skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Assessing Chemical Transformation of Reactive, Interfacial Thin Films Made of End-Tethered Poly(2-vinyl-4,4-dimethyl azlactone) (PVDMA) Chains

Abstract

Designing thin films or surface scaffolds with an appropriate display of chemical functionality is useful for biomedical applications, sensing platforms, adhesives, and barrier coatings. Relationships between the structural characteristics of model thin films based on reactive poly(2-vinyl-4,4-dimethylazlactone) (PVDMA) brushes and the amount and distribution of primary amines used to chemically functionalize the layer in situ are quantitatively detailed via neutron reflectometry and compared with results from ellipsometry. After functionalization, the PVDMA brush thickness increases as a result of the primary amines reacting with the azlactone rings. Both techniques show that the extent of functionalization by small-molecule amines depends on the size of the amine, the grafting density of brush chains and their molecular weight. However, constrained analysis of neutron reflectivity data predicated on that technique’s sensitivity to isotopic substitution and its ability to resolve structure at the nanoscale, shows that the extent of functionalization is not accurately represented by the average extent of functionalization determined from ellipsometric thickness: reactive modification is not uniform, even in modestly dense brushes, except when the penetrant is small. Additionally, there appears to be a loss of PVDMA chains during functionalization, attributed to chain scission resulting from additional stretching brought about by functionalization. These findingsmore » provide unprecedented insight into the alteration of surface properties by reactive modification and broadly support efforts to produce tailored surfaces in which properties such as friction, colloidal stability, adhesion, wettability, and biocompatibility can be modulated in situ by chemical modification.« less

Authors:
 [1];  [1];  [2];  [2]; ORCiD logo [3]; ORCiD logo [4]; ORCiD logo [5]
  1. Univ. of Tennessee, Knoxville, TN (United States). Dept. of Chemistry
  2. Univ. of Tennessee, Knoxville, TN (United States). Dept. of Chemical and Biomolecular Engineering
  3. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Center for Nanophase Materials Science (CNMS)
  4. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Spallation Neutron Source (SNS)
  5. Univ. of Tennessee, Knoxville, TN (United States). Dept. of Chemistry; Univ. of Tennessee, Knoxville, TN (United States). Dept. of Chemical and Biomolecular Engineering
Publication Date:
Research Org.:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Org.:
USDOE; National Science Foundation (NSF)
OSTI Identifier:
1408017
DOE Contract Number:  
AC05-00OR22725
Resource Type:
Journal Article
Resource Relation:
Journal Name: Macromolecules; Journal Volume: 50; Journal Issue: 2
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY

Citation Formats

Aden, Bethany, Kite, Camille M., Hopkins, Benjamin W., Zetterberg, Anna, Lokitz, Bradley S., Ankner, John Francis, and Kilbey, S. Michael. Assessing Chemical Transformation of Reactive, Interfacial Thin Films Made of End-Tethered Poly(2-vinyl-4,4-dimethyl azlactone) (PVDMA) Chains. United States: N. p., 2017. Web. doi:10.1021/acs.macromol.6b01999.
Aden, Bethany, Kite, Camille M., Hopkins, Benjamin W., Zetterberg, Anna, Lokitz, Bradley S., Ankner, John Francis, & Kilbey, S. Michael. Assessing Chemical Transformation of Reactive, Interfacial Thin Films Made of End-Tethered Poly(2-vinyl-4,4-dimethyl azlactone) (PVDMA) Chains. United States. doi:10.1021/acs.macromol.6b01999.
Aden, Bethany, Kite, Camille M., Hopkins, Benjamin W., Zetterberg, Anna, Lokitz, Bradley S., Ankner, John Francis, and Kilbey, S. Michael. Tue . "Assessing Chemical Transformation of Reactive, Interfacial Thin Films Made of End-Tethered Poly(2-vinyl-4,4-dimethyl azlactone) (PVDMA) Chains". United States. doi:10.1021/acs.macromol.6b01999. https://www.osti.gov/servlets/purl/1408017.
@article{osti_1408017,
title = {Assessing Chemical Transformation of Reactive, Interfacial Thin Films Made of End-Tethered Poly(2-vinyl-4,4-dimethyl azlactone) (PVDMA) Chains},
author = {Aden, Bethany and Kite, Camille M. and Hopkins, Benjamin W. and Zetterberg, Anna and Lokitz, Bradley S. and Ankner, John Francis and Kilbey, S. Michael},
abstractNote = {Designing thin films or surface scaffolds with an appropriate display of chemical functionality is useful for biomedical applications, sensing platforms, adhesives, and barrier coatings. Relationships between the structural characteristics of model thin films based on reactive poly(2-vinyl-4,4-dimethylazlactone) (PVDMA) brushes and the amount and distribution of primary amines used to chemically functionalize the layer in situ are quantitatively detailed via neutron reflectometry and compared with results from ellipsometry. After functionalization, the PVDMA brush thickness increases as a result of the primary amines reacting with the azlactone rings. Both techniques show that the extent of functionalization by small-molecule amines depends on the size of the amine, the grafting density of brush chains and their molecular weight. However, constrained analysis of neutron reflectivity data predicated on that technique’s sensitivity to isotopic substitution and its ability to resolve structure at the nanoscale, shows that the extent of functionalization is not accurately represented by the average extent of functionalization determined from ellipsometric thickness: reactive modification is not uniform, even in modestly dense brushes, except when the penetrant is small. Additionally, there appears to be a loss of PVDMA chains during functionalization, attributed to chain scission resulting from additional stretching brought about by functionalization. These findings provide unprecedented insight into the alteration of surface properties by reactive modification and broadly support efforts to produce tailored surfaces in which properties such as friction, colloidal stability, adhesion, wettability, and biocompatibility can be modulated in situ by chemical modification.},
doi = {10.1021/acs.macromol.6b01999},
journal = {Macromolecules},
number = 2,
volume = 50,
place = {United States},
year = {Tue Jan 24 00:00:00 EST 2017},
month = {Tue Jan 24 00:00:00 EST 2017}
}