纳米重晶石的合成及表面改性

发布时间：2019-07-01 16:53

【摘要】：纳米重晶石具有优秀的理化特性。而在制备过程中,尺寸,粒度分布及分散性是主要的工艺参数。如何制备粒径小、分散性好的硫酸钡纳米颗粒,是当今研究的重点。本文通过混合溶剂法(醇、水等),络合法(EDTA等)进行制备硫酸钡颗粒,通过多种分析方法对不同反应条件下样品的形貌、分散性、粒径分布及大小进行了表征。混合溶剂法制备纳米硫酸钡的研究表明：反应物浓度的增加,会导致产物粒径变大,并伴有团聚现象；乙醇含量对产物分散性、粒径分布影响较大。EDTA络合法制备硫酸钡时研究不同反应条件对产物的影响：反应物浓度对产物的粒径大小和分布都有较大影响,体系pH值在8.0时,产物形貌最好。石油钻井泥浆的加重剂使用最多的是重晶石,但其表面能较大,易团聚,悬浮性较差,对重晶石进行表面改性,改变其等电点,增强其在钻井液中的分散性和悬浮性。本文通过不同链长脂肪酸、硅酸钡及二氧化硅对纳米重晶石颗粒进行改性,并通过XRD、TEM、FT-IR和粒径分布等手段表征改性后的形貌、分散性等。不同链长脂肪酸包覆改性硫酸钡颗粒时,活化指数和吸油量等表征手段都表明硫酸钡颗粒表面有部分被改性,但整体改性效果不佳。硅酸钡包覆硫酸钡粒子时,搅拌速度太快会使刚包覆在硫酸钡表面上的包覆膜脱落,pH值对包覆层结构影响较大,直接影响离子的存在形式,pH值在10.0时,会形成明显的核壳结构。二氧化硅改性硫酸钡,pH值在9.8-10.0时,硫酸钡颗粒表面形成一层致密包覆膜,加入水玻璃体积过少会引起包覆层膜太薄,水玻璃体积为40 mL时,具有良好的包覆效果,分散性也较好。
[Abstract]:The nano barite has excellent physical and chemical properties. In the preparation process, the size, particle size distribution and dispersivity are the main process parameters. How to prepare the nano-particles with small particle size and good dispersibility is the focus of the present study. The morphology, dispersion, particle size distribution and size of samples under different reaction conditions were characterized by a mixed solvent method (alcohol, water, etc.), complexing method (EDTA, etc.). The results of the preparation of the nano-sulfuric acid by the mixed solvent method show that the concentration of the reactants is increased, and the particle size of the product is increased, and the agglomeration phenomenon is accompanied; the content of the ethanol has great influence on the dispersion and the particle size distribution of the product. The effect of different reaction conditions on the product is studied by EDTA-complexing method. The concentration of reactants has a great influence on the particle size and distribution of the product, and the pH value of the system is at 8.0, and the product has the best appearance. The weighting agent for petroleum drilling mud uses the most barite, but its surface can be large, easy to agglomerate, poor in suspension property, the barite is surface modified, its isoelectric point is changed, and its dispersibility and suspension in the drilling fluid are enhanced. The nano barite particles were modified by different chain length fatty acids, silicic acid and silica, and the morphology and dispersivity of the modified barite were characterized by XRD, TEM, FT-IR and particle size distribution. The activation index and the oil absorption and other characterization means indicate that the surface of the sulfate particles is partially modified, but the overall modification effect is not good. When the silicic acid is coated with the sulfate particles, the stirring speed is too fast, so that the coating film just coated on the surface of the sulfuric acid is dropped off, the pH value is greatly influenced by the structure of the coating layer, the existence form of the ions is directly affected, and when the pH value is 10.0, the obvious core-shell structure is formed. When the pH value of the silicon dioxide modified sulfuric acid solution is 9.8-10.0, a layer of dense coating film is formed on the surface of the surface of the sodium sulfate particles, the volume of the water glass is too small to cause the coating film to be too thin, and when the volume of the water glass is 40 mL, the silicon dioxide modified sulfuric acid solution has good coating effect and good dispersibility.
【学位授予单位】：上海应用技术学院
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB383.1

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