betadex and dodecyltrimethylammonium

A novel synthesis of "hairy urchin"-shaped polyaniline (PAni) and its surface coverage with nanospikes was achieved from a simple microemulsion polymerization technique in the presence of β-cyclodextrin (β-CD). The rodlike micelle phase was characterized, and the key factors affecting the formation of PAni nanostructures were systematically examined. Ferric chloride (FeCl(3)) has played a role as a structural directing agent to fabricate the polymer as hairy urchin-like structure/nanorods via a cooperative interaction between FeCl(3) and DoTAC in an aqueous medium. Host-guest inclusion complex of β-cyclodextrin with aniline was used as a monomer. It has been revealed that the formation of the supramolecular complexes of polyaniline with β-CD due to host-guest interaction is indispensable for the fabrication of these unique PAni nanostructures, and a suitable β-CD to aniline molar ratio is essential to their exclusive formation. Different varieties of PAni nanostructures such as hairy urchin, branched particles consisting of rodlike branches, and regular rodlike particles were obtained in the presence of FeCl(3). Also, in the absence of FeCl(3), a predominant product of regular spherical particles and wirelike aggregation exhibiting faceted surfaces were obtained. The structures of polyaniline hairy urchin-like nanorods were analyzed using transmission electron microscopy (TEM). The synthesized polymer was characterized by Fourier-transform infrared spectroscopy and X-ray diffraction technique. Additionally, the relationship between the morphology and the conductivity of the PAni nanostructures was investigated as well.

Topics: Aniline Compounds; beta-Cyclodextrins; Chlorides; Ferric Compounds; Micelles; Nanostructures; Particle Size; Quaternary Ammonium Compounds; Surface Properties; Surface-Active Agents

Controlled synthesis of well-defined planar Au nanodendrites with a symmetric single-crystalline structure consisting of trunks and side branches grown along the 211 directions was realized by reducing chloroauric acid in aqueous mixed solutions of dodecyltrimethylammonium bromide (DTAB) and beta-cyclodextrin (beta-CD). It has been revealed that the formation of the supramolecular complexes of DTAB with beta-CD due to host-guest interaction is indispensable for the fabrication of these unique planar Au nanodendrites, and a proper CD-to-DTAB molar ratio is essential to their exclusive formation. A variety of Au nanostructures, such as branched particles consisting of rodlike branches and flowerlike particles consisting of platelike petals, could be readily obtained by simply changing the CD-to-DTAB molar ratio. Moreover, the obtained Au nanodendrites exhibited both a good electrocatalytic activity toward the oxidation of methanol and a good surface-enhanced Raman scattering (SERS) sensitivity for detecting p-aminothiophenol (PATP) molecules, indicating their potential applications including catalysis, biosensing, and nanodevices.

Topics: beta-Cyclodextrins; Dendrimers; Gold; Macromolecular Substances; Metal Nanoparticles; Particle Size; Quaternary Ammonium Compounds; Surface Properties; Surface-Active Agents

Polyelectrolyte complexes have been elaborated by mixing in water neutral poly(beta-CD), a cationic surfactant (DTAC) and herring sperm DNA fragments. The driving forces for the poly(beta-CD)/DTAC/DNA association in aqueous solution are, on the one hand, reversible inclusion interactions between the CD cavities of poly(beta-CD) and the alkyl group of DTAC, leading to the formation of a polycation and, on the other hand, electrostatic interactions between the opposite charges of the cationic surfactant and anionic DNA. Viscometry and SANS have been used to prove the occurrence of such ternary complexes in dilute aqueous solutions.

Topics: beta-Cyclodextrins; Carbohydrate Sequence; Cations; DNA; Gene Transfer Techniques; Molecular Sequence Data; Propylene Glycols; Quaternary Ammonium Compounds; Rheology; Solutions; Static Electricity; Surface-Active Agents; Water