Zuo and Wang [22]

Hydrophilic/hydrophobic composite membrane Polyethylene glycol + TiO₂ deposition on PVDF by plazma grafting

Pore size reduction from 0.55 μm to 0.27 μm

CA for water decreased from 120° to 25.2°

Stable flux observed (6.3 L/m²h)

13% flux reduction to the baseline PVDF.

Wang and Lin [23]

Underwater-oleophobic/hydrophobic composite (FS/CTS/PFO-PVDF)

Stable in-air CA: 139.6°, in-water CA < 90° (hydrophilic)

Sharp reduction in permeate flux (31 L/m² h for PVDF to 0.49 L/m² h for FS/CTS/PFO-PVDF)

Lee et al. [25]

Omniphobic composite membrane Electrospun BTEAC/PVDF-HFP coated with SiNPs

Reduction of pore size from 2.23 μm for PVDF-HFP to 0.42 μm for BTEAC/PVDF-HFP

Water CA of ~150°

Stable flux and salt rejection

Lin et al. [26]

Omniphobic composite membrane APTES-coated GF with (-ve) charged SiNPs suspension treated with fluorinated alkyl silane (FAS)

High water CA (≈140°)

High oil CA (≈100°)

100% salt rejection

Low flux of 2.7 L/m² h (32.6 L/m² h for PTFE)

Wang et al. [27]

Underwater-oleophobic/hydrophobic composite (CTS-PFO/SiNPs) Silica nanoparticles-polymer coating on PVDF substrate

Composite membrane porosity of 72.5% and pore size 388 nm, compared to 75% and 392 nm for the baseline PVDF

4% membrane thickness increase in-air water CA: 0°, underwater oil CA: 149.5° Stable flux with initial value of 26.15 L/m² h

Ahmed et al. [29]

Hydrophilic/hydrophobic composite Cellulose electrospun PVDF-HFP composite membrane

Pore size reduction from 0.92 μm to 0.3 μm

Porosity reduction from 91% to 35%

PVDF hydrophobic: water CA 130°, Cellulose/PVDF composite: oil CA of 169° and 0° for water

90%–99% of oil separation efficiency achieved

Flux of 1781 L/m² h bar