Nanostructured films with electrical conductivity in the semiconductor region were prepared in a polymeric matrix of poly(vinyl alcohol) (PVA) with nanostructures of chitosan-gold nanoparticles (AuNPs)/single-wall carbon nanotubes carboxylic acid functionalized (SWCNT-COOH) (chitosan-AuNPs/SWCNT-COOH) self-assembled. Dispersion light scattering (DLS) was used to determine the average particle sizes of chitosan-AuNPs, -average particle size () and number average particle size (), and the formation of crystalline domains of AuNPs was demonstrated by X-ray diffraction (XRD) patterns and observed by means of transmission electron microscopy (TEM). The electrostatic interaction was verified by Fourier transform infrared spectroscopy (FTIR).
View Article and Find Full Text PDFThe interactions of proteins and other molecules and their adsorption onto substrates is a fascinating topic that has been applied to surface technologies, biosensors, corrosion studies, biotechnologies, and other fields. The success of these applications requires a previous characterization using some analytical techniques that, ordinarily, are not electrochemical. This work proposes analyzing the variation of the double-layer capacitance obtained through impedance electrochemical spectroscopy as an alternative strategy to show evidence of the interactions between proteins and triblock copolymers.
View Article and Find Full Text PDFThe kinetics of the sphere-to-rod transition was studied in aqueous micelle solutions of triblock copolymer poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) pluronic P103 (PEO(17)PPO(60)PEO(17)). This transition was triggered by a temperature jump from the sphere phase to the rod phase and monitored with dynamic light scattering. The combination of the scattering intensity and the hydrodynamic radius were used to show that the micelles grow steadily as rods throughout the growth process.
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