本文对原位反应合成的C-SiC-TiC-TiB2复合材料在600-1200℃空气中的抗氧化性进行了研究。在不同材料组成和试验温度下，试样分别出现氧化增重和失重，这主要取决于碳相和陶瓷相的氧化速率及氧化层的结构特征。在600℃该材料几乎不被氧化；800℃时，TiB2被优先氧化，形成B2O3液相；在1000℃以上，B2O3与SiO2生成硼硅酸盐玻璃，形成一致密氧化层。氧化过程中液相的出现和致密氧化层的形成显著降低了氧化速率，使材料进入钝氧化，从而大幅度地提高了该材料的抗氧化能力。

以硅溶胶、尿素和炭黑为原料，经氨解溶胶-凝胶、碳热还原法合成了纳米Si3N4-SiC复合粉末。通过在硅溶胶中引入Y（NO3）3，合成了Si3N4-SiC-Y2O3超细复合粉末。Y2O3的加入有助于降低Si3N4-SiC的合成温度。采用XPS和XRD分析复合粉末中Y的存在状态表明：一部分Y固溶在Si3N4-SiC中，另有一部分以Y2O3形式存在。Si3N4-SiC-Y2O3复合粉末的烧结性能良好。

The adsorption of poly(acrylic acid) (PAA) in aqueous suspension onto the surface of TiO2 nanoparticles was investigated. FTIR spectroscopic data provided evidence in support of hydrogen bonding and chemical interaction in the case of the PAA–TiO2 system. Adsorption isotherms demonstrated that part of the PAA initially added to the suspension was adsorbed onto the TiO2 surface, after which there was a gradual attainment of an adsorption plateau. The adsorption density of PAA was found to increase with an increase of PAA molecular weight, while it decreased with an increase of pH. The thickness of the PAA adsorption layer was calculated based on measurements of suspension viscosities in the absence and presence of PAA. It was shown that the thickness of the adsorption layer increased with the increase of pH, PAA molecular weight, and its concentration. The surface charge density, the diffuse charge density, and the zeta potential of TiO2 varied distinctly after PAA adsorption. The shift of pHiep toward a lower pH value was observed in the presence of PAA. PAA was found to stabilize the suspension of TiO2 nanoparticles through electrosteric repulsion. The influence of factors such as PAA molecular weight and its concentration on the colloidal stability of the aqueous suspension was also investigated.

The thermal degradation behaviour of polyacrylate and its zinc oxide composites were investigated by differential scanning calorimetry (DSC), thermogravimetry (TG) and Fourier transform infrared spectroscopy (FTIR). Reaction mechanisms of polymer degradation with and without ZnO particles were obtained. Filler-free polyacrylate exhibited one DSC peak, indicating that the polymer was degraded with only one stage of weight loss. Polyacrylate/ZnO composites underwent two minor weight losses as well as the major weight loss. ZnO stabilized or destabilized the polymer molecules according to the temperature region. Two mechanisms were proposed for the change of thermal properties of the nanocomposite. An increase of the stabilization or destabilization effect of ZnO nanoparticles was found in the nanocomposite with a higher content of the inorganic phase. Compared to micron ZnO particles, ZnO nanoparticles exhibited a greater effect due to their high specific area giving more sites for interactions. In addition, kinetics of thermal degradation of filler-free polyacrylate and polyacrylate/ZnO composite were quantitatively obtained by means of non-isothermal weight loss data analysis.

以Ti，Al和C粉末为原料，采用接触反应法制备原位TiC颗粒增强的铸造Al2Cu复合材料，研究了反应温度对反应产物的影响，探讨了TiC颗粒的形成机制。结果表明，随着反应温度的升高，副产物TiAl3和Al4C3生成的可能性减小；当反应温度为900℃时，反应副产物全部转变为TiC，且原位反应生成0.5～1.5μm的TiC颗粒均布于α2Al基体中；TiC的加入能显著提高基体的强度，特别是高温强度，但使其延伸率有所下降。