http://scholar.google.com/citations?hl=en&user=95SvbM8AAAAJ
Woellner, Cristiano F.; Owuor, Peter S.; Li, Tong; Vinod, Soumya; Ozden, Sehmus; Kosolwattana, Suppanat; Bhowmick, Sanjit; Duy, Luong X.; Salvatierra, Rodrigo V.; Wei, Bingqing; Asif, Syed A. S.; Tour, James M.; Vajtai, Robert; Lou, Jun; Galvão, Douglas S.; Tiwary, Chandra S.; Ajayan, Pulickel. M.
Mechanical Properties of Ultralow Density Graphene Oxide/Polydimethylsiloxane Foams Journal Article
Em: MRS Advances, vol. 3, não 1-2, pp. 61-66, 2018.
@article{Woellner2018c,
title = {Mechanical Properties of Ultralow Density Graphene Oxide/Polydimethylsiloxane Foams},
author = {Cristiano F. Woellner and Peter S. Owuor and Tong Li and Soumya Vinod and Sehmus Ozden and Suppanat Kosolwattana and Sanjit Bhowmick and Luong X. Duy and Rodrigo V. Salvatierra and Bingqing Wei and Syed A. S. Asif and James M. Tour and Robert Vajtai and Jun Lou and Douglas S. Galvão and Chandra S. Tiwary and Pulickel. M. Ajayan},
url = {https://www.cambridge.org/core/journals/mrs-advances/article/mechanical-properties-of-ultralow-density-graphene-oxidepolydimethylsiloxane-foams/BC2DC24B3DB5714759FC1EDC71BD9D05},
doi = {DOI: 10.1557/adv.2018. 49},
year = {2018},
date = {2018-01-18},
journal = {MRS Advances},
volume = {3},
number = {1-2},
pages = { 61-66},
abstract = {Low-density, highly porous graphene/graphene oxide (GO) based-foams have shown high performance in energy absorption applications, even under high compressive deformations. In general, foams are very effective as energy dissipative materials and have been widely used in many areas such as automotive, aerospace and biomedical industries. In the case of graphene-based foams, the good mechanical properties are mainly attributed to the intrinsic graphene and/or GO electronic and mechanical properties. Despite the attractive physical properties of graphene/GO based-foams, their structural and thermal stabilities are still a problem for some applications. For instance, they are easily degraded when placed in flowing solutions, either by the collapsing of their layers or just by structural disintegration into small pieces. Recently, a new and scalable synthetic approach to produce low-density 3D macroscopic GO structure interconnected with polydimethylsiloxane (PDMS) polymeric chains (pGO) was proposed. A controlled amount of PDMS is infused into the freeze-dried foam resulting into a very rigid structure with improved mechanical properties, such as tensile plasticity and toughness. The PDMS wets the graphene oxide sheets and acts like a glue bonding PDMS and GO sheets. In order to obtain further insights on mechanisms behind the enhanced mechanical pGO response we carried out fully atomistic molecular dynamics (MD) simulations. Based on MD results, we build up a structural model that can explain the experimentally observed mechanical behavior.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Owuor, Peter Samora; Park, Ok-Kyung; Woellner, Cristiano F; Jalilov, Almaz S; Susarla, Sandhya; Joyner, Jarin; Ozden, Sehmus; Duy, LuongXuan; Villegas Salvatierra, Rodrigo; Vajtai, Robert; Tour, James M; Lou, Jun; Galvao, Douglas S; Tiwary, Chandra S; Ajayan, P M
Lightweight Hexagonal Boron Nitride Foam for CO2 Absorption Journal Article
Em: ACS Nano, vol. 11, não 8, pp. 8944–8952, 2017.
