Zhang Shuai, Liu Qinfu, Cheng Hongfei, Li Xiaoguang, Zeng Fangui, Frost Ray L
School of Geoscience and Surveying Engineering, China University of Mining & Technology, Beijing 100083, China.
School of Geoscience and Surveying Engineering, China University of Mining & Technology, Beijing 100083, China.
J Colloid Interface Sci. 2014 Sep 15;430:345-50. doi: 10.1016/j.jcis.2014.05.059. Epub 2014 Jun 6.
Dodecylamine was successfully intercalated into the layer space of kaolinite by utilizing the methanol treated kaolinite-dimethyl sulfoxide (DMSO) intercalation complex as an intermediate. The basal spacing of kaolinite, measured by X-ray diffraction (XRD), increased from 0.72 nm to 4.29 nm after the intercalation of dodecylamine. Also, the significant variation observed in the Fourier Transform Infrared Spectroscopy (FTIR) spectra of kaolinite when intercalated with dodecylamine verified the feasibility of intercalation of dodecylamine into kaolinite. Isothermal-isobaric (NPT) molecular dynamics simulation with the use of Dreiding force field was performed to probe into the layering behavior and structure of nanoconfined dodecylamine in the kaolinite gallery. The concentration profiles of the nitrogen atom, methyl group and methylene group of intercalated dodecylamine molecules in the direction perpendicular to the kaolinite basal surface indicated that the alkyl chains within the interlayer space of kaolinite exhibited an obvious layering structure. However, the unified bilayer, pseudo-trilayer, or paraffin-type arrangements of alkyl chains deduced based on their chain length combined with the measured basal spacing of organoclays were not found in this study. The alkyl chains aggregated to a mixture of ordered paraffin-type-like structure and disordered gauche conformation in the middle interlayer space of kaolinite, and some alkyl chains arranged in two bilayer structures, in which one was close to the silica tetrahedron surface, and the other was close to the alumina octahedron surface with their alkyl chains parallel to the kaolinite basal surface.
通过利用甲醇处理的高岭石 - 二甲基亚砜（DMSO）插层复合物作为中间体，十二胺成功地插入到高岭石的层间空间。通过X射线衍射（XRD）测量，高岭石的基面间距在插入十二胺后从0.72nm增加到4.29nm。此外，当与十二胺插层时，高岭石的傅里叶变换红外光谱（FTIR）光谱中观察到的显著变化证实了十二胺插入高岭石的可行性。使用Dreiding力场进行等温等压（NPT）分子动力学模拟，以探究高岭石层间纳米受限十二胺的分层行为和结构。插入的十二胺分子的氮原子、甲基和亚甲基在垂直于高岭石基面的方向上的浓度分布表明，高岭石层间空间内的烷基链呈现出明显的分层结构。然而，在本研究中未发现基于其链长结合有机粘土的测量基面间距推断出的烷基链的统一双层、伪三层或石蜡型排列。在高岭石的中间层间空间中，烷基链聚集成有序的石蜡型类似结构和无序的gauche构象的混合物，并且一些烷基链排列成两个双层结构，其中一个靠近硅四面体表面，另一个靠近氧化铝八面体表面，其烷基链平行于高岭石基面。
