Incipient microphase separation in short chain perfluoropolyether-block-poly(ethylene oxide) copolymers
[1];
[4];
[2];
- Univ. of California, Berkeley, CA (United States). Dept. of Materials Science and Engineering; Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Materials Sciences Division
- Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Materials Sciences Division; Univ. of California, Berkeley, CA (United States). Dept. of Chemical and Biomolecular Engineering
- Univ. of North Carolina, Chapel Hill, NC (United States). Dept. of Chemistry
- Adam Mickiewicz Univ. in Poznań (Poland). Faculty of Physics. NanoBioMedical Centre
- Univ. of North Carolina, Chapel Hill, NC (United States). Dept. of Chemistry; North Carolina State Univ., Raleigh, NC (United States). Dept. of Chemical and Biomolecular Engineering
- Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Materials Sciences Division. Environmental Energy Technologies Division; Univ. of California, Berkeley, CA (United States). Dept. of Chemical and Biomolecular Engineering
Here, incipient microphase separation is observed by wide angle X-ray scattering (WAXS) in short chain multiblock copolymers consisting of perfluoropolyether (PFPE) and poly(ethylene oxide) (PEO) segments. Two PFPE–PEO block copolymers were studied; one with dihydroxyl end groups and one with dimethyl carbonate end groups. Despite having a low degree of polymerization (N ~ 10), these materials exhibited significant scattering intensity, due to disordered concentration fluctuations between their PFPE-rich and PEO-rich domains. The disordered scattering intensity was fit to a model based on a multicomponent random phase approximation to determine the value of the interaction parameter, χ, and the radius of gyration, Rg. Over the temperature range 30–90 °C, the values of χ were determined to be very large (~2–2.5), indicating a high degree of immiscibility between the PFPE and PEO blocks. In PFPE–PEO, due to the large electron density contrast between the fluorinated and non-fluorinated block and the high value of χ, disordered scattering was detected at intermediate scattering angles, (q ~ 2 nm-1) for relatively small polymer chains. Finally, our ability to detect concentration fluctuations was enabled by both a relatively large value of χ and significant scattering contrast.
- Research Organization:
- State Univ. of New York (SUNY), Syracuse, NY (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC), Basic Energy Sciences (BES)
- Grant/Contract Number:
- SC0012673; AC02-05CH11231
- OSTI ID:
- 1597269
- Alternate ID(s):
- OSTI ID: 1474994
- Journal Information:
- Soft Matter, Vol. 13, Issue 22; ISSN 1744-683X
- Publisher:
- Royal Society of ChemistryCopyright Statement
- Country of Publication:
- United States
- Language:
- English
Web of Science
Liquid-crystalline behavior and ion transport properties of block-structured molecules containing a perfluorinated ethylene oxide moiety complexed with a lithium salt
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journal | April 2018 |
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