發(fā)布時(shí)間：2018-04-08 13:13

  本文選題：陶瓷膜　切入點(diǎn)：碳化硅　出處：《合肥工業(yè)大學(xué)》2015年碩士論文

【摘要】：陶瓷膜分離技術(shù)具有耐高溫、耐腐蝕、分離效率高、耗能低及綠色環(huán)保等優(yōu)點(diǎn),在食品、化工、生物醫(yī)藥及環(huán)保等領(lǐng)域廣泛應(yīng)用。隨陶瓷膜廣泛應(yīng)用,膜材料性能要求提高,使用環(huán)境更苛刻,傳統(tǒng)的膜材料無(wú)法適用于高溫腐蝕性等環(huán)境。本文以開(kāi)發(fā)陶瓷膜材料,降低制備成本為研究目標(biāo),研究碳化硅(SiC)陶瓷膜支撐體和可作為膜材料的硅酸釔材料的制備與表征,取得如下工作成果：(1)采用溶膠包裹法低溫制備了SiC陶瓷膜支撐體。采用溶膠包裹法在1100℃低溫制備了氣孔率高達(dá)49.58%的SiC陶瓷膜支撐體。該工藝制備的SiC陶瓷膜支撐體生坯燒結(jié)之后直徑略有變大,發(fā)生不同程度的膨脹,隨燒結(jié)助劑含量增加,樣品的線收縮率不升反降,氣孔率卻在增加,這說(shuō)明以九水硝酸鋁和六水硝酸釔作為助燒劑,不僅降低燒結(jié)溫度,還能起到造孔的作用,改善支撐體的宏觀變化。在以2OpmSiC為骨料時(shí),淀粉含量為6wt%,助燒劑含量為30wt%時(shí),在1100℃下樣品的負(fù)向線性收縮率低至0.83%。(2)采用分相法制備了非對(duì)稱(chēng)型結(jié)構(gòu)的SiC中空纖維陶瓷膜。分相法與固相燒結(jié)相結(jié)合通過(guò)一步成型制備出非對(duì)稱(chēng)結(jié)構(gòu)的SiC中空纖維陶瓷膜,不添加造孔劑也可制得氣孔率高達(dá)53.83%的SiC膜管；制備的SiC膜管呈指孔結(jié)構(gòu)層-海綿狀結(jié)構(gòu)層-指孔結(jié)構(gòu)層結(jié)構(gòu),有利于提高膜的滲透性。燒結(jié)溫度對(duì)其收縮率的變化影響均很小,軸向徑向的線收縮率分別基本穩(wěn)定在10.1%和9.0%。(3)首次采用EDTA-檸檬酸絡(luò)合法成功合成了高純度的納米級(jí)的硅酸釔材料,并對(duì)合成機(jī)理進(jìn)行探討。該工藝前驅(qū)體pH值為9.38時(shí)在高于1050℃煅燒可以得到α-Y2Si2O7相,pH值為4時(shí)得到的是Y2SiO5相。這主要是因pH值不同,EDTA和檸檬酸絡(luò)合能力及TEOS水解聚合能力也不同。獲得的Y2Si207粉體具有葡萄狀結(jié)構(gòu),此結(jié)構(gòu)存在大量晶界,為其作為氣體分離膜提供特殊的物理通道和機(jī)械強(qiáng)度保障。
[Abstract]:High temperature ceramic membrane separation technology has corrosion resistance, high separation efficiency, low energy consumption and green environmental protection and other advantages, is widely used in food, chemical, biological medicine and environmental protection etc.. With the wide application of ceramic membrane, membrane material performance requirements to improve the use of the environment more demanding, the traditional film material is not suitable for high temperature corrosion such environment. Based on the development of ceramic membrane materials, reduce the preparation cost as the research object, study on the synthesis and characterization of silicon carbide (SiC) ceramic membrane support and can be used as a membrane material of yttrium silicate material, made the following achievements: (1) low temperature preparation of SiC ceramic membrane supported by sol coating method using sol coated method in low temperature of 1100 DEG C to fabricate SiC ceramic membrane up to 49.58% porosity support. After the preparation process of SiC ceramic membrane support green sintering diameter slightly larger, the expansion of the, with the help of sintering Agent content increased, sample shrinkage rate declined, the porosity has increased, indicating that the nine water and six aqueous aluminum nitrate yttrium nitrate as sintering agent, not only reduce the sintering temperature, but also play the role of macro pore, improve the supporting body. Changes in the 2OpmSiC aggregate. The starch content of 6wt%, 30wt% can burn agent content, samples at 1100 DEG C, the negative linear shrinkage rate to 0.83%. (2) SiC hollow fiber membrane asymmetric structure were synthesized by phase separation method and solid phase sintering. Through the combination of one-step molding prepared SiC hollow fiber ceramic membrane asymmetric structure, adding pore forming agent can be prepared SiC film porosity up to 53.83% tubes; SiC membrane prepared by tube with a sponge like structure layer - finger structure layer - finger structure layer structure, improve the permeability of the membrane. The effect of sintering temperature on the shrinkage rate of change very small, Axial and radial shrinkage rate were basically stable at 10.1% and 9.0%. (3) for the first time using EDTA- citric acid complexing successful high purity nanometer yttrium silicate material was synthesized, and the synthesis mechanism was discussed. The process of precursor pH value was 9.38 higher than 1050 in calcined can get a -Y2Si2O7 phase. When the pH value is 4 by Y2SiO5 phase. This is mainly due to different value of pH, EDTA and citric acid complexing ability and TEOS hydrolysis polymerization is different. Y2Si207 powder obtained with grape like structure, the structure of the existence of a large number of grain boundaries, providing special physical channel and mechanical strength as the guarantee for the gas separation membrane.

【學(xué)位授予單位】：合肥工業(yè)大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類(lèi)號(hào)】：TQ051.893

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本文編號(hào)：1721773