title: Nanometer-scale decomposition of ultrathin multilayered polyelectrolyte films.
abstract: We report that ultrathin multilayered films fabricated from plasmid DNA and synthetic polyamines undergo nanometer-scale transformations that resemble spinodal decomposition when incubated in aqueous media. The patterns and structures generated by this transformation are similar to those observed for the spinodal dewetting of thin films of conventional polymers. This behavior has not, however, been observed for this class of multilayered assemblies, for which long-range electrostatic interactions play significant roles in governing film structure and stability. We demonstrate that it is possible to promote this behavior, prevent it, or control it by varying polymer structure, film composition, or the conditions to which these materials are exposed. These results suggest the basis of methods that could prove useful for the generation of nanostructure on complex surfaces and contribute to methods for the localized delivery of DNA from surfaces.
authors.affiliation: Department of Chemical and Biological Engineering, University of Wisconsin-Madison, 1415 Engineering Drive, Madison, WI 53706, USA.
authors.forename: Nathaniel J
authors.initials: NJ
authors.lastname: Fredin
authors.forename: Jingtao
authors.initials: J
authors.lastname: Zhang
authors.forename: David M
authors.initials: DM
authors.lastname: Lynn
mesh_terms: D002627:Chemistry, Physical / Q000379:methods; D004247:DNA / Q000737:chemistry*; D004563:Electrochemistry / Q000379:methods*; D004573:Electrolytes / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D018625:Microscopy, Atomic Force; D008855:Microscopy, Electron, Scanning; D008956:Models, Chemical; D010957:Plasmids / Q000378:metabolism*; D011108:Polymers / Q000737:chemistry; D055672:Static Electricity; D013499:Surface Properties
chemical_list: D004573:Electrolytes; D011108:Polymers; D004247:DNA