Rational Design of Surface Wettability Toward Clean Water Production

Event Date: 

Monday, April 4, 2016 - 4:00pm to 5:00pm

Event Date Details: 

Event Location: 

  • Bren Hall 1424

Peng Wang, Associate Professor, Environmental Technology Lab, KAUST

The talk is composed of three parts: (1) surface with switchable oil attraction and repulsion for selective oil/water separation. Advanced materials with surfaces that have controllable oil wettability when submerged in aqueous media have great potential for various water-related applications. Smart surfaces can be made on commonly used materials, including non-woven textiles and polyurethane sponges, which are able to switch between superoleophilicity and superoleophobicity in aqueous media. The smart surfaces were obtained by grafting a block copolymer, comprising blocks of pH-responsive poly(2-vinylpyridine) and oleophilic/hydrophobic polydimethylsiloxane (i.e., P2VP-b-PDMS) on these materials. (2) A bio-inspired method for direct preparation of stable superhydrophilic micropatterns onto superhydrophobic surface for efficient fog collection. By directly inkjet printing a bio-inspired ink of dopamine solution with delicately optimized solution composition, stable Wenzel’s microdroplets of dopamine solution with well-defined micropatterns were obtained onto the superhydrophobic surfaces, and after the formation of polydopamine via the in-situ polymerization of dopamine, superhydrophilic micropatterns can be readily achieved. (3) A photothermal, self-floating and self-healing membrane for enhanced solar-driven water desalination. The membrane was prepared by deposition of light-to-heat conversion materials onto porous stainless steel mesh, followed by a hydrophobic modification. The results confirm that with the membrane floating on water surface, a sharp local temperature gradient was generated on the water surface, leading to significantly increasing water evaporation rate. The membrane recovered its hydrophobicity once lost autonomously.

Prof. Peng Wang joined KAUST in September 2009 as a founding faculty member and he is currently an associate professor in Environmental Science and Engineering program at KAUST. He received his M.S. and Ph.D. degree from the University of California, Santa Barbara (UCSB), both in Environmental Science and Management. His research focuses on rational design, synthesis, and application of nanomaterials for clean water and clean energy production.

Sponsored by the Mellichamp Academic Initiative in Sustainability