Fabrication And Characterization Of Magnesium Borate Nanomaterials

.Nanomaterials, which at least have one dimension smaller than 100nm and have many unique properties compared to general materials, are a new kind of materials. Magnesium borate has important application in strengthen of composite materials such as metal, plastic etc, and of lubricant. By far, many researches about the synthesis and application of magnesium borate nanomaterials have been done, and a plenty of results have been got.In this thesis, we first introduce the fundamental concepts, development histories, properties and characteristic technologies of nanomaterials; then, we discuss our research work. The detailed contents are as follows:(1) Magnesium borate(Mg₂B₂O₅(H₂O)) nanowires have been fabricated by hydrothermal method under 200℃, using MgCl₂·6H₂O and NaBH₄ as source materials. SEM result indicates that the lengths of the nanowires are range from 1μm to 10μm, and the diameters are from 30nm to 150nm. The contrasting experiments illustrate that the formation of the nanowires seriously influenced by the temperature and the concentration of the solution. The length and the diameter ratio of the nanowires is larger and the morphology is ideality under 200℃. The ratio is gradually decreased as the temperature decrease. The 1D structure disappeared and sheet-like structure appeared when the temperature achieve 120℃. It goes against to the growth of the nanowires if the concentration of the reaction matter is too high or too low. Ideality nanowires can be gained just under the appropriate concentration range.(2) Flower-like nanostructure magnesium borate is synthesized by hydrothermal method with the source materials of MgCl₂·6H₂O and NaBH₄. SEM results show that these flower-like structures are composed by nanosheet structures. The dimension of the nanosheet is nearly 200nm and the thickness is nearly 10 to 20nm. The contrasting experiments indicate that concentration will influence the morphology of the flower-like structure.(3) Banbooleaf-like and belt-like nanostructure magnesium borate are fabricated by hydrothermal method with different solvent, using Mg(NO₃)₂·6H₂O and Na₂B₄O₇·10H₂O as source materials. Banbooleaf-like nanostructure magnesium borate is synthesized with the solvent, which mixed by water and ethanol. The magnesium borate nanobanbooleaf is very pureness, highly dispersion, uniformity dimension, and high quantity. So the advanced research of the character and application is feasible. Magnesium borate nanobelts can be synthesized with the solvent of water. SEM result shows that the lengths of the nanobelts are range from 500nm t. 2μm, and the widths are from 20nm to 80nm.