Fabrication of multi-functional super-hydrophilic nano-fiber membrane

• Main Author: Tio, Wee
• Other Authors: Darren Sun Delai
• Format: Thesis-Doctor of Philosophy
• Language: English
• Published: Nanyang Technological University 2023
• Subjects: Engineering::Environmental engineering
• Online Access: https://hdl.handle.net/10356/171621
• Institution: Nanyang Technological University

Engineered surface has demonstrated possibility of creating anti-fouling surfaces for separation and water purification. Through the modification of surface, it can alter the surface properties while retaining its intrinsic membrane selective features. Superwetting is well regarded for its functionality to allow quick water spreading on a substrate. Despite research effort to functionalize the surfaces, studies have yet to develop a multi-purpose solution for water filtration purposes. Yet the pursue for these functionalities to manage fouling tendency are still worth the effort. Multi-functionality serves as the inspiration to end the plaguing issues faced in membrane application. Exposure to oxidative and harsh chemical environment, growing microbial communities on the surface and adsorption of organic matters on the surface. This study focuses on the fabrication of highly porous membrane with super hydrophilicity and multi-functional properties using engineered nano-surfaces with metal and metal oxides. This was achieved through adaptation of classic cassie wetting theory, the incorporation of hydrophilic surfaces (metal or metal oxide) together with hierarchical nanostructure minimizes the gaps and therefore reduces resistance of tiny air pockets hinders wetting of the surface. This engineered surface to achieve the intended separation with anti-bacteria, anti-fouling, anti- oxidation and chemical free disinfection. The fabrication of polysulfone (PSf) nanofiber membrane and polyvinylidene fluoride (PVDF) were attempted and subsequently engineered with facile in-situ method to incorporate hydrophilic copper oxide, titanium dioxide, silver and hybrid silver-copper oxide nanostructures. This study has engineered 4 super-hydrophilic (Water Contact Angle <0º) membranes, with multiple functionality such as anti-bacterial, anti- oxidation, anti-fouling and possesses great resistance against chemicals. This has un-fold multiple facets of future membrane fabrication. The multi-functionalized nano-surfaces has reimagined the role of membrane separation water purification industry.