DPPC与MMA混合单层LB膜缺陷结构的AFM研究

采用原子力显微镜(AFM)研究了转移到疏水石英基片上的二棕榈酰磷酯酰胆碱(DPPC)与不同浓度聚合物单体分子甲基丙烯酸甲酯(MMA)的混合物所形成的单层LB膜及其缺陷的微结构,研究了沉积压对缺陷的影响.当MMA的摩尔比为33;(即MMA∶DPPC＝1∶2),沉积压为5.0mN/m时,生成直径约3～4μm的圆形液态凝聚相(LC)畴区,LC畴区主要为DPPC与MMA的混合物,同时还分布着一些由聚合的MMA分子(即聚合物PMMA)形成的"小岛";当沉积压增加至15.0mN/m时,LC畴区中主要为聚合物PMMA的聚集体.当MMA的摩尔比增加至50;后,LC畴区中聚合物PMMA含量增加.畴区产生的主要原因是由于不同MMA含量和沉积压使DPPC和MMA及其聚合物PMMA产生不同程度的相分离所致.MMA/DPPC混合LB膜中这种圆形的畴区缺陷可以诱导形成圆形的一水草酸钙晶体沉积图形.     

不同浓度碳纳米管/聚乙烯醇薄膜的机械性能的研究

基于化学气相沉积法制备碳纳米管(CNTs),利用浸入滚动法制备CNTs/聚乙烯醇(PVA)复合薄膜.研究不同浓度的PVA对CNTs/PVA复合薄膜机械性能的影响.实验表明,CNTs/PVA复合薄膜的应力随着PVA的浓度的增加呈现先增加后减小的趋势,PVA的浓度为2wt;的时候CNTs/PVA复合薄膜的抗拉强度最大,其值为561 MPa.并且实验研究发现CNTs/PVA复合薄膜的应变随着PVA的溶度的增加而增加,不同浓度的复合薄膜具有良好的均匀性.     

Cu∶CdS/TiO2的制备及其光电化学性能研究

采用水热法制备(001)晶面裸露的TiO2纳米片阵列薄膜,并采用水热法进行CdS纳米颗粒复合,探讨不同水热反应时长对复合薄膜结构及性能的影响.为了提高复合薄膜的光电化学性能,在水热反应过程中引入Cu前驱体,并探讨不同掺杂浓度对复合薄膜性能的影响.研究结果表明Cu元素掺杂有效拓宽了CdS复合TiO2纳米片阵列薄膜(CdS/TiO2)的光吸收范围,并且提高了CdS/TiO2的光电化学性能.当水热反应3h,Cu掺杂浓度为1∶1 000时,CdS/TiO2的光电性能达到最佳.     

CoFe2O4/Ba0.9Ca0.1Ti0.9Zr0.1O3双层复合薄膜的磁电性能研究

通过脉冲激光沉积法(PLD)在(001)-SrRuO3/SrTiO3(SRO/STO)衬底上生长了CoFe2O4/Ba0.9Ca0.1Ti0.9Zr0.1O3(CFO/BCZT)双层磁电复合薄膜.采用X射线衍射仪(XRD)、原子力显微镜(AFM)和扫描电子显微镜(SEM)测试样品的晶体结构及形貌.XRD结果显示:单相BCZT铁电薄膜、CFO铁磁薄膜及CFO/BCZT磁电复合薄膜均为(00l)择优取向结构.物理性能测试结果表明:CFO/BCZT复合薄膜具有良好的铁电性能(剩余极化值,Pr=15.1μC/cm2)、铁磁性能和磁电耦合性能(磁电耦合系数,αE～82.4 mV·cm-1·Oe-1).这种无铅的磁电复合薄膜为设计新型多铁电子器件提供了一种选择.     

Ga0.8Fe1.2O3/Ba0.8Ca0.2Ti0.8Zr0.2O3复合薄膜的制备和铁电性能研究

采用脉冲激光沉积工艺在(111)取向的SrTiO3衬底上,制备了Ga0.8 Fe1.2 O3/Ba0.8 Ca0.2 Ti0.8 Zr0.2 O3层状复合薄膜.利用X射线衍射仪(XRD)和扫描电子显微镜(SEM),表征了样品薄膜的表面形貌及微观结构.从样品的XRD图谱可以看出,该复合薄膜的BCZT层呈(111)取向,而GFO层沿b轴自发极化,呈(0l0)取向.物性测试结果表明:GFO/BCZT复合薄膜表现出良好的电磁学特性,其剩余极化值Pr=11.28μC/cm2,饱和磁化强度Ms～49.17 emu/cm3,同时该复合薄膜室温下最大磁电耦合系数αE可达28.38 mV/(cm·Oe).这种无铅的磁电复合薄膜为传感器、换能器和多态存储器的潜在应用提供了新的思路.     

