轻质碳酸钙／聚丙烯共混物中聚丙烯β－晶的成核结晶研究

用Ｘ射线衍射和差示扫描量热法研究了轻质碳酸钙／聚丙烯共混物（Ｌ－ＣａＣＯ３／ＰＰ）中ＰＰβ－晶的成核结晶现象，发现ＰＰβ－晶的成核结晶与ＰＰ的来源和Ｌ－ＣａＣＯ３在共混物中的含量有关，铝酸酯偶联剂对共混体系的ＰＰβ－晶的成核结晶有显著的增强作用．分析认为共混物中ＰＰβ－晶的成核结晶现象是ＰＰ中存在的某些杂质（主要是催化剂残余物）与Ｌ－ＣａＣＯ３组成的复合成核剂作用的结果，而铝酸酯是这种复合成核剂的一种促进剂．     

二氧化钒和三氧化二钒研究进展

VO₂和V₂O₃是优异的光、电、磁热敏材料，在多种技术领域中具有广阔的应用前景，已成为国内外新颖功能材料研究的热点之一。本文综述了VO₂和V₂O₃的粉体、陶瓷和薄膜的研究进展，并对相关问题进行讨论。     

氧钒(Ⅳ)碱式碳酸铵的热分析和纳米氧化钒的制备

The violet polycrystalline (NH₄)₅[(VO)₆(CO₃)₄(OH)₉]·10H₂O(NVCO) was simply synthesized by solution reaction using V₂O₅, HCl, N₂H₄·2HCl and NH₄HCO₃ as the starting materials. The results of TGA and DTA of NVCO under H₂(99.999%) atmosphere show that V₂O₃ forms at 620℃. The data of TG/DTG and DTA of NVCO under N₂(99.999%) atmosphere indicate that VO₂ forms at 367℃ and crystallizes at 390℃. In air atmosphere, the TG/DTG and DTA of NVCO show that V₂O₅ forms at 354℃, crystallizes at 366℃ and melts at 664℃. The three thermolysis processes of NVCO show that a large amount of H₂O, CO₂ and NH₃ gases fast releases during the thermolysis of NVCO, causing that the particles of the materials split and atomize strongly, thus to obtain V₂O₃, VO₂ and V₂O₅ nano-powders finally. According to the above of thermoanalytical results, V₂O₃, VO₂ and V₂O₅ powders were prepared respectively under H₂, N₂ and oxygen in a tube furnace. Chemical analysis and XRD ex-periments of the powders identify that pure V₂O₃ is obtained at 800℃ for 0.5h under H₂ atmosphere; crystalline VO₂ is obtained at 480℃ for 0.5h in N₂; amorphous VO₂ is obtained at 350℃ for 20min under N₂ atmosphere, this has been first reported to prepare amorphous VO₂ powder so far; pure V₂O₅ is obtained at 400℃ for 10min under oxygen. From the micrographs of the powders, the particle size of the V₂O₃, the crystalline VO₂ or the V₂O₅ powders is 35nm, 24nm or < 40nm, respectively. Above-mentioned results prove that NVCO is a good precursor for preparation of pure V₂O₃, VO₂ and V₂O₅ nano-powders under mild conditions.     

氧钒(Ⅳ)碱式碳酸铵的氨解和纳米VN的制备

氮化钒(VN)具有十分高的热、化学稳定性和强的机械性能,用于切削工具和结构材料。VN作为催化剂,具有高催化活性、高选择性、良好的稳定性和抗中毒性能;其催化行为类似Pt、Pd和Rh,是这些稀贵金属的经济的代用物。细的球状     

对“三草酸合铁(Ⅲ)酸钾的制备”的改进

在Ｋ３［Ｆｅ（Ｃ２Ｏ４）３］·３Ｈ２Ｏ合成过程中,当草酸加入Ｈ２Ｏ２氧化ＦｅＣ２Ｏ４·２Ｈ２Ｏ产物制备Ｋ３［Ｆｅ（Ｃ２Ｏ４）３］·３Ｈ２Ｏ溶液时,原实验条件控制不严格,易发生草酸还原高铁的副反应而导致产品不纯。本文通过改进草酸加入方式和酸溶终了ｐＨ的控制,可降低副反应,提高产品质量。     

不同整比性VO2纳米粉体的合成

以V₂O₅,HCl,N₂H₄·2HCl和NH₄HCO₃为原料合成了紫红色多晶(NH₄)₅[(VO)₆(CO₃)₄(OH)₉]·10H₂O(I),产率80％～95％.在N₂气流中对前体I进行了TG/DTG和DTA热分析.研究了前体I在N₂-空气气流中热解时氧分压(po₂)和反应温度对产物VO₂整比性的影响.结果表明,在500℃条件下,VO_x中的x值与po₂呈正比关系,在po₂=30.3Pa条件下,在450～520℃区间,产物为缺氧VO₂;在t<450℃和t>520℃时,产物为富氧VO₂.在合适的条件下,成功地合成了从VO_1.927到VO_2.080之间不同整比性的VO₂粉体.产物组成均匀,其XRD谱未观察到非VO₂的杂质峰.VO₂粉体颗粒的平均粒径为20nm,粒度分布均匀并呈球形.