Investigation on the binding force between lignin and magnetic Fe3O4 nanoparticles with AFM

摘要

Preparation of lignin-based magnetic materials has attracted more and more attention. In order to illustrate the interaction mechanism, the binding force between Fe3O4 and lignin was tested with AFM in different environments in this study. It was shown that at pH4.8, the electrostatic attraction was the main driving force, which occupied about 88.0%, 69.8% and 42.1% of the total binding force between Fe3O4 and LS, LSQA-40, LSQA-80, respectively. As the pH value increased, the electrostatic attraction decreased greatly. At pH6.8, the average binding force between Fe3O4 and LS, LSQA-40, LSQA-80 retained as 0.39, 0.55, 0.87 mN/m, respectively. van der Waals force played the main role at pH6.8, which accounted for 70.9%, 57.8% and 52.9% of the total binding force in forming of Fe3O4/LS, Fe3O4/LSQA-40 and Fe3O4/LSQA-80. This study could point out a direction in the preparation of lignin-based magnetic materials.

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