@article{Owuor2017b,
title = {Lightweight Hexagonal Boron Nitride Foam for CO2 Absorption},
author = {Owuor, Peter Samora and Park, Ok-Kyung and Woellner, Cristiano F and Jalilov, Almaz S and Susarla, Sandhya and Joyner, Jarin and Ozden, Sehmus and Duy, LuongXuan and Villegas Salvatierra, Rodrigo and Vajtai, Robert and Tour, James M and Lou, Jun and Galvao, Douglas S and Tiwary, Chandra S and Ajayan, P M},
url = {http://pubs.acs.org/doi/abs/10.1021/acsnano.7b03291},
doi = {10.1021/acsnano.7b03291},
year = {2017},
date = {2017-08-03},
journal = {ACS Nano},
volume = {11},
number = {8},
pages = {8944–8952},
abstract = {Weak van der Waals forces between inert hexagonal boron nitride (h-BN) nanosheets make it easy for them to slide over each other, resulting in an unstable structure in macroscopic dimensions. Creating interconnections between these inert nanosheets can remarkably enhance their mechanical properties. However, controlled design of such interconnections remains a fundamental problem for many applications of h-BN foams. In this work, a scalable in situ freeze-drying synthesis of low-density, lightweight 3D macroscopic structures made of h-BN nanosheets chemically connected by poly(vinyl alcohol) (PVA) molecules via chemical cross-link is demonstrated. Unlike pristine h-BN foam which disintegrates upon handling after freeze-drying, h-BN/PVA foams exhibit stable mechanical integrity in addition to high porosity and large surface area. Fully atomistic simulations are used to understand the interactions between h-BN nanosheets and PVA molecules. In addition, the h-BN/PVA foam is investigated as a possible CO2 absorption and as laser irradiation protection material.
},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Cristiano F Woellner Peter Samora Owuor, Tong Li
High Toughness in Ultralow Density Graphene Oxide Foam Journal Article
Em: Advanced Materials Interfaces, vol. 4, não 10, pp. 1700030, 2017.
@article{Owuor2017,
title = {High Toughness in Ultralow Density Graphene Oxide Foam},
author = {Peter Samora Owuor, Cristiano F Woellner, Tong Li, Soumya Vinod, Sehmus Ozden, Suppanat Kosolwattana, Sanjit Bhowmick, Luong Xuan Duy, Rodrigo V Salvatierra, Bingqing Wei, Syed AS Asif, James M Tour, Robert Vajtai, Jun Lou, Douglas S Galvão, Chandra Sekhar Tiwary, Pulickel Ajayan},
url = {http://onlinelibrary.wiley.com/doi/10.1002/admi.201700030/abstract },
doi = {10.1002/admi.201700030},
year = {2017},
date = {2017-03-01},
journal = {Advanced Materials Interfaces},
volume = {4},
number = {10},
pages = {1700030},
abstract = {Here, the scalable synthesis of low-density 3D macroscopic structure of graphene oxide (GO) interconnected with polydimethylsiloxane (PDMS) is reported. A controlled amount of PDMS is infused into the freeze-dried foam to result into a very rigid structure with improved mechanical properties, such as tensile plasticity and toughness. The PDMS wets the graphene oxide sheets and acts like glue between the 2D sheets. Molecular dynamics simulations are used to further elucidate the mechanisms of the interactions of graphene oxide layers with PDMS. The ability of using the interconnecting graphene oxide foam as an effective oil–water separator and stable insulating behavior to elevated temperatures are further demonstrated. The structural rigidity of the sample is also tested using laser impact and compared with GO foam.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Chandra Sekhar Tiwary Soumya Vinod, Leonardo D Machado
Synthesis of ultralow density 3D graphene–CNT foams using a two-step method Journal Article
Em: Nanoscale, vol. 8, não 35, pp. 15857-15863, 2016.
@article{Vinod2016b,
title = {Synthesis of ultralow density 3D graphene–CNT foams using a two-step method},
author = {Soumya Vinod, Chandra Sekhar Tiwary, Leonardo D Machado, Sehmus Ozden, Robert Vajtai, Douglas S Galvao, Pulickel M Ajayan},
url = {xlink.rsc.org/?DOI=c6nr04252j},
doi = {10.1039/C6NR04252J},
year = {2016},
date = {2016-08-09},
journal = {Nanoscale},
volume = {8},
number = {35},
pages = {15857-15863},
abstract = {Here, we report a highly scalable two-step method to produce graphene foams with ordered carbon nanotube reinforcements. In our approach, we first used solution assembly methods to obtain graphene oxide foam. Next, we employed chemical vapor deposition to simultaneously grow carbon nanotubes and thermally reduce the 3D graphene oxide scaffold. The resulting structure presented increased stiffness, good mechanical stability and oil absorption properties. Molecular dynamics simulations were carried out to further elucidate failure mechanisms and to understand the enhancement of the mechanical properties. The simulations showed that mechanical failure is directly associated with bending of vertical reinforcements, and that, for similar length and contact area, much more stress is required to bend the corresponding reinforcements of carbon nanotubes, thus explaining the experimentally observed enhanced mechanical properties.
