Fast and clean functionalization of MWCNTs by DBD plasma and its influence on mechanical properties of C–epoxy composites

Abstract

Multiwalled carbon nanotubes (MWCNTs) were functionalized under helium/air plasma and the surface characteristics were compared with that of chemical functionalization. Changes in surface functional groups of MWCNTs due to plasma/chemical treatment were estimated by using temperature programmed decomposition (TPD), elemental analysis, Raman spectroscopy and BET surface area analysis. Raman spectroscopic studies highlighted that chemical functionalization increases the degree of disorder for MWCNTs when compared to plasma treatment. TPD also confirmed that air plasma treatment leads to the highest number of acidic groups on the surface that decomposes to evolve carbon dioxide. The modified MWCNTs were used as additional reinforcements to fabricate carbon fiber reinforced plastics (CFRPs). It has been observed that air plasma treated MWCNTs improved the tensile and flexural strength of C-epoxy composites significantly as compared to conventional chemical functionalization, whereas the best performance of air plasma treated MWCNTs is due to higher acid functional groups on the surface, which improves interface compatibility between the MWCNTs to the epoxy matrix.

Plasma functionalization of carbon nanotubes and radical penetration mechanism

“…[ 22,23 ] Plasma functionalization has several advantages over wet chemical functionalization, including shorter treatment times, reduced damage to the CNT structure and reduced environmental impact as no wastewater is produced. [ 24,25 ]…”

“…[22,23] Plasma functionalization has several advantages over wet chemical functionalization, including shorter treatment times, reduced damage to the CNT structure and reduced environmental impact as no wastewater is produced. [24,25] Many studies have been conducted to optimize the conditions (e.g., applied power, process pressure, and gas type) for plasma functionalization. [26][27][28] However, achieving functionalization in the deepest regions of CNTs within a suitable treatment time for industrial applications has not been reported previously.…”

Improvement of carbon nanotube dispersion in electrospun polyacrylonitrile fiber through plasma surface modification

“…So far, different CVD strategies, such as initiated CVD (iCVD) and plasma‐enhanced CVD (PECVD), have been employed to modify CNT surfaces. Previously, it was reported that PECVD‐modified CNTs show better interface compatibility with an epoxy matrix, compared to those with chemical functionalization . In another study, CNTs were modified by PECVD to improve their dispersion capability in water …”

“…matrix, compared to those with chemical functionalization. 22 In another study, CNTs were modified by PECVD to improve their dispersion capability in water. 23 In this study, CNTs were encapsulated with poly(hexafluorobutyl acrylate) (PHFBA) thin films by PECVD.…”

Long‐lasting oil wettability patterns fabrication on superoleophobic surfaces by atmospheric pressure DBD plasma jet

“…Compared with bare electrode discharge, the electrodes of dielectric barrier discharge (DBD) are covered or separated by dielectrics, therefore resulting in their different characteristics. During the past decade, atmospheric pressure DBD plasma treatment of polymers and silicon has been widely studied [9,[21][22][23][24][25][26], while that of metal substrates still requires further research. Bónová et al [27] reported that APPJ generated by DBD could hydrophilise flat aluminium surfaces within 1 s, which is much more efficient than APPJ generated by bare electrode discharge.…”