Jump to main content
Jump to site search
PLANNED MAINTENANCE Close the message box

Scheduled maintenance work on Wednesday 22nd May 2019 from 11:00 AM to 1:00 PM (GMT).

During this time our website performance may be temporarily affected. We apologise for any inconvenience this might cause and thank you for your patience.

Issue 48, 2018
Previous Article Next Article

Percolation behaviors of model carbon black pastes

Author affiliations


The percolation behaviors of a series of high-structured carbon black (CB) pastes (CB weight fractions 10–25 wt%, ethyl cellulose as the binder, α-terpineol as the solvent) were systematically investigated using analyses of rheology and impedance spectra together with characterization via small-angle X-ray scattering (SAXS) and scanning electron microscopy (SEM). When the CB concentration was near the static percolation threshold (∼20 wt%), the permittivity, ac conductance, and elastic modulus of the paste displayed notable increases, whereas the SAXS profile revealed the prevalence of isolated CB aggregates (mean radius of gyration ∼40 nm). Upon further aging at 25 and 40 °C (up to 6 h), two CB pastes near the static percolation threshold (i.e., 20 and 25 wt%) exhibited prominent temporally evolving responses, including more than tenfold increases in their ac conductance and elastic modulus, as well as a pronounced upturn in the low-q SAXS profile (q < 0.03 nm−1) and the formation of a (partially) interconnected cluster network in SEM observations of the morphologies of screen-printed films. In this case, we provide the first evidence of “(aging) Time-(relaxation) Time-Temperature-Concentration Superposition (TTTCS)” for the dynamic modulus data over a frequency range of seven orders of magnitude. This suggests that prolonged aging time imparted to CB aggregate interaction and restructuring (or gelation) may work in tandem with the known effects of the system temperature and concentration to further extend the accessible range of dynamic modulus data, in a similar way to recent reports on the effect of the curing (crosslinking) time on a carbon nanotube suspension and caramel. In combination with existing (three) master curves for two different colloidal materials, we show that there is a reasonable superposition of all the dynamic modulus data over a frequency range of 12 orders of magnitude.

Graphical abstract: Percolation behaviors of model carbon black pastes

Back to tab navigation

Supplementary files

Publication details

The article was received on 03 Aug 2018, accepted on 15 Oct 2018 and first published on 17 Oct 2018

Article type: Paper
DOI: 10.1039/C8SM01591K
Soft Matter, 2018,14, 9786-9797

  •   Request permissions

    Percolation behaviors of model carbon black pastes

    J. Jiang, R. Guo, Y. Chiu and C. Hua, Soft Matter, 2018, 14, 9786
    DOI: 10.1039/C8SM01591K

Search articles by author