Novel Effects of Surface Modification on Activated Carbon Fibers Using a Low Pressure Plasma Treatment

Abstract

Activated carbon fibers (ACFs) were surface modified with oxygen plasma at low pressure. The novel effects of the plasma treatment on the microstructural properties of the ACFs were characterized using the Brunauer, Emmett, and Teller method and scanning electron microscopy. Micropores developed on the ACFs. Moreover, the specific surface area and micropore volume increased by 10% at a certain plasma treatment time and power. The changes in the structural properties of the ACFs are discussed in detail with the respect of plasma etching. X-ray photoelectron spectroscopy revealed new oxygen-containing groups, such as CsO, CdO, and OsCdO, had formed on the surface of the ACFs after plasma treatment. Plasma surface oxidative reactions such as the generation of radicals, the combination of the radicals and active oxygen species in the plasma chamber, and the generation of the various oxygen-containing groups are believed to have occurred. The effect of the plasma treatment parameters such as plasma treatment time and power was examined from the perspective of both surface structure and chemistry. It was observed that the micropores and surface functionalities of the ACFs were increased under moderate treatment conditions (50 s and 100 W).

Oxygen/Carbon Ratio Effects on Surface-Modified Carbon Nanotubes

“…These peaks are identified as C−C at 283.7 eV, C−O at 285.2 eV, C=O at 286.7 eV, O−C=O at 288.6 eV, and π−π* shake up bonds at 290.7 eV. Similar results were reported by Tang et al, claiming that oxygen-containing functional groups were created on the surface of activated carbon fibers by oxygen plasma treatment [18]. The distributions of the binding functional groups are listed in Table 1, which were calculated by integrating the peak area.…”

Microwave‐based treatments for multi‐walled carbon nanotubes

“…It is likely that increasing the exposure time of samples to the high temperature and plasma conditions causes the destruction of other unsaturated moieties, and this leads to a decrease in number of carbonyl and carboxylic acid groups by protonizing them with active H radicals (and thus more hydroxyl functionalities). The high concentration of sp 3 -hybridized carbon concentration in plasma treated samples indicates the destruction of the π-conjugation, followed by transformation to the amorphous carbon phase, the same effect is reported other plasma-based modification methods for carbon nanotubes [15,16]. …”

A Chromium Discharge Minimizing Tanning Technology Assisted by O2 Low Temperature Plasma

“…It is believed that there must be oxidation reaction which adds surface functionality and introduces more oxygen containing groups such as carboxyl, carbonyl and hydroxyl to the treated substrate. The C1s peak was fitted with four peaks, including C-C (284.6), C-O (286.1), C=O (287.6) and O-C=OH (288.6 eV) [13] as is shown in Fig. 4.…”