POS3-1540
High-Pressure CO₂ Texturing of PMMA/CQD/Ti₃C₂Tₓ Composite Films: Surface Hydrophobicity and Retained Sensing Function
Topic
S3. Processing / Fabrications (Emerging Horizons in Polymer Processing and Fabrication)
When and Where
Sep 30, 2026
08:30 - 09:30
Room 301 (Grand Ballroom)
Session Chairs
Heesuk KIM
Jinhye BAE
Presenter(s)
Shih Han Wang (Department of Chemical and Materials Engineering, National Yunlin University of Science and Technology)
Co-Author(s)
Abstract
A PMMA/CQD/Ti₃C₂Tₓ composite film was developed to combine reversible gas sensing, charge transport, and resistance to water-vapor interference. High-pressure CO₂ treatment was applied to modify the morphology and hydrophobicity of the composite surface. The initially compact film developed a rough and porous structure, with the degree of surface texturing depending on the processing temperature. After CO₂ treatment, the apparent water contact angle increased to above 100°, indicating a marked reduction in surface wettability. This change may be associated with the lower water affinity of the composite surface and partial retention of air within the newly formed surface features. More extensive processing, however, did not improve the sensing response. Films subjected to severe processing showed a marked loss of sensing function, whereas a milder treatment retained reversible chemiresistive behavior and stable operation over wide range of relative humidity. The selected composite responded to ppb-level formaldehyde at 30 °C. These results show that pore formation, hydrophobicity, gas transport, and electrical function must be considered together when processing porous polymer/ Ti₃C₂Tₓ films for formaldehyde gas sensing.
