Macro-corrugated and nano-patterned hierarchically structured superomniphobic membrane for treatment of low surface tension oily wastewater by membrane distillation

Research output: Journal Publications and ReviewsRGC 21 - Publication in refereed journalpeer-review

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Author(s)

  • Muhammad Usman FARID
  • Hassan A. Arafat
  • Alicia Kyoungjin An

Related Research Unit(s)

Detail(s)

Original languageEnglish
Article number115600
Journal / PublicationWater Research
Volume174
Online published10 Feb 2020
Publication statusPublished - 1 May 2020

Abstract

A hierarchically assembled superomniphobic membrane with three levels of reentrant structure was designed and fabricated to enable effective treatment of low surface tension, hypersaline oily wastewaters using direct contact membrane distillation (DCMD). The overall structure is a combination of macro corrugations obtained by surface imprinting, with the micro spherulites morphology achieved through the applied phase inversion method and nano patterns obtained by fluorinated Silica nanoparticles (SiNPs) coating. This resulted in a superomniphobic membrane surface with remarkable anti-wetting properties repelling both high surface tension water and low surface tension oils. Measurements of contact angle (CA) with DI water, an anionic surfactant, oil, and ethanol demonstrated a robust wetting resistance against low surface tension liquids showing both superhydrophobicity and superoleophobicity. CA values of 160.8 ± 2.3° and 154.3 ± 1.9° for water and oil were obtained, respectively. Calculations revealed a high liquid-vapor interface for the fabricated membrane with more than 89% of the water droplet contact area being with air pockets entrapped between adjacent SiNPs and only 11% come into contact with the solid membrane surface. Moreover, the high liquid-vapor interface imparts the membrane with high liquid repellency, self-cleaning and slippery effects, characterized by a minimum droplet-membrane interaction and complete water droplet bouncing on the surface within only 18 ms. When tested in DCMD with synthetic hypersaline oily wastewaters, the fabricated superomniphobic membrane demonstrated stable, non-wetting MD operation over 24 h, even at high concentrations of low surface tension 1.0 mM Sodium dodecyl sulfate and 400 ppm oil, potentially offering a sustainable option for treatment of low surface tension oily industrial wastewater.

Research Area(s)

  • Re-entrant structure, Water repellent, Self-cleaning, Micro patterns, Oily wastewater, Silica nanoparticles

Citation Format(s)

Macro-corrugated and nano-patterned hierarchically structured superomniphobic membrane for treatment of low surface tension oily wastewater by membrane distillation. / Kharraz, Jehad A.; FARID, Muhammad Usman; Khanzada, Noman Khalid et al.
In: Water Research, Vol. 174, 115600, 01.05.2020.

Research output: Journal Publications and ReviewsRGC 21 - Publication in refereed journalpeer-review