Layer-by-layer assembly of polyelectrolyte/TiO2 thin films with reflection-enhancing function

Colloidal TiO₂ was prepared by hydrolyzing tetra-n-butyl titanate. Composite multilayer films of poly(sodium 4-styrenesulfonate) (PSS) and colloidal TiO₂ particles were layer-by-layer assembled onto optic fibers and microscope glass slides. As the PSS/TiO₂ film was deposited onto the end face of a glass fiber, the reflected optic intensity periodically oscillated as the bilayer number of the film increased. After a 24-bilayer film was coated onto the both sides of a glass slide, the transmittance at 850 nm decreased more than 20%, which means that the film could serve the function as a reflection-enhancing coating. X-ray diffraction analysis and data of TEM electron diffraction analysis show that the colloidal TiO₂ particles are mainly brookite nanocrystals and that the PSS/TiO₂ films are polycrystalline films. Scratching experiments indicate that the composite films are of relatively high hardness.     

氢敏元件的种类及半导体薄膜材料在其中的应用

随着氢燃料电池技术在汽车应用中的日益完善,对高性能氢敏元件的需求也更加迫切。本文介绍了采用不同工作原理制备的氢敏元件的种类,着重描述了半导体薄膜材料的工作原理和改性途径,并针对我国目前研究较少的Ga2O3新型薄膜材料进行了较为详细的综合论述。     

聚苯胺/磺化酞菁铜自组装复合薄膜的制备与表征

运用层层自组装的技术制备了聚苯胺/磺化酞菁铜(PANI/CuTsPc)超分子复合薄膜,并通过紫外-可见-近红外吸收光谱、傅立叶红外光谱、X射线衍射仪与原子力显微镜对薄膜进行了表征与分析.紫外-可见-近红外吸收光谱表明,PANI和CuTsPe具有良好的层层自组装特性,沉积过程具有均匀性与重复性;傅立叶红外光谱表明,复合薄膜是由PANI和CuTsPc组成的,PANI和cuTsPc通过静电力的作用组装成膜;X射线衍射结果表明,复合薄膜是非晶态的;原子力显微镜观察到薄膜表面是比较均匀和致密的,但有一定的粗糙度.     

Fabrication of two-dimensional close-packed shell structure in ceramic thin films

TiO₂ thin films with a periodical two-dimensional close-packed hemispherical structure were prepared on Si substrates using pulsed laser deposition and close-packed monolayer polystyrene colloidal crystals as a template. Compared with conventional methods, which use a top-down approach, this route supports low-cost production of a periodic structure. Additionally, it is applicable to various ceramics for use in applications related to photonic crystals, surface self-cleaning materials, data storage media, bioassays, and so on.     

Fabrication of two-dimensional close-packed shell structure in ceramic thin films

Abstract

TiO₂ thin films with a periodical two-dimensional close-packed hemispherical structure were prepared on Si substrates using pulsed laser deposition and close-packed monolayer polystyrene colloidal crystals as a template. Compared with conventional methods, which use a top-down approach, this route supports low-cost production of a periodic structure. Additionally, it is applicable to various ceramics for use in applications related to photonic crystals, surface self-cleaning materials, data storage media, bioassays, and so on.     

Layer-by-layer assembly of thin film oxygen barrier

Thin films of sodium montmorillonite clay and cationic polyacrylamide were grown on a polyethylene terephthalate film using layer-by-layer assembly. After 30 clay–polymer layers are deposited, with a thickness of 571 nm, the resulting transparent film has an oxygen transmission rate (OTR) below the detection limit of commercial instrumentation (< 0.005 cc/m²/day/atm). This low OTR, which is unprecedented for a clay-filled polymer composite, is believed to be due to a brick wall nanostructure comprised of completely exfoliated clay in polymeric mortar. With an optical transparency greater than 90% and potential for microwaveability, this thin composite is a good candidate for foil replacement in food packaging and may also be useful for flexible electronics packaging.     

