simple post-annealing the adhesion of the plated films to various polymer films can be improved by three orders of magnitude in comparison to that of “as-deposited” film. The process developed in this work is expected to be an environment-friendly thin metal film deposition process without the use of toxic and hazardous substances.     

Micro/nano-tribological behaviors of crown-type phosphate ionic liquid ultrathin films on self-assembled monolayer modified silicon

A series of novel imidazolium-based crown-type phosphate ionic liquid ultrathin films were fabricated on silicon substrates modified by a self-assembled monolayer. The formation and surface properties of the films were analyzed by means of ellipsometric thickness measurement, X-ray photoelectron spectroscopy, and atomic force microscope. Meanwhile, the adhesive and nano-tribological behaviors of the films were tested by a homemade colloidal probe, and a ball-on-plate tribometer was used to evaluate their micro-tribological performances in the reciprocating mode. As a result, the dual-layer films show enhanced micro/nano-tribological properties as compared to single-component ionic liquid films coated directly on the silicon surfaces, which is ascribed to synergic effect of the steady self-assembled underlayer as a load-carrying phase and the proper amount of flowable ionic liquid fraction with self-replenishment property. Hopefully, the novel dual-layer ultrathin films based on fluorine-free ionic liquids and self-assembled monolayer produced in the present work might find promising applications in the lubrication of micro-electromechanical systems.     

快淬工艺对Mg2Ni型合金气态及电化学贮氢动力学的影响

以聚苯乙烯胶体晶体为模板,通过调制溅射功率和溅射时间制备了相同厚度、不同孔间距的Co有序大孔阵列.利用扫描电子显微镜(SEM)、原子力显微镜(AFM)、X射线衍射(XRD)和振动样品磁强计(VSM)考察了样品的结构和磁学特性.发现Co有序大孔阵列的矫顽力和剩磁比最大达到175.02×10-4 T和0.76,分别为Co薄膜的2.2倍和2.5倍,并且随孔间距的增大逐渐降低.结合理论分析结果表明,Co有序大孔阵列本身的形状各向异性是其取得优良磁学性能的原因,孔洞形状各向异性和薄膜本身磁晶各向异性的竞争机制是造成其磁性发生变化的物理本质.     

Properties of cadmium sulfide thin films deposited by chemical bath deposition with ultrasonication

Ultrasonic agitation was applied during the chemical bath deposition of CdS thin films. Ultrasonication resulted in a dramatic change in the surface morphology, growth rate, and optical properties of CdS films. There were virtually no colloidal particles adsorbed on the surface. The surface roughness measured by atomic force microscopy was reduced by a factor of two. Band gap energy increased to 2.39 eV from 2.37 eV. X-ray patterns showed that the preferred orientation changed from hexagonal (002)/cubic (111) to hexagonal (101). Optical transmission improved in the wavelength range larger than 520nm. The chemical reaction for CdS formation started at a lower temperature under ultrasonication, and dense films were obtained even when the chemical composition of the aqueous solution deviated far from optimum conditions.     

High near-infrared photoluminescence quantum efficiency from PbS nanocrystals in polymer films

We investigate the effect of film morphology and phase segregation in polymer/colloidal PbS nanocrystal films on the near-infrared photoluminescence quantum efficiency (PLQE) of the nanocrystals. A direct correlation between the size of closed packed nanocrystal phase separated domains and lower PLQE was established. Films with a near-infrared PLQE of up to 12% have been prepared.     

Sol–gel derived films in meso-porous matrices: porous silicon,anodic alumina and artificial opals

Processing of the sol–gel derived films doped with the lanthanides onto generally available microelectronic materials-like porous silicon (po-Si) and porous anodic alumina is considered as a low-cost method of fabricating the thin luminescent films. The origin of 1.53 μm emission from Er-doped xerogels fabricated onto micro-, meso- and macro-porous silicon is discussed. Further, porous anodic alumina, exhibiting regular pore morphology was shown to be an effective template for fabricating the luminescent xerogels. Finally, application of sol–gel process for synthesis the 3D colloidal photonic crystals is discussed.     

非晶硅薄膜的金属诱导晶化研究现状

概述了非晶硅薄膜的金属诱导晶化原理,介绍了Al,Ni两种金属诱导非晶硅薄膜晶化的一般规律,详细探讨了金属诱导条件下非晶硅薄膜的本质晶化机理,旨在为非晶硅薄膜的低温成核、晶化机理研究和多晶硅薄膜的研发制备提供实验支持与理论参考.