Fabrication of nitrogen donor macro-and meso-porous materials for group 11 metal ions sorption

Macro(meso) porous polymer materials were prepared via a modified TIPS method using reagent grade polymers mixtures; polyacrylonitrile (PAN) and polyvinylpyridine-co-styrene (PVPS). Reaction conditions such as concentration, temperature and the solvents used were found to affect the morphology of the polymer materials formed. The use of low heat for polymer dissolution, near critical point polymer concentration and a miscible solvent/non-solvent pair in excess non-solvent were found to produce porous polymers. The macro-(meso-) porous materials were further used in metal adsorption/desorption studies and they were found to remove up to 80 % of Cu(II), Ag(I) and Au(III) from aqueous solution. Adsorption/desorption experiments were performed using the polymer monolith KSP1{(PAN : PVPS = 75 : 25 (w/w) in DMSO : H2O = 90 : 10(v/v)} and it showed excellent reusability adsorbing and desorbing up to 90 % of the metal ions in a series of five cycles. Ternary solutions for adsorption/ desorption experiments were added in the order Cu(II), Ag(I) and Au(III).