1.
Leonardo D. Machado Cristiano F. Woellner, Pedro A. S. Autreto
The Influence of Morphology on the Charge Transport in Two-Phase Disordered Organic Systems Online
2015, (ArXiv draft of MRS Proceedings, 1737, mrsf14-1737-u18-21 (2015)).
@online{Woellner2015,
title = {The Influence of Morphology on the Charge Transport in Two-Phase Disordered Organic Systems},
author = {Cristiano F. Woellner, Leonardo D. Machado, Pedro A. S. Autreto, Jose A. Freire, Douglas S. Galvao},
url = {http://arxiv.org/abs/1501.01343},
year = {2015},
date = {2015-01-01},
booktitle = {MRS Proceedings},
volume = {1737},
pages = {mrsf14-1737-u18-21},
abstract = {In this work we use a three-dimensional Pauli master equation to investigate the charge carrier mobility of a two-phase system, which can mimic donor-acceptor and amorphous- crystalline bulk heterojunctions. Our approach can be separated into two parts: the morphology generation and the charge transport modeling in the generated blend. The morphology part is based on a Monte Carlo simulation of binary mixtures (donor/acceptor). The second part is carried out by numerically solving the steady-state Pauli master equation. By taking the energetic disorder of each phase, their energy offset and domain morphology into consideration, we show that the carrier mobility can have a significant different behavior when compared to a one-phase system. When the energy offset is non-zero, we show that the mobility electric field dependence switches from negative to positive at a threshold field proportional to the energy offset. Additionally, the influence of morphology, through the domain size and the interfacial roughness parameters, on the transport was also investigated.},
note = {ArXiv draft of MRS Proceedings, 1737, mrsf14-1737-u18-21 (2015)},
keywords = {},
pubstate = {published},
tppubtype = {online}
}
In this work we use a three-dimensional Pauli master equation to investigate the charge carrier mobility of a two-phase system, which can mimic donor-acceptor and amorphous- crystalline bulk heterojunctions. Our approach can be separated into two parts: the morphology generation and the charge transport modeling in the generated blend. The morphology part is based on a Monte Carlo simulation of binary mixtures (donor/acceptor). The second part is carried out by numerically solving the steady-state Pauli master equation. By taking the energetic disorder of each phase, their energy offset and domain morphology into consideration, we show that the carrier mobility can have a significant different behavior when compared to a one-phase system. When the energy offset is non-zero, we show that the mobility electric field dependence switches from negative to positive at a threshold field proportional to the energy offset. Additionally, the influence of morphology, through the domain size and the interfacial roughness parameters, on the transport was also investigated.
2.
Leonardo D Machado Cristiano F Woellner, Pedro AS Autreto
The Influence of Morphology on the Charge Transport in Two-Phase Disordered Organic Systems Proceedings
vol. 1737, no. mrsf14-1737-u18-21, 2015, (MRS Proceedings, 1737, mrsf14-1737-u18-21).
@proceedings{Woellner2015b,
title = {The Influence of Morphology on the Charge Transport in Two-Phase Disordered Organic Systems},
author = {Cristiano F Woellner, Leonardo D Machado, Pedro AS Autreto, José A Freire, Douglas S Galvão},
url = {http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=9707375&fileId=S1946427415005023},
doi = {10.1557/opl.2015.502},
year = {2015},
date = {2015-01-01},
booktitle = {MRS Proceedings},
volume = {1737},
number = {mrsf14-1737-u18-21},
pages = {mrsf14-1737-u18-21},
abstract = {In this work we use a three-dimensional Pauli master equation to investigate the charge carrier mobility of a two-phase system, which can mimic donor-acceptor and amorphous-crystalline bulk heterojunctions. Our approach can be separated into two parts: the morphology generation and the charge transport modeling in the generated blend. The morphology part is based on a Monte Carlo simulation of binary mixtures (donor/acceptor). The second part is carried out by numerically solving the steady-state Pauli master equation. By taking the energetic disorder of each phase, their energy offset and domain morphology into consideration, we show that the carrier mobility can have a significant different behavior when compared to a one-phase system. When the energy offset is non-zero, we show that the mobility electric field dependence switches from negative to positive at a threshold field proportional to the energy offset. Additionally, the influence of morphology, through the domain size and the interfacial roughness parameters, on the transport was also investigated.
