Anomalous effect of Cu2O and CuO deposit on the porosity of a macroreticular anion exchanger

Ewa Stanisławska,Elżbieta Kociołek-Balawejder,Marek Jasiorski,Irena Jacukowicz-Sobala

doi:10.1007/s11051-021-05246-w

Abstract

When synthesizing copper compounds containing polymeric adsorbents, it was found that the two copper oxides, Cu2O and CuO, deposited in the skeleton of a strongly basic macroreticular anion exchanger (An) radically diminished the porosity of the obtained composites in relation to the host material. In order to investigate this phenomenon more closely, An/Cu2O and An/CuO (both based on the commercial anion exchanger Amberlite IRA900Cl), containing 8.6 and 8.2 wt% Cu, respectively, were subjected to scrutiny. The porous characteristics of the thermally dried and freeze-dried samples were determined using the N2 adsorption–desorption method and mercury intrusion porosimetry. The thermally dried samples lost their porosity and increased their bulk density in relation to the pure resin indicated a significant reduction in their volume. It was found that during drying, the grains shrank as much as the pores collapsed. The decay of the porous structure resulted from the surface morphology of the Cu2O and CuO particles and their tendency to agglomerate. Both freeze-dried samples retained the porous characteristics typical for macroporous anion exchangers. In contrast to the most popular hybrid ion exchangers containing hydrated polyvalent metal oxides (such FeOOH), An/Cu2O and An/CuO showed markedly strong volume contraction effect in relation to moisture content.Graphical abstract

Highlights

The porous characteristic is a set of data whose knowledge is important in understanding the formation, structure, and potential use of polymeric composite materials Wang et al 2015; Wang et al 2016; Tan et al 2018)
The functional groups of a strongly basic anion exchanger are quantitatively transformed into the form and using appropriate solutions, the ions are decomposed and appropriate copper oxide precipitated in the ion exchanger skeleton
After obtaining the semi-final product rich as possible in copper, it was important to select the reactant and reaction parameters which ensured formation of the coper oxide almost quantitatively remaining in the anion exchanger phase

Summary

Introduction

The porous characteristic is a set of data whose knowledge is important in understanding the formation, structure, and potential use of polymeric composite materials Wang et al 2015; Wang et al 2016; Tan et al 2018). In the 2000s as nanotechnology developed, a group of adsorbents called hybrid ion exchangers (HIXs) appeared. They are polymeric/ inorganic porous composite materials in the form of spherical beads in which ion (cation or anion). The introduction of dispersed NPs into the porous matrix of an ion exchanger significantly changed the novel material’s porous characteristic, ion transport, selectivity, and practical application in comparison with the pure resin (Li et al 2016). The adsorption, permeability, density, and other characteristics influenced by the substance’s porosity determine the way in which it can be appropriately used (Dzyazko et al 2019)

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