利用小角X射线散射技术研究组分对聚酰亚胺/Al2O3杂化薄膜界面特性与分形特征的影响

采用溶胶-凝胶方法制备无机纳米杂化聚酰亚胺(PI),应用同步辐射小角X射线散射(SAXS)方法研究不同组分杂化PI薄膜的界面特性与分形特征.研究结果表明:散射曲线不遵守Porod定理,形成负偏离,说明薄膜中有机相与Al₂O₃纳米颗粒间存在界面层,界面层厚度在0.54 nm到1.48 nm范围内;随无机纳米组分增加,界面层厚度增加,有机相与无机相作用变强;无机纳米颗粒同时具有质量分形和表面分形特征,其分布、集结是一种非线性动力学过程;随组分增加,其质量分形维数降低 关键词： 小角X射线散射 纳米杂化 聚酰亚胺 界面     

花状掺杂W-VO_2/ZnO热致变色纳米复合薄膜研究

为解决掺杂引起的二氧化钒薄膜的红外调制幅度下降以及二氧化钒复合薄膜相变温度需要进一步降低等问题,采用纳米结构、掺杂改性和复合结构等多种机理协同作用的方案,利用共溅射氧化法,先在石英玻璃上制备高(002)取向的Zn O薄膜,再在Zn O层上室温共溅射沉积钒钨金属薄膜,最后经热氧化处理获得双层钨掺杂W-VO2/Zn O纳米复合薄膜.利用X射线衍射、X射线光电子能谱、扫描电镜和变温光谱分析等对薄膜的结构、组分、形貌和光学特性进行了分析.结果显示,W-VO2/Zn O纳米复合薄膜呈花状结构,取向性提高,在保持掺杂薄膜相变温度(约39?C)和热滞回线宽度(约6?C)较低的情况下,其相变前后的红外透过率差量增加近2倍,热致变色性能得到协同增强.     

电化学方法制备ZnO纳米颗粒掺杂类金刚石薄膜及其场发射性能研究

采用液相电化学沉积技术制备了ZnO纳米颗粒掺杂的类金刚石(DLC)薄膜, 研究了ZnO纳米颗粒掺杂对DLC薄膜场发射性能的影响. 利用X射线光电子能谱、透射电子显微镜、Raman光谱以及原子力显微镜分别对薄膜的化学组成、 微观结构和表面形貌进行了表征. 结果表明: 薄膜中的ZnO纳米颗粒具有纤锌矿结构, 其含量随着电解液中Zn源的增加而增加. ZnO纳米颗粒掺杂增强了DLC薄膜的石墨化和表面粗糙度. 场发射测试表明, ZnO纳米颗粒掺杂能提高DLC薄膜的场发射性能, 其中Zn与Zn+C的原子比为10.3%的样品在外加电场强度为20.7 V/μm时电流密度达到了1 mA/cm². 薄膜场发射性能的提高归因于ZnO掺杂引起的表面粗糙度和DLC薄膜石墨化程度的增加.     

花状掺杂W-VO$lt;sub$gt;2$lt;/sub$gt;/ZnO热致变色纳米复合薄膜研究

为解决掺杂引起的二氧化钒薄膜的红外调制幅度下降以及二氧化钒复合薄膜相变温度需要进一步降低等问题, 采用纳米结构、掺杂改性和复合结构等多种机理协同作用的方案, 利用共溅射氧化法, 先在石英玻璃上制备高(002)取向的ZnO薄膜, 再在ZnO层上室温共溅射沉积钒钨金属薄膜, 最后经热氧化处理获得双层钨掺杂W-VO₂/ZnO纳米复合薄膜. 利用X射线衍射、X射线光电子能谱、扫描电镜和变温光谱分析等对薄膜的结构、组分、形貌和光学特性进行了分析. 结果显示, W-VO₂/ZnO 纳米复合薄膜呈花状结构, 取向性提高, 在保持掺杂薄膜相变温度(约39 ℃)和热滞回线宽度(约6 ℃)较低的情况下, 其相变前后的红外透过率差量增加近2倍, 热致变色性能得到协同增强. 关键词： 2')" href="#">VO₂ ZnO W掺杂 热致变色     

掺杂4-苯基卟啉的聚苯乙烯／二氧化硅复合纳米微球的制备

采用溶胶-凝胶法,首先利用苯乙烯与3-甲基丙烯酰氧基丙基三甲氧基硅烷(KH-570)化学反应合成共聚前驱物,利用TEOS在一定的条件下水解与缩合,一步合成了有机-无机复合纳米微球。用扫描电镜、红外光谱对共聚物及复合纳米粒子进行了表征。将非水溶性发光材料四苯基卟啉掺杂其中,制备出荧光复合纳米粒子。该粒子表现出了良好的发光性能,染料泄漏与猝灭几乎为零,可以作为一种新型的高效率的生物标记材料。     

