A series of 10 polythiophene derivatives is reported, in which each polymer has a different percentage of carboxylic acid‐bearing repeat units. The properties of these polymers are explored under acidic conditions, where the carboxylic acid moieties remain neutral, and under basic conditions, where the carboxylic acid units become anionic carboxylates. The properties that are examined for both solutions and films include UV–vis absorption spectroscopy, photoluminescence spectroscopy, and red‐edge optical band gaps. All the properties studied are strongly dependent both on protonation state and percentage of carboxylic acid/carboxylate side chains along the polymer backbone. The anionic form of each polythiophene derivative was also used in layer‐by‐layer film deposition with a cationic phosphonium polyelectrolyte. The film growth process was studied by spectroscopic techniques to assess the influence of side‐chain composition on the film growth and optical properties. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem.
The properties of phosphonium polyelectrolytes (PELs) were evaluated in an effort to assess the influence of both side chain and main chain composition. The influence of side chain was examined by comparing properties of a series of PELs having hydrophobic octyloxy side chains to those of structural analogues lacking the side chains. The influence exerted by backbone flexibility/length of spacer between charges was revealed by comparing properties of two series of polymers with a variable number of methylene units between phosphonium charge‐bearing sites. Side chain composition and spacing between phosphonium units lead to noteworthy influence on thermal stability, glass transition, and crystallinity. The molecular structure of PELs also correlates with trends in film morphology and critical surface energy of PEL dip‐cast films. Sensitivity of morphology to humidity or water in the casting solvent was observed. Supramolecular assembly of films via layer‐by‐layer deposition of PELs alternating with anionic polythiophene derivative layers was also undertaken. The linearity of film growth, amount of material deposited in each bilayer, polycation:polyanion ratio, and film roughness all show noteworthy trends that depend on both the presence/absence of side chains and on spacing between ionic centers. The relationship between side chain and spacer on bactericidal activity against
- PAR ID:
- 10463131
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Journal of Polymer Science Part A: Polymer Chemistry
- Volume:
- 57
- Issue:
- 1
- ISSN:
- 0887-624X
- Page Range / eLocation ID:
- p. 24-34
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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