OTS自组装单层膜诱导定向生长SrTiO3功能陶瓷薄膜

采用自组装单层膜技术,以三氯十八烷基硅烷(octadecyl-trichioro-silane,OTS)为模版,在玻璃基片上成功制备了钛酸锶晶态薄膜.改性基板的亲水性测定与金相显微镜测试表明,紫外光照射使基板由疏水转变为亲水,OTS单分子膜对薄膜的沉积具有诱导作用:X射线衍射(XRD)与扫描电镜(SEM)表征显示,制备成功的钛酸锶薄膜结晶良好,样品表面均匀,在垂直基板表面方向上呈花状生长:EDS能谱测试为钛酸锶薄膜的化学组成提供了有力的证据;同时探讨了白组装单层膜和钛酸锶薄膜的形成机理.     

基体表面性质对原位聚合沉积导电聚苯胺薄膜性能的影响

以水溶性高分子聚乙烯吡咯烷酮(PVP)为空间稳定剂,在经十八烷基三氯硅烷(OTS)改性的玻璃表面进行原位聚合,沉积得到导电聚苯胺(PANI)薄膜。采用表面界面张力仪、扫描电镜(SEM)、紫外可见光谱(UV-Vis)、红外光谱(FT-IR)、四探针电导率测试仪及光学显微镜对不同基体表面的接触角、PANI膜的形貌、厚度、结构、导电性及其在亲/憎水表面选择性沉积性能进行测定。结果表明:OTS对玻璃表面的改性促进了聚苯胺的沉积且提高了薄膜厚度,薄膜饱和厚度达到200 nm;缩短了溶液中苯胺分散聚合的诱导期,反应速率增大;与未改性玻璃表面沉积的薄膜相比,改性的玻璃表面得到的聚苯胺薄膜更加细密均匀,聚苯胺颗粒尺寸小,堆积紧密;薄膜的电导率达到7.5×10-3S/cm;OTS改性对基体表面的薄膜生长和溶液中的苯胺聚合具有催化作用。     

Bi2Ti2O7薄膜的自组装法制备及表征

以Bi(NO3)3·5H2O和Ti(OC4H9)4为原料,采用自组装单层膜技术,在负载有功能化三氯十八烷基硅烷(octadecyl-trichloro-silane,OTS)的FTO基板上制备了Bi2Ti2O7薄膜。基板表面的亲水性测试表明,紫外照射使OTS自组装单层膜表面由疏水转变为亲水,实现功能化。借助X射线衍射(XRD)、X射线能量色散谱(EDS)、扫描电子显微镜(SEM)和原子力显微镜(AFM)分析分别对Bi2Ti2O7薄膜的组成、结构和微观形貌进行了表征。结果表明,沉积溶液浓度为0.02 mol·L-1时,所得Bi2Ti2O7薄膜均匀致密。560℃热处理1 h、厚度为0.4μm的Bi2Ti2O7薄膜在100 kHz的介电常数为153,介电损耗为0.089。     

溶液电沉积法制备苝酰亚胺类化合物薄膜

溶液电沉积法是一种具有沉积时间短,可以常温沉积以及沉积物在基底上附着力高等优点的薄膜制备方法.本文用水合肼增溶苝酰亚胺类化合物(PTCDI)的方法制备了可用于溶液电沉积的苝酰亚胺类化合物溶液.用紫外-可见分光光度法(UV-Vis)对溶解的过程进行了表征,并用顺磁共振(ESR)验证了水合肼对PTCDI的增溶过程实质上是化学反应过程.在制备苝酰亚胺类化合物溶液的基础上,采用阳极电沉积法在ITO导电玻璃上沉积出了薄膜.采用UV-Vis,扫描电镜(SEM)和X射线衍射仪(XRD)对薄膜进行了表征,证实得到了表面较为平整、具有可控结晶结构和形貌的PTCDI薄膜以及具有较宽光谱吸收范围的复合薄膜.     

纳米TiO2薄膜的热致亲水性与光致亲水性机理

应用真空磁控溅射，溶胶－凝胶方法和电沉积方法分别在玻璃和导电玻璃表面制备了纳米TiO2薄膜，纳米TiO2薄膜的热致亲水性研究表明，这是由于热处理对TiO2薄膜表面的清洁作用除去了吸附的水和有机污染物而产生的。TiO2薄膜的光致亲水性可能也源于紫外光照产生的活性粒子对TiO2薄膜的“光清洁作用”所致。     

