中文摘要：

采用氨水和氯化镁为原料制备氢氧化镁晶体，在自制的纤维素膜上进行原位生长，对纤维素膜进行羧基改性，使纤维素膜表面产生具有能与氢氧化镁结合的活性结合点，控制氯化钠的添加，研究Na^＋对氢氧化镁晶体生长的影响．利用扫描电子显微镜（SEM）观察氢氧化镁晶体的表面形态；X射线衍射（XRD）分析其晶型结构；电感耦合等离子体（ICP）分析纤维素膜上镁元素的含量．研究结果表明，添加氯化钠，纤维素膜上得到棒状氢氧化镁晶体；不添加氯化钠，纤维素膜上得到片状的氢氧化镁晶体；生长有棒状氢氧化镁晶体的纤维素膜上镁元素含量比片状氢氧化镁晶体高．另外，生长有氢氧化镁晶体后纤维素膜的热稳定性有所提高，且生长有棒状氢氧化镁晶体的纤维素膜比生长有片状氢氧化镁晶体纤维素膜的热稳定性更好．

英文摘要：

The ammonia and magnesium chloride were selected as the raw materials to prepare magnesium hydroxide crystal. The cellulose fiber membrane was modified by citric acid to create carboxyl groups to combine magnesium hydroxide nanoparticles. Sodium chloride was added to the above system to study the influence of Na＋ for magnesium hydroxide crystal growth. Scanning electron microscopy（SEM）was used to observe the surface morphology, X-ray diffraction （XRD） was used to analyse the crystal structure of magnesium hydroxide and inductively coupled plasma （ICP） was used to analyse the content of magnesium hydroxide on the membrane. The research results show that the magnesium hydroxide crystal morphology is rod-like with sodium chloride id the solution, while it is lamellar without sodium chloride, and the content of magnesium hydroxide on the membrane is higher with sodium chloride. The membrane covered by magnesium hydroxide has better thermal stability than original membrane, and the rod-like magnesium hydroxide covered membrane shows better thermal stability.