The effects of iCVD film thickness and conformality on the permeability and wetting of MD membranes

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journal

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Author(s)

  • Amelia T. Servi
  • Elena Guillen-Burrieza
  • David M. Warsinger
  • William Livernois
  • Katie Notarangelo
  • John H. Lienhard V
  • Hassan A. Arafat
  • Karen K. Gleason

Detail(s)

Original languageEnglish
Pages (from-to)470-479
Number of pages10
Journal / PublicationJournal of Membrane Science
Volume523
Online published6 Oct 2016
Publication statusPublished - 1 Feb 2017
Externally publishedYes

Abstract

Membranes possessing high permeability to water vapor and high liquid entry pressure (LEP) are necessary for efficient membrane distillation (MD) desalination. A common technique to prepare specialized MD membranes consists of coating a hydrophilic or hydrophobic base membrane with a low surface-energy material. This increases its liquid entry pressure, making the membrane suitable for MD. However, in addition to increasing LEP, the surface-coating may also decrease permeability of the membrane by reducing its average pore size. In this study, we quantify the effects of initiated chemical vapor deposition (iCVD) polymer coatings on membrane permeability and LEP. We consider whether the iCVD films should have minimized thickness or maximized non-conformality, in order to maximize the permeability achieved for a given value of LEP. We determined theoretically that permeability of a single pore is maximized with a highly non-conformal iCVD coating. However, the overall permeability of a membrane consisting of many pores is maximized when iCVD film thickness is minimized. We applied the findings experimentally, preparing an iCVD-treated track-etched polycarbonate (PCTE) membrane and testing it in a permeate gap membrane distillation (PCMD) system. This study focuses on membranes with clearly defined, cylindrical pores. However, we believe that the principles we discuss will extend to membranes with more complex pore architectures. Overall, this work indicates that the focus of surface-coating development should be on minimizing film thickness, not on increasing their non-conformality.

Research Area(s)

  • Desalination, Dusty gas model, Initiated chemical vapor deposition (iCVD), Membrane distillation (MD), Track-etched polycarbonate (PCTE) membranes

Citation Format(s)

The effects of iCVD film thickness and conformality on the permeability and wetting of MD membranes. / Servi, Amelia T.; Guillen-Burrieza, Elena; Warsinger, David M.; Livernois, William; Notarangelo, Katie; Kharraz, Jehad; Lienhard V, John H.; Arafat, Hassan A.; Gleason, Karen K.

In: Journal of Membrane Science, Vol. 523, 01.02.2017, p. 470-479.

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journal