Electrically Conducting Compatible Blends Of Polyaniline / Poly (Vinyl Pyrrolidone)

Abstract

Blending polyaniline (PAn) with a host polymer has the advantage of reducing the amount of polyaniline necessary for conductivity, increasing the stability of this conduction, and enhancing the overall mechanical integrity, versatility, and processability of PAn. PAn blends have generally been observed to be immiscible, reducing many of the above mentioned advantages. In this work, PAn was solution blended with poly (vinyl pyrrolidone) (PVP) in either NMP or DMAc, both polar solvents with an amide linkage. We have found PAn to be miscible with PVP under certain processing conditions. The extent of this compatibility and resulting mechanical properties were assessed by DMA, DSC, TGA, SAXS, and light Microscopy. DSC thermograms exhibit a single Tg for all blends ranging from 3 to 30 % by weight PAn. Light Microscopy and SAXS also suggest no phase separation. TGA results show that NMP binds very tightly to both PAn and PVP, with solvent cast blends retaining up to 20 wt% NMP, even after relatively vigorous drying. Electrical conductivity measurements of cast films show conductivity to range from 10-3to 2 S/cm over the same composition range.

Molecular-Level Processing of Conjugated Polymers. 4. Layer-by-Layer Manipulation of Polyaniline via Hydrogen-Bonding Interactions

“…There is likely less residual DMAc, since polyaniline retains NMP more tightly than DMAc. Similar results were seen for polyaniline/PVP blends …”

“…Thus, in the blended state, polyaniline exhibits a higher level of hydrogen bonding than it does in its nonblended state. We have previously found that polyaniline and PVP form compatible, highly phase mixed blends . It is therefore not too surprising that a large fraction of polyaniline/PVP hydrogen bonds are observed in the blend; hydrogen bonding most likely drives the mixing process.…”

“…Over the past few years, it has become very apparent that polyaniline is capable of forming strong complexes with a variety of different solvent and dopant molecules. , In many cases, the strong interactions developed between polyaniline and these other small molecule systems have been attributed to hydrogen-bonding interactions at the amine or imine sites of the polyaniline backbone. Strong interactions of this type also appear to promote a high level of phase mixing in blends of polyaniline and specific hydrogen-bonding polymers such as poly(vinyl pyrrolidone) .…”

Filmes nanoestruturados contendo lipossomos para liberação controlada do Ibuprofeno

“…Neste filme a adsorção não ocorre somente devido às forças iônicas, mas também pode ocorrer inteiramente através de ligações de hidrogênio, forças de van der Waals, interações hidrofóbicas ou em conjunto com interações iônicas. Os primeiros a sugerir que filmes automontados poderiam ser produzidos por ligações de hidrogênio foram Stockton e Rubner64 . Em outro trabalho, Stockton e Rubner 65 produziram filmes automontados de polianilina (PANI), com polímeros não condutores eletrônicos, como poli(vinil pirrolidona)…”

Influência dos polieletrólitos na resposta eletroquímica de filmes automontados contendo nanotubos de carbono para aplicação em nanomedicina

“…Neste processo, a adsorção ocorre principalmente pela utilização de ligações secundárias como ligações de hidrogênio, interações de van-der-Waals e interações hidrofóbicas, todas elas podendo ocorrer juntamente com interações eletrostáticas. Os primeiros filmes utilizando ligações secundárias foram relatados por Stockton e Rubner[41], em filmes adsorvidos utilizandose ligações de hidrogênio. Posteriormente[42], estes autores relataram filmes de PANI adsorvidos com outros polímeros não-iônicos, como poli(vinil pirrolidona) (PVP), poli(vinil álcool) (PVA), poliacrilamida (PAAm) e poli(óxido de etileno) (poly(ethylene oxide -PEO).…”