掺杂铁的CeO2纳米颗粒的制备与表征

利用反相共沉淀法,合成了掺杂过渡金属铁的CeO2纳米颗粒.通过X射线衍射(XRD)、透射电镜(TEM)、傅里叶变换红外(FTIR)光谱、紫外-可见(UV-Vis)光谱等测试手段对产物进行了分析和表征.结果表明,掺杂铁的CeO2纳米颗粒是纯立方莹石结构;过渡金属铁掺入了CeO2的晶格;其相比于不掺铁的CeO2纳米颗粒吸收...     

用于蓝光(405nm)激光直写的聚乙烯醇/银纳米复合材料薄膜的制备

利用紫外光诱导还原金属前躯体硝酸银(AgNO3),直接在聚乙烯醇(PVA)薄膜中生长银纳米颗粒,成功制备出PVA/Ag纳米复合材料薄膜。利用紫外-可见吸收光谱分析了银离子浓度、紫外光辐照功率和辐照时间对薄膜光谱的影响趋势。通过优化硝酸银浓度、辐照条件来调节薄膜中银纳米颗粒的尺寸和空间分布密度,成功地将此复合薄膜的等离子共振吸收峰位调节为406nm,并用于蓝光(405nm)激光直写光刻。扫描电子显微镜(SEM)观察表明,该材料中纳米颗粒分布均匀,粒径分布较窄;X射线光电子谱(XPS)证实了合成的纳米颗粒为单质银;原子力显微镜(AFM)分析显示薄膜光刻后获得了表面清晰、光滑、规整的图形。     

快速响应恢复的PI-SiO2/NiI2比色湿度传感器

有机-无机杂化型比色湿度传感器可通过电学信号和颜色变化获取环境湿度,并因其特征颜色区分度高、稳定性好、制备工艺简单等优点,在湿度监测领域具有广阔的应用前景,但其通常响应恢复时间长,从而不利于湿度实时监测.本文在聚酰亚胺(PI)-碘化镍(NiI₂)有机无机杂化材料中掺杂纳米SiO₂微球制备得到PI-SiO₂/NiI₂复合薄膜及比色湿度传感器,对其表面形貌和湿敏特性进行了研究.结果显示, PI-SiO₂/NiI₂薄膜具有蜂巢状的表面形貌,传感器的特征颜色显著,湿度响应时间小于1.5 s,恢复时间小于18 s.研究表明,纳米SiO₂微球掺杂能够较为显著地改善有机-无机杂化型比色湿度传感器的响应恢复特性,这对于传感器性能的提升具有一定参考意义.     

石墨烯与复合纳米结构SiO_2@Au对染料敏化太阳能电池性能的协同优化

染料敏化太阳能电池(dye-sensitized solar cells, DSCs)因其制备工艺简单、成本低廉以及优异的光学性质在近年来引起了大家的广泛关注.为了获得更优的光电性能,利用球磨法制备了一系列不同含量纳米结构SiO_2@Au和固定含量石墨烯协同掺杂的复合光阳极薄膜,并制备了相应的DSCs.研究了纳米结构SiO_2@Au和石墨烯联合掺杂对光阳极及其相应DSCs光电转换性能的影响.金纳米颗粒因其局域表面等离子体共振效应能够有效提高DSCs的短路电流密度.而石墨烯作为典型的二维材料,具有较大的比表面积以及高导电性等优异性质,有利于增加薄膜的比表面积.当纳米结构SiO_2@Au和石墨烯协同掺杂至光阳极薄膜内部,且SiO_2@Au掺杂量为1.5%时,相应电池的短路电流密度为15.59 m A·cm–2,光电转换效率为6.68%,相比基于传统纯TiO_2光阳极电池的性能分别提高了15.67%和8.8%.研究表明,基于不同含量复合纳米结构SiO_2@Au和固定量石墨烯共掺的DSCs性能的提高,主要归因于复合纳米结构SiO_2@Au的掺入,其中分布较为均匀的金纳米颗粒作为光学天线可以将光局域到颗粒表面,增强表面电磁场强度,有效增强光与物质的相互作用,优化了染料的光吸收能力,增加薄膜内部光生载流子数量.而石墨烯的引入则改善了光阳极薄膜的比表面积,增加了薄膜整体对染料的吸附量,且石墨烯良好的导电性能加快了光生载流子的传输,两者协同作用实现了DSCs的光电转换性能的优化.     

