环氧改性乙丙乳液及其内墙涂料的制备

以环氧树脂为交联剂，在室温下实现了对乙丙乳液的交联改性，制得的环氧改性乙丙乳液克服了乙丙乳液的缺点。介绍了环氧改性乙丙乳液及其内墙涂料的配方、制备工艺及性能指标。     

Porous α-Al2O3 thermal barrier coatings with dispersed Pt particles prepared by cathode plasma electrolytic deposition

Porous α-Al₂O₃ thermal barrier coatings (TBCs) containing dispersed Pt particles were prepared by cathode plasma electrolytic deposition (CPED). The influence of the Pt particles on the microstructure of the coatings and the CPED process were studied. The prepared coatings were mainly composed of α-Al₂O₃. The average thickness of the coatings was approximately 100 μm. Such single-layer TBCs exhibited not only excellent high-temperature cyclic oxidation and spallation resistance, but also good thermal insulation properties. Porous α-Al₂O₃ TBCs inhibit further oxidation of alloy substrates because of their extremely low oxygen diffusion rate, provide good thermal insulation because of their porous structure, and exhibit excellent mechanical properties because of the toughening effect of the Pt particles and because of stress relaxation induced by deformation of the porous structure.     

Effect of TiO<Subscript>2</Subscript> pigment gradation on the properties of thermal insulation coatings

This study was designed to evaluate the thermal performance and mechanical properties of coatings with different gradations of TiO₂ pigments. The solar reflectance, cooling performance, wash resistance, and film adhesion strength of the coatings were investigated. The influence of TiO₂ powder gradation on the final properties of the coatings was studed. The solar reflectance and the thermal insulation were observed to increase with increasing content of nanosized TiO₂. The mechanical properties of the coatings, such as their wash resistance and film adhesion strength, were observed to increase with increased incorporation of nanosized TiO₂. Such improvements in the properties of the coatings were attributed to the greater specific surface area and lower thermal conductivity of nanosized TiO₂ particles compared to normal TiO₂ particles.     

Microstructural evolution and growth kinetics of thermally grown oxides in plasma sprayed thermal barrier coatings

The formation of thermally grown oxide(TGO) during high temperature is a key factor to the degradation of thermal barrier coatings(TBCs)applied on hot section components. In the present study both the Co Ni Cr Al Y bond coat and Zr O_2-8 wt.% Y_2O_3(8YSZ) ceramic coat of TBCs were prepared by air plasma spraying(APS). The composition and microstructure of TGO in TBCs were investigated using scanning electron microscopy(SEM), energy dispersive spectroscopy(EDS) and X-ray diffraction(XRD) analysis. The growth rate of TGO for TBC and pure BC were gained after isothermal oxidation at 1100 °C for various times. The results showed that as-sprayed bond coat consisted of β and γ/γ'phases,β phase reducesd as the oxidation time increased. The TGO comprised α-Al_2O_3 formed in the first 2 h. Co O, Ni O, Cr_2O_3 and spinel oxides appeared after 20 h of oxidation. Contents of Co O and Ni O reduced while that of Cr_2O_3 and spinel oxides increased in the later oxidation stage.The TGO eventually consisted of a sub-Al2O3 layer with columnar microstructure and the upper porous CS clusters. The TGO growth kinetics for two kinds of samples followed parabolic laws, with oxidation rate constant of 0.344 μm/h~(0.5) for TBCs and 0.354 μm/h0.5for pure BCs.     

六棱柱状Au-ZnO的一步合成及其光催化性能

采用一步法制备结构均一的六棱柱状Au-ZnO复合纳米材料,并通过X射线衍射仪(XRD)、扫描电子显微镜(SEM)等对其结构和形貌进行表征.结果表明,改变HAuCl4的用量能够很好地调控所合成的纳米复合物的形貌.在此基础上,研究了Au-ZnO纳米颗粒的光催化性能,当Au含量为2.65%时,所合成纳米复合物对罗丹明B染料的光降解能力最佳,降解率达到99.6%.     

