Orientation of Thin Polyamide Layer-by-Layer Films on Non-Porous Substrates

Tawanda J. Zimudzi; Sarah E. Sheffield; Kathleen E. Feldman; Peter A. Beaucage; Dean M. DeLongchamp; Douglas I. Kushner; Christopher M. Stafford; Michael A. Hickner

doi:10.1021/acs.macromol.1c02109

Orientation of Thin Polyamide Layer-by-Layer Films on Non-Porous Substrates

Tawanda J. Zimudzi, Sarah E. Sheffield, Kathleen E. Feldman, Peter A. Beaucage, Dean M. DeLongchamp, Douglas I. Kushner, Christopher M. Stafford, Michael A. Hickner

Research output: Contribution to journal › Article › peer-review

3 Scopus citations

Abstract

The orientation of polyamide thin films on non-porous substrates was investigated using Fourier transform infrared (FTIR) spectroscopy and corroborated by near-edge X-ray absorption fine structure (NEXAFS) measurements. Polyamide films composed of m-phenylene diamine and trimesoyl chloride were synthesized via a layer-by-layer deposition process on both gold and silicon substrates, where the number of sequential monomer deposition steps (cycles) determines the overall polyamide film thickness. These films represent model materials for metrology development that can be applied to understand the selective polyamide layers in reverse osmosis (RO) membranes. Using the fingerprint region in the infrared spectrum for the m-phenylene diamine-trimesoyl chloride (MPD-TMC) system, peaks were identified that could be used as diagnostic modes for molecular orientation analysis. At extremely low cycle numbers, FTIR measurements suggest that the MPD-derived aromatic rings exhibited a tilt angle of ∼6° from the surface parallel, while the carbonyl group of the amide was similarly oriented with an average tilt angle of ∼17°. The FTIR insights are in agreement with NEXAFS results, which indicate that the aromatic rings in the first-half layer-by-layer cycle are oriented parallel to the surface. Both FTIR and NEXAFS measurements further show high anisotropy in the materials at low cycle numbers. As the films approach 60 cycles (∼13 nm films), the films become isotropic and no orientation was detected.

Original language	English (US)
Pages (from-to)	11296-11303
Number of pages	8
Journal	Macromolecules
Volume	54
Issue number	24
DOIs	https://doi.org/10.1021/acs.macromol.1c02109
State	Published - Dec 28 2021

All Science Journal Classification (ASJC) codes

Organic Chemistry
Polymers and Plastics
Inorganic Chemistry
Materials Chemistry

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10.1021/acs.macromol.1c02109

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@article{f20516ad0db74376aa68ecd253d6141c,

title = "Orientation of Thin Polyamide Layer-by-Layer Films on Non-Porous Substrates",

abstract = "The orientation of polyamide thin films on non-porous substrates was investigated using Fourier transform infrared (FTIR) spectroscopy and corroborated by near-edge X-ray absorption fine structure (NEXAFS) measurements. Polyamide films composed of m-phenylene diamine and trimesoyl chloride were synthesized via a layer-by-layer deposition process on both gold and silicon substrates, where the number of sequential monomer deposition steps (cycles) determines the overall polyamide film thickness. These films represent model materials for metrology development that can be applied to understand the selective polyamide layers in reverse osmosis (RO) membranes. Using the fingerprint region in the infrared spectrum for the m-phenylene diamine-trimesoyl chloride (MPD-TMC) system, peaks were identified that could be used as diagnostic modes for molecular orientation analysis. At extremely low cycle numbers, FTIR measurements suggest that the MPD-derived aromatic rings exhibited a tilt angle of ∼6° from the surface parallel, while the carbonyl group of the amide was similarly oriented with an average tilt angle of ∼17°. The FTIR insights are in agreement with NEXAFS results, which indicate that the aromatic rings in the first-half layer-by-layer cycle are oriented parallel to the surface. Both FTIR and NEXAFS measurements further show high anisotropy in the materials at low cycle numbers. As the films approach 60 cycles (∼13 nm films), the films become isotropic and no orientation was detected.",

author = "Zimudzi, {Tawanda J.} and Sheffield, {Sarah E.} and Feldman, {Kathleen E.} and Beaucage, {Peter A.} and DeLongchamp, {Dean M.} and Kushner, {Douglas I.} and Stafford, {Christopher M.} and Hickner, {Michael A.}",

note = "Funding Information: T.J.Z. would like to thank Ian T. McCrum for helpful advice about the execution of DFT simulations. K.E.F. and P.A.B. acknowledge financial support from the National Research Council through the Research Associateship Program. Publisher Copyright: {\textcopyright} 2021 American Chemical Society",

year = "2021",

month = dec,

day = "28",

doi = "10.1021/acs.macromol.1c02109",

language = "English (US)",

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journal = "Macromolecules",

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T1 - Orientation of Thin Polyamide Layer-by-Layer Films on Non-Porous Substrates

