二维蛭石膜的制备及其水中稳定性研究

Preparation and Characterization of Two-dimension Vermiculite Membranes with Excellent Water Stability

通过二价阳离子与带负电的蛭石(VMT)片层之间的静电作用力,制备了具有稳定层间距的蛭石膜。利用SEM和EDX考察了VMT-Li膜和VMT-Ca膜的形貌结构及VMT-Ca膜的元素分布,考察了VMT-Li膜和VMT-Ca膜的稳定性及层间距变化,并测试了膜的水蒸汽扩散通量。结果表明,VMT-Li膜和VMT-Ca膜均具有典型的层状结构,膜表面平整无明显缺陷。VMT-Ca膜在水溶液和盐溶液中均具有良好的稳定性,VMT-Li膜和VMT-Ca膜的水蒸汽扩散通量分别为24.12、18.17 g/(h·m^(2))。该工作为后续研究蛭石膜层间离子传输奠定了基础。

In this paper, vermiculite(VMT) membranes with stable interlayer spacing are prepared by the electrostatic interaction between divalent cations and negatively charged vermiculite sheets. The morphology and elemental distribution of the vermiculite films are investigated by SEM, EDX. The stability of VMT-Li membranes and VMT-Ca membranes are investigated. The insight of the stability of the vermiculite membranes is taken in the interlayer spacing by XRD. The intrinsic diffusion rate of water molecules though the membrane was obtained by measuring the water vapor diffusion flux of the membrane. The results show that both the VMT-Li membrane and the VMT-Ca membrane have a typical layered structure, and the surface of the membranes demonstrates no obvious defects. VMT-Ca membrane has excellent stability in both aqueous and salt solutions, and the water vapor diffusion fluxes of VMT-Li membrane and VMT-Ca membrane are 24.12 and 18.17g/(h·m^(2)).This work lays a foundation for the study of interlayer ion transport in vermiculite films.