改进的机械化学法合成形貌均匀的层状双金属氢氧化物.docVIP

 An improved mechanochemical approach to synthesize the stunningly uniform particles of layered double hydroxides# LI Shuping, ZHANG Xiaoqing, WEI Shaohua, ZHU Yinyan, ZHOU Jiahong* 5 10 15 20 25 30 35 40 (Jiangsu Key Laboratory of Biofunctional Material, College of Chemistry and Material Science, Nanjing Normal University, Nanjing 210097, China) Abstract: The stunningly uniform particles of Magnesium-Aluminum Layered Double Hydroxides (Mg-Al-LDHs) were synthesized by an improved mechanochemical approach, and this method is engaged in grinding and ageing process. The properties of LDHs including crystallinity, morphology and thermal stability were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and scanning electron microscope (SEM) as well as fourier transform infrared spectroscopy (FTIR) and thermogravimetric/differential thermal analyzer (TG-DTA). The particles after ageing are of high quality in terms of morphology, uniformity and crystallinity, and also exhibit higher thermal stability and zeta potentials. Our study showed that ageing process plays an important role in the synthesis of highly crystalline and regular LDHs. Key words: Layered Double Hydroxides; Mechanochemical Approach; Stunningly Uniform Particles 0 Introduction Layered double hydroxides (LDHs) are a class of anionic clays, also well-known as “hydrotalcite-like compounds”, which can be represented by the general formula of [M2+1-xM3+x(OH)2]x+An-x/n.mH2O (M2+ and M3+ are divalent and trivalent metal ions, An- is n-valent ions). They consist of positively charged brucite-like host layers and the hydrated exchangeable anions which located in the interlayer gallery for charge balance [1]. Due to the special lamellar structure and ion exchange property, LDHs can be found useful in many applications such as catalysts, supports of catalysts, drug carriers and so on [2]. To date, many methods have been developed in the preparation of LDHs with various composition a