【摘要】： 納米氧化鎂是一種新型高功能精細(xì)無機(jī)材料。其本身具有的量子尺寸效應(yīng),小尺寸效應(yīng),表面效應(yīng),宏觀量子隧道效應(yīng)等使其具有明顯優(yōu)于本體材料的性能。本文介紹了納米氧化鎂的國內(nèi)外研究現(xiàn)狀,探討了均勻沉淀法以及微乳液法反應(yīng)的原理,并采用白云石均勻沉淀法以及反相微乳液法制得了納米氧化鎂晶體。 本文直接以湖南永州市東安縣白云石礦為鎂源,采用均勻沉淀法制得了納米氧化鎂晶體,并且用正交試驗(yàn)等研究了制備粒徑小、分散程度好的納米氧化鎂顆粒的最佳條件。用原子吸收(AAS)、X射線衍射(XRD)、掃描電鏡(SEM)、熱重分析(TGA)等方法對(duì)產(chǎn)物進(jìn)行了表征和分析。研究了分散劑種類、分散劑用量、沉淀劑種類、溶劑等對(duì)納米氧化鎂粒徑的影響,并應(yīng)用相關(guān)理論對(duì)各因素造成的影響進(jìn)行了機(jī)理探討。這對(duì)納米氧化鎂的工業(yè)化制備具有一定的參考價(jià)值。 采用正交試驗(yàn)法確定了制備納米氧化鎂的最佳工藝條件為：以淀粉為分散劑,用量為45%(質(zhì)量百分含量),以尿素為沉淀劑,在70℃下超聲波20分鐘,然后沉淀離心洗滌,真空常溫干燥,灼燒。結(jié)果表明采用該法制備的納米粒子分散性好,晶體粒子分布均勻,結(jié)晶度高,納米顆粒粒徑為12.5納米,且粒子產(chǎn)率達(dá)到86%。該法制備納米氧化鎂,具有廣泛的應(yīng)用前景。 由于微乳液法制備納米材料不僅可以實(shí)現(xiàn)粒徑可控,而且可以實(shí)現(xiàn)形貌可控,它已成為合成納米顆粒的一種有效方法,受到人們的青睞,但目前通過反相微乳液制備納米MgO的文獻(xiàn)很少。本工作采用反相膠團(tuán)作為微反應(yīng)器,使溶解在水核內(nèi)的試劑在水核內(nèi)發(fā)生反應(yīng),并研究了不同水相/表面活性劑質(zhì)量比(w0),煅燒溫度,反應(yīng)物濃度,陳化時(shí)間,以及反應(yīng)溫度等對(duì)制備MgO納米粒子的影響,表征了粒子的結(jié)構(gòu),并對(duì)其形成機(jī)理進(jìn)行了探討。 通過聚乙二醇辛基苯基醚(曲拉通X-100)/正丁醇/正庚烷/水溶液形成的反相微乳體系,合成了MgO納米粒子。對(duì)前驅(qū)體進(jìn)行熱重分析(TGA),確定了合適的煅燒溫度為600℃。采用X射線衍射(XRD)、掃描電鏡(SEM)、紫外可見分光光度法(UV-vis)分別對(duì)產(chǎn)物的結(jié)構(gòu)、粒度和形貌進(jìn)行了表征,考察了微乳液中水與表面活性劑的質(zhì)量比(w0)對(duì)納米氧化鎂紫外屏蔽性能的影響以及煅燒溫度、反應(yīng)物濃度、陳化時(shí)間、反應(yīng)溫度等關(guān)鍵因素對(duì)產(chǎn)物粒子尺寸形貌的影響,并通過分析進(jìn)一步揭示了Mg0納米粒子的形成機(jī)理。結(jié)果表明,控制w0為15,煅燒溫度為600℃,反應(yīng)物濃度為0.05mol/L,陳化時(shí)間為15小時(shí)且反應(yīng)溫度在30℃時(shí)可得到分散性好,粒徑分布均勻的MgO納米粒子。
[Abstract]:Nanometer magnesium oxide is a new high function fine inorganic material. The quantum size effect, the small size effect, the surface effect and the macroscopic quantum tunneling effect make it superior to the bulk material. This paper introduces the research status of nano-MgO at home and abroad, discusses the reaction principle of homogeneous precipitation method and microemulsion method, and uses dolomite homogeneous precipitation method and reverse microemulsion method to obtain nano-MgO crystal. In this paper, nanocrystalline magnesium oxide was prepared by homogeneous precipitation method with dolomite ore in Dongan County, Yongzhou City, Hunan Province as the source of magnesium. The optimum conditions for preparing nanometer magnesium oxide particles with small particle size and good dispersion degree were studied by orthogonal test. The products were characterized and analyzed by atomic absorption (AAS), X diffraction (AAS), X) (XRD), scanning electron microscopy (XRD),) (SEM), thermogravimetric analysis (TGA). The effects of dispersant, amount of dispersant, precipitator and solvent on the particle size of nano-MgO were studied. It has certain reference value for the industrial preparation of nanometer magnesium oxide. The optimum technological conditions for preparing nanometer magnesium oxide were determined by orthogonal test: starch as dispersant, dosage 45% (mass%), urea as precipitant, ultrasonic wave for 20 minutes at 70 鈩，

本文編號(hào)：2325390