| 玫瑰花状多孔碱式碳酸镁微球的合成(英文) |
| Synthesis of Porous Hydromagnesite Microspheres with Rosette-Like Morphology |
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| 摘要: 介绍了一种便利的玫瑰花状多孔碱式碳酸镁(4MgCO3·Mg(OH)2·4H2O)微球的合成方法，该方法分为三水碳酸镁(MgCO3·3H2O)前驱物合成与其在水中的热解制备过程。采用搅拌诱导结晶辅助陈化的方法合成前驱物，得到长约115 μm，长径比约10.4的均一微棒，将微棒在353.2 K的水中热解，即可得到由弯曲的纳米片组成的具有“卡片箱”结构（house of cards）的玫瑰花状多孔碱式碳酸镁微球，微球直径为30~60 μm，平均约40 μm，具有良好分散性。研究了热解过程中的形貌转变和相转移过程，采用XRD，FTIR及SEM表征样品的结构和形貌。结果表明：MgCO3·3H2O在较高温度下因不稳定而溶解，形成局部过饱和，生成无定形颗粒，并在微棒上成核结晶为4MgCO3·Mg(OH)2·4H2O纳米片。纳米片由与微棒附着部位向外生长，形成玫瑰花状微球，微球长大伴随微棒的消溶，生长在棒上不同部位的颗粒在微观结构上将留有不同痕迹。分析认为热解转变过程是(MgCO3·3H2O)溶解－无定形物生成-(4MgCO3·Mg(OH)2·4H2O)结晶的过程。 |
| 关键词: 三水碳酸镁 碱式碳酸镁 形貌 热解 |
| 基金项目: |
| Abstract: Porous hydromagnesite (4MgCO3·Mg(OH)2·4H2O) microspheres with rosette-like morphology were synthesized by a facile pathway. The procedure involved the synthesis of nesquehonite (MgCO3·3H2O) precursor and its pyrogenation in water. MgCO3·3H2O precursors were synthesized via a stirring-induced crystallization method assisted by aging. Uniform rod-like precursor could be obtained with a length of about 115 μm and aspect ratio of about 10.4. 4MgCO3·Mg(OH)2·4H2O porous microspheres with “house of cards” structure composed of curly nano-sheets crystals were obtained via the pyrogenation of MgCO3·3H2O in water at 353.2 K. The diameter of hydromagnesite spheres is in the range of 30~60 μm and 40 μm in average with well dispersity. Shape evolution and phase transfer during the transformation were studied by time-evolution experiments. The synthesized samples were characterized by XRD and FTIR as well as SEM. The results show that MgCO3·3H2O dissolves and local supersaturation is formed. Amorphous particles are produced and crystallized into 4MgCO3·Mg(OH)2·4H2O nanosheets on the microrods. Hydromagnesite nano-sheets grow outward from the attachment site forming porous rosette-like microspheres. A mechanism form MgCO3·3H2O microrods to 4MgCO3·Mg(OH)2·4H2O microspheres is suggested to be (MgCO3·3H2O) dissolution-amorphous particles formation-(4MgCO3·Mg(OH)2·4H2O) crystallization. |
| Keywords: nesquehonite hydromagnesite morphology pyrogenation |
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| 摘要点击次数: 1842 |
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| 宋兴福,杨 晨,汪 瑾,孙淑英,于建国.玫瑰花状多孔碱式碳酸镁微球的合成(英文)[J].无机化学学报,2011,27(5):1008-1014. |
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