Functionalized and postfunctionalizable porous polymeric films through evaporation-induced phase separation using mixed solvents

Ashok Zachariah Samuel, S. Umapathy, S. Ramakrishnan

Research output: Contribution to journalArticle

15 Citations (Scopus)

Abstract

Condensation of water droplets during rapid evaporation of a polymer solution, under humid conditions, has been known to generate uniformly porous polymer films. Similar porous films are also formed when a solution of the polymer in THF containing small amounts of water, is allowed to evaporate rapidly under air flow; this suggests that water droplets may be formed during the final stages of film formation. In the presence of added surfactants, the interface of water droplets could become lined with the surfactants and consequently the internal walls of the pores generated, upon removal of the water, could become decorated with the hydrophilic head groups of the surfactant molecules. In a series of carefully designed experiments, we have examined the effect of added surfactants, both anionic and cationic, on the formation of porous PMMA films; the films were prepared by evaporating a solution of the polymer in THF containing controlled amounts of aqueous surfactant solutions. We observed that the average size of the pores decreases with increasing surfactant concentration, while it increases with increasing amounts of added water. The size of the pores and their distribution were examined using AFM and IR imaging methods. Although IR imaging possessed inadequate resolution to confirm the presence of surfactants at the pore surface, exchange of the inorganic counterion, such as the sodium-ion of SDS, with suitable ionic organic dyes permitted the unequivocal demonstration of the presence of the surfactants at the interface by the use of confocal fluorescence microscopy.

Original languageEnglish
Pages (from-to)3293-3299
Number of pages7
JournalACS Applied Materials and Interfaces
Volume3
Issue number9
DOIs
Publication statusPublished - 2011 Sep 28
Externally publishedYes

Fingerprint

Polymer films
Surface-Active Agents
Phase separation
Evaporation
Surface active agents
Water
Infrared imaging
Polymers
Anionic surfactants
Confocal microscopy
Cationic surfactants
Fluorescence microscopy
Polymethyl Methacrylate
Polymer solutions
Condensation
Coloring Agents
Demonstrations
Dyes
Sodium
Ions

Keywords

  • atomic force microscope
  • confocal fluorescence
  • IR imaging
  • PMMA
  • porous membranes
  • surfactant

ASJC Scopus subject areas

  • Materials Science(all)

Cite this

Functionalized and postfunctionalizable porous polymeric films through evaporation-induced phase separation using mixed solvents. / Samuel, Ashok Zachariah; Umapathy, S.; Ramakrishnan, S.

In: ACS Applied Materials and Interfaces, Vol. 3, No. 9, 28.09.2011, p. 3293-3299.

Research output: Contribution to journalArticle

@article{400f923a744247d4969ef3990e424e15,
title = "Functionalized and postfunctionalizable porous polymeric films through evaporation-induced phase separation using mixed solvents",
abstract = "Condensation of water droplets during rapid evaporation of a polymer solution, under humid conditions, has been known to generate uniformly porous polymer films. Similar porous films are also formed when a solution of the polymer in THF containing small amounts of water, is allowed to evaporate rapidly under air flow; this suggests that water droplets may be formed during the final stages of film formation. In the presence of added surfactants, the interface of water droplets could become lined with the surfactants and consequently the internal walls of the pores generated, upon removal of the water, could become decorated with the hydrophilic head groups of the surfactant molecules. In a series of carefully designed experiments, we have examined the effect of added surfactants, both anionic and cationic, on the formation of porous PMMA films; the films were prepared by evaporating a solution of the polymer in THF containing controlled amounts of aqueous surfactant solutions. We observed that the average size of the pores decreases with increasing surfactant concentration, while it increases with increasing amounts of added water. The size of the pores and their distribution were examined using AFM and IR imaging methods. Although IR imaging possessed inadequate resolution to confirm the presence of surfactants at the pore surface, exchange of the inorganic counterion, such as the sodium-ion of SDS, with suitable ionic organic dyes permitted the unequivocal demonstration of the presence of the surfactants at the interface by the use of confocal fluorescence microscopy.",
keywords = "atomic force microscope, confocal fluorescence, IR imaging, PMMA, porous membranes, surfactant",
author = "Samuel, {Ashok Zachariah} and S. Umapathy and S. Ramakrishnan",
year = "2011",
month = "9",
day = "28",
doi = "10.1021/am200735t",
language = "English",
volume = "3",
pages = "3293--3299",
journal = "ACS applied materials & interfaces",
issn = "1944-8244",
publisher = "American Chemical Society",
number = "9",

