For a hydrogel based on a zwitterionic dendritic surfactant, we report an apparently unprecedented reversible temperature-induced gel-to-gel phase transition below the melting point of its alkyl chains, where the supramolecular self-assembly of surfactant molecules underwent a dramatic transformation from low-temperature surfactant bilayers to high-temperature entangled surfactant worm-like micelles.
View Article and Find Full Text PDFThe release of double-stranded DNA from its interpolyelectrolyte complex with positively charged poly(allylamine hydrochloride) via exchange reaction with added polyanion, poly(sodium styrenesulfonate), is directly observed by fluorescence microscopy. It is shown that the pathways of DNA release depend essentially on the amount of added low-molecular-weight salt. At low salt content, the DNA release proceeds via the formation of an intermediate "beads-on-string" structure, whereas at high salt content the release goes directly from globule to coil states without any intermediate structures.
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