甲烷浓度对碳化硅基底金刚石薄膜摩擦性能影响

利用热丝化学气相沉积法(HFCVD)在碳化硅基底上制备金刚石薄膜,采用场发射扫描电子显微镜、拉曼光谱仪、原子力显微镜研究了在不同甲烷浓度条件下制备的金刚石薄膜表面形貌及物相组成,在干摩擦条件下通过往复式摩擦磨损实验测试并计算了已制备金刚石薄膜的摩擦系数和磨损率,结合物相分析及摩擦磨损实验结果分析了甲烷浓度的改变对金刚石薄膜摩擦磨损性能的影响。结果表明,由于甲烷气体含量的升高,金刚石薄膜结晶质量下降,薄膜由微米晶向纳米晶转变。摩擦磨损实验结果显示:3%甲烷浓度条件下制备的金刚石薄膜耐磨性较好,磨损率为2.2×10^-7 mm³/mN;5%甲烷浓度条件下制备的金刚石薄膜摩擦系数最低(0.032),磨损率为5.7×10^-7 mm³/mN,制备的金刚石薄膜的耐磨损性能相比于碳化硅基底(磨损率为9.89×10^-5 mm³/mN)提升了两个数量级,显著提高了碳化硅基底的耐磨性。     

NiTiO3薄膜的溶胶-凝胶工艺研究

以无机镍盐和钛酸四丁酯为起始原料,柠檬酸为络合剂,采用溶胶-凝胶法制备了NiTiO3薄膜.采用X射线衍射(XRD)、综合热分析仪(DSC/TG)、场发射扫描电镜(FESEM)对制备的薄膜进行了测试和表征.研究了保温时间,溶胶浓度对钛酸镍薄膜晶相组成、显微结构的影响.结果表明:保温时间为3 h,溶胶浓度为0.5 mol/L是制备NiTiO3薄膜的最佳工艺条件;随着保温时间的延长,薄膜的结晶度和致密度均有所提高;在1～0.5 mol/L的浓度范围内,溶胶浓度的降低有利于薄膜的生长.     

溅射温度对ITO/Ag/ITO多层复合薄膜的结构和光电性能的影响

本文采用直流磁控溅射分层溅射制备了氧化铟锡(ITO)/银(Ag)/ITO多层复合薄膜。系统研究了溅射温度对ITO/Ag/ITO多层复合薄膜的结构和光电性能影响。采用ITO(m(In₂O₃)∶m(SnO₂)=9∶1;直径60 mm)靶材和Ag(纯度99.999%;直径60 mm)靶材分层溅射,使ITO薄膜和Ag薄膜依次沉积在钠-钙玻璃基片上。结果表明,溅射温度对该薄膜的形貌和结构具有显著的影响。在中间Ag薄膜和顶层ITO薄膜的溅射温度均为120 ℃时,薄膜表面晶粒形貌由类球形转变为菱形,此时薄膜方阻为3.68 Ω/Sq,在488 nm处透射率为88.98%,且品质因数为0.03 Ω^-1,实现了低方阻高可见光透射率ITO/Ag/ITO多层复合薄膜的制备。     

纳米颗粒复合介电层柔性有机薄膜晶体管的制备与性能研究

使用聚酰亚胺(PI)作为柔性有机薄膜晶体管(OTFT)的衬底,通过掺入钛酸锶钡(BST)纳米颗粒来提高PVP聚合物栅介电层的电容,再使用聚甲基丙烯酸甲酯(PMMA)来修饰介电层,改善介电层薄膜的质量和性能,从而降低柔性OTFT的阈值电压,提高电流开关比和迁移率.测试结果表明,优化后的柔性OTFT阈值电压为-2.5V,电流开关比大于104,迁移率为0.0703 cm2/(V·s).器件在3 mm弯曲半径下依然可以正常工作,电流开关比保持在104级别.     

NiFe2O4/(0.8BaTiO3-0.2Na0.5Bi0.5TiO3)异质结层状复合薄膜的磁电性能

采用脉冲激光沉积法在(001)-SrRuO3/SrTiO3(SRO/STO)衬底上生长了2-2型NiFe2O4/(0.8BaTiO3-0.2Na0.5 Bi0.5TiO3)(NFO/BT-NBT)磁电复合薄膜.X射线衍射仪(XRD)结果显示所有薄膜均为(00l)择优取向结构.物理性能测试结果表明:NFO/BT-NBT复合薄膜同时具有良好的铁磁性和铁电性,但不同的沉积顺序对复合薄膜的磁电耦合性能产生重要影响.以铁磁材料NFO为顶层的NFO/BT-NBT/SRO/STO异质结的磁电耦合系数(αE～110 mV·cm-1·Oe-1)大于以铁电材料BT-NBT为顶层的BT-NBT/NFO/SRO/STO异质结的磁电耦合系数(αE～80 mV·cm-1·Oe-1),这是NFO层受到衬底束缚作用不同的结果.     

