New Structural Model of PANI/CSA Conducting Polymer System Obtained by Molecular Dynamics Simulations

Abstract

Structural properties of polyaniline (PANI) protonated with camphorsulfonic acid (CSA) have been investigated by means of molecular dynamics simulations. New OPLS‐AA based force field has been applied to calculations done within the Gromacs package. All partial charges were derived from DFT quantum calculations using NWChem package. After testing the force field applied to the simulated macromolecules and ions, we have performed a series of long calculations for the system containing (at least) 42 PANI chains of 7 monomers each, doped with 294 CSA ions (equal amounts of both enantiomers). Our calculations show that the only stable and highly ordered structure of the system studied is characterized by double layers of PANI separated by double layers of CSA. The most important conclusion is that identical final result is reached while starting from several quite different initial arrangements. Here the new model is discussed and justified.

Further Investigations of the New Structural Model of PANI/CSA Conducting Polymer System

“…None of the existing tools are obvious and it is difficult to make a choice which would be undisputable. This is already highlighted in the previous paper …”

“…This paper is a direct continuation of the original article, in which the principles of the method used to obtain the new structural model of the PANI/CSA conducting polymer system are described. The model is in need of a thorough investigation of its X‐ray diffraction pattern, obtained by means deemed appropriate, as well as of a study of its properties with respect to the calculated diffraction curve.…”

All-Atom Model of Atactic 2-Vinyl Pyridine Polymer: Structural Properties Investigation by Molecular Dynamics Simulations

“…Our choice is based on the wide range of applicability of OPLS-AA and the possibility to easily combine its force field parameters to study complex polymer systems. In fact, OPLS-AA was successfully adopted to study different polymer families, such as: polyacrylamides, 27 polyaniline, 28 polyglutamine, 39 macrocyclic polyketidies, 40 polystyrene, 38 polymer/carbon nanotube interfaces, 41 and long hydrocarbons. 23,29 According to the OPLS-AA force-field, the bond stretching between two atoms and the angle bending, are both represented by a harmonic potential (Equations 3,4):…”

“…20 In this study, we propose an all-atom model of P2VP, based on the OPLS-AA. 21 We have chosen to base our model on the well-known OPLS-AA force field because of its high adaptability to include and combine other organic molecules, [21][22][23] polymer models, [24][25][26][27][28][29] nanoparticles and other possible interfaces 30,31 which represents the common employment of the P2VP technological applications. In particular, equilibrated melt configurations were successfully obtained by applying a procedure, based on the hybrid particle-field molecular dynamics (PF-MD) approach which is described in our previous works.…”

PANI-CSA/Co3O4 Nanocomposite Films: Optical, Morphological, and Structural Properties

“…Another new rise at plot A is evident, and the amorphous phase diffused set much decreased, indicating high crystalline content [17] (a) The X-ray diffraction patterns of the first three peaks for PANI-CSA film match [17]. The second peak is not double the first peak (Table 2 [18,19]) in Figure 5 (a, b, c and d). Despite this, the third peak is near the second-order location of the first peak (Figure 4b: X-ray diffraction patterns of (PANI-CSA)/(Co3O4 NPs) nanocomposite films) (c).…”