Enhanced intercalation of organo-muscovite prepared via hydrothermal reaction at low temperature

Abstract

Muscovite clay is an ideal reinforcing filler due to its high-aspect ratio. However, it does not swell in water, making it hard to be treated and intercalated. In this study, ion exchange treatment is carried out on muscovite clay using cetyltrimethylammonium bromide (CTAB) cations via two-step intercalation method. The intercalation steps included: inorganic-inorganic ion exchange treatment and inorganic-organic ion exchange treatment under hydrothermal conditions. The intercalation of muscovite particles was examined with various techniques to analyse the physical and chemical changes. Furthermore, the hydrothermal conditions for effective CTA + ion intercalation within muscovite interlayers prepared via the hydrothermal process at low temperature, 180 • C, under different hydrothermal reaction times and CTAB/Li-Mus mass ratio were investigated. Fourier transform infra-red (FTIR) analysis revealed that the CTA + ions are diffused into the interlayers of aluminosilicate and formed a strong electrostatic bond with the clay surface. X-ray powder diffraction analysis showed that the interplanar spacing in the organo-muscovite samples is almost identical as the hydrothermal reaction time is prolonged beyond 12 h. An optimum limit of the CTAB to Li-Mus ratio is observed as the d 002 plane spacing is increased with an increase of the mass ratio of CTAB to Li-Mus up to 1.0 C and decreased with a further increase in the mass ratio. In addition, the intercalated CTA + chains are homogenously distributed and formed a paraffin-like arrangement in the muscovite clay. Besides, the structure of aluminosilicate layers is not affected or damaged after both treatments according to FTIR analysis.

Upcycled Polyvinyl Chloride (PVC) Electrospun Nanofibers from Waste PVC-Based Materials for Water Treatment

“…The XRD pattern of the PVC pool float (Figure b) exhibited structures that confirm the existence of muscovite (mica) in the PVC pool float used as a filler to provide a silky/shiny luster. The sharp peaks at 2θ values of 9.03, 17.8, 26.7, 35.9, and 45.2° match exactly with the XRD peaks of muscovite reported in the literature. , The FTIR spectra of a solid PVC pipe (Figure c) and a solid PVC pool float (Figure d) indicated the presence of additives such as adipate in the PVC pipe by the characteristic adipate peak at 1685 cm –1 and muscovite in the PVC pool by the peak at 1020 cm –1 , which represent the stretching and bending vibrational motions of Si–O bonds in the range of 950–1100 cm –1 and phthalates in the PVC pool float at 1730 cm –1 (CO stretching vibration), the peak at 1575 cm –1 (C–C stretching vibration), the peak at 1599 cm –1 (C–C stretching vibration peaks of the benzene ring), and the peak at 745 cm –1 (ortho-substituted benzene stretching vibrations). , The FTIR of the solid PVC pipe (Figure c) and solid PVC pool float (Figure d) also showed the presence of calcium carbonate (CaCO 3 ) at 876 and 712 cm –1 …”

“…As it was observed in the FTIR spectrum of a solid sample of the PVC float, the stretching and bending vibrational motions of Si–O in the range of 950–1100 cm –1 imply the presence of muscovite. The peaks between 500 and 1300 cm –1 correspond to vibrations in the aluminosilicate layers in muscovite . Furthermore, the presence of adipate in the PVC pipe and centrifuged sediment (white solid) is represented by the characteristic adipate peak at 1685 cm –1 , which represents the stretching vibration of the −COOH groups …”

“…32,33 The FTIR spectra of a solid PVC pipe (Figure 2c) and a solid PVC pool float (Figure 2d) indicated the presence of additives such as adipate in the PVC pipe by the characteristic adipate peak at 1685 cm −1 and muscovite in the PVC pool by the peak at 1020 cm −1 , which represent the stretching and bending vibrational motions of Si−O bonds in the range of 950−1100 cm −1 and phthalates in the PVC pool float at 1730 cm −1 (C�O stretching vibration), the peak at 1575 cm −1 (C−C stretching vibration), the peak at 1599 cm −1 (C−C stretching vibration peaks of the benzene ring), and the peak at 745 cm −1 (orthosubstituted benzene stretching vibrations). 34,35 The FTIR of the solid PVC pipe (Figure 2c) and solid PVC pool float (Figure 2d) also showed the presence of calcium carbonate (CaCO 3 ) at 876 and 712 cm −1 . 36 The viscosity at different shear rates for all six casting solutions is shown in Figure 3.…”

Growth of van der Waals Halide Perovskites within the Interlayer Spacings of Mica

“…It has been established that due to strong electrostatic interactions, muscovite mica does not swell in aqueous solutions. This hinders intercalation and ion exchange reactions with K + ions of the muscovite. − Although exchange of organic ions and surfactants with K + ions has been demonstrated, the process is nontrivial, requires large surface areas with mica in a powder form, and is often limited to the exposed surface of muscovite. − Hence, it cannot directly explain the observed growth of (BA) 2 PbI 4 in the interlayer spacings of large substrates of mica. However, it is known that liquids can enter the interlayer spacings of mica from its edges due to capillarity effects. , Such penetration of the growth solution into the interlayer spacings of mica, possibly aided by defects and cracks along the edges, can open up possibilities of ion exchange and cooling of the growth solution can promote crystallization of (BA) 2 PbI 4 in pockets extending inward from the edges.…”

The Synthesis of Organoclays Based on Clay Minerals with Different Structural Expansion Capacities

“…Weng-Lip et al [80] accomplished the intercalation of muscovite cations of cetyltrimethylammonium bromide with the two-stage method, including, at first, the melting of the mineral with lithium nitrate at 300 • C and then, at the second stage, interaction with the organic substance solution in an autoclave at 180 • C. Fourier transform infrared spectroscopy showed that cetyltrimethylammonium cations diffuse into the aluminosilicate laminas and make up a stable electrostatic bond with the clay surface. In addition, the intercalated chains of organic cation are distributed uniformly to make up the paraffin-type structures in the muscovite clay.…”