铝掺杂对非晶SiOx薄膜电致发光的影响

为提高硅基薄膜（SiOx）发光材料的发光效率，采用双离子束溅射法制备了不同铝含量的Al—Si—SiOx薄膜。对所制备样品的电致发光（EL）测试表明：由于金属（Al）的掺入，使得在同样的电压下。薄膜中的电流随着铝含量的增加而增加；并且铝含量增大使得通过薄膜的电流增强，因而得到较高强度的电致发光。所以当硅基薄膜中掺入铝时，薄膜的发光效率得以提高；并且，随着铝含量的增加，薄膜的发光效率亦相应提高。     

胶原蛋白纳米超薄膜在生物材料表面的原位构建及表征

采用静电层层自组装技术构建了以I型胶原蛋白(COL)为主要构成的纳米超薄膜。该类型薄膜厚度与涂层层数呈线性关系。通过"喷涂"方式,在未经任何理化作用处理的生物可降解聚酯材料表面可原位形成厚度可控的胶原蛋白薄膜结构,改善聚酯材料的亲水性。在小鼠成纤维细胞(L929)培养实验中,聚乳酸(PLA)表面负载多层膜以后,表现出良好的细胞生物相容性,有利于细胞的生长和铺展。     

铝诱导非晶硅薄膜快速低温晶化研究

采用金属铝诱导晶化非晶硅薄膜的方法制备多晶硅薄膜。研究了不同的退火温度对a-Si薄膜晶化的影响，采用XRD，Raman，SEM等测试手段分析了实验结果。实验结果发现非晶硅薄膜在400℃下退火20min薄膜仍为非晶结构（a-Si），在450℃下退火20min后非晶硅开始晶化且随着温度的升高，且晶化程度加强。     

YSZ薄膜的制备及应用

研究了在ＮＡＳＩＣＯＮ基板上使用溅射法制备的ＹＳＺ薄膜的结构,晶相和导电性,实验表明,刚制备的ＹＳＺ薄膜７５０℃常规退火处理后,薄膜表面致密、均匀、无裂纹,具备良好的导电性能,ＹＳＺ／ＮＡＳＩＣＯＮ组合再加上Ｂａ（ＮＯ３）２辅助电极构成的ＮＯｘ气体传感器在４５０℃下响应迅速（响应时间约为３ｍｉｎ）、稳定、能检测到１０ｐｐｍ量级的ＮＯ２气体。     

二元合金薄膜的表面偏析

本文评述了广泛应用于描述平衡态和动态偏析的修正Darken模型。该模型首次提出了偏析的驱动力是化学势梯度,并成功地应用于定量描述体块材料的平衡态和动态的表面偏析。在考虑到薄膜体系中的尺寸效应后,引入了一个约束条件,再将其应用于修正的Darken模型,实现了在所有的浓度和薄膜厚度范围内,对合金薄膜体系的平衡态和动态的表面偏析的模拟计算。并利用该模型模拟了N(i111)Cu二元合金薄膜系统的平衡态和动态的表面偏析。     

层层自组装技术的研究进展及应用情况

层层自组装技术(Layer-by-layer self-assembly,LbL)是正处于发展阶段的新技术。与传统成膜技术相比,该技术能组装的材料多种多样(如聚电解质、纳米颗粒、有机小分子等),可以通过模板精确控制薄膜的表面结构和尺寸。薄膜的通透性能和力学性能可以通过控制组装材料、沉积层数、组装条件等来改善。对层层自组装技术的研究进展及应用情况进行了综述,较为详细地介绍了层与层之间作用力的研究进展,阐述了LbL技术在电化学电容器、光敏微胶囊、分离膜、生物化学及药物释放中的应用,并对LbL技术的发展前景进行了展望     

层层自组装制备PANI/CuTsPc复合薄膜及其性能研究

运用层层自组装技术制备了聚苯胺/磺化酞菁铜(PANI/CuTsPc)超分子复合薄膜,并通过紫外-可见-近红外吸收光谱、红外光谱、电导率测试仪与热分析仪对复合薄膜进行了分析表征以及导电性、光吸收与热稳定性能的研究.紫外-可见-近红外光谱表明,PANI与CuTsPc具有良好的层层自组装特性,沉积过程具有均匀性与重复性,复合薄膜在可见光区和近红外区均具有平而且宽的强吸收谱带;红外光谱表明,PANI和CuTsPc通过静电力的作用成功组装成膜,复合薄膜的共轭体系得到加强;电导率测试结果表明复合薄膜具有较高的电导率,达到了0.3S/cm;热分析结果表明CuTsPc组分的加入使复合薄膜具有良好的热稳定性.     

Sulfidation growth and characterization of nanocrystalline ZnS thin films

Nanocrystalline ZnS thin films are prepared on glass and quartz substrates by sulfurizing ZnO thin films in the H₂S-containing mixture at 500 °C. These films are investigated by X-ray diffraction, scanning electron morphology, optical transmittance and photoluminescence spectra. The results show that the ZnS thin films have the hexagonal structure with a c-axis preferred orientation. Also, these nanostructure ZnS thin films with the grain size of ∼50 nm along the c-axis, exhibit the optical transparency as high as ∼80% in the visible region. It is found that sulfur replacement of oxygen sites in crystal lattices and recrystallization can take place during sulfidation, resulting in an evident increase of the grain size for the sulfurized films. Under the optimum sulfidation time of 2 h, the resultant ZnS thin films have a high crystallinity, low defect concentration and good optical properties with the band gap of 3.66 eV.     