高温固相法制备Sm2O3掺杂La2Ce2O7热障涂层材料

以La2 O3、CeO2和Sm2 O3为原料,采用高温固相反应法制备了Sm2 O3部分掺杂La2 Ce2 O7热障涂层陶瓷材料,其化学式为(SmxLa1-x)2Ce2O7.采用X射线衍射法研究了试样的物相结构,并通过对比各实验条件下制备的试样的X射线衍射图谱,对试样的掺杂比例、烧制温度及烧制时间进行了探究.结果表明,所制备试样为萤石结构,当掺杂摩尔比Sm：La为1：2或1：3时试样均能保持良好的相结构,以掺杂摩尔比Sm：La=1：2制备的( Sm0.33 La0.67)2 Ce2 O7材料在1600℃下具有良好的相稳定性,且其最佳制备条件为1550℃下烧制10 h,该材料是一种很有潜力的新型热障涂层陶瓷材料.     

Au@P4VP纳米复合粒子的制备与性能

本文首先采用RAFT聚合法合成了端基为双硫酯的聚-4-乙烯基吡啶(P4VP),进一步使用NaBH4还原得到端基为巯基的P4VP,最后通过原位还原法在HAuCl4水溶液中合成了Au@P4VP纳米复合粒子(Au@P4VP NPs).通过UV-vis、FT-IR、XRD、SEM、DLS及TEM等手段表征其结构,证明成功合成了金纳米复合粒子.研究表明:金纳米复合粒子的粒径和形貌与P4VP的浓度及溶液的pH值有关.当P4VP和HAuCl4的物质的量之比为2时,得到的金纳米粒子的形貌和粒径最好;在P4VP的物质的量很小时,得到了三角形和不规则形状的金纳米粒子.当金纳米复合粒子溶液的pH3.2时,得到的纳米粒子具有很好的分散性且粒径较小;若溶液的pH3.2,得到的纳米粒子粒径较大,且发生一定程度的团聚.     

Microstructure and high-temperature wear properties of in situ TiC composite coatings by plasma transferred arc surface alloying on gray cast iron

In this work, an in situ synthesized TiC-reinforced metal matrix composite (MMC) coating of approximately 350–400μm thick-ness was fabricated on a gray cast iron (GCI) substrate by plasma transferred arc (PTA) surface alloying of Ti–Fe alloy powder. Microhard-ness tests showed that the surface hardness increased approximately four-fold after the alloying treatment. The microstructure of the MMC coating was mainly composed of residual austenite, acicular martensite, and eutectic ledeburite. Scanning electron microscopy (SEM) and X-ray diffraction analyzes revealed that the in situ TiC particles, which were formed by direct reaction of Ti with carbon originally contained in the GCI, was uniformly distributed at the boundary of residual austenite in the alloying zone. Pin-on-disc high-temperature wear tests were performed on samples both with and without the MMC coating at room temperature and at elevated temperatures (473 K and 623 K), and the wear behavior and mechanism were investigated. The results showed that, after the PTA alloying treatment, the wear resistance of the sam-ples improved significantly. On the basis of our analysis of the composite coatings by optical microscopy, SEM with energy-dispersive X-ray spectroscopy, and microhardness measurements, we attributed this improvement of wear resistance to the transformation of the microstruc-ture and to the presence of TiC particles.     

基于纳米银-二氧化钛-壳聚糖复合物修饰电极的 芦丁电化学传感器的构建及其应用研究

本实验以Ag-TiO_2-CS纳米复合物修饰电极构建电化学传感器,建立适用于其分析检测的电化学分析新方法。利用Ag-TiO_2-CS修饰电极,以此制备芦丁电化学传感器。用循环伏安法(CV)对电极的电化学特性进行研究,之后用差分脉冲伏安法(DPV)对芦丁进行检测,建立芦丁的电化学检测新方法。CV实验表明Ag-TiO_2-CS纳米复合物具有良好的电化学活性,可以应用于芦丁检测。DPV实验进一步表明,修饰电极峰电流值与芦丁浓度在一定范围内呈线性关系,稳定性、抗干扰性等良好,此电化学传感器可以对芦丁片中的芦丁进行测定,结果良好。该传感器制作方法简单,灵敏度较高,稳定性好,可用于芦丁片中芦丁的分析测定。     

可见光减反膜的设计原则研究

分析了光学零件表面的光能量的反射损失,从膜系选择、膜料选择、膜层厚度,镀制工艺四个方面,对可见光减反膜的膜系设计特点进行了研究,确定了基本的设计原则.