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《化工学报》2017,(10)
以轻烧粉、氯化铵、硝酸铵、乙酸铵、硫酸铵为原料,氨气为沉淀剂,采用氨循环法制备氢氧化镁晶体,并通过扫描电镜(SEM)、X射线衍射(XRD)对其进行表征分析。采用Materials Studio分子模拟软件中的CASTEP模块,计算了Cl~-、NO_3~-、CH_3COO~-对氢氧化镁晶体(001)、(101)晶面生长的影响。结果表明,采用不同的镁盐得到不同形貌的氢氧化镁晶体阴离子电负性越大,对晶体形貌影响越小;Mg(OH)_2晶体的(001)、(101)晶面能量与布居数分析表明,Cl~-、NO_3~-、CH_3COO~-使晶体的(001)、(101)面的表面能增大、Fermi能级减小,阴离子与(001)、(101)晶面之间形成新的具有微弱共价性的离子键,影响晶体晶面的生长。理论计算较好地解释了不同形貌的氢氧化镁晶体的形成原因。 相似文献
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采用化学沉淀法分别以六水合氯化镁和取自察尔汗盐湖的天然水氯镁石为原料制备了不同形貌的纳米 Mg(OH)2催化剂,通过扫描电子显微镜、X射线衍射、傅里叶变换红外光谱等手段对所合成的催化剂的表面形貌、晶体结构和表面官能团等性质进行了表征。将两种不同形貌的纳米Mg(OH)2材料首次应用于催化臭氧化过程,研究了两种不同形貌的纳米Mg(OH)2[Mg(OH)2-1和Mg(OH)2-2]催化剂对甲硝唑的降解和矿化能力。结果表明,在单独臭氧化过程中,反应10min时甲硝唑的降解和矿化效率均较低,分别为51.9%和17.4%,而在臭氧化系统中分别加入Mg(OH)2-1和Mg(OH)2-2,甲硝唑的去除效率和矿化效率均明显提高,且Mg(OH)2-2的催化臭氧化性能要优于Mg(OH)2-1。另外,单独臭氧化过程、Mg(OH)2-1催化臭氧化以及Mg(OH)2-2催化臭氧化过程中甲硝唑的降解均较好地符合伪一级动力学反应模型(R2>0.97)。除此之外,对这两种不同形貌的纳米Mg(OH)2催化剂的稳定性进行了考察,结果表明,催化剂在循环使用六次后对甲硝唑仍有较高的催化臭氧化去除效率。因此,所合成的两种形貌的纳米Mg(OH)2催化剂将是一种很有前景的、能用于去除抗生素的臭氧化催化剂。 相似文献
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Mg(OH)2表面处理对LDPE力学性能及加工性的影响 总被引:1,自引:0,他引:1
选择了多种偶联剂对氢氧化镁(MH)进行表面处理;研究了表面处理对LDPE/MH体系的力学、加工和分散性能的影响。结果表明,偶联剂能显著提高材料的断裂伸长率,但会略微降低其拉伸强度。硅烷、钛酸酯偶联剂的最佳使用量在1%~2%;而脂肪酸处理剂的最佳使用量在4%~6%。偶联剂的选择影响到材料的力学性能,脂肪酸ste—zn,硅烷偶联剂中Al51,钛酸酯偶联剂JN201有较好的处理效果。表面处理体系有较好的流动性和加工性能。SEM观察表明,未经表面处理体系的粒子分散性比经表面处理体系的粒子分散性要差。 相似文献
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纳米Mg(OH)_2对PVC泡沫塑料力学性能的影响 总被引:1,自引:0,他引:1
在一定的PVC泡沫塑料配方体系下,研究了阻燃材料纳米Mg(OH)2 对PVC泡沫材料的主要力学性能的影响。结果表明,在25℃,纳米Mg(OH)2 添加量在1. 5%以下,对拉伸强度、断裂伸长率两项指标基本没有影响;在105℃,纳米Mg(OH)2 添加量在2. 0 %以下,对热负荷下伸长率、冷却后永久伸长率两项指标基本没有影响。 相似文献
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Crystallization of Al(OH)3 that occurs during the decomposition of caustic soda solutions is an important part of Bayer process for alumina production. Several phenomena, which influence the physicochemical characteristics of precipitated Al(OH)3, occur simultaneously during this process. They are nucleation, agglomeration, and crystal growth of Al(OH)3. In this article, we have investigated the mechanism of Al(OH)3 crystal growth from pure caustic soda solutions and in the presence of oxalic acid. The results have shown that the growth of Al(OH)3 crystals from caustic soda solutions follow the B + S model (birth and spread). New Al(OH)3 particles, formed during the decomposition process of pure caustic soda solutions, are characterized by regular hexagonal shape. The nuclei have the same geometry as the contact face. However, microstructural investigations of Al(OH)3 samples, obtained by crystallization from caustic soda solutions in the presence of oxalic acid, have shown the presence of nuclei of irregular shape in addition to regular ones. So, the presence of oxalic acid in the caustic soda solutions leads to a change in crystal habit. Besides, the results obtained by kinetic investigation confirmed the mentioned mechanism of Al(OH)3 crystal growth. 相似文献
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SDS/MAP复配表面活性剂改性纳米氢氧化镁作用机理研究 总被引:1,自引:0,他引:1
