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W. Łużny, K. Piwowarczyk

Hydrogen bonds in camphorsulfonic acid doped polyaniline (in English)

Polimery 2011, No 9, 652

DOI: dx.doi.org/10.14314/polimery.2011.652


We conducted a set of computer simulations to explore in details the way polyaniline (PANI) interacts with its dopant molecules like camphorsulfonic acid (CSA) and with solvent like chloroform, m-cresol or a mixture of m-cresol and water. The simulated system was built of a single layer of polyaniline chains in protonated state with attached camphorsulfonic acid ions as dopants. The system of the size above 50 Å was subject to the periodic boundary conditions. All atoms in simulated molecules were assigned to atom types from OPLS-AA force field. However the inter-ring torsion profile for polyaniline in protonated emeraldine state was modified according to the density functional theory simulations. Prepared systems were simulated for 1 ns under the constant temperature (293 K) and constant pressure (1000 hPa) conditions. The results of molecular dynamics simulation exhibit a broad variety of hydrogen bond patterns between PANI-CSA as well as solvent molecules. We observed high probability (36 %) of configurations where single CSA molecule is attached to a PANI chain via a single hydrogen bond. However, the high probability (44 %) of a configuration where single CSA molecule bridges two or more PANI chains via hydrogen bonds was quite unexpected. Our simulations show also that in the presence of solvent, PANI-CSA interaction slightly weakens. Nevertheless, in the case of solvents being able to form hydrogen bonds in which CSA molecule is involved.

Key words: polyaniline, camphorsulfonic acid, hydrogen bonds

e-mail: konrad.piwowarczyk@gmail.com

W. Łużny, K. Piwowarczyk (791.7 KB)
Hydrogen bonds in camphorsulfonic acid doped polyaniline (in English)