},
note = {MRS Proceedings, 1737, mrsf14-1737-u18-21},
keywords = {},
pubstate = {published},
tppubtype = {proceedings}
}
In this work we use a three-dimensional Pauli master equation to investigate the charge carrier mobility of a two-phase system, which can mimic donor-acceptor and amorphous-crystalline bulk heterojunctions. Our approach can be separated into two parts: the morphology generation and the charge transport modeling in the generated blend. The morphology part is based on a Monte Carlo simulation of binary mixtures (donor/acceptor). The second part is carried out by numerically solving the steady-state Pauli master equation. By taking the energetic disorder of each phase, their energy offset and domain morphology into consideration, we show that the carrier mobility can have a significant different behavior when compared to a one-phase system. When the energy offset is non-zero, we show that the mobility electric field dependence switches from negative to positive at a threshold field proportional to the energy offset. Additionally, the influence of morphology, through the domain size and the interfacial roughness parameters, on the transport was also investigated.
3.
Giro, Ronaldo; Caldas, Mar'ilia Junqueira; Galvao, Douglas Soares
Band gap engineering for poly (p-phenylene) and poly (p-phenylene vinylene) copolymers using the tight-binding approach Journal Article
In: International Journal of Quantum Chemistry, vol. 103, no. 5, pp. 588–596, 2005.
@article{giro2005band,
title = {Band gap engineering for poly (p-phenylene) and poly (p-phenylene vinylene) copolymers using the tight-binding approach},
author = {Giro, Ronaldo and Caldas, Mar'ilia Junqueira and Galvao, Douglas Soares},
url = {http://onlinelibrary.wiley.com/doi/10.1002/qua.20551/full},
year = {2005},
date = {2005-01-01},
journal = {International Journal of Quantum Chemistry},
volume = {103},
number = {5},
pages = {588--596},
publisher = {Wiley Online Library},
abstract = {The interest in poly(p-phenylene) (PPP) and poly(p-phenylene vinylene) (PPV) copolymers stems from the fact that these homopolymers present interesting optical and electronic properties that allow a great variety of technological applications. Combining different numbers of PPP and PPV units it is possible, in principle, to obtain new structures presenting intermediate gap values (2.8 eV and 2.4 eV for PPP and PPV, respectively). For this study we used a Hückel Hamiltonian tight-binding coupled to the negative factor counting (NFC) technique. We carried out a systematic search to determine optimum relative concentrations for disordered binary polymeric alloys with predefined gap values. Once these structures were obtained, we used the semiempirical methods AM1/PM3 and ZINDO/S-CI for geometrical and optical studies, respectively. Our theoretical results show that it is possible to obtain copolymers of PPP and PPV with intermediate gap values of their parent structures. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The interest in poly(p-phenylene) (PPP) and poly(p-phenylene vinylene) (PPV) copolymers stems from the fact that these homopolymers present interesting optical and electronic properties that allow a great variety of technological applications. Combining different numbers of PPP and PPV units it is possible, in principle, to obtain new structures presenting intermediate gap values (2.8 eV and 2.4 eV for PPP and PPV, respectively). For this study we used a Hückel Hamiltonian tight-binding coupled to the negative factor counting (NFC) technique. We carried out a systematic search to determine optimum relative concentrations for disordered binary polymeric alloys with predefined gap values. Once these structures were obtained, we used the semiempirical methods AM1/PM3 and ZINDO/S-CI for geometrical and optical studies, respectively. Our theoretical results show that it is possible to obtain copolymers of PPP and PPV with intermediate gap values of their parent structures. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
4.
Del Nero, J; Galvao, DS; Laks, B
Electronic structure investigation of biosensor polymer Journal Article
In: Optical Materials, vol. 21, no. 1, pp. 461–466, 2003.
