Preparation of boronate affinity controllable-oriented polysaccharides magnetic molecularly imprinted polymer and its application for membrane flux improvement

Abstract

In this study, researchers successfully developed a novel Magnetic Molecularly Imprinted Polymer of Boronate Affinity Controllable-Oriented Dextran (MMIP-Dextran) to enhance membrane flux by selectively adsorbing polysaccharide-type substances. The structure and components of the MMIP-Dextran were thoroughly investigated using various techniques such as Transmission Electron Microscopy (TEM), Vibrating Sample Magnetometer (VSM), Brunauer-Emmett Teller (BET), Fourier Transform Infrared (FT-IR), and Thermogravimetric Analysis (TGA). Batch experiments were conducted to assess the adsorption performance and mechanisms. Results showed that the MMIP-Dextran exhibited a high adsorption capacity of 31.2 mg g−1 and good specific recognition performance (imprinting factor, IF=2.83) for the Dextran template. Furthermore, the MMIP-Dextran had a superior polysaccharide adsorption capacity of 22.10 mg g−1 compared to the Non-Imprinted Polymer (NIP) in soluble microbial products (SMPs) derived from a bioreactor, showing a 2.45-fold improvement. Meanwhile, the Specific Filtration Resistance (SFR) tests indicated that the membrane flux improvement by MMIP-Dextran (15.2 %) is 2.1 times better than NIP (7.2 %). Adsorption kinetics and thermodynamics analyses revealed that the spontaneous adsorption process was predominantly governed by chemically rate-limiting steps. Density Functional Theory (DFT) analysis further revealed that the spatial configuration transformation of the Boric Acid Ligand (BAL) played a crucial role in the adsorption/desorption process. Overall, this study offers a promising approach to promoting the permeate flux of membrane and provides a deeper understanding of the antifouling mechanism using MMIPs.