Hydration Contributions to Association in Polyelectrolyte Multilayers and Complexes: Visualizing Hydrophobicity.
Thin films of polyelectrolyte complex were assembled using the multilayering method with direct, in situ observation of all multilayer components using attenuated total internal reflectance FTIR (AIR-FTIR). Buildup and ion doping of two representative combinations of positive and negative polyelectr...
| Publicado en: | Journal of the American Chemical Society Vol. 130; no. 41; pp. 13589 - 13598 |
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| Autores principales: | , , |
| Formato: | Artículo |
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American Chemical Society
10/15/2008
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| Acceso en línea: | Ver este registro en EBSCOhost |
| fields | @attributes: recordID: 1 pdfLink: plink: https://search.ebscohost.com/login.aspx?direct=true&db=hlh&AN=34936249&site=ehost-live header: @attributes: shortDbName: hlh uiTerm: 34936249 longDbName: Humanities International Complete uiTag: AN controlInfo: bkinfo: jinfo: jid: 00027863 ACS jtl: Journal of the American Chemical Society issn: 00027863 maglogo: N pubinfo: dt: 10/15/2008 vid: 130 iid: 41 pid: 997 pub: American Chemical Society artinfo: ui: 34936249 10.1021/ja802054k ppf: 13589 ppct: 9 formats: tig: atl: Hydration Contributions to Association in Polyelectrolyte Multilayers and Complexes: Visualizing Hydrophobicity. aug: au: Schlenoff, Joseph B. Rmaile, Amir H. Bucur, Claudiu B. affil: Department of Chemistry and Biochemistry, The Florida State University, Tallahassee, Florida 32306 su: Inorganic chemistry Polyelectrolytes Electrolytes Polymers Ions sug: subj: Inorganic chemistry Polyelectrolytes Electrolytes Polymers Ions ab: Thin films of polyelectrolyte complex were assembled using the multilayering method with direct, in situ observation of all multilayer components using attenuated total internal reflectance FTIR (AIR-FTIR). Buildup and ion doping of two representative combinations of positive and negative polyelectrolytes are controlled by salt type. The internal hydration of multilayers, measured precisely by ATR-FTIR, depends on the chemical identities of the polymers and the salt ions. The efficiency of doping inversely tracks the degree of hydration: less hydrated ("hydrophobic") ions are more efficient dopants, and less hydrated polyelectrolye complexes are harder to dope. Given that polyelectrolyte complexation is essentially entropy-driven, driving forces for doping, or association (the inverse of doping), are rationalized by counting all species in the condensed polyelectrolyte phase, including water molecules. For any combination of uni-univalent salt ions and polyelectrolyte, the strength of polyelectrolyte association is described by a single universal parameter. The magnitudes of the interactions per repeat unit are not high—a few kT—and are proportional to the number of water molecules released from the polymers when they form ion pairs. Hydration within multilayers due to residual salt is extensive but may be removed by an external osmotic stressing agent. pubtype: Academic Journal doctype: Article src: R language: English refInfo: copyright: @attributes: flag: Y dt: @attributes: year: 2008 holdings: @attributes: islocal: N |
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