薄膜制备技术中溶胶-凝胶工艺研究

综述了溶胶-凝胶工艺在薄膜制备技术中的现状和技术动态、溶胶-凝胶工艺的成膜理论和成膜工艺对薄膜工业发展的促进,并简要提出了溶胶-凝胶薄膜工艺影响薄膜厚度的因素和存在的主要技术问题.     

中国专利

正一种使用多次涂覆成膜工艺制备聚乙烯醇薄膜的方法本发明公开了一种使用多次涂覆成膜工艺制备聚乙烯醇薄膜的方法。包括如下步骤:1)采用精密涂覆模头将聚乙烯醇水溶液涂布在聚对苯二甲酸乙二酯(PET)薄膜上,干燥;2)重复步骤1)操作1次以上,剥离脱膜,强化干燥,定型,收卷,得到聚乙烯醇薄膜。本发明方法能有效改善和解决现有生产聚乙烯醇薄膜技术中存在的不足和缺陷,使生产速度和效率提高30%以上,且公差精度提高,薄膜厚度公差≤5%;同时,本发明方法不添加脱膜剂,采用PET薄膜作为基膜,干燥后容易顺利脱膜,提高了聚乙烯醇薄膜的外观质量,同时保障了聚乙烯醇薄膜正常的热封性能和印刷性能。     

高介电常数超薄PTFE/TiO2复合薄膜的厚度均匀性研究

采用涂覆工艺制备聚四氟乙烯/二氧化钛(PTFE/TiO₂)复合薄膜,针对TiO₂粉体密度大容易沉降问题,探究浆料总量、浆料黏度、涂覆速率的压力差等因素对成膜厚度均匀性的影响。结果表明：在涂覆速度为0.20 m/s条件下,浆料黏度范围为969～1 139 mPa·s(测试转速20 r/min)时,制备了目标厚度(55±10)μm的PTFE/TiO₂复合薄膜。通过扫描电镜观察,PTFE/TiO₂复合薄膜的表面均匀平整,TiO₂分散性良好,成膜质量良好。复合薄膜的相对介电常数、薄膜拉伸强度、断裂伸长率的离散系数均≤5%,证明制备的薄膜的介电性能和力学性能一致性良好。     

电加热石墨烯薄膜材料的制备及应用研究进展

介绍了制备低缺陷的电加热石墨烯薄膜材料的几种方法,以及由不同方法得到的石墨烯材料在制备成膜时所采用的不同的成膜技术及其应用,并且分析了不同的方法在大批量制备过程中亟待解决的问题。指出在考虑到低成本大批量制备高性能的电加热石墨烯薄膜材料时,超临界流体剥离法是一种环保无VOC的制备方法,将得到的石墨烯制成浆料可以突破基底的限制而被广泛应用。     

CIGS薄膜制备工艺研究进展

本文综述了CIGS薄膜太阳能电池的研究进展,介绍了薄膜太阳能领域的吸收层材料CIGS吸收层的制备工艺,如蒸发沉积硒化、磁控溅射硒化、喷涂热解、涂覆成膜-硒化、电化学沉积等。最后从理论和实践方面展望了CIGS吸收层制备工艺的研究方向。     

表面修饰在MOF薄膜制备中的应用

综述了近几年表面修饰手段在金属-有机骨架(MOF)薄膜制备中的应用研究进展。MOF材料由于具有结构可设计、孔道尺寸可调且可功能化等特点,在气体分离膜领域具有极大的应用价值。制备连续致密MOF膜的关键是解决MOF与基底之间的界面结合问题。表面修饰可改善基底表面的物理化学性质,增强MOF与基底之间的相互作用力。本文从有机分子修饰、无机化合物修饰和MOF晶种修饰三方面入手,介绍修饰手段在MOF薄膜制备中的应用研究进展。其中,着重阐述了不同修饰手段的修饰机理,分析了修饰手段对MOF薄膜的制备及其气体分离性能的影响。研究表明,MOF的种类繁多且成膜过程复杂,有时单一的修饰手段无法制备高质量的MOF薄膜。因此,文中指出根据MOF和基底的性质,选择不同的修饰手段结合使用将是MOF薄膜制备的一个重要发展方向。     

