Self-assembly and Characterization of Polypyrrole and Polyallylamine Multilayer Films and Hollow Shells

Abstract

Conductive multilayer films have been fabricated from the alternating adsorption of the charged polymers, polypyrrole (PPy) and polyallylamine hydrochloride (PAH), on planar substrates as well as onto the surfaces of melamine formaldehyde (MF) microparticles based on the sequenced electrostatic layer-by-layer assembly technique. Hollow microcapsules are achieved after the removal of MF cores by dissolution in acid solution. The structure and conductive properties of the multilayer films and the hollow shells were characterized by UV−visible spectroscopy, phase contrast optical microscopy, atomic force microscopy, transmission electron microscopy, and scanning electron microscopy, respectively. The conductivity of all the composite films calculated from the measured resistivity is about 0.007 S/cm, which is comparable to other conductive polyelectrolyte films. The measurement of cyclic voltammetry showed that the PPy/PAH planar multilayer films, PPy/PAH-modified colloid particles, and hollow shells maintained their oxidative stability and electrochemical properties.

Layer-by-layer assemblies in nanoporous templates: nano-organized design and applications of soft nanotechnology

“…In particular, like AAO, track-etched polycarbonate (TEPC) membranes also exhibit straight, cylindrical nanopores and became widely utilized. 10 Release of the 1D nano-objects from the AAO or TEPC is simply accomplished by selective dissolution of the nanoporous matrix. Undoubtedly, the convenience and conceptual simplicity of the template method have given a decisive impetus to the development of a plethora of nanotubes and nanowires.…”

An effective layer-by-layer adsorption and polymerization method to the fabrication of polyoxometalate-polypyrrole nanoparticle ultrathin films

“…But it is still a challenge to fabricate PPy films and hence PPy nanoparticle ultrathin films. The reason for that may be PPy always exists in an intractable state and suffers from insolubility in most solvents and poor processability that is not satisfactory for practical application [12,[34][35][36][37][38][39][40][41].…”

Conductive Polypyrrole and Poly(allylamine hydrochloride) Nanotubes Fabricated with Layer‐by‐Layer Assembly

“…It is noted that the average thickness of each polyelectrolyte layer is around 1 nm. [11] The above obtained value is obvious larger. This may be because the diameter of the tubes is nearly in the range of the radius of gyration of the polyelectrolyte molecules.…”

“…[36] With the alternating current impedance measurements we have directly detected the conductivity of the (PAH/ PPy) 10 nanotubes as 0.008 S Á cm À1 , which is in good agreement with the results measured for the microcapsules and film constructed using the same materials, i.e., PAH and PPy. [11] In comparison to the electronic conductivity of the pure water-soluble polypyrrole, which is measured as 0.002 S Á cm À1 , the conductivity of the as-prepared (PAH/PPy) 10 nanotubes is four times greater. It should be noted that water-dispersed polypyrrole has an extreme low conductivity (10 À3 -10 À8 S Á cm À1 ).…”

“…Thus it is eventually combined with other flexible compounds to make complex materials, like multilayer films or microcapsules. [10,11] In view of this, a current challenge is now to synthesize various nanometerscale materials. Conductive PPy nanotubes would be of specific interest.…”