},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Vinod, Soumya; Tiwary, Chandra Sekhar; da Silva Autreto, Pedro Alves; Taha-Tijerina, Jaime; Ozden, Sehmus; Chipara, Alin Cristian; Vajtai, Robert; Galvao, Douglas S; Narayanan, Tharangattu N; Ajayan, Pulickel M
Low-density three-dimensional foam using self-reinforced hybrid two-dimensional atomic layers Journal Article
Em: Nature Communications, vol. 5, 2014.
@article{vinod2014low,
title = {Low-density three-dimensional foam using self-reinforced hybrid two-dimensional atomic layers},
author = {Vinod, Soumya and Tiwary, Chandra Sekhar and da Silva Autreto, Pedro Alves and Taha-Tijerina, Jaime and Ozden, Sehmus and Chipara, Alin Cristian and Vajtai, Robert and Galvao, Douglas S and Narayanan, Tharangattu N and Ajayan, Pulickel M},
url = {http://www.nature.com/ncomms/2014/140729/ncomms5541/full/ncomms5541.html},
year = {2014},
date = {2014-01-01},
journal = {Nature Communications},
volume = {5},
publisher = {Nature Publishing Group},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
2018

Woellner, Cristiano F.; Owuor, Peter S.; Li, Tong; Vinod, Soumya; Ozden, Sehmus; Kosolwattana, Suppanat; Bhowmick, Sanjit; Duy, Luong X.; Salvatierra, Rodrigo V.; Wei, Bingqing; Asif, Syed A. S.; Tour, James M.; Vajtai, Robert; Lou, Jun; Galvão, Douglas S.; Tiwary, Chandra S.; Ajayan, Pulickel. M.
Mechanical Properties of Ultralow Density Graphene Oxide/Polydimethylsiloxane Foams Journal Article
Em: MRS Advances, vol. 3, não 1-2, pp. 61-66, 2018.
Resumo | Links | BibTeX | Tags: foams, Mechanical Properties, Molecular Dynamics
@article{Woellner2018c,
title = {Mechanical Properties of Ultralow Density Graphene Oxide/Polydimethylsiloxane Foams},
author = {Cristiano F. Woellner and Peter S. Owuor and Tong Li and Soumya Vinod and Sehmus Ozden and Suppanat Kosolwattana and Sanjit Bhowmick and Luong X. Duy and Rodrigo V. Salvatierra and Bingqing Wei and Syed A. S. Asif and James M. Tour and Robert Vajtai and Jun Lou and Douglas S. Galvão and Chandra S. Tiwary and Pulickel. M. Ajayan},
url = {https://www.cambridge.org/core/journals/mrs-advances/article/mechanical-properties-of-ultralow-density-graphene-oxidepolydimethylsiloxane-foams/BC2DC24B3DB5714759FC1EDC71BD9D05},
doi = {DOI: 10.1557/adv.2018. 49},
year = {2018},
date = {2018-01-18},
journal = {MRS Advances},
volume = {3},
number = {1-2},
pages = { 61-66},
abstract = {Low-density, highly porous graphene/graphene oxide (GO) based-foams have shown high performance in energy absorption applications, even under high compressive deformations. In general, foams are very effective as energy dissipative materials and have been widely used in many areas such as automotive, aerospace and biomedical industries. In the case of graphene-based foams, the good mechanical properties are mainly attributed to the intrinsic graphene and/or GO electronic and mechanical properties. Despite the attractive physical properties of graphene/GO based-foams, their structural and thermal stabilities are still a problem for some applications. For instance, they are easily degraded when placed in flowing solutions, either by the collapsing of their layers or just by structural disintegration into small pieces. Recently, a new and scalable synthetic approach to produce low-density 3D macroscopic GO structure interconnected with polydimethylsiloxane (PDMS) polymeric chains (pGO) was proposed. A controlled amount of PDMS is infused into the freeze-dried foam resulting into a very rigid structure with improved mechanical properties, such as tensile plasticity and toughness. The PDMS wets the graphene oxide sheets and acts like a glue bonding PDMS and GO sheets. In order to obtain further insights on mechanisms behind the enhanced mechanical pGO response we carried out fully atomistic molecular dynamics (MD) simulations. Based on MD results, we build up a structural model that can explain the experimentally observed mechanical behavior.},
keywords = {foams, Mechanical Properties, Molecular Dynamics},
pubstate = {published},
tppubtype = {article}
}
2017

Owuor, Peter Samora; Park, Ok-Kyung; Woellner, Cristiano F; Jalilov, Almaz S; Susarla, Sandhya; Joyner, Jarin; Ozden, Sehmus; Duy, LuongXuan; Villegas Salvatierra, Rodrigo; Vajtai, Robert; Tour, James M; Lou, Jun; Galvao, Douglas S; Tiwary, Chandra S; Ajayan, P M
Lightweight Hexagonal Boron Nitride Foam for CO2 Absorption Journal Article
Em: ACS Nano, vol. 11, não 8, pp. 8944–8952, 2017.
