Novel approach to recover copper ions using poly(ethylene imine) based layer-by-layer coatings on icosane particles

The low-density materials are developed for the wastewater treatment, the particles could be easily recovered when floating upon water surface and be recycling of a large fraction. Simultaneously, we selected the low melting point of material, which is possible to separate easily the compounds after usage. We chose icosane as a core material with layer-by-layer (LbL) films as an adsorbent for wastewater containing copper ions. The icosane particles were coated by poly(ethylene imine) (PEI) as positively charged layer and either poly(acrylic acid) (PAA) or poly(styrene sulfonate) as counterpart. Glutaraldehyde was introduced as a crosslinking agent to create multilayered shells with various active sites as scavenger. The copper adsorption abilities of PEI-PAA-coated particles were examined by inductively coupled plasma mass spectrometry. Interestingly, the adsorption amount of copper ions on PEI/PAA coated particles (16.5 mg) was optimized at 82 μg/L after 5 min of elution time, which shows a good potential of our material in the field of application. With the facile and consistent separation of the core and LbL coating, the thermal properties were revealed a stable melting temperature at around 38°C.