Molecular Potential Structures of Heat-Treated Single-Wall Carbon Nanohorn Assemblies

Abstract

The microporosity of the heat-treated single-wall carbon nanohorn (SWNH) particles is characterized by nitrogen adsorption at 77 K and the molecular potential calculation using the function, which is based on the Lennard-Jones pair potential. The depth difference of the molecular potential for N 2 between the SWNH intraparticle pore and the interparticle space is close to 1000 K. Although the SWNH without the heattreatment has no open intra-nanohorn space, the intraparticle pores open with the high-temperature treatment in O 2 . The heat-treatment at 693 K opens almost perfectly the intraparticle pores, leading to 0.47 mL g -1 of the micropore volume and 1010 m 2 g -1 of the specific surface area. The subtraction of the N 2 adsorption isotherm of the SWNH from that of the SWNH treated at 693 K gave the N 2 adsorption isotherm only in the intraparticle pore spaces. The adsorption sites derived from the difference adsorption isotherm are assigned to the pores having different interaction potentials.

Highly Ultramicroporous Single‐Walled Carbon Nanohorn Assemblies

“…[15] Earlier results also showed that heat treatment of SWNHs in O 2 at 693 K opens the SWNHs almost perfectly, and a micropore volume of 0.47 mL g ±1 and a specific surface area of 1010 m 2 g ±1 were obtained. [16] This result suggests that there is a limitation in microporosity enhancement by only opening the nanohorns. Therefore, it is necessary to control the interstitial pores as well as internal pores, in order to obtain more highly microporous SWNH assemblies.…”

Fabrication of ZnPc/protein nanohorns for double photodynamic and hyperthermic cancer phototherapy

“…To avoid the aggregation, we loaded ZnPc onto SWNHox, a novel drug carrier. SWNHox is graphitic tubule with a diameter of 2-5 nm and lengths of 40-50 nm (2) that have a relatively large inner space (24,25) suitable for carrying drugs. Thousands of SWNHox partially coalesce to form an 80-to 100-nm spherical aggregate (2), and this aggregate is expected to have enhanced permeability and retention properties (26,27) that make SWNHox effective for passive delivery of drugs to tumors.…”

Effect of nanoscale curvature sign and bundle structure on supercritical H2 and CH4 adsorptivity of single wall carbon nanotube

“…Figure 10 shows the interaction potential profiles of SWCNT with CH4 and H2 using moleculenanopore interaction potential using the established potential functions for carbon cylinder of an infinite length. (Tjatjopoulos et al 1988;Murata et al 2001). …”