TiNi形状记忆合金薄膜的研究现状

TiNi形状记忆合金薄膜是近几年来随着微电子电路发展的新兴材料。目前,涂覆TiNi合金薄膜的材料被广泛用作集成电路中微驱动器、微动开关等智能电路元件等。介绍了TiNi合金薄膜的制备方法,总结了制备过程中影响薄膜性质的因素,结合TiNi合金薄膜的应用现状,提出了未来TiNi合金薄膜研究发展方向。     

耐高温复合型离型膜材的成型加工技术

简要介绍了高温复合型离型膜材的的主要成型加工技术,包括熔融共挤、复合、淋膜等各种离型膜材的加工方法及其技术控制要点,重点阐述了3~200μm挤出工艺制备离型膜材的挤出成膜技术,包括了具体的塑化、成膜、厚度、粘合牢度等的工艺设计、控制技术,最后简要的介绍该离型膜材薄膜应用趋势。     

机械力化学在陶瓷材料研究中的应用

机械力化学是机械合金化技术研究中的最新进展，在球磨过程中机械力化学使颗粒和晶粒细化产生裂纹、比表面积增大、晶格缺陷增多、晶格发生畸变和结晶程度降低，乃至诱发低温化学反应，可制备出高活性陶瓷粉体和性能优异的陶瓷基材料。本介绍了机械力化学在陶瓷材料研究中的最新研究进展，同时讨论了不同球磨工艺条件对材料制备过程的影响，并对其未来发展进行了展望。     

溶胶-凝胶法制备NiO薄膜及影响因素

NiO薄膜可作为电致变色材料、电容器材料、气敏材料、电极材料等而受到人们关注。溶胶凝胶法(sol-gel)制备NiO薄膜材料因其无可比拟的优点成为研究的热点。简要介绍了sol-gel法制备NiO薄膜的特点及基本原理,重点论述了成膜方式、溶胶性质以及热处理条件对薄膜形貌、结构和电化学性能的影响,展望了NiO薄膜材料的发展方向,旨在为NiO薄膜材料的研究和开发提供一些借鉴和启发。     

Tribomechanical and microstructural properties of cathodic arc-deposited ternary nitride coatings

Sintered carbides are promising materials for surfaces that are exposed to extreme wear. Owing to their high service load, ceramic-based thin films are coated on carbides using different techniques. In this study, non-toxic and cobalt-free powder metallurgy-sintered carbide samples were coated with TiN, TiAlN, CrAlN, and TiSiN ceramic-based thin film coatings by cathodic arc physical vapor deposition. The microstructure (phase formation, coating thickness, surface roughness, and topography), mechanical properties (hardness, modulus of elasticity, and plasticity indices), and tribological properties (nanoscratch and wear behavior) of the thin film coatings were investigated. No cracks or defects were detected in these layers. The ceramic-based ternary nitride thin film coatings exhibited better mechanical performance than the TiN coating. The TiN thin film coating had the highest average surface roughness, which deteriorated its tribological performance. The ternary nitride thin film coatings exhibited high toughness, while the TiN thin film coating exhibited brittle behavior under applied loads when subjected to nanoscratch tests. The wear resistance of the ternary nitride coatings increased by nearly 9–17 times as compared to that of the TiN coating and substrate. Among all the samples investigated, the substrate showed the highest coefficient of friction (COF), while the TiSiN coating exhibited the lowest COF. The TiSiN thin film coating showed improved mechanical and tribological properties as compared to other binary and ternary nitride thin film coatings.     

