生物微孔SiC的制备

发布时间：2018-03-05 22:18

  本文选题：硅藻土　切入点：原位合成　出处：《长春工业大学》2015年硕士论文　论文类型：学位论文

【摘要】：碳化硅材料具有特殊的机械性能、化学性能和电性能,是一种耐氧化、耐腐蚀且具有高度化学惰性的物质,它的热稳定性和热传导性能较高、热膨胀系数较小,并且在高温条件下表现出半导体性质。因此,它可做磨料、建材、热交换器、电子、传感等材料,在国防、航空、冶金、化工等领域都有广泛的应用。多孔异形碳化硅又拓宽了在催化、能源存储、生物医疗和环境保护等领域的的应用。硅藻土是一种存在于自然界中的天然矿藏,其主要成分为SiO2,然而它的纯度不高,主要含有氧化铁、氧化铝等杂质。以往只是将其做为过滤脱色材料使用,没有充分利用其特有的生物微孔结构,属于初期开发产品,经济效益不高,因此,开发其新的应用价值十分有意义。以硅藻土为原料制备的生物微孔碳化硅具有硅藻土的规则的微孔结构和碳化硅的优良性能,同时具有良好的生物相容性、理化性能稳定、无毒副作用。将其开发成经济效益较高的生物材料,例如人造骨质,在生物医药及生物医学领域的研究将成为未来的研究热点之一。因此,生物微孔碳化硅将具有良好的经济效益和应用价值。本文选用生物微孔结构的硅藻土作为原料。首先将硅藻土进行酸浸和煅烧处理得到SiO2含量较高且比表面积较大的精硅藻土,再以精硅藻土和碳粉为原料利用原位碳热还原法在1200～1500℃不同时间下煅烧制备了高纯β-SiC产品。实验结果表明,随着煅烧温度和煅烧时间的增加,产率提高,然而比表面积降低。硅藻土与碳粉按物质的量比1：3均匀混合制坯,在1400℃煅烧4h为制备生物微孔SiC的最佳条件。通过FT-IR和XRD证明最佳条件下制备的产物为β-SiC,SEM表明生物微孔SiC保持了硅藻土的微观形貌,氮气吸附测试产品的比表面积为97.56 m2/g,并且测试了产品的平均粒径为40μm,表观密度为1.4336h/cm3、孔隙率为68.41%、硬度为7.8 GPa、耐酸碱性、耐氧化性等。此方法制备的生物微孔碳化硅,纯度较高,孔隙率较高,能耗低,经济效益较好。
[Abstract]:Silicon carbide has special mechanical properties, chemical properties and electrical properties. It is an oxidizing, corrosion-resistant and highly chemically inert material. Its thermal stability and thermal conductivity are relatively high, and its thermal expansion coefficient is small. It can be used as abrasives, building materials, heat exchangers, electronics, sensors, etc., in national defense, aviation, metallurgy, etc. Porous shaped silicon carbide has been widely used in the fields of catalysis, energy storage, biomedicine and environmental protection. Diatomite is a natural mineral deposit in nature. Its main component is SiO2, however, its purity is not high, it mainly contains impurities such as iron oxide, alumina and so on. In the past, it was only used as filter decolorizing material, but it did not make full use of its unique biological micropore structure, so it belongs to the early development product. Since the economic benefits are not high, it is of great significance to develop its new application value. The bioporous silicon carbide prepared from diatomite has the regular micropore structure of diatomite and the excellent properties of silicon carbide. At the same time, it has good biocompatibility, stable physical and chemical properties, no toxic side effects. It can be developed into biomaterials with high economic benefits, such as artificial bone, The research in the field of biomedicine and biomedicine will become one of the hotspots in the future. Biological microporous silicon carbide will have good economic benefit and application value. In this paper, diatomite with biological micropore structure is used as raw material. Diatomite with high SiO2 content and large specific surface area is obtained by acid leaching and calcination of diatomite. The high purity 尾 -SiC products were prepared by in-situ carbothermal reduction method with diatomite and carbon powder as raw materials at 1200 鈩，

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