@article{del2003electronic,
title = {Electronic structure investigation of biosensor polymer},
author = {Del Nero, J and Galvao, DS and Laks, B},
url = {http://www.sciencedirect.com/science/article/pii/S0925346702001830},
year = {2003},
date = {2003-01-01},
journal = {Optical Materials},
volume = {21},
number = {1},
pages = {461--466},
publisher = {Elsevier},
abstract = {We report a theoretical study of the ground, excited and ionic states of 3-methyl pyrrole-4-carboxilic acid (MPC) oligomers and related compounds which present conformational defects. Our results reveal the existence of differentiated electronic behavior for MPC with relation to oligopyrrole derivatives. These electronic features might explain why MPC works properly as a biosensor for cytochrome C while no voltametric response is observed for unsubstituted poly(pyrrole).},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
We report a theoretical study of the ground, excited and ionic states of 3-methyl pyrrole-4-carboxilic acid (MPC) oligomers and related compounds which present conformational defects. Our results reveal the existence of differentiated electronic behavior for MPC with relation to oligopyrrole derivatives. These electronic features might explain why MPC works properly as a biosensor for cytochrome C while no voltametric response is observed for unsubstituted poly(pyrrole).
5.
Giro, R; Galvao, DS
Semiempirical studies of the electronic structure of polyphenylene sulfide phenyleneamine Journal Article
In: International journal of quantum chemistry, vol. 95, no. 3, pp. 252–259, 2003.
@article{giro2003semiempirical,
title = {Semiempirical studies of the electronic structure of polyphenylene sulfide phenyleneamine},
author = {Giro, R and Galvao, DS},
url = {http://onlinelibrary.wiley.com/doi/10.1002/qua.10722/full},
year = {2003},
date = {2003-01-01},
journal = {International journal of quantum chemistry},
volume = {95},
number = {3},
pages = {252--259},
publisher = {Wiley Subscription Services, Inc., A Wiley Company},
abstract = {Polyphenylene sulfide (PPS) and polyaniline (PANI) are heteroatom-containing polymers with unique properties. While PPS provides a good level of chemical and thermal stability, PANI is important due to its ability to form electrically conducting films. A combination of PPS and PANI, with alternating phenyleneamine and phenylene sulfide blocks, resulted in a new material combining the structural features of PPS and PANI. This copolymer is known as polyphenylene sulfide–phenyleneamine (PPSA). In this work we present geometric and spectroscopic studies on PPSA oligomers using the well-known semiempirical methods PM3 (parametric method 3) and ZINDO-S/CI (Zerner's intermediate neglect of differential overlap/spectroscopic-configuration interaction). PM3 results show that long PPSA oligomers present alternating in- and out-of-plane rings with torsion angles about 60°. The ZINDO-simulated spectra compare well with the available experimental data. The origin of the low PPSA conductivity is addressed in terms of electronic features presented by isolated polymeric chains. © 2003 Wiley Periodicals, Inc. Int J Quantum Chem 95: 252–259, 2003},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Polyphenylene sulfide (PPS) and polyaniline (PANI) are heteroatom-containing polymers with unique properties. While PPS provides a good level of chemical and thermal stability, PANI is important due to its ability to form electrically conducting films. A combination of PPS and PANI, with alternating phenyleneamine and phenylene sulfide blocks, resulted in a new material combining the structural features of PPS and PANI. This copolymer is known as polyphenylene sulfide–phenyleneamine (PPSA). In this work we present geometric and spectroscopic studies on PPSA oligomers using the well-known semiempirical methods PM3 (parametric method 3) and ZINDO-S/CI (Zerner's intermediate neglect of differential overlap/spectroscopic-configuration interaction). PM3 results show that long PPSA oligomers present alternating in- and out-of-plane rings with torsion angles about 60°. The ZINDO-simulated spectra compare well with the available experimental data. The origin of the low PPSA conductivity is addressed in terms of electronic features presented by isolated polymeric chains. © 2003 Wiley Periodicals, Inc. Int J Quantum Chem 95: 252–259, 2003
6.
Giro, Ronaldo; Cyrillo, Marcio; Galvao, Douglas Soares
Using artificial intelligence methods to design new conducting polymers Journal Article
In: Materials Research, vol. 6, no. 4, pp. 523–528, 2003.
