TY - JOUR
T1 - Effect of quantum partial charges on the structure and dynamics of water in single-walled carbon nanotubes
AU - Won, Chang Y.
AU - Joseph, Sony
AU - Aluru, N. R.
N1 - Funding Information:
The authors would like to thank Dr. J. H. Park for many helpful discussions. This research was supported by NSF under Grant Nos. 0120978 (the Water CAMPWS Center at UIUC), 0325344, 0328162 (the nano-CEMMS Center at UIUC), and 0523435 and by NIH under Grant No. PHS 2 PN2 EY016570B.
PY - 2006
Y1 - 2006
N2 - In this work, using quantum partial charges, computed from 6-31G**/B3LYP density functional theory, in molecular dynamics simulations, we found that water inside (6,6) and (10,0) single-walled carbon nanotubes with similar diameters but with different chiralities has remarkably different structural and dynamical properties. Density functional calculations indicate that tubes with different chiralities have significantly different partial charges at the ends of tubes. The partial charges at the ends of a (10,0) tube are around 4.5 times higher than those of a (6,6) tube. Molecular dynamics simulations with the partial charges show different water dipole orientations. In the (10,0) tube, dipole vectors of water molecules at the end of the tube point towards the water reservoir resulting in the formation of an L defect in the center region. This is not observed in the (6,6) tube where dipole vectors of all the water molecules inside the tube point towards either the top or the bottom water reservoir. The water diffusion coefficient is found to increase in the presence of the partial charges. Water in the partially charged (10,0) tube has a lower diffusion coefficient compared to that of in the partially charged (6,6) tube.
AB - In this work, using quantum partial charges, computed from 6-31G**/B3LYP density functional theory, in molecular dynamics simulations, we found that water inside (6,6) and (10,0) single-walled carbon nanotubes with similar diameters but with different chiralities has remarkably different structural and dynamical properties. Density functional calculations indicate that tubes with different chiralities have significantly different partial charges at the ends of tubes. The partial charges at the ends of a (10,0) tube are around 4.5 times higher than those of a (6,6) tube. Molecular dynamics simulations with the partial charges show different water dipole orientations. In the (10,0) tube, dipole vectors of water molecules at the end of the tube point towards the water reservoir resulting in the formation of an L defect in the center region. This is not observed in the (6,6) tube where dipole vectors of all the water molecules inside the tube point towards either the top or the bottom water reservoir. The water diffusion coefficient is found to increase in the presence of the partial charges. Water in the partially charged (10,0) tube has a lower diffusion coefficient compared to that of in the partially charged (6,6) tube.
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U2 - 10.1063/1.2338305
DO - 10.1063/1.2338305
M3 - Article
C2 - 16999495
AN - SCOPUS:33749018220
SN - 0021-9606
VL - 125
JO - Journal of Chemical Physics
JF - Journal of Chemical Physics
IS - 11
M1 - 114701
ER -