https://tore.tuhh.de/bitstream/11420/394/1/Article_5._free.pdf

A review and analysis of electrical percolation in carbon nanotube polymer composites

Polyaniline nanostructures and the role of aniline oligomers in their formation

With the aim of fabricating multifunctional fibers with enhanced mechanical properties, electrical conductivity and electrochemical performance, we develop wet-spinning of composite formulation based on functionalized PEG-SWNT and PEDOT:PSS. The method of addition and loading are directly correlated to the quality and the ease of spinnability of the formulation and to the mechanical and electrical properties of the resultant fibers. Both the fiber modulus (Y) and strength (σ) scaled linearly with PEG-SWNT volume fraction (Vf). A remarkable reinforcement rate of dY/dVf = 417 GPa and dσ/dVf = 4 GPa were obtained when PEG-SWNTs at Vf ≤ 0.02. Further increase of PEG-SWNTs loading (i.e. up to Vf 0.12) resulted in further enhancements up to 22.8 GPa and 254 MPa in Modulus and ultimate stress, respectively. We also show the enhancement of electrochemical supercapacitor performance of composite fibers. These outstanding mechanical, electrical and electrochemical performances place these fibers among the best performing multifunctional composite fibers.

/pdf/wet-spinning-of-pedot-pss-functionalized-swnts-composite-a-3h84976vdq.pdf

Wet-spinning of PEDOT:PSS/Functionalized-SWNTs Composite: a Facile Route Toward Production of Strong and Highly Conducting Multifunctional Fibers

Seeding a conventional chemical oxidative polymerization of aniline with even very small amounts of biological, inorganic, or organic nanofibers (usually <1%) dramatically changes the morphology of the resulting doped electronic polymer polyaniline from nonfibrillar (particulate) to almost exclusively nanofibers. The nanoscale morphology of the original seed template is transcribed almost quantitatively to the bulk precipitate. These findings could have immediate impact in the design and development of high-surface area electronic materials.

/pdf/synthesis-of-polyaniline-nanofibers-by-nanofiber-seeding-1oh6cjxdjd.pdf

Synthesis of Polyaniline Nanofibers by “Nanofiber Seeding”

Recent advances in polyaniline research: Polymerization mechanisms, structural aspects, properties and applications

Polyaniline is one of the most important conducting and responsive polymers. A molecular mechanism for the oxidation of aniline is proposed. This mechanism explains the specific features of aniline oligomerization and polymerization in various acidity ranges. The formation of polyaniline precipitates, colloids and thin films is reviewed and discussed on the basis of the chemistry of aniline oxidation. The generation of nanostructures, i.e. granules, nanotubes, nanowires and microspheres, is also considered. Oligomers containing phenazine constitutional units play an important role in self-assembly to form templates. Polyaniline chains then grow from these templates and produce the various individual morphologies. Copyright © 2008 Society of Chemical Industry

The mechanism of the oxidative polymerization of aniline and the formation of supramolecular polyaniline structures

The genesis of polyaniline nanotubes

Multi-wall carbon nanotubes coated with polyaniline

The courses of aniline oxidation with ammonium peroxydisulfate in aqueous solutions of strong (sulfuric) and in weak (acetic) acids, followed by temperature and acidity changes, are different. In solutions of sulfuric acid, granular polyaniline (PANI) was produced; in solutions of acetic acid, PANI nanotubes were obtained. The external diameter of the nanotubes was 100–300 nm, the internal cavity 20–100 nm, and the length extended to several micrometres. The morphology of PANI, granular or tubular, depends on the acidity conditions during the reaction rather than on the chemical nature of the acid. PANI nanotubes were also produced when aniline was oxidized in the absence of any acid. The bulk conductivity of PANI prepared in solutions of acetic acid was 0.08–0.27 S cm−1, depending on the acid concentration. Protonated PANI prepared in sulfuric and acetic acids were deprotonated with ammonium hydroxide to obtain PANI bases and the ammonium salt of the protonating acid. FTIR spectroscopy showed the differences in the molecular structure of the PANI bases. Irrespective of whether the polymerization was performed in solutions of sulfuric or acetic acid, PANI had hydrogen sulfate counter-ions only. The PANI morphology is thus not controlled by the nature of counter-ions. The acidity of the reaction medium determines the protonation of monomer, oligomer and polymer species. The chemistry of aniline oxidation is likely to be affected especially by the protonation of an intermediate in the pernigraniline form. It is proposed that, in the course of aniline oxidation, pH-dependent self-assembly of aniline oligomers predetermines the final PANI morphology. Copyright © 2005 Society of Chemical Industry

Irina Sapurina

Papers

The mechanism of the oxidative polymerization of aniline and the formation of supramolecular polyaniline structures

The genesis of polyaniline nanotubes

Multi-wall carbon nanotubes coated with polyaniline

Polyaniline nanotubes: conditions of formation

In-situ polymerized polyaniline films