Nanosilica modified with polyaspartic acid as an industrial circulating water scale inhibitor

Abstract Given the special performance of nanosilica with its small size, large specific surface area and high surface activity, nanosilica containing reactive amino group (denoted as SiO 2 –NH 2 ) and polysuccinimide were allowed to take part in polymerization reaction to afford SiO 2 –NH 2 modified polyaspartic acid (denoted as SiO 2 –NH 2 /PASP), a potential polymer scale inhibitor with good water solubility for industrial circulating water. The scale inhibition performance of the as-prepared SiO 2 –NH 2 /PASP was evaluated by static scale inhibition test; and its scale inhibition mechanism was explored by means of scanning electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. Results indicated that SiO 2 –NH 2 /PASP exhibits excellent scale inhibition performance against CaSO 4 and CaCO 3 at very low concentrations (optimum scale inhibition rate of 100% and 68%, respectively), and the presence of 5 mg/L of SiO 2 –NH 2 /PASP greatly increases the inhibition efficiency of CaSO 4 and CaCO 3 scale by 21% and 53%, obviously higher than that of pure PASP.