@article{giro2003using,
title = {Using artificial intelligence methods to design new conducting polymers},
author = {Giro, Ronaldo and Cyrillo, Marcio and Galvao, Douglas Soares},
url = {http://www.scielo.br/scielo.php?pid=S1516-14392003000400017&script=sci_arttext},
year = {2003},
date = {2003-01-01},
journal = {Materials Research},
volume = {6},
number = {4},
pages = {523--528},
publisher = {SciELO Brasil},
abstract = {In the last years the possibility of creating new conducting polymers exploring the concept of copolymerization (different structural monomeric units) has attracted much attention from experimental and theoretical points of view. Due to the rich carbon reactivity an almost infinite number of new structures is possible and the procedure of trial and error has been the rule. In this work we have used a methodology able of generating new structures with pre-specified properties. It combines the use of negative factor counting (NFC) technique with artificial intelligence methods (genetic algorithms - GAs). We present the results for a case study for poly(phenylenesulfide phenyleneamine) (PPSA), a copolymer formed by combination of homopolymers: polyaniline (PANI) and polyphenylenesulfide (PPS). The methodology was successfully applied to the problem of obtaining binary up to quinternary disordered polymeric alloys with a pre-specific gap value or exhibiting metallic properties. It is completely general and can be in principle adapted to the design of new classes of materials with pre-specified properties},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
In the last years the possibility of creating new conducting polymers exploring the concept of copolymerization (different structural monomeric units) has attracted much attention from experimental and theoretical points of view. Due to the rich carbon reactivity an almost infinite number of new structures is possible and the procedure of trial and error has been the rule. In this work we have used a methodology able of generating new structures with pre-specified properties. It combines the use of negative factor counting (NFC) technique with artificial intelligence methods (genetic algorithms - GAs). We present the results for a case study for poly(phenylenesulfide phenyleneamine) (PPSA), a copolymer formed by combination of homopolymers: polyaniline (PANI) and polyphenylenesulfide (PPS). The methodology was successfully applied to the problem of obtaining binary up to quinternary disordered polymeric alloys with a pre-specific gap value or exhibiting metallic properties. It is completely general and can be in principle adapted to the design of new classes of materials with pre-specified properties
7.
Giro, R; Cyrillo, M; Galvao, DS
Designing conducting polymers using genetic algorithms Journal Article
In: Chemical Physics Letters, vol. 366, no. 1, pp. 170–175, 2002.
@article{giro2002designing,
title = {Designing conducting polymers using genetic algorithms},
author = {Giro, R and Cyrillo, M and Galvao, DS},
url = {http://www.sciencedirect.com/science/article/pii/S0009261402015476},
year = {2002},
date = {2002-01-01},
journal = {Chemical Physics Letters},
volume = {366},
number = {1},
pages = {170--175},
publisher = {North-Holland},
abstract = {We have developed a new methodology to design conducting polymers with pre-specified properties. The methodology is based on the use of genetic algorithms (GAs) coupled to Negative Factor Counting technique. We present the results for a case study of polyanilines, one of the most important families of conducting polymers. The methodology proved to be able of generating automatic solutions for the problem of determining the optimum relative concentration for binary and ternary disordered polyaniline alloys exhibiting metallic properties. The methodology is completely general and can be used to design new classes of materials.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
We have developed a new methodology to design conducting polymers with pre-specified properties. The methodology is based on the use of genetic algorithms (GAs) coupled to Negative Factor Counting technique. We present the results for a case study of polyanilines, one of the most important families of conducting polymers. The methodology proved to be able of generating automatic solutions for the problem of determining the optimum relative concentration for binary and ternary disordered polyaniline alloys exhibiting metallic properties. The methodology is completely general and can be used to design new classes of materials.
2015
7.
Leonardo D. Machado Cristiano F. Woellner, Pedro A. S. Autreto
The Influence of Morphology on the Charge Transport in Two-Phase Disordered Organic Systems Online
2015, (ArXiv draft of MRS Proceedings, 1737, mrsf14-1737-u18-21 (2015)).
