Oxidant-Induced
High-Efficient Mussel-Inspired Modification
on PVDF Membrane with Superhydrophilicity and Underwater Superoleophobicity
Characteristics for Oil/Water Separation
In
this work, a facile one-step approach was developed to modify
hydrophobic polyvinylidene fluoride (PVDF) microfiltration membrane
with superhydrophilicity and underwater superoleophobicity properties
via a high-efficient deposition of polydopamine (PDA) coating oxidized
by sodium periodate in a slightly acidic environment (pH = 5.0). In
contrast to the traditional PDA coating on hydrophobic membranes autoxidized
by O<sub>2</sub> in a weak basic buffer solution, the superhydrophilicity
and ultrahigh pure water permeability (about 11 934 L m<sup>–2</sup> h<sup>–1</sup> under 0.038 MPa) of the PDA-decorated
PVDF membrane are derived from optimized chemical oxidation without
postmodifications or additional reactants. The as-prepared membrane
exhibits excellent oil/water separation ability evaluated by water
fluxes and oil rejection ratios of various oil/water mixtures and
oil-in-water emulsions. Moreover, the outstanding antifouling performance
and reusability of the PDA-modified PVDF membrane provide a long-term
durability for many potential applications. The modified membrane
also exhibits excellent chemical stability in harsh pH environments
and mechanical stability for practical applications