Youssry M, Kamand FZ, Magzoub MI, Nasser MS. Aqueous dispersions of carbon black and its hybrid with carbon nanofibers.
RSC Adv 2018;
8:32119-32131. [PMID:
35547476 PMCID:
PMC9086548 DOI:
10.1039/c8ra05446k]
[Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2018] [Accepted: 09/12/2018] [Indexed: 11/21/2022] Open
Abstract
The aqueous dispersions of a special type of carbon black (CB) in 1 M lithium bis(trifluoromethanesulfonimide) electrolyte is mainly controlled by the affinity of the aqueous electrolyte towards the CB particles rather than the particle size. In spite of its small particle size (30 nm), this type of CB forms a three-dimensional open network which is rheologically and electrically percolated at a relatively high threshold (2.0 wt%) with enhanced rheological and electrical properties. At this percolating threshold, replacing a trace amount of CB with equivalent carbon nanofibers (CNFs) produces hybrid dispersions with higher electrical conductivity and comparable rheological behavior to pure CB dispersions. This hybrid dispersion is dominated by a cooperatively supporting network, which is wired by the flexible filamentous nanofibers so that it is able to recover the conductivity loss under flow conditions due to flow-induced breaking up of the conductive pathways of CB and presumably sustain a higher load of active materials. This finding suggests hybrid dispersions as a promising precursor in the formulation of electrode suspensions for aqueous semi-solid redox flow cells.
Optimal hybrid dispersion of carbon black (CB) and nanofibers (CNFs) is formed at a critical content of CNFs before its aggregation concentration so that CNFs wire CB aggregates to recover the conductivity loss without increasing of CB rigidity.![]()
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