基板界面对PS/PMMA共混物薄膜相逆转组成比的影响

近年来高分子共混体系中的界面、表面效应逐渐引起了越来越多研究者的兴趣 .人们发现 ,当共混物薄膜厚度减至一定程度时 ,聚合物共混物薄膜中的相形态、相容性及相分离动力学与本体中有较大的不同[1～ 3] .基板界面作用对共混薄膜体系的热力学、动力学行为产生很大的影响 .我们以往的研究 [4 ,5]也发现 ,PP/EVAc(70 /30 )共混体系退火过程中 ,基板界面 (如玻璃 )作用可大大加速分散相(EVAc)粒子的粗化凝聚过程 .本研究用聚甲基丙烯酸甲酯和聚苯乙烯共混物的四氢呋喃溶液在不同基板介质 (如玻璃基板 ,PP基板 )上成膜 ,用相差显微镜观测了…     

多孔TiO2薄膜自洁净玻璃的亲水性和光催化活性

亲水性多孔TiO₂薄膜自洁净玻璃以含聚乙二醇的钛醇盐溶胶前驱体中通过浸渍提拉法制备;随着前驱物中聚乙二醇加入量的增加,多孔TiO₂薄膜表面的羟基含量也增加,薄膜表面的亲水性增强,水与薄膜表面的接触角下降为0°.该亲水性多孔TiO₂薄膜自洁净玻璃具有明显的自洁净和易清洗功能.紫外-可见光透过光谱分析表明,随着TiO₂薄膜中孔径的增大,光的散射增强,透光率减小.该TiO₂镀膜玻璃对于紫外线具有吸收作用.甲基橙水溶液的光催化降解实验表明,在TiO₂薄膜中引入适当大小的微孔可显著增强薄膜的光催化活性,但当孔径接近400nm时,薄膜的光催化活性减弱.     

一种新型的亲水性聚丙烯酸-陶瓷复合膜

通过化学气相沉积和丙烯酸(AA)在大孔陶瓷膜表面的接枝共聚制备了一种新型的亲水性PAA-陶瓷复合膜. 用FT-IR、SEM、EDS、表面接触角等方法对复合膜接枝层的化学组成、表面形态、元素分布和亲水性进行了表征. 通过系统研究气相沉积和接枝反应的主要条件对膜的渗透汽化性能的影响, 发现当TEOS用量为5 mL, 汽化温度为175 ℃时进行气相沉积, 然后在丙烯酸浓度为7.5%的溶液中进行接枝聚合, 制得的复合膜对醇水混合物显示了优良的分离性能.     

HA在PVA/CMC共混膜上的交互沉积及其表征

用溶液浇铸法制备聚乙烯醇/羧甲纤维素钠(PVA/CMC)共混膜,在对其进行交联改性的基础上,通过交互沉积法在膜表面沉积羟基磷灰石(HA),以制备PVA/CMC/HA复合材料。通过SEM、FT-IR、XRD等对其进行表征,探索PVA与CMC共混比例及交互周期对HA矿化速率的影响。结果表明,经过交联后的薄膜,在醇水混合溶液中能够稳定存在,其表面生成的HA含量随着交互周期和CMC含量的增加有明显增加,这种共混薄膜材料有望成为软骨修复材料的有效基体。     

LY12铝合金表面电化学沉积制备DTMS硅烷膜及其耐蚀性研究

采用电化学技术在LY12铝合金表面沉积制备了十二烷基三甲氧基硅烷(DTMS)膜. 反射吸收红外光谱表明, DTMS硅烷试剂与铝合金基体表面发生了化学键合作用, 生成—SiOAl键实现成膜. 通过对膜覆盖电极在质量分数为3.5%的NaCl溶液中的电化学阻抗谱(EIS)测试结果表明, 与开路电位下相比, 采用阴极电位沉积方法得到硅烷膜的耐蚀性能有明显提高, 且存在一个最佳“临界电位”, 在此电位下沉积得到的硅烷膜具有最高的耐蚀性. 扫描电镜观察结果表明, 在“临界电位”下制备得到的硅烷膜的结构最致密. 给出了硅烷膜覆盖电极的阻抗模型及相关参数的拟合结果.     