Characterization of organic adsorbates on model glass surfaces

Model silicate glasses in planar thin film structures are prepared using sol/gel techniques. A typical structure consists of 3.0–12.0 nm of glass on vapor deposited Ag. In this study, a pure silica and a 50/50 binary alumina-silica films are examined. Poly(methyl methacrylate) (PMMA) is adsorbed from chlorobenzene solution onto the surfaces. Infrared reflection (IR) spectroscopy, ellipsometry and quartz oscillator microgravimetry (QOM) are applied to characterize the PMMA/silicate glass interfaces formed. The QOM and IR data show that PMMA adsorption on the pure silica surface is irreversible with respect to removal by pure solvent rinse while on the binary glass surface and on a pure alumina surface, solvent rinses remove the initially adsorbed polymer. These results are interpreted in terms of Bronsted acid-base interactions involving the basic properties of the PMMA C=O group, the acidic nature of the silica and the more basic nature of the alumina containing surfaces. Further evidence for this interpretation is given by the IR spectral data which show broadening of the C=O stretching mode to lower frequencies for the irreversible adsorbed polymer on silica as compared with simulated spectra of non-surface bonding PMMA thin films. This spectral perturbation is interpreted as evidence for a hydrogen bonding interaction between OH groups on the silica surface and the C=O groups. The overall conclusion is that the surface of a 50/50 binary alumina-silica composition is dominated by the basic nature of alumina.     

乙酰丙酮对PMMA负载锐钛矿型TiO2薄膜及其光催化性能影响

以钛酸丁酯作为钛源,水为溶剂,乙酰丙酮(AcAcH)为表面修饰剂,采用微波水热辅助溶胶-凝胶法制备了纳米晶二氧化钛水溶液,利用提拉镀膜法在聚合物聚甲基丙烯酸甲酯(PMMA)基板上沉积得到了透明TiO2纳米晶薄膜.通过X射线衍射(XRD)、红外光谱(FTIR)、透射电子显微镜(TEM)、原子力显微镜(AFM)和紫外-可见光吸收光谱(UV-Vis)等对TiO2纳米颗粒和薄膜的晶相组成、表面形貌及光学性能进行表征.同时通过紫外光光催化降解罗丹明B研究了TiO2薄膜的光催化性能.结果表明:通过引入乙酰丙酮,可以得到高度分散、晶相为锐钛矿型的TiO2水溶胶,在PMMA基板上沉积得到的薄膜表面平整、致密,具有良好的透光率,经过180 min紫外光照射,对罗丹明B的降解率达到90;以上.     

不同形貌TiO2薄膜的可控制备及其光电化学性能研究

采用水热法在FTO(fluorine-doped tin oxide)基底上制备不同形貌的锐钛矿结构TiO2薄膜.通过不断增大反应前驱物中盐酸浓度,TiO2薄膜由球状颗粒薄膜逐渐演变生长成大面积高能(001)面裸露的TiO2纳米片阵列薄膜.通过对形貌演化规律及X射线衍射图谱变化规律进行分析,提出了不同形貌TiO2薄膜的...     

Liquid Crystals and Polymer-Based Photonic Crystal Fibers

Experimental results of polymer photonic liquid crystal fibers based on commercially available (Kiriama) PMMA and cyclo-olefin polymer (Zeonex 480R) microstructured polymer fibers infiltrated with nematic liquid crystals (2CHBT/8CHBT and PCB) are presented and thermally-tuned photonic band-gap propagation mechanism is observed. These preliminary results suggest, that polymers binding to liquid crystals much easier than silica, can offer new opportunities while using polymer-based photonic crystal fibers.     

磁控溅射（TiO2-ZnO）/TiO2梯度复合薄膜的制备及光致亲水性研究

采用磁控溅射离子镀设备制备了(TiO2-ZnO)/TiO2梯度复合薄膜,通过TEM、AFM、Raman、XPS分析了复合薄膜的结构、形貌和表面羟基含量,以甲基橙作为有机降解物,研究了(TiO2-ZnO)/TiO2梯度复合薄膜与普通TiO2-ZnO复合薄膜和TiO2薄膜在光催化性能和光致亲水性能上的差异。结果表明:(TiO2-ZnO)/TiO2梯度复合薄膜具有以主体为TiO2-ZnO层、顶层为TiO2的梯度结构,且薄膜表面致密、粒径均匀(10～14 nm),光催化性和亲水性均优于普通TiO2-ZnO复合薄膜和TiO2薄膜,且其光波响应范围红移至450 nm、表面羟基含量高达12.53%,同时梯度复合薄膜的抗光腐蚀性能良好,4 h以后其润湿角仍保持不变。     

