本工作研究了应用均匀沉淀法合成LiAl–LDH晶体，并对其形成过程和晶体结构进行了深入的探讨；将MgAl–NO3 LDH进行剥离，得到二维结构的纳米片晶体，将此纳米片同羧甲基纤维素（CMC）进行共组装，制备纳米复合材料；另外，应用离子交换的方法，用具有引发作用的2-溴丁酸对LDH进行插层，得到LDH引发剂。主要结论如下：(1) 采用均匀沉淀法（尿素分解法）来合成结晶度高、形状规则的LiAl–LDH。温度在90~160 ºC范围内得到了纯相的CO32–型LDH单晶。化学式都符合LiAl–LDH的理想配比，LiAl2(OH)6(CO3)0.50•yH2O。得到的单晶是单斜对称结构，晶胞参数为a = 0.50901 (8) nm、 b = 8.801(1) nm、 c = 7.730(1) nm、 β=103.08(1)°。层板的堆积是无序的，且不随温度和时间的变化而改变的。晶体的形成过程是：开始阶段尿素在加热的条件下分解使得Al(OH)3从混合溶液中沉淀出来；然后，随着pH值得增加，Li+进入Al(OH)3层板占据了层板上的空位，同时尿素分解产生的CO32–作为抗衡离子进入层间，即为吸入（imbibition）过程。(2) 尿素分解法合成了高度结晶的MgAl–CO3 LDH，并且通过离子交换制得了MgAl–NO3 LDH。在甲酰胺中成功剥离了MgAl–NO3 LDH，得到了LDH纳米片。剥离得到的LDH纳米片对水较敏感，一接触到水溶液立即发生再配列，干燥后得到层间距为0.87 nm的NO3ˉ–LDH。在LDH纳米片的甲酰胺溶液中，加入CMC没有破坏其胶体状态。并且，由于CMC对LDH纳米片的包裹作用，使得LDH纳米片能够均匀分散在水溶液中，不发生再配列。通过干燥，纳米片和CMC共组装，得到具有1.75nm层间距的层状纳米复合材料。其中CMC分子双层排列在层与层中间，NO3–夹杂在CMC中。通过纳米片和CMC的共组装，将CMC的起始热降解温度提高了160ºC，增强了CMC的热稳定性。(3) 高度结晶的MgAl–CO3 LDH和 CoAl–CO3 LDH在酸-盐溶液中通过离子交换得到NO3ˉ和Clˉ型的LDH，它们具有较强的离子交换能力，可容易地在水溶液中同2-溴丁酸钠进行离子交换，得到结构稳定的具有引发作用的2-溴丁酸型LDH。由其层间距，可以推测2-溴丁酸根在层间中以双层堆积的形式排列。得到的这种复合体，为采用剥离聚合方法制备聚合物/LDH复合材料提供了LDH引发剂前驱物。

In this work, LiAl–LDH compound was synthesized using homogeneous precipitation method, and the formation process and the crystal structure were studied intensively. 2-dimentional nanosheet crystals obtained by exfoliating MgAl–NO3 LDH, and nanocomposite were prepared by co-assembly of nanosheets and carboxymethyl cellulose. In addition, 2-bromobutyric acid was intercalated into the interlayer of LDH by ion-exchange which was excellent initiator. The main useful results were obtained as follows:(1) Highly crystallized and well-shaped LiAl–LDH crystals were synthesized using homogeneous precipitation method (urea hydrolysis method). The single crystals of CO32––LDH were obtained in the temperature range of 90~160 ºC. The formula of LiAl–LDHs was LiAl2(OH)6(CO3)0.50•yH2O coinciding with stoichiometric composition. The single crystals was monoclinic symmetry with the lattice parameters of a = 0.50901 (8) nm, b = 8.801(1) nm, c = 7.730(1) nm, β=103.08(1)°. The stacking of layers was disordered and did not change with the reaction temperature and time. The formation process of single crystal was considered to be that, at the initial stage, Al(OH)3 precipitated from the mixture solution due to the hydrolysis of urea under heating; and then, with the increasing pH values, Li+ ions occupied the holes in layers of Al(OH)3 accompanying with CO32– anions intercalated into the interlayer as counterions which was known as imbibition process.(2) The highly crystallized CO32– type MgAl–LDH was synthesized by urea hydrolysis method. The LDH nanosheets were obtained by an exfoliation of NO3– type LDH in formamide, which were produced by NO3–/CO32– ion exchange of the precursor. The removal of formamide by water can result in the restacking of the LDH nanosheets to a layered structure with 0.87 nm of basal spacing. However, the solution of cellulose and LDH nanosheets in formamide was in a colloidal state, and the removal of formamide can not provoke the restacking of LDH nanosheets, i. e. the CMC-nanosheets-NO3– system is a stable colloid in aqueous solution. After drying and dehydrating the gel of the system, the restacking of the nanosheets happened and the final layered composite had a basal spacing of 1.75 nm with bi- or mult-layer CMC as well as NO3– as interlayer anions. Thermal degradation temperature of CMC is elevated about 160 ºC in the composite.(3) Well-crystallized MgAl–CO3 LDH and CoAl–CO3 LDH crystals were transformed to NO3ˉ or Clˉ type by ion exchange in acid-salt solutions, and due to the high ion-exchangeability of these type LDHs, 2-bromobutyric anion was easily intercalated into the interlayer by ion-exchange in aqueous solutions. The obtained 2-bromobutyric anion type LDHs had a stable structure with bilayer arranged 2-bromobutyric anions in the interlayer. The 2-bromobutyric anion/LDH composite could be an initiator precursor to polymer/LDH composites.