Effects of surface charging treatment on outer and inner surfaces of a nanoporous carbon

Abstract

As the outer surface of a nanoporous carbon is treated with 16-mercaptohexadecanoic acid, the carbon particles can form a stable suspension in water. When the water phase is compressed, the liquid infiltration behavior in the nanopores becomes significantly different from that of untreated material, suggesting that the inner surface is also modified. After the treatment, the infiltration pressure does not decrease. Therefore, the surface-chain configurations at the inner and outer surfaces must be different, which explains the variations in infiltration pressure and volume.

Ion repelling effect of nanopores in a hydrophobic zeolite

“…Since formation of monopolar phase is prohibitively difficult, the motion of like-charged ions becomes the "bottleneck," suppressing the ion infiltration. 11 As the ion concentration in the bulk liquid phase increases, the zeta potential rises nonlinearly, slower than the rate of increase of the required energy barrier of ion repelling, and consequently, partial ion infiltration would occur.…”

“…The ZSM-5 was of a regular nanopore structure, with the effective pore size of about 0.7 nm. 11 According to a gas absorption analysis by using a TriStar-2000 Analyzer (Micromeritics, Norcross, GA), the porosity was 220 mm 3 /g; the Brunauer-Emmett-Teller surface area was around 400 m 2 /g. The particle size ranged from 5 to 20 lm.…”