Resumo | Links | BibTeX | Tags: foams, Mechanical Properties, Molecular Dynamics
@article{Owuor2017b,
title = {Lightweight Hexagonal Boron Nitride Foam for CO2 Absorption},
author = {Owuor, Peter Samora and Park, Ok-Kyung and Woellner, Cristiano F and Jalilov, Almaz S and Susarla, Sandhya and Joyner, Jarin and Ozden, Sehmus and Duy, LuongXuan and Villegas Salvatierra, Rodrigo and Vajtai, Robert and Tour, James M and Lou, Jun and Galvao, Douglas S and Tiwary, Chandra S and Ajayan, P M},
url = {http://pubs.acs.org/doi/abs/10.1021/acsnano.7b03291},
doi = {10.1021/acsnano.7b03291},
year = {2017},
date = {2017-08-03},
journal = {ACS Nano},
volume = {11},
number = {8},
pages = {8944–8952},
abstract = {Weak van der Waals forces between inert hexagonal boron nitride (h-BN) nanosheets make it easy for them to slide over each other, resulting in an unstable structure in macroscopic dimensions. Creating interconnections between these inert nanosheets can remarkably enhance their mechanical properties. However, controlled design of such interconnections remains a fundamental problem for many applications of h-BN foams. In this work, a scalable in situ freeze-drying synthesis of low-density, lightweight 3D macroscopic structures made of h-BN nanosheets chemically connected by poly(vinyl alcohol) (PVA) molecules via chemical cross-link is demonstrated. Unlike pristine h-BN foam which disintegrates upon handling after freeze-drying, h-BN/PVA foams exhibit stable mechanical integrity in addition to high porosity and large surface area. Fully atomistic simulations are used to understand the interactions between h-BN nanosheets and PVA molecules. In addition, the h-BN/PVA foam is investigated as a possible CO2 absorption and as laser irradiation protection material.
},
keywords = {foams, Mechanical Properties, Molecular Dynamics},
pubstate = {published},
tppubtype = {article}
}

Cristiano F Woellner Peter Samora Owuor, Tong Li
High Toughness in Ultralow Density Graphene Oxide Foam Journal Article
Em: Advanced Materials Interfaces, vol. 4, não 10, pp. 1700030, 2017.
