Linking interfacial energies with proton conductivity in sulfonated poly (ether ether ketone) nanocomposite

Autor: Ahmad Mousavi Shoushtari, Mohammad Karimi, Zahra Esmaeilzadeh, Mehran Javanbakht
Rok vydání: 2021
Předmět:
Zdroj: Polymer. 230:124067
ISSN: 0032-3861
DOI: 10.1016/j.polymer.2021.124067
Popis: So far, numerous studies have been conducted to enhance the proton conductivity of sulfonated poly (ether ether ketone) (SPEEK) as a proton exchange membrane (PEM) by incorporating nanofillers. However, the role of the filler-matrix interface in the proton conduction process has been inadequately understood. Herein, the SPEEK nanocomposite of polydopamine coated multi-walled carbon nanotube (P@MWCNT) was successfully fabricated and characterized by field emission electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDS), Raman spectroscopy, thermogravimetric analysis (TGA), and Fourier-transform infrared spectroscopy (FTIR). The physicochemical properties revealed that the dimensional stability of nanocomposite was improved by 32% compared to the SPEEK due to lower water uptake. Moreover, the proton conductivity of SPEEK was significantly enhanced to 0.064 S cm−1 by adding 3.5% of P@MWCNTs. The contribution of the interface of P@MWCNT-SPEEK to proton conduction was explored through an innovative approach based on the interfacial energies. By polydopamine modification, the surface free energy (SFE) of nanotubes increased from 23.6 mJ/m2 to 29.4 mJ/m2, and the interfacial energy of SPEEK-P@MWCNT augmented by 192%. These findings suggest that due to the increase of interfacial energy between the P@MWCNTs and polymer chains, the transfer of protons along with the interface region of nanofiller and matrix is an acceptable mechanism.
Databáze: OpenAIRE
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