本文選題：硅藻土　切入點：原位合成　出處：《長春工業(yè)大學》2015年碩士論文　論文類型：學位論文

【摘要】：碳化硅材料具有特殊的機械性能、化學性能和電性能,是一種耐氧化、耐腐蝕且具有高度化學惰性的物質(zhì),它的熱穩(wěn)定性和熱傳導性能較高、熱膨脹系數(shù)較小,并且在高溫條件下表現(xiàn)出半導體性質(zhì)。因此,它可做磨料、建材、熱交換器、電子、傳感等材料,在國防、航空、冶金、化工等領域都有廣泛的應用。多孔異形碳化硅又拓寬了在催化、能源存儲、生物醫(yī)療和環(huán)境保護等領域的的應用。硅藻土是一種存在于自然界中的天然礦藏,其主要成分為SiO2,然而它的純度不高,主要含有氧化鐵、氧化鋁等雜質(zhì)。以往只是將其做為過濾脫色材料使用,沒有充分利用其特有的生物微孔結(jié)構(gòu),屬于初期開發(fā)產(chǎn)品,經(jīng)濟效益不高,因此,開發(fā)其新的應用價值十分有意義。以硅藻土為原料制備的生物微孔碳化硅具有硅藻土的規(guī)則的微孔結(jié)構(gòu)和碳化硅的優(yōu)良性能,同時具有良好的生物相容性、理化性能穩(wěn)定、無毒副作用。將其開發(fā)成經(jīng)濟效益較高的生物材料,例如人造骨質(zhì),在生物醫(yī)藥及生物醫(yī)學領域的研究將成為未來的研究熱點之一。因此,生物微孔碳化硅將具有良好的經(jīng)濟效益和應用價值。本文選用生物微孔結(jié)構(gòu)的硅藻土作為原料。首先將硅藻土進行酸浸和煅燒處理得到SiO2含量較高且比表面積較大的精硅藻土,再以精硅藻土和碳粉為原料利用原位碳熱還原法在1200～1500℃不同時間下煅燒制備了高純β-SiC產(chǎn)品。實驗結(jié)果表明,隨著煅燒溫度和煅燒時間的增加,產(chǎn)率提高,然而比表面積降低。硅藻土與碳粉按物質(zhì)的量比1：3均勻混合制坯,在1400℃煅燒4h為制備生物微孔SiC的最佳條件。通過FT-IR和XRD證明最佳條件下制備的產(chǎn)物為β-SiC,SEM表明生物微孔SiC保持了硅藻土的微觀形貌,氮氣吸附測試產(chǎn)品的比表面積為97.56 m2/g,并且測試了產(chǎn)品的平均粒徑為40μm,表觀密度為1.4336h/cm3、孔隙率為68.41%、硬度為7.8 GPa、耐酸堿性、耐氧化性等。此方法制備的生物微孔碳化硅,純度較高,孔隙率較高,能耗低,經(jīng)濟效益較好。
[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，

本文編號：1572145