Abstract | Links | BibTeX | Tags: Conducting Polymers, Monte Carlo, Transport
@online{Woellner2015,
title = {The Influence of Morphology on the Charge Transport in Two-Phase Disordered Organic Systems},
author = {Cristiano F. Woellner, Leonardo D. Machado, Pedro A. S. Autreto, Jose A. Freire, Douglas S. Galvao},
url = {http://arxiv.org/abs/1501.01343},
year = {2015},
date = {2015-01-01},
booktitle = {MRS Proceedings},
volume = {1737},
pages = {mrsf14-1737-u18-21},
abstract = {In this work we use a three-dimensional Pauli master equation to investigate the charge carrier mobility of a two-phase system, which can mimic donor-acceptor and amorphous- crystalline bulk heterojunctions. Our approach can be separated into two parts: the morphology generation and the charge transport modeling in the generated blend. The morphology part is based on a Monte Carlo simulation of binary mixtures (donor/acceptor). The second part is carried out by numerically solving the steady-state Pauli master equation. By taking the energetic disorder of each phase, their energy offset and domain morphology into consideration, we show that the carrier mobility can have a significant different behavior when compared to a one-phase system. When the energy offset is non-zero, we show that the mobility electric field dependence switches from negative to positive at a threshold field proportional to the energy offset. Additionally, the influence of morphology, through the domain size and the interfacial roughness parameters, on the transport was also investigated.},
note = {ArXiv draft of MRS Proceedings, 1737, mrsf14-1737-u18-21 (2015)},
keywords = {Conducting Polymers, Monte Carlo, Transport},
pubstate = {published},
tppubtype = {online}
}
In this work we use a three-dimensional Pauli master equation to investigate the charge carrier mobility of a two-phase system, which can mimic donor-acceptor and amorphous- crystalline bulk heterojunctions. Our approach can be separated into two parts: the morphology generation and the charge transport modeling in the generated blend. The morphology part is based on a Monte Carlo simulation of binary mixtures (donor/acceptor). The second part is carried out by numerically solving the steady-state Pauli master equation. By taking the energetic disorder of each phase, their energy offset and domain morphology into consideration, we show that the carrier mobility can have a significant different behavior when compared to a one-phase system. When the energy offset is non-zero, we show that the mobility electric field dependence switches from negative to positive at a threshold field proportional to the energy offset. Additionally, the influence of morphology, through the domain size and the interfacial roughness parameters, on the transport was also investigated.
6.
Leonardo D Machado Cristiano F Woellner, Pedro AS Autreto
The Influence of Morphology on the Charge Transport in Two-Phase Disordered Organic Systems Proceedings
vol. 1737, no. mrsf14-1737-u18-21, 2015, (MRS Proceedings, 1737, mrsf14-1737-u18-21).
Abstract | Links | BibTeX | Tags: Conducting Polymers, Monte Carlo, Solar Cells
@proceedings{Woellner2015b,
title = {The Influence of Morphology on the Charge Transport in Two-Phase Disordered Organic Systems},
author = {Cristiano F Woellner, Leonardo D Machado, Pedro AS Autreto, José A Freire, Douglas S Galvão},
url = {http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=9707375&fileId=S1946427415005023},
doi = {10.1557/opl.2015.502},
year = {2015},
date = {2015-01-01},
booktitle = {MRS Proceedings},
volume = {1737},
number = {mrsf14-1737-u18-21},
pages = {mrsf14-1737-u18-21},
abstract = {In this work we use a three-dimensional Pauli master equation to investigate the charge carrier mobility of a two-phase system, which can mimic donor-acceptor and amorphous-crystalline bulk heterojunctions. Our approach can be separated into two parts: the morphology generation and the charge transport modeling in the generated blend. The morphology part is based on a Monte Carlo simulation of binary mixtures (donor/acceptor). The second part is carried out by numerically solving the steady-state Pauli master equation. By taking the energetic disorder of each phase, their energy offset and domain morphology into consideration, we show that the carrier mobility can have a significant different behavior when compared to a one-phase system. When the energy offset is non-zero, we show that the mobility electric field dependence switches from negative to positive at a threshold field proportional to the energy offset. Additionally, the influence of morphology, through the domain size and the interfacial roughness parameters, on the transport was also investigated.
},
note = {MRS Proceedings, 1737, mrsf14-1737-u18-21},
keywords = {Conducting Polymers, Monte Carlo, Solar Cells},
pubstate = {published},
tppubtype = {proceedings}
}
In this work we use a three-dimensional Pauli master equation to investigate the charge carrier mobility of a two-phase system, which can mimic donor-acceptor and amorphous-crystalline bulk heterojunctions. Our approach can be separated into two parts: the morphology generation and the charge transport modeling in the generated blend. The morphology part is based on a Monte Carlo simulation of binary mixtures (donor/acceptor). The second part is carried out by numerically solving the steady-state Pauli master equation. By taking the energetic disorder of each phase, their energy offset and domain morphology into consideration, we show that the carrier mobility can have a significant different behavior when compared to a one-phase system. When the energy offset is non-zero, we show that the mobility electric field dependence switches from negative to positive at a threshold field proportional to the energy offset. Additionally, the influence of morphology, through the domain size and the interfacial roughness parameters, on the transport was also investigated.
