Separation of water-ethanol solutions with carbon nanotubes and electric fields

Winarto, Daisuke Takaiwa, Eiji Yamamoto, Kenji Yasuoka

Research output: Contribution to journalArticle

9 Citations (Scopus)

Abstract

Bioethanol has been used as an alternative energy source for transportation vehicles to reduce the use of fossil fuels. The separation of water-ethanol solutions from fermentation processes is still an important issue in the production of anhydrous ethanol. Using molecular dynamics simulations, we investigate the effect of axial electric fields on the separation of water-ethanol solutions with carbon nanotubes (CNTs). In the absence of an electric field, CNT-ethanol van der Waals interactions allow ethanol to fill the CNTs in preference to water, i.e., a separation effect for ethanol. However, as the CNT diameter increases, this ethanol separation effect significantly decreases owing to a decrease in the strength of the van der Waals interactions. In contrast, under an electric field, the energy of the electrostatic interactions within the water molecule structure induces water molecules to fill the CNTs in preference to ethanol, i.e., a separation effect for water. More importantly, the electrostatic interactions are dependent on the water molecule structure in the CNT instead of the CNT diameter. As a result, the separation effect observed under an electric field does not diminish over a wide CNT diameter range. Moreover, CNTs and electric fields can be used to separate methanol-ethanol solutions too. Under an electric field, methanol preferentially fills CNTs over ethanol in a wide CNT diameter range.

Original languageEnglish
Pages (from-to)33310-33319
Number of pages10
JournalPhysical Chemistry Chemical Physics
Volume18
Issue number48
DOIs
Publication statusPublished - 2016

Fingerprint

Carbon Nanotubes
ethyl alcohol
Ethanol
carbon nanotubes
Electric fields
electric fields
Water
water
Coulomb interactions
Molecules
Methanol
methyl alcohol
interactions
electrostatics
molecules
Bioethanol
fermentation
fossil fuels
energy sources
Fossil fuels

ASJC Scopus subject areas

  • Physics and Astronomy(all)
  • Physical and Theoretical Chemistry

Cite this

Separation of water-ethanol solutions with carbon nanotubes and electric fields. / Winarto; Takaiwa, Daisuke; Yamamoto, Eiji; Yasuoka, Kenji.

In: Physical Chemistry Chemical Physics, Vol. 18, No. 48, 2016, p. 33310-33319.

Research output: Contribution to journalArticle

@article{359a29f21282485f841aadd12635bf31,
title = "Separation of water-ethanol solutions with carbon nanotubes and electric fields",
abstract = "Bioethanol has been used as an alternative energy source for transportation vehicles to reduce the use of fossil fuels. The separation of water-ethanol solutions from fermentation processes is still an important issue in the production of anhydrous ethanol. Using molecular dynamics simulations, we investigate the effect of axial electric fields on the separation of water-ethanol solutions with carbon nanotubes (CNTs). In the absence of an electric field, CNT-ethanol van der Waals interactions allow ethanol to fill the CNTs in preference to water, i.e., a separation effect for ethanol. However, as the CNT diameter increases, this ethanol separation effect significantly decreases owing to a decrease in the strength of the van der Waals interactions. In contrast, under an electric field, the energy of the electrostatic interactions within the water molecule structure induces water molecules to fill the CNTs in preference to ethanol, i.e., a separation effect for water. More importantly, the electrostatic interactions are dependent on the water molecule structure in the CNT instead of the CNT diameter. As a result, the separation effect observed under an electric field does not diminish over a wide CNT diameter range. Moreover, CNTs and electric fields can be used to separate methanol-ethanol solutions too. Under an electric field, methanol preferentially fills CNTs over ethanol in a wide CNT diameter range.",
author = "Winarto and Daisuke Takaiwa and Eiji Yamamoto and Kenji Yasuoka",
year = "2016",
doi = "10.1039/c6cp06731j",
language = "English",
volume = "18",
pages = "33310--33319",
journal = "Physical Chemistry Chemical Physics",
issn = "1463-9076",
publisher = "Royal Society of Chemistry",
number = "48",

}

TY - JOUR

T1 - Separation of water-ethanol solutions with carbon nanotubes and electric fields

AU - Winarto,

AU - Takaiwa, Daisuke

AU - Yamamoto, Eiji

AU - Yasuoka, Kenji

PY - 2016

Y1 - 2016

N2 - Bioethanol has been used as an alternative energy source for transportation vehicles to reduce the use of fossil fuels. The separation of water-ethanol solutions from fermentation processes is still an important issue in the production of anhydrous ethanol. Using molecular dynamics simulations, we investigate the effect of axial electric fields on the separation of water-ethanol solutions with carbon nanotubes (CNTs). In the absence of an electric field, CNT-ethanol van der Waals interactions allow ethanol to fill the CNTs in preference to water, i.e., a separation effect for ethanol. However, as the CNT diameter increases, this ethanol separation effect significantly decreases owing to a decrease in the strength of the van der Waals interactions. In contrast, under an electric field, the energy of the electrostatic interactions within the water molecule structure induces water molecules to fill the CNTs in preference to ethanol, i.e., a separation effect for water. More importantly, the electrostatic interactions are dependent on the water molecule structure in the CNT instead of the CNT diameter. As a result, the separation effect observed under an electric field does not diminish over a wide CNT diameter range. Moreover, CNTs and electric fields can be used to separate methanol-ethanol solutions too. Under an electric field, methanol preferentially fills CNTs over ethanol in a wide CNT diameter range.

AB - Bioethanol has been used as an alternative energy source for transportation vehicles to reduce the use of fossil fuels. The separation of water-ethanol solutions from fermentation processes is still an important issue in the production of anhydrous ethanol. Using molecular dynamics simulations, we investigate the effect of axial electric fields on the separation of water-ethanol solutions with carbon nanotubes (CNTs). In the absence of an electric field, CNT-ethanol van der Waals interactions allow ethanol to fill the CNTs in preference to water, i.e., a separation effect for ethanol. However, as the CNT diameter increases, this ethanol separation effect significantly decreases owing to a decrease in the strength of the van der Waals interactions. In contrast, under an electric field, the energy of the electrostatic interactions within the water molecule structure induces water molecules to fill the CNTs in preference to ethanol, i.e., a separation effect for water. More importantly, the electrostatic interactions are dependent on the water molecule structure in the CNT instead of the CNT diameter. As a result, the separation effect observed under an electric field does not diminish over a wide CNT diameter range. Moreover, CNTs and electric fields can be used to separate methanol-ethanol solutions too. Under an electric field, methanol preferentially fills CNTs over ethanol in a wide CNT diameter range.

UR - http://www.scopus.com/inward/record.url?scp=85003633098&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85003633098&partnerID=8YFLogxK

U2 - 10.1039/c6cp06731j

DO - 10.1039/c6cp06731j

M3 - Article

AN - SCOPUS:85003633098

VL - 18

SP - 33310

EP - 33319

JO - Physical Chemistry Chemical Physics

JF - Physical Chemistry Chemical Physics

SN - 1463-9076

IS - 48

ER -