Polyaniline hydrogen bonds

Hydrogen bond formation as a result of the interaetion of polymer with solvent was found to contribute to changes in the electric properties of polyaniline.Hydrogen bonding causes changes in conformal structure of polymer chains. This increases the electrical conductivity of polyaniline. Water is especially effective in causing such changes but other hy-... 

Stockton WB, Rubner MF (1997) Molecular-level processing of conjugated polymers. 4. Layer-by-layer manipulation of polyaniline via hydrogen-bonding interactions. Macromolecules 30 2717-2725... 

Polyaniline was converted into A -t-BOC polyaniline, (I), by Lee [1] to reduce intermolecular hydrogen bonding when used in conductive polymer applications. 

Inelastic neutron scattering studies have shown [7-11] that many hydrogen-bonded crystals [potassium carbonate (i.e., KHCO3), various polyanilines, Ca(OH)2, and others] are characterized by the proton dynamics that is very decoupled from the backbone lattice. 

A related, but alternative, approach uses layer-by-layer adsorption driven by hydrogen-bonding interactions [51]. This has been accomplished with polyvinylpyrrohdone, polyvinyl alcohol, polyacrylamide, and polyethylene oxide. In the case of polyaniline, comparisons with films assembled via the electrostatic mechanism, using sulphonated polystyrene, indicate that the nonionic polymers adsorb onto polyanihne with a greater density of loops and tails and form highly interpenetrated bilayers with high polyaniline content. 

L. Zhang, Y. Long, Z. Chen, and M. Wan, Effect of hydrogen bonding on self-assembled polyaniline nanostructures, Adv. Funct. Mater., 14, 693-698 (2004). 

Kan s researeh group also investigated the effect of alcohols on the electrochemical polymerization of aniline at a constant potential of 0.8 V (vs. SCE) [61]. They found that the presence of alcohols favors formation of nanofibers. This is attributed to hydrogen bonding between alcohols and polyaniline chains, which results in the polymer chains being pushed apart [62]. 

The PPV precursor polymer was converted to the fully conjugated form by thermal treatment. The films were dried under dynamic vacuum overnight and then heated up to 210°C. This temperature was maintained for 10 hours and the samples were left to cool down for a period of about 10 more hours. The whole procedure was carried out under vacuum. Details concerning the layer-by-layer processing of polyaniline via hydrogen bond interactions can be found in a previous publication (74). 

Gruger, A., A. Novak, A. Regis, and P. Colomban. 1994. Infrared and Raman-study of polyaniline. 2. Influence of ortho substituents on hydrogen-bonding and UV/Vis near-lR electron charge-transfer. 7 Mol Struct 328 153-167. 

Other Heterocycles (Nonhydrogen Bonding) Polyanilines and Other Hydrogen Bonding Analogs Stepladders,... 

Zheng, W., M. Angelopoulos, A.J. Epstein, and A.G. MacDiarmid. 1997. Experimental evidence for hydrogen bonding in polyaniline mechanism of aggregate formation and dependency. Macromolecules 30 2953. 

Ikkala, O.T., L.O. Pietilac, P. Passiniemi, T. Vikki, H. Osterholm, L. Ahjopalo, and J.E. Osterholm. 1997. Processible polyaniline complexes due to molecular recognition Supramolecular structures based on hydrogen bonding and phenyl stacking. Synth Met 84 55. 

---