Electroless deposition of poly(2-alkoxyaniline)s

Incorporation of pyrene in polypyrrole/polystyrene magnetic beads

Pyrene, a fluorescent dye, was incorporated into polystyrene particles coated with polypyrrole. The incorporation was achieved by treating the polypyrrole/polystyrene (PPy/PS) beads in a tetrahydrofuran (THF) solution of the pyrene fluorophore followed by rinsing with methanol. The polystyrene cores of the beads swell in THF, allowing penetration of pyrene molecules into the polystyrene structure. The addition of methanol causes contraction of the swollen polystyrene, which encapsulates the dye molecules inside the beads. It is shown that the polypyrrole coating is permeable with respect to both the dye and the solvent, allowing the transport of molecules between the polystyrene cores and the contacting solution. The polypyrrole adlayer can be used as a matrix for the incorporation of magnetic nanoparticles. Embedded particles provide magnetic functionality to the PPy/PS beads. It is demonstrated that the pyrene-loaded beads can be manipulated with an external magnetic field.

Polymerization of aniline in the solutions of strong and weak acids: the evolution of infrared spectra and their interpretation using factor analysis

The progress of the oxidative polymerization of aniline with ammonium peroxydisulfate in an aqueous medium has been monitored in situ by attenuated total reflection Fourier transform infrared spectroscopy. The growth of polyaniline film at the crystal surface, as well as the changes proceeding in the surrounding aqueous medium, are reflected in the spectra. The evolution of the spectra during aniline polymerization in the presence of acetic or sulfuric acid was studied with the aim of understanding the influence of acidity on the observed morphology of the final polyaniline films, granular or nanotubes. The changes occurring during polymerization are discussed with the help of differential spectra. Several processes connected with the various stages of aniline oxidation, the evolution of film morphology, or protonation, were distinguished by using factor analysis applied to a large number of spectra obtained in the course of aniline polymerizations on the crystal.

Enhanced conductivity of thin film polyaniline by self-assembled transition metal complexes

In a recent study, the transition metal complex, cis-dichlorobis(2-,2'-dipyridyl)ruthenium (II) (Ru(bpy)2Cl2), and the macrocycle Ru(TPP)CO (TPP:- tetraphenylporphine) were bound to pyridine terminated self-assembled monolayers on quartz. Following modification of the quartz surface with metal complexes, the conducting polymer polyaniline was deposited via in situ polymerization. The sheet conductivity (as measured by the four-probe method) of the resulting polyaniline films deposited onto Ru(bpy)2Cl2 and Ru(TPP)CO surfaces was significantly enhanced relative to films deposited onto unmodified quartz. It is postulated that either the macrocycle or the transition metal complex-modified surface interacts with the conducting polymer as it is forming, resulting in a more ordered expanded coil conformation for the polymer. The net result of such an interaction is a thin film possessing significantly greater electrical conductivity.

Polymerization of 2-methylaniline and 2-methoxyaniline in water/pentane biphasic system

We report on chemical polymerization of two aniline derivatives - 2-methylaniline and 2-methoxyaniline -- in a two-phase water/pentane system. We have found that poly(2-methylaniline) is produced in form of an amorphous material regardless of the fact whether the monomer is initially dissolved in aqueous or organic phase. The behavior of 2-methoxyaniline is significantly different. The oxidation of this monomer generally results in formation of a water soluble oligomer and an insoluble polymeric product. In consequence, depending on the experimental setup, the polymer is prepared in form of a thin film at the organic/aqueous interface or as micrometer-sized spherical particles dispersed in the aqueous phase.

Photo-cross-linked Immobilization of Polyelectrolytes for Enzymatic Construction of Conductive Nanocomposites

Horseradish peroxidase has been demonstrated to catalyze the oxidative polymerization of aniline to form conductive polyaniline. This process is facilitated by the presence of a macromolecular template with sulfonic acid groups that provide a unique environment for the formation of the conducting polymer. Here we report the use of a photo-cross-linkable thymine-based polymer with phenylsulfonate groups as a templating substrate. This allows for an aqueous-based environmentally benign photopatterning of a conductive material. A description and results of this process are presented.