Development of multiple-droplet drop-casting method for the fabrication of coatings and thin solid films

Spray coating is a commercial and low-cost technique for the fabrication of large-area coatings and thin films, but it is a stochastic process that is hard to control, as far as the fabrication of thin coatings and solid films is concerned. On the other hand, drop-casting is a facile and more controllable coating technique than spray coating, but its application is limited to small-area thin solid films and coatings. The objective of this work is, therefore, to study the feasibility of impinging an array of droplets, rather than just one droplet, to fabricate polymeric and other solution-processed thin films with larger surface areas than those produced by conventional drop-casting. To this end, in this study, four droplets of poly(3,4-ethylenedioxythiophene)–polystyrene sulfonate (PEDOT:PSS) solution are released simultaneously and impinged on the four vertices of a square on a wettable solid surface to make a thin film. The effect of the substrate texture on the spreading and the film formation process is studied. As a novel idea, the substrate is excited by ultrasonic vibration to improve the droplet spreading and coalescence. It is shown that as time elapses, the impinged droplets successfully coalesce and make a thin film. Surface morphology and roughness of the resulting PEDOT:PSS thin solid films show that, except on the edges, the resulting thin solid films are uniform. This leads us to conclude that the application of equal-sized and equally-spaced multiple droplets released simultaneously and impinged on vibrating substrates could be considered as a new coating technique, which has some of the benefits of the spray coating, but it is much more controllable than spray coating.     

Optimizing inkjet printing process to fabricate thick ceramic coatings

This article describes the use of Taguchi optimization and ANOVA techniques on inkjet printing process to determine optimal parameters for fabrication of thick ceramic coatings over glass substrates. Stable nanoparticle suspensions are synthesized through high energy milling of precursor powders with adequate quantities of binder and suspending solvent. Most often, inkjet printing process is being used for developing fine and thin layers (<10 µm). However, an attempt is made to fabricate thick ceramic films by varying only IJP process parameters and without multiple layer deposition, thereby reducing efforts in ink synthesis and processing time of coated substrates. Three parameters of IJP were varied for developing a model that was used for precisely predicting the printed layer thickness under varying process parameters. ANOVA technique showed that open time interval in combination with nano particle concentration in the ink could potentially lead to thick coatings. The higher volume % of solvent in the diluted suspension ink under the influence of substrate heating contributed significantly to coffee stain effect with irregular surface coatings. However, increasing the concentration of nanoparticles in the diluted ink resulted in substantial improvement in thickness of the layer with simultaneous control of coating defects.     

Elaboration and mechanical characterization of nanocomposites thin films: Part I: Determination of the mechanical properties of thin films prepared by in situ polymerisation of tetraethoxysilane in poly(methyl methacrylate)

The sol–gel process allows to design hybrid organic–inorganic materials constituted by organic molecules or macromolecules and inorganic metal oxo-polymers interpenetrated at the nanometer scale. These hybrids were deposited as functional coatings with tunable thickness on float glass substrates. Good adhesion and mechanical behaviour of the coatings are required to keep their functionality in time hence; the performance of the PMMA-SiO₂ based thin films was investigated using nanoindentation. This study validates nanoindentation measurements as an appropriate technique to characterize hybrid organic–inorganic thin films, despite visco-elastic behaviours. Specific analysis procedures and the use of appropriate models allowed us to determine the indentation modulus and hardness of the hybrid layers reproductively. The structure and the mechanical behaviour are reported for thin films as a function of the fraction of silica.     