Epitaxial Growth of Sr x Ba1 − x Nb2O6 Thin Films Prepared from Sol-Gel Process

In this study, we prepared Sr _x Ba_{1 – x} Nb₂O₆ (x = 0.3, 0.5 and 0.7) thin film on 0.75 wt% La doped SrTiO₃ (100) and (110) single crystal substrates. A homogeneous coating solution was prepared with Sr and Ba acetates and Nb(OEt)₅ as raw materials, and acetic acid and diethlene glycol monomethyl ether as solvents. The substrates were coated with the solution by spin coating method. As-coated thin films were heated from 973 to 1273 K in air. The grains of the thin film on La doped SrTiO₃ (100) were pillar shaped and arranged in right angle to each other. On the other hand, the grains of these thin films on La doped SrTiO₃ were pillar shape and arranged in one direction. The crystallographic relationship of the thin film between Sr _x Ba_{1 – x} Nb₂O₆ and substrate that the 130 and 310 direction of the thin film on the substrate were oriented with c-axis in parallel to the substrate surface. On the other hand, (hk0) phase diffractions of Sr _x Ba_{1 – x} Nb₂O₆ thin film on the substrate (110) were investigated in the XRD theta-2theta measurement. It is expected that the Sr _x Ba_{1 – x} Nb₂O₆ (x = 0.3, 0.5 and 0.7) were highly oriented or epitaxial growing on La doped SrTiO₃ (110) single crystal substrate.     

Synthesis and characterization of nano-silica gel aged under microwave radiation from white sandstone

Double perovskite La₂NiMnO₆ thin film was successfully prepared on (001)-oriented 0.7 wt% Nb-doped SrTiO₃ single crystal substrate by chemical solution deposition method. The microstructures as well as properties were investigated. The results show that the derived thin film is an admixture of Ni/Mn ordering, and two ferromagnetic transitions are observed with Curie temperatures of 289 and 110 K, respectively. A crossover from positive to negative magnetodielectric effect is observed near room temperature. The success preparation of La₂NiMnO₆ thin film by chemical solution deposition will provide a useful method to deposit double perovskite multiferroic thin films with low-cost.     

Synthesis and Properties of Highly Conductive Thin Films as Buffer Layer from Sol-Gel Process

We prepared epitaxial growth SrRuO₃ thin film on LaAlO₃ (001) (LAO) single crystal substrate and highly oriented BaTiO₃ ferroelectric thin film on the epitaxial SrRuO₃ thin film. A homogeneous precursor solution for preparing SrRuO₃ thin film was prepared with Sr(O—i—C₃H₇)₂ and Ru(NO)(NO₃)₃ as starting materials, and 2-methoxy ethanol as solvents. The as-coated thin films were heat treated at temperatures from 723 to 1273 K for 1 h in air. SrRuO₃ grew epitaxially on LAO(001) substrate, which were confirmed by XRD theta-2theta method and XRD pole figure analysis. The crystallographic relationship of the film and substrate was SrRuO₃(001) parallel to LAO(001) and SrRuO₃[110] parallel to LAO[100]. A homogeneous precursor solution for preparing BaTiO₃ thin film was prepared with Ti[O—n—(CH₂)₃CH₃]₄ and Ba(OCOCH₃)₂ as starting materials, and acetic acid, 2-methoxy ethanol. SrRuO₃ coated LAO substrates were coated by spin-coating method with the coating solution. The as-coated thin films were heat treated at temperatures from 973 to 1173 K in air. It was confirmed that the thin films were growing orientated for c-axis by measurement of XRD theta-2theta method.     

Crystallization of textured PbTiO3 films deposited from gels

Sol-gel processed PbTiO₃ thin films have been deposited by spin coating onto different subtrates; Si[111], Si/Al, Si/SiO₂/Cr/Pt, MgO[100], SrTiO₃[100] and sapphire. Interactions between the substrate and PbTiO₃ films after heat treatment have been studied by X-ray diffraction and Rutherford Back Scattering. When deposited onto sapphire and Si[111], PbTiO₃ films exhibit a preferred orientation with (101) perpendicular to the substrate. These films become oriented along (100) onto MgO and (001) onto SrTiO₃[100] substrates. A strong channelling effect is observed by the RBS technique when the film is oriented along the c axis on SrTiO₃[100] suggesting that these films are epitaxially grown. The diffusion of metal atoms during the thermal treatment gives rise to the formation of lead silicate on Si[111] substrates. As a result a pyrochlore phase is formed. Lead titanate films on Si/SiO₂/Cr/Pt and Si/Al substrates are polycrystalline and do not exhibit any texture.     

Low-temperature synthesis of photocatalytic TiO2 thin film from aqueous anatase precursor sols

Anatase TiO₂ sols (RS) were synthesized by peptizing the hydrolysis of titanyl sulfate in abundant hydrogen peroxide solution and subsequent reflux to enhance crystallization. The influences of various reflux time on crystallinity, morphology, and size of the obtained TiO₂ sol and dried TiO₂ film particles were investigated. At room temperature, crystalline TiO₂ thin film was deposited on glass silde from the as prepared TiO₂ sol by dip-coating method. No further thermal posttreatment was required to eliminate organics from the film or to induce titania crystallization. TiO₂ thin film on substrates could be thickened by means of consecutive dip-coating process. Titania film thus obtained was transparent and showed proper adherence. The photocatalytic activities of the TiO₂ thin film was assessed by the degradation of methyl orange in aqueous solution. The preparation process of photocatalytic TiO₂ thin film was quite simple and a low-temperature route.     

