The integrated utilization of typical clays in removal of organic dyes and polymer nanocomposites

In this work, typical clays such as montmorillonite (MMT) and Layered double hydroxides (LDHs) were firstly used as adsorbents for organic dyes. Removal efficiency of methylene blue (MB) and methyl orange (MO) could reach 74% and 88%, respectively. The color of clays showed a significant variation before and after organic dyes removal. The clays after organic dyes removal (MMT-MB and LDH-MO) were incorporated into polystyrene (PS) to prepare fashionable layered polymer nanocomposites. Transmission electron microscopy (TEM) results demonstrated that MMT-MB and LDH-MO nanosheets were well dispersed in PS matrix. The thermal stability of the PS/clay nanocomposites was increased obviously comparing with that of pure PS. Furthermore, the release volume of carbon monoxide (CO) was reduced significantly comparing with pure PS. Thermogravimetric analysis/infrared spectrometry (TG-IR) results showed that much less flammable gas products were released relative to pure PS which further leads to the inhibition of smoke. Such a great improvement in thermal stability and smoke suppression properties was mainly attributed to the physical barrier effect of clay nanosheets and the presence of clays promoting char formation. The research results in this work indicated that the physical adsorption and nanocomposite technique can be combined together to play a better role in remediation of wastewater and fire rescue which can bring many benefits for human life.