稀土发光铁电薄膜的研究进展

稀土掺杂是提高光电功能材料性能的重要途径.把稀土掺杂铁电材料与稀土发光相结合,还可拓展出铁电材料的新性能,比如,选择合适的稀土元素掺入钛酸铋铁电材料,可使之在保持较好的铁电性能的同时,又显示良好的发光性能.近年来,这类在氧化物铁电材料中由于稀土离子掺杂产生光致发光特性的研究引起了人们的关注,有望研制集成发光铁电器件.本文简要介绍了稀土发光铁电材料的研究状况,重点介绍我们在稀土发光铁电薄膜方向的研究进展.我们的研究表明,稀土掺杂钛酸铋铁电薄膜同时具有较好的发光特性和铁电特性,这与其独特的成分构成和层状钙钛矿结构密切相关; Eu3+离子荧光结构探针可以为进一步研究Eu~(3+)掺杂铁电薄膜材料的结构与性能关系提供新思路;在某些铁电薄膜(如Pr离子掺杂的x(K_(1/2)Bi_(1/2))TiO_3-(1-x)(Na_(1/2)Bi_(1/2))TiO_3薄膜等)中掺入稀土离子后,稀土离子的发光可用于检测铁电薄膜中是否存在准同型相界;将ZnO纳米材料和金、银纳米颗粒与掺铕钛酸铋薄膜复合,可显著增强稀土发光.     

Al_2O_3杂化聚酰亚胺薄膜Al含量测试方法研究

无机粒子杂化聚酰亚胺(PI)薄膜具有优良的耐电晕特性,广泛用于变频电机中,文章首先用偶联剂处理过的超细氧化铝粉掺杂聚酰胺酸(PAA)制备了不同氧化铝含量的聚酰亚胺杂化膜.通过傅里叶变换红外光谱(FTIR)、X射线光电子能谱(XPS)、电感耦合等离子发射光谱(ICP)、重量法、热失重(TG/空气气氛)等测试方法对制备的不同Al2O3含量杂化聚酰亚胺薄膜的无机成分进行了定性和定量分析.结果表明:FTIR和XPS能很好地对杂化膜进行定性分析,FTIR主要对材料的结构进行分析从而推断出其可能的成分,而XPS则主要得到材料所含各元素信息,它具有操作简单,重复性好等优点;通过研究内层电子结合能及其氧化态的变化,XPS可以鉴别元素种类和价态、测定元素的相对含量.XPS和TG的实测值和理论值相差较大,相对标准偏差(RSD)很大,其中,XPS的RSD值大于5.0%,而TG的RSD值也都大于2.0%,只能对杂化膜进行半定量分析.而ICP和重量法的实测值和理论值相差较小且相对标准偏差(RSD)很小,它们的RSD)值均小于1.0%,能进行精确的定量分析,其中重量法的实测值最接近理论值,但只能用于单一无机组分的分析;而ICP法最精确且可以对多无机组分的复合物进行分析,它有简便、快速、灵敏度高、准确性好、可多元素同时测定,且对环境污染小等优点.由上面的结论可以得到一种分析复合材料中的无机成分的方法:首先,用FTIR和XPS对复合材料进行定性分析;然后,以XPS半定量分析结果作为参考,用重量法(单一组分)和ICP法对复合材料进行精确的定量分析.     

Preparation and characterizations of SiO2/TiO2/γ-glycidoxypropyltrimethoxysilane composite materials for optical waveguides

SiO₂/TiO₂/γ-glycidoxypropyltrimethoxysilane composite materials processed by the sol-gel technique were studied for optical waveguide applications. Waveguide films with thickness more than 1.7 μm were prepared on a silicon substrate by a single-coating process and low-temperature heat treatment from these high-titanium-content composite materials. Scanning electron microscopy (SEM), atomic force microscopy (AFM), thermal gravimetric analysis (TGA), UV-visible spectroscopy (UV-VIS), Fourier-transform infrared spectroscopy (FT-IR), and X-ray photoelectron spectroscopy (XPS) have been used to characterize the waveguide films. TGA curves showed that organic compounds in the composite materials would decompose in the temperature range from 200 °C to 480 °C. SEM, AFM and UV-VIS results showed that a dense, porous-free, and high transparency in the visible range waveguide film could be obtained at a low heat-treatment temperature. It was also noted that the carbon content in the film with higher titanium content heated at high temperature was evidenced by XPS. The waveguide propagation loss properties of the composite material films were also investigated and showed a dependence on the titanium molar fraction. Received: 13 June 2000 / Accepted: 21 June 2000 / Published online: 20 September 2000     