2005
5.
Giro, Ronaldo; Caldas, Mar'ilia Junqueira; Galvao, Douglas Soares
Band gap engineering for poly (p-phenylene) and poly (p-phenylene vinylene) copolymers using the tight-binding approach Journal Article
In: International Journal of Quantum Chemistry, vol. 103, no. 5, pp. 588–596, 2005.
Abstract | Links | BibTeX | Tags: Conducting Polymers, Electronic Structure, PPP, PPV
@article{giro2005band,
title = {Band gap engineering for poly (p-phenylene) and poly (p-phenylene vinylene) copolymers using the tight-binding approach},
author = {Giro, Ronaldo and Caldas, Mar'ilia Junqueira and Galvao, Douglas Soares},
url = {http://onlinelibrary.wiley.com/doi/10.1002/qua.20551/full},
year = {2005},
date = {2005-01-01},
journal = {International Journal of Quantum Chemistry},
volume = {103},
number = {5},
pages = {588--596},
publisher = {Wiley Online Library},
abstract = {The interest in poly(p-phenylene) (PPP) and poly(p-phenylene vinylene) (PPV) copolymers stems from the fact that these homopolymers present interesting optical and electronic properties that allow a great variety of technological applications. Combining different numbers of PPP and PPV units it is possible, in principle, to obtain new structures presenting intermediate gap values (2.8 eV and 2.4 eV for PPP and PPV, respectively). For this study we used a Hückel Hamiltonian tight-binding coupled to the negative factor counting (NFC) technique. We carried out a systematic search to determine optimum relative concentrations for disordered binary polymeric alloys with predefined gap values. Once these structures were obtained, we used the semiempirical methods AM1/PM3 and ZINDO/S-CI for geometrical and optical studies, respectively. Our theoretical results show that it is possible to obtain copolymers of PPP and PPV with intermediate gap values of their parent structures. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005},
keywords = {Conducting Polymers, Electronic Structure, PPP, PPV},
pubstate = {published},
tppubtype = {article}
}
The interest in poly(p-phenylene) (PPP) and poly(p-phenylene vinylene) (PPV) copolymers stems from the fact that these homopolymers present interesting optical and electronic properties that allow a great variety of technological applications. Combining different numbers of PPP and PPV units it is possible, in principle, to obtain new structures presenting intermediate gap values (2.8 eV and 2.4 eV for PPP and PPV, respectively). For this study we used a Hückel Hamiltonian tight-binding coupled to the negative factor counting (NFC) technique. We carried out a systematic search to determine optimum relative concentrations for disordered binary polymeric alloys with predefined gap values. Once these structures were obtained, we used the semiempirical methods AM1/PM3 and ZINDO/S-CI for geometrical and optical studies, respectively. Our theoretical results show that it is possible to obtain copolymers of PPP and PPV with intermediate gap values of their parent structures. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
2003
4.
Del Nero, J; Galvao, DS; Laks, B
Electronic structure investigation of biosensor polymer Journal Article
In: Optical Materials, vol. 21, no. 1, pp. 461–466, 2003.
