An ultra-absorbent alkyne-rich porous covalent polycalix[4]arene for water purification

The development of novel materials for removal of organic contaminants from water is of global importance for the preservation of the environment. Here, we describe the synthesis and characterization of the first porous covalent calix[4]arene-based polymer (CalP) and its use for water purification. CalP has a high surface area, large pore volume and excellent sorption capacity for a range of organic solvents, oils, and toxic dyes. The polymer can selectively absorb up to seven times its weight of oil from oil/water mixtures. From aqueous solutions, it can adsorb both anionic and cationic dyes in under 15 minutes. Its uptake capacity is significantly higher than those of the most adsorbent materials reported to date, including commercial activated carbon. Additionally, the polymer can be easily regenerated using mild washing procedures and reused several times with no loss of absorption efficiency.