The microporosity of the heat-treated single-wall carbon nanohorn (SWNH) pa
rticles is characterized by nitrogen adsorption at 77 K and the molecular p
otential calculation using the function, which is based on the Lennard-Jone
s pair potential. The depth difference of the molecular potential for N-2 b
etween the SWNH intraparticle pore and the interparticle space is close to
1000 K. Although the SWNH without the heat-treatment has no open intra-nano
hom space, the intraparticle pores open with the high-temperature treatment
in O-2. The heat-treatment at 693 K opens almost perfectly the intrapartic
le 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 iso
therm of the SWNH from that of the SWNH treated at 693 K gave the N-2 adsor
ption isotherm only in the intraparticle pore spaces. The adsorption sites
derived from the difference adsorption isotherm are assigned to the pores h
aving different interaction potentials.