纳米晶ZnFe2O4薄膜的制备及其丙酮气体敏感性能研究

以尖晶石结构ZnFe2O4材料为研究对象,以可溶性无机盐为原料,利用溶胶-凝胶技术在Al2O3基片上制备了ZnFe2O4薄膜,研究其对低浓度丙酮气体的敏感特性.通过DTA,TG,XRD及SEM分析手段对制膜过程及薄膜形态进行了表征.研究发现,采用柠檬酸作为络合剂的无机盐原料溶液-溶胶-凝胶(ISG)工艺,在700℃烧结温度下,可以得到覆盖良好、结构均匀、晶粒尺寸约在100nm的尖晶石结构ZnFe2O4薄膜.通过该薄膜对丙酮气敏特性测试表明,ZnFe2O4材料对丙酮具有较好的敏感性,在550℃的操作温度下,材料对丙酮气体敏灵敏度为8,响应与恢复时间小于5s.     

Multidimensional CdS nanowire/CdIn<Subscript>2</Subscript>S<Subscript>4</Subscript> nanosheet heterostructure for photocatalytic and photoelectrochemical applications

Nanomaterial shapes can have profound effects on material properties,and therefore offer an efficient way to improve the performances of designed materials and devices.The rational fabrication of multidimensional architectures such as one dimensional (1D)-two dimensional (2D) hybrid nanomaterials can integrate the merits of individual components and provide enhanced functionality.However,it is still very challenging to fabricate 1D/2D architectures because of the different growth mechanisms of the nanostructures.Here,we present a new solventmediated,surface reaction-driven growth route for synthesis of CdS nanowire (NW)/CdIn2S4 nanosheet (NS) 1D/2D architectures.The as-obtained CdS NW/CdIn2S4 NS structures exhibit much higher visible-light-responsive photocatalytic activities for water splitting than the individual components.The CdS NW/CdIn2S4 NS heterostructure was further fabricated into photoelectrodes,which achieved a considerable photocurrent density of 2.85 mA.cm-2 at 0 V vs.the reversible hydrogen electrode (RHE) without use of any co-catalysts.This represents one of the best results from a CdS-based photoelectrochemical (PEC) cell.Both the multidimensional nature and type Ⅱ band alignment of the 1D/2D CdS/CdIn2S4 heterostructure contribute to the enhanced photocatalytic and photoelectrochemical activity.The present work not only provides a new strategy for designing multidimensional 1D/2D heterostructures,but also documents the development of highly efficient energy conversion catalysts.     

纳米晶TiO2薄膜的制备、表征及其光催化性能的研究

采用sol-gel法制备TiO2薄膜。用XRD、UV－vis、AFM对其结构、光谱吸收及表面形貌进行了表征。以具有典型偶氮染料结构的甲基橙水溶液为目标反应物，对膜的光催化性能进行了研究。结果表明，在普通玻璃衬底上得到了比较好的锐钛矿型TiO2薄膜，其紫外吸收谱带拓宽，该膜对低浓度甲基橙有较好的光催化降解功能。     

CuInS2薄膜的制备及光学特性

真空共蒸发在玻璃衬底上制备CuInS2薄膜.研究不同Cu、In、S元素配比、不同热处理条件对薄膜的结构、化学计量比及光学性能的影响.实验结果给出:在元素配比中S的原子比x选择极为重要(实验选0.2≤x≤2),本实验Cu、In、S最佳原子比为1:0.1:1.2.用x(Cu).x(In):x(S)=1:0.1:1.2原子比...     

Theoretical study of the gas sensitivity and response time of metal oxide thin films

In this paper, based on the gas sensitive mechanism of metal oxide semiconductor thin film, the law of gas diffusion, first order aerodynamics and the relative assumption, we present a simple model for the simulation of the steady state gas sensitivity of metal oxide thin film. Our model provides a general mathematical relationship between the steady state sensitivity and the film thickness. The metal oxide semiconductor thin film is supposed to be formed with a finite number of independent layers. Each layer consists of ideally spherical grains with close-packed structure. The target gas is assumed to affect the inner layers either by penetrating through the grain boundaries or by direct interacting with each layer surface. Besides we propose a model to analyze the thickness dependence of the response time for metal oxide gas-sensing film.