Nanostructure formation in polyelectrolyte-surfactant complexes: Gel collapse and morphology.

摘要

The interaction of slightly cross-linked positively charged gels of poly-acrylamid-co-(diallyldimethylammonium chloride) (PDADMACl) with sodium iodide and n-alkyl sulfates (octyl-(SOS), nonyl-(SNS), decyl-(SDCS), undecyl-(SUS), dodecyl-(SDS), tetradecyl-(STS), and hexadecyl-(SHS) sulfates) in aqueous media has been investigated. A phase transition of the polymer network in the collapsed state was observed for NaI and for all of the surfactants.;The PDADMACl gel-surfactant complexes, except for the gel-SOS complex, but not gel - I;The PDADMACl gel-SOS, -SNS, -SDCS, -SUS and -SDS complexes were also studied at different temperatures. The gel-SOS complex, which does not otherwise exhibit crystallinity, was successfully crystallized at approximately ;Gel complexes of mixed SDCS-SDS surfactants were also studied with SAXS. It was observed that the mixed surfactants crystallized together forming a multitude of crystalline phases gradually changing from cubic (SDCS) to hexagonal (SDS) as the composition of the mixture was changed from SDCS to SDS.;Anionic linear polymers-cationic surfactant complexes were also tested in order to show that the crystalline structure formation was due to a combination of electrostatic and hydrophobic interactions and was not affected by the charge polarity. The crystalline structure formation was observed in acrylamide - hydroxamate - acrylate copolymer/cetylpyridinium bromide complexes.