Exfoliation of Layered Silicates through Immobilization of Imidazolium Groups
Exfoliation of Layered Silicates through Immobilization of Imidazolium Groups
复制标题
DOI：
10.1021/cm102942s
复制
发表时间：
2011-01-25
影响因子：
8.6
通讯作者：
Kuroda, Kazuyuki
中科院分区：
文献类型：
--
作者：
Takabashi, Nobuyuki;Hata, Hideo;Kuroda, Kazuyuki
以丁基咪唑基团共价固定的层状硅酸盐在水中完全剥离成单层纳米片。纳米片的厚度为1.9nm（原子力显微镜（AFM））。纳米片的胶体聚集体在较低的角度下没有显示X射线衍射（XRD）峰，表明不存在层堆叠。胶体聚集体干燥后，观察到在1.9 nm处的尖锐峰。该d值与AFM观察到的厚度一致。剥离后，由于存在可归属于硅酸盐的（400）面的0.19nm处的XRD峰，所以硅酸盐的面内晶体结构得以保留。Bim-Oct的层间表面固定与丁基咪唑基团被认为是容易水合，这导致溶胀和随后的剥离成纳米片。通过固定化，硅酸盐表面的显著变化是新颖的，这反映了丁基咪唑基团的独特性质。通过在玻璃基底上旋涂纳米片的胶体聚集体成功地获得了透明无色的膜：阴离子染料橙子II插入到膜中重新堆叠的纳米片的层间。咪唑鎓基团在层状硅酸盐上的固定化对于可设计用于各种应用的纳米片的制备是创新的。
Layered octosilicate immobilized covalently with butylimidazolium groups was fully exfoliated into monolayer nanosheets in water. The thickness of the nanosheets was 1.9 nm (atomic force microscopy (AFM)). The colloidal aggregates of the nanosheets did not show X-ray diffraction (XRD) peaks at lower angles, suggesting the absence of layer stacking. After drying of the colloidal aggregates, a sharp peak at 1.9 nm was observed. This d-value agreed well with the thickness observed by AFM. The in-plane crystal structure of octosilicate was retained after exfoliation because of the presence of the XRD peak at 0.19 nm assignable to the (400) plane of octosilicate. The interlayer surface of Bim-Oct immobilized with butylimidazolium groups is suggested to be easily hydrated, which leads to the swelling and the following exfoliation into nanosheets. The significant change of the silicate surface by the immobilization is novel, which reflects the unique property of butylimidazolium groups. A transparent and colorless film was successfully obtained by spin-coating the colloidal aggregates of nanosheets on a glass substrate: An anionic dye of Orange II was intercalated into the interlayer of restacked nanosheets in the film. The immobilization of imidazolium groups on layered silicates is innovative for the preparation of nanosheets which are designable for various applications.