Formation and characterization of polyamide membranes via interfacial polymerization

Chai, G.-Y.; Krantz, William B.

doi:10.1016/0376-7388(94)80006-5

Cited by 225 publications

(153 citation statements)

References 12 publications

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“…This is consistent with the postulate that MPD-TMC polyamide thin films grow towards the organic phase [4,9]. The formation of bubble-like voids with equivalent asymmetric size distributions has been documented for other IP processes producing polyamide [44] and polyester [45] films that are, however, orders of magnitude thicker than MPD-TMC thin films.…”

Section: The Internal Morphology Of Fully Aromatic Polyamide Thin Filmssupporting

confidence: 77%

“…The presence of pores is the only other characteristic of back surfaces of MPD-TMC polyamide thin films that has been described [9][10][11][12][13]. We also observed pore openings routinely in our samples ( Fig.…”

Section: The Back Surface Of Fully Aromatic Polyamide Thin Filmssupporting

confidence: 60%

“…Previous studies of the back surface of polyamide thin films have highlighted its relative smoothness, but have not described nodules or any texture [8][9][10][11][12][13]. In our previous work [32], we referred to the bottom part of the thin film as a "nodular polyamide base" because of the presence of these small nodules.…”

Section: The Back Surface Of Fully Aromatic Polyamide Thin Filmsmentioning

confidence: 99%

“…Since the development of the FT-30 membrane, limited characterization work has been done on the morphology of back surfaces of MPD-TMC-based polyamide thin films [8][9][10][11][12][13]. Nevertheless, the presence of pores was confirmed consistently regardless of whether the thin films came from RO membranes (i.e., formed directly on porous supports) or whether they were made as stand-alone films.…”

Section: Introductionmentioning

confidence: 99%

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3D visualization of the internal nanostructure of polyamide thin films in RO membranes

Pacheco

Sougrat

Reinhard

et al. 2016

Journal of Membrane Science

165

123

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The front and back surfaces of fully aromatic polyamide thin films isolated from reverse osmosis (RO) membranes were characterized by TEM, SEM and AFM. The front surfaces were relatively rough showing polyamide protuberances of different sizes and shapes; the back surfaces were all consistently smoother with very similar granular textures formed by polyamide nodules of 20-50 nm. Occasional pore openings of approximately the same size as the nodules were observed on the back surfaces.Because traditional microscopic imaging techniques provide limited information about the internal morphology of the thin films, TEM tomography was used to create detailed 3D visualizations that allowed the examination of any section of the thin film volume. These tomograms confirmed the existence of numerous voids within the thin films and revealed structural characteristics that support the water permeance difference between brackish water (BWRO) and seawater (SWRO) RO membranes.Consistent with a higher water permeance, the thin film of the BWRO membrane ESPA3 contained relatively more voids and thinner sections of polyamide than the SWRO membrane SWC3. According to the tomograms, most voids originate near the back surface and many extend all the way to the front surface shaping the polyamide protuberances. Although it is possible for the internal voids to be connected to the outside through the pore openings on the back surface, it was verified that some of these voids comprise nanobubbles that are completely encapsulated by polyamide. TEM tomography is a powerful technique for investigating the internal nanostructure of polyamide thin films. A comprehensive knowledge of the nanostructural distribution of voids and polyamide sections within the thin film may lead to a better understanding of mass transport and rejection mechanisms in RO membranes.3

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Section: The Internal Morphology Of Fully Aromatic Polyamide Thin Filmssupporting

confidence: 77%

Section: The Back Surface Of Fully Aromatic Polyamide Thin Filmssupporting

confidence: 60%

Section: The Back Surface Of Fully Aromatic Polyamide Thin Filmsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

3D visualization of the internal nanostructure of polyamide thin films in RO membranes

Pacheco

Sougrat

Reinhard

et al. 2016

Journal of Membrane Science

165

123

View full text Add to dashboard Cite

show abstract

“…Yadav et al [9] used an on-line pH probe to follow the consumption of the aqueous monomer, since in their system, the reaction does not produce any species that changes the pH of the system. Chai and Krantz [23] proposed the techniques of light reflectometry and pendant drop tensiometry to follow the development of film thickness and rigidity. While these techniques have potential, they would need considerable refinement before quantitative information on kinetics can be obtained from them.…”

Section: Introductionmentioning

confidence: 99%