Search arXivSearch

arXiv · 0812.1473

Water transport inside a single-walled carbon nanotube driven by temperature gradient

Abstract

In this work, by means of molecular dynamics simulations, we consider mass transport of a water cluster inside a single-walled carbon nanotube (SWNT) with the diameter of about 1.4 nm. The influence of the non-equilibrium thermal environment on the confined water cluster has been investigated by imposing a longitudinal temperature gradient to the SWNT. It is demonstrated that the water cluster is transported with the average acceleration proportional to the temperature gradient. Additional equilibrium simulations suggest that the temperature dependence of the potential energy of the confined water is sufficient to realize the transport. Particularly for the system with hydrophobic interface, the water-water intrinsic potential energy appears to play a dominant role. The transport simulations were also performed for a system with a junction between two different SWNTs. The results suggest that an angstrom difference in diameter may result in large barrier for water transported through a small diameter SWNT.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Junichiro Shiomi, Shigeo Maruyama. 2008-12-08. Water transport inside a single-walled carbon nanotube driven by temperature gradient. https://doi.org/10.1088/0957-4484%2F20%2F5%2F055708

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

Microscopic Understanding of Thermal-magnon Transport in a Low-damping Ferrimagnetic Thin Films

Thermally generated magnons enable heat-driven spin transport in magnetic insulators, yet the relative importance of multiple microscopic mechanisms governing their propagation remains incompletely understood. Here, we investigate thermal magnon transport in low-damping Li$_{0.5}$Al$_{1.0}$Fe$_{1.5}$O$_4$/Pt nanodevices using a nonlocal spin Seebeck geometry that separates magnon transport from local thermoelectric effects. Thermal imaging establishes a detector region outside the thermal healing length, enabling intrinsic nonlocal measurements. We find that thermal magnon transport is strongly suppressed by magnetic fields far above saturation, and further that thermal magnon transport decreases with increasing temperature despite an increasing magnon population. Brillouin light scattering reveals the key microscopic mechanism driving this effect: increasing field reduces the group velocity of backward volume magnons, directly reducing the magnon spin diffusion length. Micromagnetic simulations reproduce this behavior only when a temperature-dependent exchange stiffness is included. These results identify magnon group velocity and exchange stiffness as key parameters governing thermal magnon transport in ferrimagnetic thin films.

cond-mat.other

Intrinsic excitations and a proposed ground state in an Ammann-Beenker artificial spin ice

Artificial spin ices built on quasiperiodic geometries remain under-explored. Here we investigate an ASI based on the octagonal Ammann-Beenker tiling, whose six vertex types present local environments inaccessible in periodic lattices. Combining Monte Carlo simulations of dipolar-coupled macrospins with micromagnetic calculations of individual vertex energies, we find that vertex types freeze in an order set not by coordination number, but by quasi-degenerate levels at five-island vertices and their local environment. Excitations in the low energy state are correspondingly localised to specific, geometrically determined sites. Using twice-inflated substitution rules as an energetic backbone, we propose an analytical ground state combining a long-range ordered fixed spin network with a sparse set of degenerate regions.

cond-mat.other

Transport properties and topological phase transitions for a Creutz-Su-Schrieffer-Heeger ladder

In this work, we investigate the electronic, topological, and transport properties of a Creutz-Su-Schrieffer-Heeger (CSSH) ladder. Using a tight-binding model within the Green's function formalism, we calculate the energy spectrum, local density of states (LDOS), and electronic transmission. We first determine the energy spectrum of the CSSH ladder and analyze the different topological phases present in the system, identifying one trivial phase and three distinct nontrivial regions. We then study electronic transport and show that the transmission reproduces the different topological phases through characteristic transport signatures. Finally, we derive the conditions for the emergence of non-topological flat bands and demonstrate that these bands also provide the necessary conditions for the formation of bound states in the continuum (BICs). Our results establish a direct connection between the topological properties, flat-band formation, and electronic transport in the CSSH ladder.

cond-mat.other