High-performance polyethyleneimine/sodium silicate material: one-step strategy at ambient temperature and application in removing heavy metal ion

Polyethyleneimine (PEI) composites containing silicon have shown extraordinary potential in scavenging heavy metal ions, but usually suffer from difficulty in recycling/separating after usage, quite complex and time-consuming procedures, expensive and higher toxic starting materials or being processed desired shapes. To overcome these defects, here, high-performance PEI composite with unexpectedly enhanced elasticity and flexibility by Na2SiO3, for the first time, has been successfully constructed by a green one-step strategy at ambient conditions. Strikingly, the composite can be easily moulded into various shapes and displays excellent elasticity and flexibility like sponge. Moreover, after bending and compression, the original shape can be restored, which is impossible for conventional PEI composites containing silicon. Interestingly, the resultant composite displayed ultra-fast and ultra-strong water adsorption efficiency. Most importantly, the composite exhibits efficient Cu2+ adsorption capacity. Furthermore, adsorption kinetics, thermodynamics and isotherms have also been investigated to reveal Cu2+ adsorption behaviours of the composite.Graphical abstract High-performance polyethyleneimine composite has been successfully constructed by a green and ultraconvenient strategy at ambient temperature using commercially available and low cost of starting materials PEI, polyethylene glycol diglycidyl ether and Na2SiO3.