Synthesis of Magnetic Metal Organic Framework Fe3O4 @ NH2-MIL-53 (Al) Materials and Application to the Adsorption of LeadSCIEI北大核心CSCD

Metal organic framework, a novel class of organic inorganic hybrid functional materials, has been widely used in the fields of gas adsorption, catalysis, separation, and biological medicine due to its large specific surface area, diverse structural, and adjustable channel. In this work, a new amine-functionalized magnetic metal-organic framework material was synthesized. Nano-Fe3O4 was prepared by a solvothermal method, after which polyvinyl pyrrolidone was employed to modify Fe3O4. Finally, amino groups were introduced to prepare Fe3O4@NH2-MIL-53(Al). The crystal structure and functional groups of the material were characterized by means of X-ray diffraction (XRD) and Fourier transform infrared spectrometry (FT-IR). Combined with flame atomic absorption spectroscopy (FAAS), the adsorption of lead by the magnetic adsorbent was investigated. The magnetic adsorbent possesses high adsorption capacity because of the large specific surface area of Fe3O4@NH2-MIL-53 (Al) and the coordination between amino group and lead. Experimental conditions affecting the adsorption percentage were discussed and the experimental operation parameters were optimized (pH value of 6.0 and adsorption time of 120 min). Kinetics and thermodynamics studies were conducted for the adsorption process. Langmuir/Freundlich and pseudo-first-order/pseudo-second-order models were applied to analyze the experimental data. Thermodynamic functions, i.e., changes of Gibbs energy, entropy, and enthalpy, were calculated from temperature experiments. In addition, the regeneration of the adsorbent was considered with hydrochloric acid as the desorption solution. Several adsorption and desorption experiments were carried out, illustrating that the Fe3O4@NH2-MIL-53(Al) adsorbent can be used repeatedly.     

溶胶-凝胶法制备SiO2基片Er3+∶Al2O3光学薄膜

用溶胶凝胶法在SiO2 基片上提拉制备了掺Er3 + ∶Al2 O3 光学薄膜。采用扫描电子显微镜、原子力显微镜、差热热重分析仪、X射线衍射仪研究了掺Er3 + ∶Al2 O3 光学薄膜的形貌和结构特性。在 90 0℃烧结后 ,SiO2 基片上提拉 15次形成厚度 8μm掺摩尔比 0 .0 1Er3 + 的面心立方结构γ Al2 O3 薄膜具有明显 (110 )择优取向 ,掺摩尔比 0 .0 1Er3 + 对γ Al2 O3 的晶体结构和结晶生长过程未产生显著影响。薄膜具有均匀多孔结构 ,平均粒径为 30～ 10 0nm ,平均孔径为 5 0～ 10 0nm ,表面起伏度为 10～ 2 0nm。掺摩尔比 0 .0 1Er3 + ∶γ Al2 O3 薄膜 ,获得了中心波长为1.5 34μm(半峰全宽为 36nm)的光致发光谱。     

Influences of annealing on structural and compositional properties of Al_2O_3 thin films grown on 4H–SiC by atomic layer deposition

Annealing effects on structural and compositional performances of Al_2O_3 thin films on 4H–Si C substrates are studied comprehensively. The Al_2O_3 films are grown by atomic layer deposition through using trimethylaluminum and H_2 O as precursors at 300?C, and annealed at various temperatures in ambient N_2 for 1 min. The Al_2O_3 film transits from amorphous phase to crystalline phase as annealing temperature increases from 750?C to 768?C. The refractive index increases with annealing temperature rising, which indicates that densification occurs during annealing. The densification and grain formation of the film upon annealing are due to crystallization which is relative with second-nearest-neighbor coordination variation according to the x-ray photoelectron spectroscopy(XPS). Although the binding energies of Al 2p and O 1s increase together during crystallization, separations between Al 2p and O 1s are identical between as-deposited and annealed sample, which suggests that the nearest-neighbour coordination is similar.     

Preparation and characterization of alkyl sulfate and alkylbenzene sulfonate surfactants/TiO2 hybrid thin films by the liquid phase deposition (LPD) method

Hybrid titanium oxide thin films containing surfactants, sodium dodecyl benzylsulfonate and sodium dodecyl sulfate, have been prepared by a novel liquid-phase deposition method. It is a new attempt to prepare organic–inorganic hybrid thin film by this method which usually be applied in preparing metal oxide thin film before. The two kinds of surfactants/TiO₂ hybrid thin films were characterized by means of FT-IR, SEM, XRD, fluorescence X-ray, ICP–AES and Raman spectroscopy, and showed noticeable differences in surface top view and particle diameter, cross-section image and thickness, deposited amount of Ti, XRD patterns and Raman shift. The reasons giving rise to above differences of the two kinds composite thin films has been discussed. The deposition mechanism of organic–inorganic hybrid thin film has been also presumed. The use of this processing parameter may open up a new way to the preparing of the organic–inorganic hybrid thin film.     