}

TY - JOUR

T1 - Functionalized and postfunctionalizable porous polymeric films through evaporation-induced phase separation using mixed solvents

AU - Samuel, Ashok Zachariah

AU - Umapathy, S.

AU - Ramakrishnan, S.

PY - 2011/9/28

Y1 - 2011/9/28

N2 - Condensation of water droplets during rapid evaporation of a polymer solution, under humid conditions, has been known to generate uniformly porous polymer films. Similar porous films are also formed when a solution of the polymer in THF containing small amounts of water, is allowed to evaporate rapidly under air flow; this suggests that water droplets may be formed during the final stages of film formation. In the presence of added surfactants, the interface of water droplets could become lined with the surfactants and consequently the internal walls of the pores generated, upon removal of the water, could become decorated with the hydrophilic head groups of the surfactant molecules. In a series of carefully designed experiments, we have examined the effect of added surfactants, both anionic and cationic, on the formation of porous PMMA films; the films were prepared by evaporating a solution of the polymer in THF containing controlled amounts of aqueous surfactant solutions. We observed that the average size of the pores decreases with increasing surfactant concentration, while it increases with increasing amounts of added water. The size of the pores and their distribution were examined using AFM and IR imaging methods. Although IR imaging possessed inadequate resolution to confirm the presence of surfactants at the pore surface, exchange of the inorganic counterion, such as the sodium-ion of SDS, with suitable ionic organic dyes permitted the unequivocal demonstration of the presence of the surfactants at the interface by the use of confocal fluorescence microscopy.

AB - Condensation of water droplets during rapid evaporation of a polymer solution, under humid conditions, has been known to generate uniformly porous polymer films. Similar porous films are also formed when a solution of the polymer in THF containing small amounts of water, is allowed to evaporate rapidly under air flow; this suggests that water droplets may be formed during the final stages of film formation. In the presence of added surfactants, the interface of water droplets could become lined with the surfactants and consequently the internal walls of the pores generated, upon removal of the water, could become decorated with the hydrophilic head groups of the surfactant molecules. In a series of carefully designed experiments, we have examined the effect of added surfactants, both anionic and cationic, on the formation of porous PMMA films; the films were prepared by evaporating a solution of the polymer in THF containing controlled amounts of aqueous surfactant solutions. We observed that the average size of the pores decreases with increasing surfactant concentration, while it increases with increasing amounts of added water. The size of the pores and their distribution were examined using AFM and IR imaging methods. Although IR imaging possessed inadequate resolution to confirm the presence of surfactants at the pore surface, exchange of the inorganic counterion, such as the sodium-ion of SDS, with suitable ionic organic dyes permitted the unequivocal demonstration of the presence of the surfactants at the interface by the use of confocal fluorescence microscopy.

KW - atomic force microscope

KW - confocal fluorescence

KW - IR imaging

KW - PMMA

KW - porous membranes

KW - surfactant

UR - http://www.scopus.com/inward/record.url?scp=84856432889&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84856432889&partnerID=8YFLogxK

U2 - 10.1021/am200735t

DO - 10.1021/am200735t

M3 - Article

VL - 3

SP - 3293

EP - 3299

JO - ACS applied materials & interfaces

JF - ACS applied materials & interfaces

SN - 1944-8244

IS - 9

ER -