本文關(guān)鍵詞：硅溶膠的制備及其在硅酸鹽長余輝材料中的應(yīng)用研究　出處：《上海應(yīng)用技術(shù)學(xué)院》2016年碩士論文　論文類型：學(xué)位論文

  更多相關(guān)文章： 單質(zhì)硅溶解法 離子交換法 硅溶膠 長余輝材料 硅酸鹽

【摘要】：硅溶膠作為一種重要的無機(jī)高分子材料,因其具有良好的分散性、較好的耐磨性、較大的比表面積、親水性和憎水性等性能,被廣泛應(yīng)用在精密鑄造、涂料、蓄電池、粘結(jié)劑和催化劑等工業(yè),而且國內(nèi)外對其產(chǎn)品種類的要求越來越高。另外,硅酸鹽體系長余輝發(fā)光材料,有極強(qiáng)的耐水性,發(fā)光顏色與鋁酸鹽體系形成互補(bǔ),越來越受到人們的重視。本文的研究內(nèi)容主要分為兩部分：實(shí)驗(yàn)前一部分結(jié)合單質(zhì)硅溶解法和離子交換法制備酸性硅溶膠,并對制備過程中影響產(chǎn)品性能的各種工藝參數(shù)進(jìn)行分析和探討；另一部分利用前一部分制備的酸性硅溶膠作為硅的來源,采用燃燒合成法制備了離子摻雜硅酸鹽長余輝材料,通過X射線粉末衍射(XRD)和熒光分光光度計(jì)以及掃描電鏡等對其進(jìn)行物相結(jié)構(gòu)和發(fā)光性能進(jìn)行了分析。主要得到以下結(jié)論：(1)在制取酸性硅溶膠的過程中,母液濃度、硅粉量、催化劑、反應(yīng)溫度、反應(yīng)時(shí)間等都會(huì)對最終產(chǎn)品的粒徑以及穩(wěn)定性有一定的影響。當(dāng)母液濃度小于2.5wt%時(shí),平均粒徑和SiO2含量隨著母液濃度的增加而變大；當(dāng)母液濃度大于2.5wt%時(shí),平均粒徑隨著母液濃度的增加而變小。每200m1水溶液中硅粉加入量在26g之前,硅溶膠的平均粒徑隨著硅粉的加入量的增加而增加,且在20g以前增加迅速,在20g-26g之間增加緩慢。當(dāng)硅粉加入量超過26g之后,硅溶膠的平均粒徑隨著硅粉的加入量增加反而緩慢減小,最終趨于穩(wěn)定。用不同種類的催化劑時(shí),最終硅溶膠產(chǎn)品的平均粒徑也會(huì)不同,用氨水和九水硅酸鈉溶液作為復(fù)合催化劑時(shí),硅溶膠的平均粒徑會(huì)比單獨(dú)使用一種催化劑或者不使用催化劑時(shí)的硅溶膠的平均粒徑大。反應(yīng)溫度由75℃升至95℃時(shí),硅溶膠平均粒徑呈現(xiàn)逐漸增大的趨勢。硅溶膠平均粒徑隨著反應(yīng)時(shí)間的延長先增加后減小。(2)制備酸性硅溶膠的最佳工藝條件：活性硅酸母液為2.5wt%,用量為200ml,硅粉用量為26g,采用氨水和九水硅酸鈉作為復(fù)合催化劑,反應(yīng)溫度為90℃,反應(yīng)時(shí)間為8h。在此基礎(chǔ)上進(jìn)行實(shí)驗(yàn),制得的酸性硅溶膠產(chǎn)品粒徑可達(dá)30nm以上,常溫下穩(wěn)定時(shí)間可達(dá)200天左右。(3)以自制酸性硅溶膠為硅源合成的Sr2MgSi2O7:Eu2+,Eu3+,Dy3+材料發(fā)射光譜為一半寬帶,主發(fā)射峰位于568nm處,為Eu3+的5D→7F特征峰值,次發(fā)射峰位于475 nm處,為Eu2+的4f5d→4f躍遷引起的發(fā)光,該材料主要為黃光發(fā)射。(4)本實(shí)驗(yàn)合成硅酸鎂鍶粉體的最佳工藝參數(shù)為：n(硝酸鍶)/n(硅溶膠)=1：1.1,n(尿素)/n(硝酸鹽)=3：1,燃燒溫度為850℃。用自制的酸性硅溶膠作為原料采用燃燒合成法制備的Sr2MgSi2O7:Eu2+,,Eu3+,Dy3+,產(chǎn)物顆粒均勻細(xì)小,易粉碎,生產(chǎn)周期短,可成為合成硅酸鍶鎂的一種新型技術(shù)路線。
[Abstract]:As an important inorganic polymer material, silica sol has been widely used in precision casting and coating because of its good dispersion, good wear resistance, large specific surface area, hydrophilicity and hydrophobicity. Batteries, binders, catalysts and other industries, but also at home and abroad to its product types of higher and higher requirements. In addition, silicate system long afterglow materials, has a strong water resistance. Luminescent colors complement each other with aluminate system, and people pay more and more attention to it. The research contents in this paper are divided into two parts: one is the synthesis of acidic silica sol by the combination of simple silicon dissolution method and ion exchange method before the experiment. The process parameters that affect the properties of the product during the preparation process are analyzed and discussed. In the other part, the ion-doped silicate long afterglow material was prepared by combustion synthesis using the acidic silica sol prepared in the former part as the source of silicon. The phase structure and luminescence properties of the samples were analyzed by X-ray powder diffraction (XRD), fluorescence spectrophotometer and scanning electron microscope. The main conclusions are as follows: 1). In the process of preparing acidic silica sol. The concentration of mother liquor, amount of silica fume, catalyst, reaction temperature and reaction time all have some effects on the particle size and stability of the final product, when the concentration of mother liquor is less than 2.5 wt%. The average particle size and SiO2 content increased with the increase of mother liquor concentration. When the concentration of the mother liquor is more than 2.5 wt%, the average particle size decreases with the increase of the concentration of the mother liquor. The amount of silicon powder added into the water solution of 200m1 is before 26g. The average particle size of silica sol increases with the addition of silica fume, and increases rapidly before 20g, and slowly between 20g and 26g, when the addition of silica fume exceeds 26g. The average particle size of silica sol decreases slowly with the increase of silica fume content and eventually tends to be stable. The average particle size of the final silica sol product will be different with different kinds of catalysts. Ammonia and sodium silicate solution were used as composite catalysts. The average particle size of silica sol is larger than that of silica sol using one catalyst alone or without catalyst. The reaction temperature increases from 75 鈩，

本文編號：1356199