Temperature-dependent gas transport performance of vertically aligned carbon nanotube/parylene composite membranes

Lei Zhang, Junhe Yang, Xianying Wang, Bin Zhao, Guangping Zheng

Research output: Journal article publicationJournal articleAcademic researchpeer-review

13 Citations (Scopus)

Abstract

A novel composite membrane consisting of vertically aligned carbon nanotubes (CNTs) and parylene was successfully fabricated. Seamless filling of the spaces in CNT forests with parylene was achieved by a low-pressure chemical vapor deposition (CVD) technique and followed with the Ar/O2plasma etching to expose CNT tips. Transport properties of various gases through the CNT/parylene membranes were explored. And gas permeances were independent on feed pressure in accordance with the Knudsen model, but the permeance values were over 60 times higher than that predicted by the Knudsen diffusion kinetics, which was attributed to specular momentum reflection inside smooth CNT pores. Gas permeances and enhancement factors over the Knudsen model firstly increased and then decreased with rising temperature, which confirmed the existence of non-Knudsen transport. And surface adsorption diffusion could affect the gas permeance at relatively low temperature. The gas permeance of the CNT/parylene composite membrane could be improved by optimizing operating temperature.
Original languageEnglish
JournalNanoscale Research Letters
Volume9
Issue number1
DOIs
Publication statusPublished - 1 Jan 2014

Keywords

  • Carbon nanotube
  • Composite membrane
  • Gas transport
  • Parylene

ASJC Scopus subject areas

  • Materials Science(all)
  • Condensed Matter Physics

Cite this