Fabricating of grape seed proanthocyanidins loaded Zein-NaCas composite nanoparticles to exert effective inhibition of Q235 steel corrosion in seawater

Abstract

Grape Seed Proanthocyanidins (GSP), underutilized by-products, exhibit encouraging biological activities, but their structural instability limits practical applications. A solution to this problem was found here by using GSP-loaded zein– sodium caseinate (NaCas) composite nanoparticles. Core-shell biopolymer nanoparticles were fabricated by antisolvent precipitation method to form NaCas stabilized zein core nanoparticles. The GSP-loaded zein-NaCas composite nanoparticles were self-assembled into spherical nanoparticles with homogeneous distribution (PDI around 0.2) and high negative charge (about –30 mV). FTIR analysis indicated that hydrogen bonding, hydrophobic and electrostatic attractions act as the main energy for the formation of colloidal particles. Stability test showed that the particles have stable corrosion inhibition efficiency for Q235 steel within 15 d in a wide range of ionic strength and pH value, and thus can adapt to the changes of seawater environment. Corrosion results manifested that GSP-loaded zein-NaCas composite nanoparticles display good re-dispensability and controlled release performance, whose inhibitive efficiency for Q235 steel in seawater is obviously higher than that of GSP (200 mg/L, 96.06% versus 71.89%).