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Quasi-one-dimensional4Heinside carbon nanotubes

“…However, contrary to the situation for dilute classical gases [14][15][16], there are no many body calculations of quantum fluids inside nanotubes yet. In this work, we address the question of the quasi-one dimensionality of 4 He absorbed in a tube by a direct comparison between the results of diffusion Monte Carlo (DMC) for strictly 1D 4 He and 4 He inside a nanotube of radius equal to 3.42 A, which corresponds to a (5,5) armchair tube in the standard nomenclature [2].…”

Experimental probes of the molecular hydrogen–carbon nanotube interaction

“…Fig. 1(a)) as E B (channels)>E B (grooves)>E B (pores)>E B (surface) [1,2]. Access of molecules to the internal tube pores must either be through open SWNT ends or through defects (holes) in the tube walls.…”

“…As pointed out previously [5], O 2 -doped SWNTs are considered to be p-type because the chemisorbed O 2 acts as an acceptor. Theoretical calculations indicate that O 2 is present as O 2 Àd , d ¼ 0:1e [6]. The reason for the negative thermopower of the degassed mat is not well understood.…”

“…Although the geometrical surface area associated with the internal pore surface of a B1.4 nm diameter SWNT is B1350 m 2 /g, no one to our knowledge has reported values exceeding B400 m 2 /g for SWNT materials. 2 This indicates that the N 2 molecule is too large to gain access to many of these internal pores in a ''real'' material, despite the fact that the mean internal pore after selective oxidation/mild HCl reflux, followed by a heat treatment at 10001C in vacuum (10 À7 Torr) for 20 h, and (c) after selective oxidation followed by aggressive HNO 3 reflux, followed by a heat treatment at 10001C in vacuum (10 À7 Torr) for 20 h. diameter is B1 nm. As pointed out previously [14], this may be associated with carboxylic acid and other functional groups that are attached to Catoms present around holes in the tube walls, or at open tube ends.…”

Structure of a model one-dimensional liquid 3He–4He mixture

“…Our main motivation is to study the 1D liquid 3 He- 4 He mixture since a dilute solution of 3 He atoms in liquid 4 He form a fascinating quantum liquid as an example of interacting boson-fermion mixture [5]. There has been some experimental interest in 1D quantum liquids following the suggestion [6] and subsequent realization [7,8] of confining He in carbon nanotubes. On the theoretical side, the ground state properties of 1D liquid 4 He have recently been investigated by the variational hypernetted-chain calculations [9] and quantum Monte Carlo methods [10,11].…”