Preparation And Surface Modification Of Basic Magnesium Chloride Nanorods

Basic magnesium chloride possesses interesting properties such as a low thermal conductivity, high fire retardancy, and good mechanical, acoustic, and elastic properties. It is the main component of magnesium oxychloride cement and a very important precursor for preparation of micro-nano structured Mg(OH)₂ and MgO. At present, basic magnesium chloride of nanostructure is mainly produced by hydrothermal method which demands high equipments and technical conditions and has large energy consumption. This paper mainly works on preparation of basic magnesium chloride nanorods synthesized by MgCl₂ and MgO using liquid method. Based on the experiments, the effects of process parameters on the morphology and production of basic magnesium chloride nanorods are analyzed, the optimal process and key factors of the process parameters are determined. Surface modification of basic magnesium chloride nanorods is carried out using stearic acid, titanate coupling agent and silane coupling agent. Effect of calcining condition on activity of different kinds of MgO powders is discussed. The composition and production of basic magnesium chloride nanorods synthesized by using MgO with different activity and morphology are studied. The products are characterized and detected by means of X-ray diffraction, Scanning Electron Microscopy (SEM), Thermogravimetric technique (TG) and chemical titration.Basic magnesium chloride single crystal nanorods with diameter of 100nm and length of more than 10 FFUm are prepared under the following conditions:molar ratio of MgO/MgCl₂:0.07, concentration of magnesium chloride:4mol·L^-1, synthesis temperature:50℃, ageing time:48h, aging temperature: 20℃, volume ratio of C₂H₅OH/H₂O:2.5:1.Surface modification is available using stearic acid, titanate coupling agent and silane coupling agent. Activation grade of basic magnesium chloride nanorods modified by stearic acid and titanate coupling agent is higher than 90% while the activation grade is 47% using silane coupling agent.Calcining temperature and calcining time have great influence on activity of MgO powders. In this research, activity of MgO has a little influence on composition of basic magnesium chloride while has great effect on production and strain of basic magnesium chloride.