十二烷基硫酸钠(SDS)/磷酸酯(MAP)复配表面活性剂作为改性剂,对纳米氢氧化镁进行改性研究。通过X射线衍射(XRD)、透射电镜(TEM)、红外光谱分析(FT-IR)、BET法比表面积测定和在液体石蜡中的悬浮液体积测定等手段,研究了SDS与MAP以1︰1的质量比复配时其添加量对改性纳米氢氧化镁性能的影响,并初步探讨了改性机理。结果表明:随着SDS/MAP添加量的增加,样品表面的疏水性能呈现先增加后减小的趋势,其用量为样品质量的0.2%时达到最大值;粒径呈现先减小后增大又减小的变化规律,其用量分别在0.2%和0.5%时出现拐点;比表面积的变化规律与粒径一致。说明在水相中随着SDS/MAP添加量的不同,其可能分别以双分子层和单分子层吸附于氢氧化镁颗粒表面。 相似文献
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Cathodic reduction of aqueous solutions of Mg(NO3)2 results in the deposition of Mg(OH)2 coatings on stainless steel cathodes. The coating growth is controlled by varying the deposition time, current density and the bath concentration. The coatings comprise thin scaly particles having sub-micron dimensions. DIFFaX simulations of the X-ray line broadening indicate the formation of small anisotropic particles having a thickness 134 Å measured along the [0 0 1] direction. 相似文献
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采用偶联剂对氢氧化铝(ATH)和氢氧化镁(MH)进行表面改性处理,并将其应用于木塑复合材料的环氧树脂基表面防火涂层中.通过显微镜、红外光谱和热失重分析等手段研究了表面处理前后的ATH和MH及其填充量和两者的不同配比对防火涂层的防火性能影响.结果表明:与未经表面改性处理的ATH和MH相比,其经表面改性处理后更有利于提高防火涂层的防火性能;当经钛酸酯偶联剂处理的ATH用量为120份时,表面涂层的防火性能最好;经硅烷偶联剂处理的MH的最佳用量为50份;当ATH/MH质量比为2∶1时,防火涂层的防火性能最好,其耐燃时间达到了527 s. 相似文献
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采用正交实验,使用热压机制备了含阻燃剂和55#白油的苯乙烯-乙烯-丁烯-苯乙烯嵌段共聚物(SEBS)复合弹性体,对其进行了力学性能、极限氧指数、水平燃烧测定和差热分析,探讨了阻燃剂对其阻燃性能和力学性能的影响。实验结果表明:55#白油/氢氧化镁/APP/IPPP/SiO2/SEBS的质量比为3/0.2/3/0.25/0.05/1时,SEBS复合弹性体的阻燃性能和力学性能较好,拉伸强度为0.7 MPa;在89~777℃范围内碳残留量高达31.43%,水平燃烧符合GB/T 2408的FH-1级,极限氧指数为24。 相似文献
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The morphologies of the fracture surface under impact and flexural testing of Mg(OH)2/Polypropylene (PP) composites and their modified composites were investigated by scanning electron microscopy. Experimental results indicated that addition of functionalized polypropylene (FPP) and acrylic acid (AA) and the formation of in situ FPP changed the fracture morphologies of Mg(OH)2/PP composites. We believe that addition of these modifiers improved the interfacial interaction and enhanced the interface adhesion between the particle and the matrix in Mg(OH)2/PP composites. The degree of improvement was more significant in Mg(OH)2/PP composites modified by the formation of in situ FPP. At low Mg(OH)2 content, 2 phr AA exhibited a marked effect, but at high Mg(OH)2 content, 4 phr AA afforded good effect. Due to the improved interface adhesion by interface interactions the fracture mechanism transformed from interface debonded fracture into a matrix fracture. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 2148–2159, 2003 相似文献
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Detrital Mg(OH)2 and Al(OH)3 in Microwaved Hydrotalcites 总被引:1,自引:0,他引:1
Microwave irradiation power (90, 180, 270 or 360 W) determines the composition and the structure of the compounds obtained when pH is increased, decreased or maintained constant during preparation. Although in all cases the X-ray diffraction patterns show that the obtained compounds are hydrotalcite-like, the surface areas (40 up to 240 m2/g) as well as other microcrystalline compounds have to be inferred, such as Al(OH)3 or Mg(OH)2. 相似文献
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