發(fā)布時(shí)間：2018-05-10 17:28

  本文選題：棕櫚藤 + SiC復(fù)相陶瓷��； 參考：《中國(guó)林業(yè)科學(xué)研究院》2017年碩士論文

【摘要】：本研究根據(jù)C-Si反應(yīng)機(jī)理從黃藤(Daemonorops margaritae(Hance)Beccari)材中制備SiC復(fù)相陶瓷。所制備的棕櫚藤基Si C復(fù)相陶瓷(R-SiC)包含SiC、未反應(yīng)的生物質(zhì)炭和SiO_2,是一種具高附加值的藤基陶瓷,對(duì)拓寬棕櫚藤材的應(yīng)用領(lǐng)域具有重要意義。通過(guò)X射線衍射(XRD)、傅里葉變換紅外光譜(FT-IR)、X射線熒光光譜(XRF)、氮?dú)馕锢砦�、�?chǎng)發(fā)射環(huán)境掃描電子顯微鏡(FESEM)和透射電子顯微鏡(TEM)以及X射線能譜分析(EDAX)等手段分析了不同制備方法、溶膠制備及浸漬工藝、熱解參數(shù)對(duì)SiC復(fù)相陶瓷物相、化學(xué)組成、微觀形貌和元素分布的影響,優(yōu)化制備工藝。論文主要研究?jī)?nèi)容和結(jié)果如下:(1)以單質(zhì)硅粉和SiO_2溶膠為硅源,棕櫚藤粉為碳源,分別采用液相熔融硅滲透法(LSI)、溶膠-凝膠法(Sol-Gel)制備SiC復(fù)相陶瓷。結(jié)果表明:Sol-Gel制備的SiC復(fù)相陶瓷(R-SiCSiO_2)中SiC含量為24.57%,比表面積為21.99 m2/g;LSI制備的SiC復(fù)相陶瓷(R-SiCSi)中SiC含量為23.28%,比表面積為6.25 m2/g;Sol-Gel能將藤材的孔隙結(jié)構(gòu)較好的保留在R-SiCSi O_2中,而LSI很難將藤材孔隙結(jié)構(gòu)保留在R-SiCSi中。相對(duì)于LSI,Sol-Gel制備的R-SiC具有較完整的孔隙結(jié)構(gòu)、較高的SiC產(chǎn)率和比表面積,在制備多孔SiC復(fù)相陶瓷上更具優(yōu)勢(shì)。(2)以正硅酸乙酯(TEOS)、無(wú)水乙醇(EtOH)、去離子水(H2O)為原料,鹽酸或氨水為催化劑制備SiO_2溶膠。結(jié)果表明:以鹽酸為催化劑制備酸性Si O_2溶膠的穩(wěn)定性、固含量、粘度和浸漬性能分別為24.33 h、15.90%、7.14 mPa·s和8.75%,相對(duì)于堿性SiO_2溶膠,其粘度低,固含量高,浸漬性能好;采用正交實(shí)驗(yàn)系統(tǒng)研究原料配比和pH值對(duì)酸性溶膠穩(wěn)定性、固含量、粘度和浸漬性能的影響,優(yōu)選出的溶膠制備參數(shù)為原料配比n(TEOS):n(EtOH):n(H2O)=1:4:6、p H=2.5;通過(guò)對(duì)酸性溶膠輔助超聲波處理,研究處理時(shí)間對(duì)溶膠性能的影響,優(yōu)選的處理時(shí)間為10 min。(3)通過(guò)調(diào)節(jié)熱解溫度和保溫時(shí)間,采用溶膠-凝膠法一步熱解制備R-SiC。結(jié)果表明:不同熱解參數(shù)制備的R-SiC均能保留棕櫚藤材的孔隙結(jié)構(gòu);隨著溫度的升高、保溫時(shí)間的延長(zhǎng),R-SiC的密度減小、比表面積增大且SiC產(chǎn)率升高;溫度為1500℃、保溫時(shí)間為120 min的熱解參數(shù)下制備的R-SiC具有最高的比表面積(43.38 m2/g)、最低的密度(0.25 g/cm3)和最高的SiC產(chǎn)率(44.24%);R-SiC橫切面上的SiC主要以晶須的形式存在。
[Abstract]:Based on the mechanism of C-Si reaction, SiC multiphase ceramics were prepared from Daemonorops margaritae Hancea Beccarii. The prepared palm based sic multiphase ceramics (R-SiC) contain sic, unreacted biomass carbon and SiO2. it is a kind of rattan based ceramics with high added value, which is of great significance to broaden the application field of rattan wood. Different preparation methods were analyzed by means of X-ray diffraction, Fourier transform infrared spectroscopy (FT-IR), X-ray fluorescence spectroscopy (XRF), physical adsorption of nitrogen, field emission environment scanning electron microscope (FESEM) and transmission electron microscope (TEM), as well as X-ray energy spectrum analysis (EDAX). The preparation and impregnation process of sols, the effects of pyrolysis parameters on the phase, chemical composition, micromorphology and element distribution of SiC multiphase ceramics were optimized. The main contents and results of this paper are as follows: (1) SiC multiphase ceramics were prepared by liquid-phase melt silicon permeation method and sol-gel method using SiO_2 sol as silicon source and palm rattan powder as carbon source. The results showed that the content of SiC and specific surface area of SiC multiphase ceramics prepared by SiC / Sol-Gel were 24.57 and 23.28 respectively. The specific surface area was 21.99 m2 / g / g LSI, and the specific surface area was 6.25 m2 / g / g Sol-Gel, which could keep the pore structure of vine in R-SiCSi O _ 2, and the specific surface area was 6.25 m ~ (2) 路g ~ (-1) 路L ~ (-1) 路L ~ (-1) 路L ~ (-1) 路L ~ (-1) 路L ~ (-1) 路L ~ (-1) 路L ~ (-1) 路L ~ (-1). However, it is difficult for LSI to retain the pore structure in R-SiCSi. Compared with the R-SiC prepared by LSI-Sol-Gel, R-SiC has relatively complete pore structure, higher yield and specific surface area of SiC, and it has an advantage in the preparation of porous SiC composite ceramics. It uses tetraethyl orthosilicate (TEOS), anhydrous ethanol (EtOHH) and deionized water (H _ 2O) as raw materials. SiO_2 sol was prepared with hydrochloric acid or ammonia as catalyst. The results showed that the stability, solid content, viscosity and impregnation performance of acidic Sio _ 2 sol prepared with hydrochloric acid as catalyst were 24.33 h ~ 15.90 mPa / s and 8.75%, respectively. Compared with alkaline SiO_2 sol, its viscosity was low, solid content was high, and impregnation performance was good. The effects of raw material ratio and pH value on stability, solid content, viscosity and impregnation properties of acidic sol were studied by orthogonal experiment system. The influence of treatment time on the properties of sol was studied. The optimal treatment time was 10 min. 3) R-SiC was prepared by one step pyrolysis with sol-gel method by adjusting the pyrolysis temperature and holding time. The results show that R-SiC prepared with different pyrolysis parameters can retain the pore structure of rattan wood, and with the increase of temperature, the density of R-SiC decreases, the specific surface area increases and the yield of SiC increases with the increase of temperature, and the temperature is 1500 鈩，

本文編號(hào)：1870214