Hybrid membrane adsorbents: preparation and their adsorptions for copper(II) ions

A new type of hybrid membrane adsorbents was prepared via a sol-gel reaction. As typical examples, the adsorption performances of samples D and E for copper(II) ions were investigated. TGA measurement showed that the thermal stability of these hybrid membrane adsorbents could exceed 240 degrees C. DSC thermal analysis displayed that the incorporation of 3-aminopropyl triethoxysilane (APTES) into 3-methacrcypropyl trimethoxysilane (MPTMS) did not result in larger transformation of crystallization in these samples. Adsorption experiments confirmed that the adsorption of copper(II) ions onto the samples D and E followed the Langmuir isotherm model, suggested that such adsorption was Langmuir monolayer adsorption. The negative Gibbs free energy values further demonstrated that copper(II) adsorption onto these hybrid membrane adsorbents was spontaneous in nature. The desorption experiment revealed that these samples could be effectively regenerated via aqueous HCl solution as a desorbent. These findings imply that these hybrid membranes are promising adsorbents in the separation and recovery of copper(II) ions from the copper-curing wastewater or the contaminated water.