A suitable model for emeraldine salt

Varela‐Álvarez, Adrián; Sordo, José

doi:10.1063/1.2913246

Cited by 27 publications

(16 citation statements)

References 36 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, firstprinciple energy stability calculations point into the opposite direction. A BL is by far the more stable energy configuration when compared to a PL [17] or its variants [18]. A picture that could unify these conclusions is that of segregated metallic (PL) regions and insulating (BL) domains.…”

Section: Introductionmentioning

confidence: 95%

Crucial role of decoherence for electronic transport in molecular wires: Polyaniline as a case study

2010

View full text Add to dashboard Cite

In this work we attempt to elucidate the nature of conductivity in polymers by taking the acidbase doped polyaniline (PAni) polymer. We evaluate the PAni conductance by using realistic ab initio parameters and including decoherent processes within the minimal parametrization model of D'Amato-Pastawski. In contrast to general wisdom, which associates the conducting state with coherent propagation in a periodic polaronic lattice, we show that decoherence can account for high conductance in the strongly disordered bipolaronic lattice. Hence, according to our results, there is no need of considering a mix model of "conducting" polaronic lattice islands separated by "insulating" bipolaronic lattice strands as is usually assumed for PAni. We find that without dephasing events, even very short strands of bipolaronic lattices are not able to sustain electronic transport. We also include a discussion of specific mechanisms that should be involved in decoherence rates of PAni and relate them with Marcus-Hush theory of electron transfer.

show abstract

Section: Introductionmentioning

confidence: 95%

Crucial role of decoherence for electronic transport in molecular wires: Polyaniline as a case study

2010

View full text Add to dashboard Cite

show abstract

“…Conductive polymers for various applications can be evaluated and selected using purely computational approaches, which have generally focused on the development of a fundamental electronic- and atomic-level description to provide insight into the structure and properties of materials 14 15 16 17 18 19 . For instance, Varela-Álvarez et al 16 17 evaluated the effect the chain length and number of monomers on the electronic properties of polyaniline. Using density-functional theory (DFT) simulations, Wang et al 18 systematically studied the stability and electronic structure of HCl-protonated polyaniline and polyaniline–graphene composites.…”

mentioning

confidence: 99%

First-principles study of the effect of functional groups on polyaniline backbone

Chen

Jiang

Liang

et al. 2015

Sci Rep

View full text Add to dashboard Cite

We present a first-principles density functional theory study focused on how the chemical and electronic properties of polyaniline are adjusted by introducing suitable substituents on a polymer backbone. Analyses of the obtained energy barriers, reaction energies and minimum energy paths indicate that the chemical reactivity of the polyaniline derivatives is significantly enhanced by protonic acid doping of the substituted materials. Further study of the density of states at the Fermi level, band gap, HOMO and LUMO shows that both the unprotonated and protonated states of these polyanilines are altered to different degrees depending on the functional group. We also note that changes in both the chemical and electronic properties are very sensitive to the polarity and size of the functional group. It is worth noting that these changes do not substantially alter the inherent chemical and electronic properties of polyaniline. Our results demonstrate that introducing different functional groups on a polymer backbone is an effective approach to obtain tailored conductive polymers with desirable properties while retaining their intrinsic properties, such as conductivity.

show abstract

“…When doped with HCl, PANI demonstrates a significant increase in conductivity by approximately 10 orders of magnitude. Although this mechanism is not entirely understood, it has been proposed that protonation of the emeraldine base of the polymer leads to a spinless bipolaron structure, which rearranges and splits into two polaron units resulting in the emeraldine salt form [18].…”

Section: Polyanilinementioning

confidence: 99%

Exfoliated Nanocomposites Based on Polyaniline and Tungsten Disulfide

Lane¹,

Bissessur²,

Abd‐El‐Aziz³

et al. 2016

Conducting Polymers

View full text Add to dashboard Cite

Nanocomposite materials consisting of polyaniline (PANI) and exfoliated WS 2 were synthesized. The WS 2 was prepared by reacting tungstic acid with thiourea at 500°C under nitrogen flow. Samples were prepared with a WS 2 content of 1, 5, 7.5, 10, 12.5, 15, 20, 37, and 64% by mass. An improvement in the electronic conductivity value of the PANI was observed through the incorporation of exfoliated WS 2. The electronic conductivity of PANI-15%WS 2 was 24.5 S/cm, an eightfold increase when compared to pure PANI. Powder X-ray diffraction (XRD), transmission electron microscopy (TEM) and electron paramagnetic resonance (EPR) provided evidence that the nanocomposites are in an exfoliated state. XRD and TEM showed that the nanocomposites were completely amorphous, suggesting lack of structural order in these materials, while their EPR signals were considerably narrower compared to pure PANI, indicating the formation of genuine exfoliated systems. Furthermore, our research showed that WS 2 can be used as a filler to improve activation energy of decomposition of the polymer. By using the Ozawa method, we studied the decomposition kinetics for the nanocomposites, as well as for the pure polymer. The activation energy for the decomposition of pure PANI was found to be 131.2 kJ/mol. Increasing the amount of WS 2 to 12.5% in the PANI increases the activation energy of decomposition to 165.4 kJ/mol, an enhancement of 34.2 kJ/mol over the pure polymer.

show abstract

A suitable model for emeraldine salt

Cited by 27 publications

References 36 publications

Crucial role of decoherence for electronic transport in molecular wires: Polyaniline as a case study

Crucial role of decoherence for electronic transport in molecular wires: Polyaniline as a case study

First-principles study of the effect of functional groups on polyaniline backbone

Exfoliated Nanocomposites Based on Polyaniline and Tungsten Disulfide

Contact Info

Product

Resources

About