Water Adsorption Behavior on a Highly Dense Single-Walled Carbon Nanotube Film with an Enhanced Interstitial Space

Abstract

In this study, we describe the adsorption behavior of water (H 2 O) in the interstitial space of single-walled carbon nanotubes (SWCNTs). A highly dense SWCNT (HD-SWCNT) film with a remarkably enhanced interstitial space was fabricated through mild HNO 3 /H 2 SO 4 treatment. The N 2 , CO 2 , and H 2 adsorption isotherm results indicated remarkably developed micropore volumes (from 0.10 to 0.40 mL g –1 ) and narrower micropore widths (from 1.5 to 0.9 nm) following mild HNO 3 /H 2 SO 4 treatment, suggesting that the interstitial space was increased from the initial densely-packed network assembly structure of the SWCNTs. The H 2 O adsorption isotherm of the HD-SWCNT film at 303 K showed an increase in H 2 O adsorption (i.e., by ∼170%), which increased rapidly from the critical value of relative pressure (i.e., 0.3). Despite the remarkably enhanced adsorption capacity of H 2 O, the rates of H 2 O adsorption and desorption in the interstitial space did not change. This result shows an adsorption behavior different from that of the fast transport of H 2 O molecules in the internal space of the SWCNTs. In addition, the adsorption capacities of N 2 , CO 2 , H 2 , and H 2 O molecules in the interstitial space of the HD-SWCNT film showed a linear relationship with the kinetic diameter, indicating an adsorption behavior that is highly dependent on the kinetic diameter.

Hybrid 1D/2D nanocarbon-based conducting polymer nanocomposites for high-performance wearable electrodes

“…[20][21][22][23][24][25][26] In particular, CNTs allow easy interfacial engineering and selective control of structural properties even in solution-based processing via the introduction of various functional groups to the carbon atoms and surface defect sites. [27][28][29] Therefore, various studies have been conducted on transparent and flexible functional electrodes composed of CNT-based soft polymers. [30][31][32] Specifically, it is possible to establish a scalable solution-based process by controlling the CNT content of the non-porous network in the soft polymer and the strength of the interface between the polymer and CNTs functionalized with various functional groups.…”