Q: Why is polymer water absorbent resin not good at absorbing saltwater?

Q: Why is polymer water absorbent resin not good at absorbing saltwater?

Answer:The main component of polymer water absorbent resin is sodium polyacrylate, which is a water-soluble sol with only water as the only good solvent. The inorganic sodium chloride molecules contained in saltwater will hinder the entry of water molecules into sodium polyacrylate, causing uneven internal and external osmotic pressures. Not only saltwater, but even if you switch to sucrose solution, citric acid solution, and DMF solution, it will still be the same. This product absorbs water selectively. In addition to organic-inorganic salts, the formation of a hydrophobic layer on its surface by organic solvents will greatly slow down water absorption. Please refer to it as appropriate. So, we would rather use anhydrous calcium chloride to remove water from the solvent than the highly absorbent sodium polyacrylate, for the same reason.