由Mg-Fe(Ⅱ)-Fe(Ⅲ)LDH层状前体制备MgFe2O4尖晶石的研究

提出了一种由层状前体合成单一晶相镁铁尖晶石的新方法，首先对Mg-Fe(Ⅱ)- Fe(Ⅲ)水滑石的制备进行了系统研究，成功合成了Mg^2+/Fe^2+/Fe^3+摩尔比分别 为1／2／1，4／5／3，2／1／1的系列水滑石层状前体，结果表明在以上三种投料 比下均可制备出晶型较好的水滑石层状前体，并探讨了合成条件对晶体结构的影响 规律。在此基础上，利用X射线衍射、振动样品磁强计和穆斯堡尔谱等手段研究了 层状前体焙烧产物的结构、组成、磁性及微观信息，研究表明当 Mg^2+/Fe^2+/Fe^3+投料摩尔比为2／1／1时，焙烧层状前体可得到晶相单一的尖晶 石型铁氧体。     

Preparation of nanocomposite superabsorbents based on hydrotalcite and poly(acrylic-co-acrylamide) by inverse suspension polymerization

Firstly, hydrotalcite (HT) was synthesized by the urea method. Then, sodium methyl allyl sulfonate (SMAS) was used as intercalation agent to prepare intercalated HT (SMAS–HT). Finally, a novel poly(acrylic-co-acrylamide)/HT nanocomposite superabsorbent was prepared by inverse suspension polymerization, using N,N′-methylenebisacrylamide (NMBA) as a cross-linking agent and potassium persulfate (KPS) as an initiator. The morphology of the superabsorbents was characterized by FT-IR, XRD, SEM and TEM. The influences of the amount of SMAS–HT on the water (salt) absorbency were investigated. Results showed that the intercalation was successful and the intercalated SMAS–HT incorporated into the superabsorbent was completely exfoliated. The superabsorbent particles approach a spherical shape and the average size is 200–300 nm. The particle sizes of the superabsorbents decrease with increasing the content of SMAS–HT. In addition, the superabsorbent acquired its highest water (salt) absorbency when the content of SMAS–HT is 3 wt%. The highest absorbencies of the superabsorbent for deionized water and 0.9% NaCl_(aq) were 900 g/g and 140 g/g, respectively.     

过氧杂多阴离子柱撑水滑石的合成、表征及催化性能的研究

通过离子交换法, 将含钛过渡金属离子一、三取代钨硅、钨磷过氧杂多配合物嵌入Zn2Al类水滑石中, 获得了柱撑化合物, 并用XRD, IR, XPS, 元素分析等手段对产物的结构和组成进行了表征。结果表明, 过氧杂多阴离子进入水滑石层间后, 水滑石的层间距从0.92nm增大到1.47nm, 且O2^2^-链没有被破坏。柱撑产物在环己烯氧化反应中显示优良的催化性能。     

Cu-Ni-Mg-Al-CO3四元水滑石的合成及结构分析

以Cu(NO3)2·2H2O,Ni(NO3)2·6H2O,Mg(NO3)2·6H2O和Al(NO3)3·9H2O为原料 ，以NaOH和Na2CO3为沉淀剂，采用成核／晶化隔离法合成了Cu-Ni-Mg-Al-CO3四元 水滑石，通过XRD，FT－IR，TG－DTA，ICP等手段对样品进行测试和表征，并且对 水滑石结构的层板和层间阴离子相互作用进行分析和讨论。结果表明，控制Cu^2+ 离子与其它二价金属离子的配比，可制备晶体结构规整的M(Ⅱ）4M(Ⅲ)2(OH) 12CO3·4H2O型水滑石；Cu^2+离子的引入导致了明显的Jahn-Teller效应；且随 Mg^2+量的增加，使得这种效应更加显著，另一方面Mg^2+量的增加有利于Cu-Ni- Mg-Al-CO3四元水滑石晶体在a方向上生长，增强其热稳定性。