Abstract | Links | BibTeX | Tags: Conducting Polymers, Electronic Structure, Sensors
@article{del2003electronic,
title = {Electronic structure investigation of biosensor polymer},
author = {Del Nero, J and Galvao, DS and Laks, B},
url = {http://www.sciencedirect.com/science/article/pii/S0925346702001830},
year = {2003},
date = {2003-01-01},
journal = {Optical Materials},
volume = {21},
number = {1},
pages = {461--466},
publisher = {Elsevier},
abstract = {We report a theoretical study of the ground, excited and ionic states of 3-methyl pyrrole-4-carboxilic acid (MPC) oligomers and related compounds which present conformational defects. Our results reveal the existence of differentiated electronic behavior for MPC with relation to oligopyrrole derivatives. These electronic features might explain why MPC works properly as a biosensor for cytochrome C while no voltametric response is observed for unsubstituted poly(pyrrole).},
keywords = {Conducting Polymers, Electronic Structure, Sensors},
pubstate = {published},
tppubtype = {article}
}
We report a theoretical study of the ground, excited and ionic states of 3-methyl pyrrole-4-carboxilic acid (MPC) oligomers and related compounds which present conformational defects. Our results reveal the existence of differentiated electronic behavior for MPC with relation to oligopyrrole derivatives. These electronic features might explain why MPC works properly as a biosensor for cytochrome C while no voltametric response is observed for unsubstituted poly(pyrrole).
3.
Giro, R; Galvao, DS
Semiempirical studies of the electronic structure of polyphenylene sulfide phenyleneamine Journal Article
In: International journal of quantum chemistry, vol. 95, no. 3, pp. 252–259, 2003.
Abstract | Links | BibTeX | Tags: co-polymers, Conducting Polymers, Electronic Structure, PANi, PPS, PPSA
@article{giro2003semiempirical,
title = {Semiempirical studies of the electronic structure of polyphenylene sulfide phenyleneamine},
author = {Giro, R and Galvao, DS},
url = {http://onlinelibrary.wiley.com/doi/10.1002/qua.10722/full},
year = {2003},
date = {2003-01-01},
journal = {International journal of quantum chemistry},
volume = {95},
number = {3},
pages = {252--259},
publisher = {Wiley Subscription Services, Inc., A Wiley Company},
abstract = {Polyphenylene sulfide (PPS) and polyaniline (PANI) are heteroatom-containing polymers with unique properties. While PPS provides a good level of chemical and thermal stability, PANI is important due to its ability to form electrically conducting films. A combination of PPS and PANI, with alternating phenyleneamine and phenylene sulfide blocks, resulted in a new material combining the structural features of PPS and PANI. This copolymer is known as polyphenylene sulfide–phenyleneamine (PPSA). In this work we present geometric and spectroscopic studies on PPSA oligomers using the well-known semiempirical methods PM3 (parametric method 3) and ZINDO-S/CI (Zerner's intermediate neglect of differential overlap/spectroscopic-configuration interaction). PM3 results show that long PPSA oligomers present alternating in- and out-of-plane rings with torsion angles about 60°. The ZINDO-simulated spectra compare well with the available experimental data. The origin of the low PPSA conductivity is addressed in terms of electronic features presented by isolated polymeric chains. © 2003 Wiley Periodicals, Inc. Int J Quantum Chem 95: 252–259, 2003},
keywords = {co-polymers, Conducting Polymers, Electronic Structure, PANi, PPS, PPSA},
pubstate = {published},
tppubtype = {article}
}
Polyphenylene sulfide (PPS) and polyaniline (PANI) are heteroatom-containing polymers with unique properties. While PPS provides a good level of chemical and thermal stability, PANI is important due to its ability to form electrically conducting films. A combination of PPS and PANI, with alternating phenyleneamine and phenylene sulfide blocks, resulted in a new material combining the structural features of PPS and PANI. This copolymer is known as polyphenylene sulfide–phenyleneamine (PPSA). In this work we present geometric and spectroscopic studies on PPSA oligomers using the well-known semiempirical methods PM3 (parametric method 3) and ZINDO-S/CI (Zerner's intermediate neglect of differential overlap/spectroscopic-configuration interaction). PM3 results show that long PPSA oligomers present alternating in- and out-of-plane rings with torsion angles about 60°. The ZINDO-simulated spectra compare well with the available experimental data. The origin of the low PPSA conductivity is addressed in terms of electronic features presented by isolated polymeric chains. © 2003 Wiley Periodicals, Inc. Int J Quantum Chem 95: 252–259, 2003
2.
Giro, Ronaldo; Cyrillo, Marcio; Galvao, Douglas Soares
Using artificial intelligence methods to design new conducting polymers Journal Article
In: Materials Research, vol. 6, no. 4, pp. 523–528, 2003.
