不同形貌氢氧化镁微纳米结构的干燥动力学研究

Drying Kinetics of Different Morphological Micro-nanostructures of Mg(OH)_2

采用沉淀转化法制备出两种氢氧化镁纳米片;采用直接沉淀法合成出氢氧化镁微米颗粒。通过干燥动力学实验得到三种形貌氢氧化镁的干燥曲线和干燥速率曲线;测定出三种形貌氢氧化镁在12℃下的平衡水分吸附等温线。研究结果表明,三种形貌氢氧化镁滤饼的初始含水量,纳米片的高于微米颗粒;它们的干燥速率曲线形状相似,但氢氧化镁纳米片的恒速段干燥速率曲线略有下降趋势;在相同的空气相对湿度下,纳米片的平衡含水量高于微米颗粒。

Two kinds Of Mg（OH） 2 nano- flakes were prepared by precipitation conversion method, and Mg（OH） 2 micro- particles were synthesized by direct precipitation method. Drying kinetics experiments of magnesium hydroxide of three morphological micro - nanostmctures were performed and their drying curves as well as drying rate curves were obtained. The equilibrium moisture adsorption isotherms of magnesium hydroxide of three morphological micro - nanostmctures at 12℃ were gained. Drying rate curves of magnesium hydroxide nano - flakes （nano - flake 1 and nano - flake 2） show that the three similar stages with a little descending trend of constant rate drying period are occurred. It is also found that initial moisture contents of nano- flake 1 was the largest of all three different Mg（OH） 2products and that equilibrium moisture contents of Mg（OH）2 nano- flakes are larger than those of Mg（OH）2 micro - particles under the same drying condition.