Characterization of TiCN and TiCN/ZrN coatings for cutting tool application

Coating a cutting tool improves wear resistance and prolongs tool life. Coating performance strongly depends on the mechanical and chemical properties of the coating material. In a machining process, the type of selected coating depends on the cutting condition because of the properties of the applied coating material. In addition, many factors, such as coating thickness, composition ratio, sequences of layers in multilayer coatings, and the deposition method influence the performance of a coating. In this study, the mechanical properties of TiCN and TiCN/ZrN were investigated using a ball on disk test. The substrate material made from a carbide-based cutting tool was also developed in-house. The analysis performed shows that the performances of TiCN and TiCN/ZrN coatings were found to be comparable to that of the commercial TiN-coated carbide-based cutting tool. Both the in-house and commercial coated inserts had significantly lower coefficient of friction than uncoated inserts, and the friction coefficient of TiCN coatings was constantly slightly lower than that of TiN coatings. Moreover, the coefficient of friction of the in-house developed TiCN was slightly lower than that of commercial TiN coating. However, the coefficient of friction of the in-house developed uncoated carbide inserts was slightly higher than that of commercial uncoated carbide inserts.     

Can graphene make better HgCdTe infrared detectors?

We develop a simple and low-cost technique based on chemical vapor deposition from which large-size graphene films with 5-10 graphene layers can be produced reliably and the graphene films can be transferred easily onto HgCdTe (MCT) thin wafers at room temperature. The proposed technique does not cause any thermal and mechanical damages to the MCT wafers. It is found that the averaged light transmittance of the graphene film on MCT thin wafer is about 80% in the mid-infrared bandwidth at room temperature and 77 K. Moreover, we find that the electrical conductance of the graphene film on the MCT substrate is about 25 times larger than that of the MCT substrate at room temperature and 77 K. These experimental findings suggest that, from a physics point of view, graphene can be utilized as transparent electrodes as a replacement for metal electrodes while producing better and cheaper MCT infrared detectors.     

TEM,XPS and thermo-mechanical properties of novel sustainable hybrid coatings

This work contributes to the development of a new generation of protective coatings composed of organic–inorganic materials. A silica based hybrid film was used in this work as high performance materials. The silica sol–gel film reveals enhanced thermo-mechanical properties in comparison with the pure polymer film. Herein, we demonstrate the possibility of employing cheap SiO₂ as prospective nano-fillers for hybrid coatings with active thermo-mechanical properties. Organic–inorganic hybrid coatings based on polyimide and silica were synthesized through a simple physical mixing technique. 3,3′,4,4′-Biphenyltetracarboxylic dianhydride (BPDA), benzene-1,3-diamine (BDA), 3,3′-oxydianiline (ODA) and SiO₂, were used as precursors for the hybrid coatings. These hybrid coatings were deposited via spin coating onto a galvanized iron, aluminum and copper in order to study the adhesive strength. The effects induced by the silica content on the mechanical properties of the coated samples were investigated. The mechanical properties of hybrid composite were found to be enhanced compared to polyimide coating. The main objective was to observe potential improvements in the mechanical and thermal properties of PI–silica hybrid films. Morphology, and structural changes in the composite films were studied as well as adhesion and impact strength and these characteristics were compared with those of unreinforced polyimide films.     

Testing of adhesion of thin films to substrates

The results of the measurement of the adhesion strength of thin films or coatings to substrates are often influenced by system parameters that may be influenced by preparation of the specimen for testing or by deposition of the film itself. In this paper, the scratch, pull, and peel tests are analyzed in terms of criteria for film/coating removal and for the effects of system parameters such as film hardness and ductility, film thickness, substrate hardness, etc.     

新型化学铣切临时保护可剥性涂料

简要介绍了化学铣切临时保护可剥性涂料技术要求和研究进展,探讨了化学铣切原理及化学铣切临时保护可剥性涂料制备、应用工艺流程,自制的化学铣切临时保护可剥性涂料应用性能基本达到了国外同类产品的水平,是理想的更新换代产品。     

氮化硅薄膜的制备技术

氮化硅薄膜是一种重要的精细陶瓷薄膜材料,具有优秀的光电性能、钝化性能、稳定性能和机械性能,在微电子、光电和材料表面改性等领域有着广阔的应用前景。本文综述了几种制备氮化硅薄膜的方法。