Adsorption behavior and mechanism of salvianolic acid A on surface molecularly imprinted nonwoven fabrics

Salvianolic acid A (SAA) is a water-soluble phenolic acid compound with high biological activity, which is widely used in the treatment of cardiovascular diseases. In this paper, we report a strategy for synthesizing surface molecularly imprinted nonwoven fabrics (SMI-PP) for the adsorption of SAA from aqueous solution using 3-acryloylaminophenylboronic acid, 1-vinylimidazole, and methacrylamido propyl trimethyl ammonium chloride as functional monomers. The adsorption kinetics conformed to a pseudo-second-order kinetic model, and the adsorption equilibrium could be reached within 24 h at 298.15 K with high adsorption selectivity. The maximum adsorption amount was found to be 89.847 mg/g calculated by Langmuir adsorption model. The adsorption mechanism was investigated in-depth via molecular orbital theory (MOT), electrostatic potential (ESP), independent gradient modeling (IGM), density functional theory (DFT), molecular dynamics (MD)，spectral analysis as well as adsorption model fitting, which can be inferred to involve covalent bond, electrostatic interaction and hydrogen bond. It is shown that SMI-PP is an efficient, highly selective, low-cost and easy-to-operate adsorbent for the effective adsorption and separation of SAA from aqueous solution.