单晶硅表面有机硅烷/Ag2O纳米微粒复合自组装膜的制备和表征

利用分子自组装成膜技术 ,在单晶硅表面制备了有机硅烷 /Ag2 O纳米微粒复合膜 .应用接触角测定仪、原子力显微镜和X射线光电子能谱仪分析表征了薄膜的组成和结构 .结果表明 ,通过硅烷偶联剂 3 氨丙基 三乙氧基硅烷在单晶硅基底表面的成功组装 ,获得了较为均匀的硅烷化表面 ,而Ag2 O纳米微粒可在硅烷化表面成功地进行组装 ,并呈亚单层排布     

光谱学研究硅烷钒锆复合钝化膜的结构和成膜机理

在热镀锌钢板表面制备了硅烷钒锆复合钝化膜。用X射线光电子能谱(XPS)、射频辉光放电发射光谱(rf-GD-OES)和傅里叶变换衰减全反射红外光谱(ATR-FTIR)表征了钝化膜的组成结构,分析了硅烷钒锆复合钝化膜的成膜机理。结果表明：硅烷之间互联构成了硅烷钒锆复合钝化膜的主成膜成分,无机缓蚀剂均匀分布在膜层中。钝化膜表面Si2p的XPS窄幅扫描谱100.7 eV处的拟合峰和红外光谱在波数1 100 cm-1 Si—O吸收峰变宽加强,表明硅烷以Si—O—Zn键的形式化学吸附在锌的表面,硅烷分子之间通过Si—O—Si键相互交联;红外光谱中1 650和1 560 cm-1的两个酰胺特征峰,结合910 cm-1的环氧特征峰的消失,表明γ-GPT的环氧基团在氨基活性氢的诱导下开环和γ-APT的氨基之间发生聚合反应形成交联的空间网状结构;rf-GD-OES分析发现钝化膜0.3 μm处存在一层富氧层,钝化反应生成的ZrF₄,ZrO₂和钒盐等无机物均匀分布在钝化膜中。分析膜层组成结构和成膜前后的ATR-FTIR光谱,研究了成膜过程中发生的物理过程和化学变化,提出了硅烷钒锆复合钝化膜的成膜机理。     

Electron beam-physical vapor deposition of SiC/SiO2 high emissivity thin film

When heated by high-energy electron beam (EB), SiC can decompose into C and Si vapor. Subsequently, Si vapor reacts with metal oxide thin film on substrate surface and formats dense SiO₂ thin film at high substrate temperature. By means of the two reactions, SiC/SiO₂ composite thin film was prepared on the pre-oxidized 316 stainless steel (SS) substrate by electron beam-physical vapor deposition (EB-PVD) only using β-SiC target at 1000 °C. The thin film was examined by energy dispersive spectroscopy (EDS), grazing incidence X-ray asymmetry diffraction (GIAXD), scanning electron microscopy (SEM), atomic force microscopy (AFM), backscattered electron image (BSE), electron probe microanalysis (EPMA), X-ray photoelectron spectroscopy (XPS) and Fourier transformed infra-red (FT-IR) spectroscopy. The analysis results show that the thin film is mainly composed of imperfect nano-crystalline phases of 3C-SiC and SiO₂, especially, SiO₂ phase is nearly amorphous. Moreover, the smooth and dense thin film surface consists of nano-sized particles, and the interface between SiC/SiO₂ composite thin film and SS substrate is perfect. At last, the emissivity of SS substrate is improved by the SiC/SiO₂ composite thin film.     

Preparation and atomic oxygen erosion resistance of silica film formed on silicon rubber by sol-gel method

Based on the characteristic that silicon coupling agents have the capability to develop ‘molecular bridge’ in the interface of organic materials and inorganic materials, silica films were prepared on the surface of flexible silicon rubber by sol-gel method and the optical transmittance of the sample before and after atomic oxygen irradiation was tested. The surface morphology and structure of silica films were investigated by scanning electronic microscope (SEM) and Fourier transformed infrared spectroscopy (FTIR). The results indicated that the silica sol could easily form a uniform thin film on the surface of silicon rubber pretreated by high concentration silicon coupling agents, and the inorganic silica films could combine with organic silicon rubber without obvious delamination on the interface.