Microstructural and optical properties of sol-gel silica-titania waveguides

Two micron silica-titania coatings made by single step sol-gel dip-coating were prepared as planar waveguides. Acid catalyzed solutions of methyltriethoxysilane (MTES) mixed with tetraethoxysilane (TEOS) and tetrabutoxytitanate were used as precursors. Purely inorganic and crackfree silica-titania coatings were obtained after annealing at 500°C. The waveguides had propagation losses, 0.3 dB/cm, of the same order as thin silica-titania films prepared without MTES. Films were studied by infrared spectroscopy. Rutherford backscattering spectrometry, nuclear reactions analysis and elastic recoil detection analysis. The waveguide structural composition after annealing at 500°C was found to be similar to MTES and TEOS derived silica-titania coatings. The waveguides were characterized by measuring refractive index, porosity and shrinkage, with thermal treatment. The MTES derived films showed a higher shrinkage during annealing but the same refractive index and porosity as the TEOS derived waveguides.     

Characterization of optical properties of amorphous BaTiO3 nanothin films

Amorphous barium titanate nanothin films were prepared by sol–gel dip-coating method. According to transmission spectrum, the refractive index and optical band gap of nanothin films have been determined. High transmission spectrum without any fluctuation in visible wavelength region was recorded. Experimental results indicated that the surface morphology of prepared nanothin films were improved and as a result of that, a better optical properties, less optical losses and higher band gap width were obtained in contrast with other reported data. It was found that optical propagation loss of BaTiO₃ nanothin film was much lower than normal polycrystalline BaTiO₃ thin film. It seems to us that, amorphous barium titanate nanothin films would be suitable for several applications.     

氧分压调控氧化铜薄膜生长及其表面功函数研究

本文采用反应磁控溅射法制备p型二元铜氧化物半导体薄膜,通过氧气流量调节实现Cu₂O、CuO和Cu₄O₃薄膜的可控生长。所制备薄膜的形貌与结构分别利用扫描电子显微镜、X射线衍射仪以及拉曼光谱进行表征。经紫外可见分光光度计测量可知,Cu₂O、CuO和Cu₄O₃薄膜的带隙分别为2.89 eV、1.55 eV和2.74 eV。为进一步研究Cu₂O、CuO和Cu₄O₃薄膜的表面物理性质,基于Kelvin探针力显微镜(KPFM)技术直接测量了薄膜样品与探针尖端间的接触电位差(V_CPD),结果表明Cu₂O、CuO和Cu₄O₃薄膜的表面功函数都随着温度的升高而呈现逐渐减小的趋势。     

Thiol-ene/hyperbranched polymer hybrid thin films: Cure behavior and gas barrier properties

In this work, novel thiol-ene (TE)/hyperbranched polymer(HBP) hybrid thin films have been prepared by a simple photopolymerization method and the TE/HBP system was also investigated in terms of thermocuring behavior and gas barrier properties. The effect of added HBP on thermal curing (cross-linking) of TE polymer was examined with dynamic and isothermal differential scanning calorimeter (DSC) and compared with photocuring reaction of identical system. The structure of prepared TE/HBP hybrid thin film was analyzed by X-ray diffraction (XRD). Themomechanical analysis (TMA) provided extensive data on the coefficient of linear thermal expansion (CTE), dimensional change upon heating, and isothermal profile of TE/HBP hybrid thin films. Light transmittance as well as water/oxygen permeability of the resulting TE/HBP hybrid thin film was also measured depending on the HBP content.     

Crystallization behavior and hydrophilic performances of V2O5–TiO2 films prepared by sol–gel dip-coating

Homogeneous and transparent V₂O₅–TiO₂ composite nanometer thin films were prepared on glass substrates by sol–gel processing and dip-coating technique. The films as well as the dried powder of bulk gel were characterized by different techniques like X-ray diffraction (XRD), high-resolution scanning electron microscopy (HRSEM), atomic force microscope (AFM) and thermogravimetry–differential thermal analysis (TG–DTA). The hydrophilicity of the films was determined by measuring the water contact angles on the films. The results showed that the dopant of V₂O₅ on TiO₂ thin films could produce a visible-light response to the films, and the introduction of V₂O₅ could suppress the structural phase transition and crystal growth of TiO₂ crystal. Finally, the relationship between crystalline size and hydrophilicity under sunlight was investigated in this article.