AU - Zimudzi, Tawanda J.

AU - Sheffield, Sarah E.

AU - Feldman, Kathleen E.

AU - Beaucage, Peter A.

AU - DeLongchamp, Dean M.

AU - Kushner, Douglas I.

AU - Stafford, Christopher M.

AU - Hickner, Michael A.

N1 - Funding Information: T.J.Z. would like to thank Ian T. McCrum for helpful advice about the execution of DFT simulations. K.E.F. and P.A.B. acknowledge financial support from the National Research Council through the Research Associateship Program. Publisher Copyright: © 2021 American Chemical Society

PY - 2021/12/28

Y1 - 2021/12/28

N2 - The orientation of polyamide thin films on non-porous substrates was investigated using Fourier transform infrared (FTIR) spectroscopy and corroborated by near-edge X-ray absorption fine structure (NEXAFS) measurements. Polyamide films composed of m-phenylene diamine and trimesoyl chloride were synthesized via a layer-by-layer deposition process on both gold and silicon substrates, where the number of sequential monomer deposition steps (cycles) determines the overall polyamide film thickness. These films represent model materials for metrology development that can be applied to understand the selective polyamide layers in reverse osmosis (RO) membranes. Using the fingerprint region in the infrared spectrum for the m-phenylene diamine-trimesoyl chloride (MPD-TMC) system, peaks were identified that could be used as diagnostic modes for molecular orientation analysis. At extremely low cycle numbers, FTIR measurements suggest that the MPD-derived aromatic rings exhibited a tilt angle of ∼6° from the surface parallel, while the carbonyl group of the amide was similarly oriented with an average tilt angle of ∼17°. The FTIR insights are in agreement with NEXAFS results, which indicate that the aromatic rings in the first-half layer-by-layer cycle are oriented parallel to the surface. Both FTIR and NEXAFS measurements further show high anisotropy in the materials at low cycle numbers. As the films approach 60 cycles (∼13 nm films), the films become isotropic and no orientation was detected.

AB - The orientation of polyamide thin films on non-porous substrates was investigated using Fourier transform infrared (FTIR) spectroscopy and corroborated by near-edge X-ray absorption fine structure (NEXAFS) measurements. Polyamide films composed of m-phenylene diamine and trimesoyl chloride were synthesized via a layer-by-layer deposition process on both gold and silicon substrates, where the number of sequential monomer deposition steps (cycles) determines the overall polyamide film thickness. These films represent model materials for metrology development that can be applied to understand the selective polyamide layers in reverse osmosis (RO) membranes. Using the fingerprint region in the infrared spectrum for the m-phenylene diamine-trimesoyl chloride (MPD-TMC) system, peaks were identified that could be used as diagnostic modes for molecular orientation analysis. At extremely low cycle numbers, FTIR measurements suggest that the MPD-derived aromatic rings exhibited a tilt angle of ∼6° from the surface parallel, while the carbonyl group of the amide was similarly oriented with an average tilt angle of ∼17°. The FTIR insights are in agreement with NEXAFS results, which indicate that the aromatic rings in the first-half layer-by-layer cycle are oriented parallel to the surface. Both FTIR and NEXAFS measurements further show high anisotropy in the materials at low cycle numbers. As the films approach 60 cycles (∼13 nm films), the films become isotropic and no orientation was detected.

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U2 - 10.1021/acs.macromol.1c02109

DO - 10.1021/acs.macromol.1c02109

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VL - 54

SP - 11296

EP - 11303

JO - Macromolecules

JF - Macromolecules

IS - 24

ER -

Orientation of Thin Polyamide Layer-by-Layer Films on Non-Porous Substrates

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