Molecular dynamics simulation of polypyrrole film in an acetonitrile solution

Polypyrrole–para-phenolsulfonic acid/tape artificial muscle as a tool to clarify biomimetic driven reactions and ionic exchanges

“…10,11 Both, reactive properties and reactive devices are based on ionic and aqueous exchanges between the conducting polymer lm and the electrolyte driven by the electrochemical reaction. Different methodologies are being used in order to quantify the key aqueous [11][12][13][14][15][16][17][18][19][20][21][22] and ionic exchanges per unit of charge: using bending articial muscles as practical tools, 12,13 by analyzing the electrochemical impedance responses from coated electrodes, [17][18][19][20][21] or through theoretical approaches from oligomeric lms in electrolytes by using molecular dynamic simulations. [14][15][16] The most popular, from 20 years ago, is the Electrochemical Quartz Crystal Microbalance (EQCM).…”

“…Different methodologies are being used in order to quantify the key aqueous [11][12][13][14][15][16][17][18][19][20][21][22] and ionic exchanges per unit of charge: using bending articial muscles as practical tools, 12,13 by analyzing the electrochemical impedance responses from coated electrodes, [17][18][19][20][21] or through theoretical approaches from oligomeric lms in electrolytes by using molecular dynamic simulations. [14][15][16] The most popular, from 20 years ago, is the Electrochemical Quartz Crystal Microbalance (EQCM). [23][24][25][26][27][28][29][30] When applied to polypyrrole lms electrogenerated from aqueous solutions of small anions, also checked in the presence of small anions, an exchange of anions (ingress/expel by oxidation/reduction, respectively) is claimed to occur in a large anodic potential range.…”

Artificial Muscles: A Tool To Quantify Exchanged Solvent during Biomimetic Reactions

“…The influence of solvation in conducting polymers was studied by Frommer . Anions and solvent exchange can be estimated for different oxidation steps by molecular dynamics simulation. − All those methodologies require complex experimental setups, expensive equipment, high qualified staff, and controversial models to quantify the solvent exchange. Understanding and quantifying simultaneous water and ion exchange at the molecular level for biological or biomimetic reactions responsible for biological functions constitutes a basic goal for the subsequent development of chemical predictive models for the quantitative description of biological functions, for states of both health and sickness.…”

Modeling oxidised polypyrrole in the condensed phase with a novel force field

“…One of the important vindications of the parametrisation approach taken here was that despite their +4e charge, the 12-Py oligomers still attract themselves within a distance of about 7.5 Å, as shown in figure 4(a) but have their minimum around 5 Å consistent with average distances between chains of 4.4 Å measured from x-ray diffraction analysis [17]. This fact enables the system to reach the high densities observed in experiments [16,21].…”

“…Simulation methodologies rely heavily on the force field (FF) employed. López Cascales et al [20,21] studied the condensed phases of 10-Py oxidised oligomers at polymer-solvent interfaces with the GROMOS(1987) FF of GROMACS 3.3.3 [22] parametrised for condensed phase properties of alkanes. Dai and Blaisten-Barojas [19] developed a coarse grained FF for reduced Py and studied the thermodynamics and structure of 12-Py oligopyrroles in the solid phase using the Adaptive Tempering Monte Carlo [23].…”