Pacific Rim Symposium on Surfaces, Coatings and Interfaces (PacSurf 2018)
    Nanomaterials Monday Sessions
       Session NM-MoE

Paper NM-MoE5
Enhanced Photocatalytic Activity of Plasma-modified Electrospun PVA/TiO2 Nanocomposites

Monday, December 3, 2018, 7:00 pm, Room Naupaka Salon 5

Session: NanoCatalysis
Presenter: Arantxa Danielle Montallana, University of the Philippines
Authors: A.D. Montallana, University of the Philippines
A.P. Cristobal, University of the Philippines
B.Z. Lai, National Taiwan University of Science and Technology, Taiwan, Republic of China
J.P. Chu, National Taiwan University of Science and Technology, Taiwan, Republic of China
M.R. Vasquez, University of the Philippines
Correspondent: Click to Email
Poly(vinyl alcohol)/titanium oxide (PVA/TiO2) nanocomposites were successfully synthesized using the electrospinning method. 1% (w/v) <25 nm TiO2 nanoparticles (NP) were dispersed in 12% (w/v) PVA solution and was electrospun using the following parameters: V = 15 kV, tip-to-collector distance = 15 cm, and flow rate = 0.5 mL/hr. The nanofibers were collected on an aluminum foil mounted to a 3 in diameter grounded electrode rotating at ~850 rpm. Scanning electron microscopy images revealed a smooth and continuous fiber morphology with average fiber diameter of 281.84 ± 53.47 nm. Energy dispersive x-ray spectroscopy maps showed the dispersion of TiO2 NPs in the nanofiber mats (NFMs). Raman spectral analysis showed TiO2 peaks at 142.76, 394.64, 515.42, and 639.07 cm-1 confirming the integration of the NPs in the NFM. No changes were observed in the PVA peak at 2911.7 cm-1 after TiO2 NP loading, implying that the addition of TiO2 NPs did not alter the chemical composition of PVA and TiO2. The NFMs were irradiated with a 13.56 MHz radio frequency plasma system using oxygen gas for 1 min exposure time. Plasma exposure allowed the controlled etching of the nanofiber to expose the TiO2 NP on the surface. Using a 3 x 3 cm2 NFM, photodegradation of methylene blue (MB) as the test analyte under UV irradiation was conducted. UV-vis spectral analysis was used to monitor the change in concentration of MB. After 9 hr irradiation, pristine samples showed 83% removal of the dye while plasma-treated samples showed 90% removal rate. Using only TiO2 NP, 95% removal efficiency was achieved after 4 hr UV irradiation. However, use of NPs only for photodegradation is not advisable since it becomes difficult to collect and reuse the NPs. Thus, immobilizing the TiO2 NPs would allow reusability of the photocatalytic nanocomposites.