Sustainable, superhydrophobic membranes based on bacterial cellulose for gravity-driven oil/water separation

Carbohydr Polym. 2021 Feb 1:253:117220. doi: 10.1016/j.carbpol.2020.117220. Epub 2020 Oct 21.

Abstract

Bacterial cellulose (BC) is a substrate material with high purity and robust mechanical strength, but due to its small pore size and relatively expensive price, it is restricted as an oil-/water separation membrane. In this study, cheaper plant cellulose needle-leaf bleached kraft pulp (NBKP) was added to BC to increase the pore size of the composite membrane, and a superhydrophobic/superoleophilic membrane was prepared for oil-/water separation. The modified membrane surface displayed a petal-like micro-structure and a water contact angle (WCA) of 162.3°, while the oil contact angle was decreased to 0°. What's more, the membrane exhibited excellent oil-/water separation under gravity, recyclability, and a separation efficiency (>95 %), and it was both pH and salt resistant. The membrane also remained durably hydrophobic after 10 separation cycles. And the separation methodology is expected to be highly energy-efficient.

Keywords: Bacterial cellulose; Needle-leaf bleached kraft pulp; Oil/water separation; Superhydrophobic membrane.

MeSH terms

  • Cellulose / chemistry*
  • Gluconacetobacter xylinus / metabolism*
  • Gravitation*
  • Green Chemistry Technology / methods*
  • Hydrogen-Ion Concentration
  • Hydrophobic and Hydrophilic Interactions*
  • Lignin / chemistry
  • Membranes, Artificial*
  • Oils / chemistry*
  • Plant Leaves / chemistry
  • Polysaccharides / chemistry
  • Polysaccharides, Bacterial / chemistry*
  • Porosity
  • Tensile Strength
  • Water / chemistry*

Substances

  • Membranes, Artificial
  • Oils
  • Polysaccharides
  • Polysaccharides, Bacterial
  • Water
  • hemicellulose
  • Cellulose
  • Lignin