(337bt) Surface Functionalization of Plastics with a Simultaneously Hydrophilic/Oleophobic Coating

Hydrophilic/oleophobic surfaces are desirable in many applications including self-cleaning, anti-fogging, oil-water separation, etc. However, making plastic surfaces hydrophilic/oleophobic is challenging due to the intrinsic hydrophobicity/oleophilicity of plastics. Here we report a simple and effective method making plastics hydrophilic/oleophobic. Plastics, including poly (methyl methacrylate) (PMMA), polystyrene (PS) and polycarbonate (PC), have been coated with a perfluoropolyether (PFPE) (i.e., commercially known as Zdol) via dip coating and then irradiated with UV/Ozone. The contact angle measurements indicate that the treated plastics have a lower water contact angle (WCA) and higher hexadecane contact angle (HCA), i.e., they are simultaneously hydrophilic/oleophobic. The Fourier transform infrared (FTIR) results suggest that UV/Ozone treatment introduces oxygen-containing polar groups on the plastic surfaces, which renders the plastic surfaces hydrophilic. Meanwhile, more orderly packed PFPE Zdol molecules, which is due to the UV-induced bonding between PFPE Zdol and the plastic surface, result in the oleophobicity. Moreover, the simultaneous hydrophilicity/oleophobicity of functionalized plastics does not degrade in aging tests, and they have superior anti-fogging performance and detergent-free cleaning capability. The simple method developed here potentially can be applied to other plastics and has important implications in the functionalization of plastic surfaces.

Ph.D. Research:

My research focuses on developing coatings with special surface wettability ranging from superhydrophobicity to simultaneous hydrophilicity/oleophobicity for different applications. For example, surface wettability plays an important role in membrane-based oil-water separation, Hydrophobic membranes always have limitations of oily fouling and required external energy, but simultaneously hydrophilic/oleophobic membranes are more promising because of their higher separation efficiency without applied external pressure. My previous research utilized a zwitterionic hydrogel coating to functionalize SLA-based 3D-printed membranes with simultaneous hydrophilicity/oleophobicity, which achieves ~100% oil-water separation without degradation of water filtration flux. The ongoing research for my Ph.D. thesis includes developing hydrophobic membranes on oral sorbents for chronic kidney disease, and tuning surface roughness for on demand wettability.

Research Interests:

Surface wettability, coatings, chemical vapor deposition, 3D-printing, surface engineering, nano-scale engineering, thin film characterization, membrane-based separation.

Representative Publications:

Song, Y.; Dunleavy, M.; Li, L. How to Make Plastic Surfaces Simultaneously Hydrophilic/Oleophobic? ACS Applied Materials & Interfaces https://doi.org/10.1021/acsami.3c06787

Song, Y.; Wang, B.; Altemose, P.; Kowall, C.; Li, L. 3D-Printed Membranes with a Zwitterionic Hydrogel Coating for More Robust Oil-Water Separation, Industrial & Engineering Chemistry Research, 59 (2020), 21058-21065