Chemical solution processing and characterization of Ba(Zr,Ti)O<Subscript>3</Subscript>/LaNiO<Subscript>3</Subscript> layered thin films

Ba(Zr,Ti)O₃/LaNiO₃ layered thin films have been synthesized by chemical solution deposition (CSD) using metal-organic precursor solutions. Ba(Zr,Ti)O₃ thin films with smooth surface morphology and excellent dielectric properties were prepared on Pt/TiO _x /SiO₂/Si substrates by controlling the Zr/Ti ratios in Ba(Zr,Ti)O₃. Chemically derived LaNiO₃ thin films crystallized into the perovskite single phase and their conductivity was sufficiently high as a thin-film electrode. Ba(Zr,Ti)O₃/LaNiO₃ layered thin films of single phase perovskite were fabricated on SiO₂/Si and fused silica substrates. The dielectric constant of a Ba(Zr_0.2Ti_0.8)O₃ thin film prepared at 700°C on a LaNiO₃/fused silica substrate was found to be approximately 830 with a dielectric loss of 5% at 1 kHz and room temperature. Although the Ba(Zr_0.2Ti_0.8)O₃ thin film on the LaNiO₃/fused silica substrate showed a smaller dielectric constant than the Ba(Zr_0.2Ti_0.8)O₃ thin film on Pt/TiO _x /SiO₂/Si, small temperature dependence of dielectric constant was achieved over a wide temperature range. Furthermore, the fabrication of the Ba(Zr,Ti)O₃/LaNiO₃ films in alternate thin layers similar to a multilayer capacitor structure was performed by the same solution deposition process.     

Influence of thermal treatment on the ion-storage capacity of Ce oxide and Ce-V mixed oxide films

Thin films and the corresponding xerogels of CeO₂ and Ce-V mixed oxides with a molar ratio equal to 2 (Ce/V=2) were prepared from CeCl₃·7H₂O and NH₄VO₃ precursors using the sol-gel route and the dip-coating technique. The thermal decomposition of both forms of samples (thin films and xerogels) were studied by dynamic TG and DSC in two different atmospheres (air and argon). For the thermal studies the thin films were deposited on aluminium foil to reduce the unfavourable substrate to film mass ratio S/F, which is a consequence of using a glass substrate. The mode of heat treatment in a tube furnace of films deposited on conductive glass was defined from the TG curves of the films. The influence of annealing conditions (temperature, atmosphere and time) on the charge capacity of the films during application of the cycling process is reported.     

Preparation and Characterization of Bismuth Doped TiO2 Thin Films

A series of Bismuth-doped titanium oxide (Bi-doped TiO₂) thin films on glass substrates have been prepared by sol-gel dip coating process. The prepared catalysts were characterized by XRD and XPS. The photocatlytic activity of the thin film catalysts was evaluated through the photodegradation of aqueous methyl orange under UV illumination. The experiments demonstrated that the Bi-doped TiO₂ prepared was anatase phase. The doped bismuth was in the 3⁺ oxidation state. The presence of Bi significantly enhanced the photocatalytic activity of TiO₂ films. At calcination temperature of 500°C, with doping concentration of 2 wt %, Bi-doped TiO₂ thin film showed the highest photocatalyic activity.     

Optimization of large area pulsed laser deposition of YBaCuO thin films by SNMS depth profiling and rutherford backscattering

The scaling up of established deposition techniques like pulsed laser deposition (PLD) to larger substrate diameter is a main condition for the technological application of high-T_c superconducting (HTSC) thin films. SNMS depth profiling and RBS have been used to control the homogeneity of film thickness and stoichiometry of Au/YBaCuO/CeO₂ thin film systems deposited on 3-inch sapphire wafers by PLD. A systematic dependence has been found for the relative SNMS sensitivity factors (RSF) on the structural state of YBaCuO. Therefore, a calculation of the composition of the epitaxial YBaCuO thin films is not possible using RSF determined from polycrystalline YBaCuO target material. The interdiffusion of thin films and substrate has been investigated in dependence on the deposition temperature by SNMS depth profiling. The obtained homogeneity of film thickness and stoichiometry over the entire 3-inch diameter proofs the suitability of PLD for in-situ deposition of 3-inch wafers by YBaCuO thin film systems for microwave applications.