Titanium Dioxide/Phosphorous-Functionalized Cellulose Acetate Nanocomposite Membranes for DMFC Applications: Enhancing Properties and Performance

Randa E Khalifa; Ahmed M Omer; Mohamed H Abd Elmageed; Mohamed S Mohy Eldin

doi:10.1021/acsomega.1c00568

Titanium Dioxide/Phosphorous-Functionalized Cellulose Acetate Nanocomposite Membranes for DMFC Applications: Enhancing Properties and Performance

ACS Omega. 2021 Jul 1;6(27):17194-17202. doi: 10.1021/acsomega.1c00568. eCollection 2021 Jul 13.

Authors

Randa E Khalifa¹, Ahmed M Omer¹, Mohamed H Abd Elmageed², Mohamed S Mohy Eldin¹

Affiliations

¹ Polymer Materials Research Department, Advanced Technologies and New Materials Research Institute (ATNMRI), City of Scientific Research and Technological Applications (SRTA-City), New Borg El-Arab City, P.O. Box 21934, Alexandria 21934, Egypt.
² Chemical Engineering Department, Faculty of Engineering, Alexandria University, Alexandria 21544, Egypt.

Abstract

This study intends to provide new TiO₂/phosphorous-functionalized cellulose acetate (Ph-CA) nanocomposite membranes for direct methanol fuel cells (DMFCs). A series of TiO₂/Ph-CA membranes were fabricated via solution casting technique using a systematic variation of TiO₂ nanoparticle content. Chemical structure, morphological changes, and thermal properties of the as-fabricated nanocomposite membranes were investigated by FTIR, TGA, SEM, and AFM analysis tools. Further, membranes' performance, mechanical properties, water uptake, thermal-oxidative stability, and methanol permeability were also evaluated. The results clarified that the ion-exchange capacity (IEC) of the developed nanocomposite membranes improved and reached a maximum value of 1.13 and 2.01 m_eq/g at 25 and 80 °C, respectively, using TiO₂ loading of 5 wt % compared to 0.6 and 0.81 m_eq/g for pristine Ph-CA membrane at the same temperature. Moreover, the TiO₂/Ph-CA nanocomposite exhibited excellent thermal stability with appreciable mechanical properties (49.9 MPa). The developed membranes displayed a lower methanol permeability of 0.98 × 10^-16 cm² s^-1 compared to 1.14 × 10^-9 cm² s^-1 for Nafion 117. The obtained results suggested that the developed nanocomposite membranes could be potentially applied as promising polyelectrolyte membranes for possible use in DMFCs.