Abstract | Links | BibTeX | Tags: Artificial Intelligence, Conducting Polymers, Genetic Algorithms, Material Design
@article{giro2003using,
title = {Using artificial intelligence methods to design new conducting polymers},
author = {Giro, Ronaldo and Cyrillo, Marcio and Galvao, Douglas Soares},
url = {http://www.scielo.br/scielo.php?pid=S1516-14392003000400017&script=sci_arttext},
year = {2003},
date = {2003-01-01},
journal = {Materials Research},
volume = {6},
number = {4},
pages = {523--528},
publisher = {SciELO Brasil},
abstract = {In the last years the possibility of creating new conducting polymers exploring the concept of copolymerization (different structural monomeric units) has attracted much attention from experimental and theoretical points of view. Due to the rich carbon reactivity an almost infinite number of new structures is possible and the procedure of trial and error has been the rule. In this work we have used a methodology able of generating new structures with pre-specified properties. It combines the use of negative factor counting (NFC) technique with artificial intelligence methods (genetic algorithms - GAs). We present the results for a case study for poly(phenylenesulfide phenyleneamine) (PPSA), a copolymer formed by combination of homopolymers: polyaniline (PANI) and polyphenylenesulfide (PPS). The methodology was successfully applied to the problem of obtaining binary up to quinternary disordered polymeric alloys with a pre-specific gap value or exhibiting metallic properties. It is completely general and can be in principle adapted to the design of new classes of materials with pre-specified properties},
keywords = {Artificial Intelligence, Conducting Polymers, Genetic Algorithms, Material Design},
pubstate = {published},
tppubtype = {article}
}
In the last years the possibility of creating new conducting polymers exploring the concept of copolymerization (different structural monomeric units) has attracted much attention from experimental and theoretical points of view. Due to the rich carbon reactivity an almost infinite number of new structures is possible and the procedure of trial and error has been the rule. In this work we have used a methodology able of generating new structures with pre-specified properties. It combines the use of negative factor counting (NFC) technique with artificial intelligence methods (genetic algorithms - GAs). We present the results for a case study for poly(phenylenesulfide phenyleneamine) (PPSA), a copolymer formed by combination of homopolymers: polyaniline (PANI) and polyphenylenesulfide (PPS). The methodology was successfully applied to the problem of obtaining binary up to quinternary disordered polymeric alloys with a pre-specific gap value or exhibiting metallic properties. It is completely general and can be in principle adapted to the design of new classes of materials with pre-specified properties
2002
1.
Giro, R; Cyrillo, M; Galvao, DS
Designing conducting polymers using genetic algorithms Journal Article
In: Chemical Physics Letters, vol. 366, no. 1, pp. 170–175, 2002.
Abstract | Links | BibTeX | Tags: Conducting Polymers, Electronic Structure, Genetic Algorithms, Material Design
@article{giro2002designing,
title = {Designing conducting polymers using genetic algorithms},
author = {Giro, R and Cyrillo, M and Galvao, DS},
url = {http://www.sciencedirect.com/science/article/pii/S0009261402015476},
year = {2002},
date = {2002-01-01},
journal = {Chemical Physics Letters},
volume = {366},
number = {1},
pages = {170--175},
publisher = {North-Holland},
abstract = {We have developed a new methodology to design conducting polymers with pre-specified properties. The methodology is based on the use of genetic algorithms (GAs) coupled to Negative Factor Counting technique. We present the results for a case study of polyanilines, one of the most important families of conducting polymers. The methodology proved to be able of generating automatic solutions for the problem of determining the optimum relative concentration for binary and ternary disordered polyaniline alloys exhibiting metallic properties. The methodology is completely general and can be used to design new classes of materials.},
keywords = {Conducting Polymers, Electronic Structure, Genetic Algorithms, Material Design},
pubstate = {published},
tppubtype = {article}
}
We have developed a new methodology to design conducting polymers with pre-specified properties. The methodology is based on the use of genetic algorithms (GAs) coupled to Negative Factor Counting technique. We present the results for a case study of polyanilines, one of the most important families of conducting polymers. The methodology proved to be able of generating automatic solutions for the problem of determining the optimum relative concentration for binary and ternary disordered polyaniline alloys exhibiting metallic properties. The methodology is completely general and can be used to design new classes of materials.
http://scholar.google.com/citations?hl=en&user=95SvbM8AAAAJ