Resumo | Links | BibTeX | Tags: foams, graphene oxide, Mechanical Properties, Molecular Dynamics
@article{Owuor2017,
title = {High Toughness in Ultralow Density Graphene Oxide Foam},
author = {Peter Samora Owuor, Cristiano F Woellner, Tong Li, Soumya Vinod, Sehmus Ozden, Suppanat Kosolwattana, Sanjit Bhowmick, Luong Xuan Duy, Rodrigo V Salvatierra, Bingqing Wei, Syed AS Asif, James M Tour, Robert Vajtai, Jun Lou, Douglas S Galvão, Chandra Sekhar Tiwary, Pulickel Ajayan},
url = {http://onlinelibrary.wiley.com/doi/10.1002/admi.201700030/abstract },
doi = {10.1002/admi.201700030},
year = {2017},
date = {2017-03-01},
journal = {Advanced Materials Interfaces},
volume = {4},
number = {10},
pages = {1700030},
abstract = {Here, the scalable synthesis of low-density 3D macroscopic structure of graphene oxide (GO) interconnected with polydimethylsiloxane (PDMS) is reported. A controlled amount of PDMS is infused into the freeze-dried foam to result into a very rigid structure with improved mechanical properties, such as tensile plasticity and toughness. The PDMS wets the graphene oxide sheets and acts like glue between the 2D sheets. Molecular dynamics simulations are used to further elucidate the mechanisms of the interactions of graphene oxide layers with PDMS. The ability of using the interconnecting graphene oxide foam as an effective oil–water separator and stable insulating behavior to elevated temperatures are further demonstrated. The structural rigidity of the sample is also tested using laser impact and compared with GO foam.},
keywords = {foams, graphene oxide, Mechanical Properties, Molecular Dynamics},
pubstate = {published},
tppubtype = {article}
}
2016

Chandra Sekhar Tiwary Soumya Vinod, Leonardo D Machado
Synthesis of ultralow density 3D graphene–CNT foams using a two-step method Journal Article
Em: Nanoscale, vol. 8, não 35, pp. 15857-15863, 2016.
Resumo | Links | BibTeX | Tags: Carbon Nanotubes, foams, Molecular Dynamics
@article{Vinod2016b,
title = {Synthesis of ultralow density 3D graphene–CNT foams using a two-step method},
author = {Soumya Vinod, Chandra Sekhar Tiwary, Leonardo D Machado, Sehmus Ozden, Robert Vajtai, Douglas S Galvao, Pulickel M Ajayan},
url = {xlink.rsc.org/?DOI=c6nr04252j},
doi = {10.1039/C6NR04252J},
year = {2016},
date = {2016-08-09},
journal = {Nanoscale},
volume = {8},
number = {35},
pages = {15857-15863},
abstract = {Here, we report a highly scalable two-step method to produce graphene foams with ordered carbon nanotube reinforcements. In our approach, we first used solution assembly methods to obtain graphene oxide foam. Next, we employed chemical vapor deposition to simultaneously grow carbon nanotubes and thermally reduce the 3D graphene oxide scaffold. The resulting structure presented increased stiffness, good mechanical stability and oil absorption properties. Molecular dynamics simulations were carried out to further elucidate failure mechanisms and to understand the enhancement of the mechanical properties. The simulations showed that mechanical failure is directly associated with bending of vertical reinforcements, and that, for similar length and contact area, much more stress is required to bend the corresponding reinforcements of carbon nanotubes, thus explaining the experimentally observed enhanced mechanical properties.
},
keywords = {Carbon Nanotubes, foams, Molecular Dynamics},
pubstate = {published},
tppubtype = {article}
}
2014

Vinod, Soumya; Tiwary, Chandra Sekhar; da Silva Autreto, Pedro Alves; Taha-Tijerina, Jaime; Ozden, Sehmus; Chipara, Alin Cristian; Vajtai, Robert; Galvao, Douglas S; Narayanan, Tharangattu N; Ajayan, Pulickel M
Low-density three-dimensional foam using self-reinforced hybrid two-dimensional atomic layers Journal Article
Em: Nature Communications, vol. 5, 2014.
Links | BibTeX | Tags: foams, Fracture, Graphene, Mechanical Properties, top20
@article{vinod2014low,
title = {Low-density three-dimensional foam using self-reinforced hybrid two-dimensional atomic layers},
author = {Vinod, Soumya and Tiwary, Chandra Sekhar and da Silva Autreto, Pedro Alves and Taha-Tijerina, Jaime and Ozden, Sehmus and Chipara, Alin Cristian and Vajtai, Robert and Galvao, Douglas S and Narayanan, Tharangattu N and Ajayan, Pulickel M},
url = {http://www.nature.com/ncomms/2014/140729/ncomms5541/full/ncomms5541.html},
year = {2014},
date = {2014-01-01},
journal = {Nature Communications},
volume = {5},
publisher = {Nature Publishing Group},
keywords = {foams, Fracture, Graphene, Mechanical Properties, top20},
pubstate = {published},
tppubtype = {article}
}