2021
3.
Barmpakos, D.; Belessi, V.; Schelwald, R.; Kaltsas, G.
In: Nanomaterials, vol. 11, iss. 2025, 2021.
Abstract | Links | BibTeX | Tags: flexible temperature sensors, graphene, inkjet-printed sensors, printed temperature sensors, Reduced graphene oxide
@article{Barmpakos2021,
title = {Evaluation of Inkjet-Printed Reduced and Functionalized Water-Dispersible Graphene Oxide and Graphene on Polymer Substrate—Application to Printed Temperature Sensors},
author = {D. Barmpakos and V. Belessi and R. Schelwald and G. Kaltsas },
doi = {https://doi.org/10.3390/nano11082025 },
year = {2021},
date = {2021-01-06},
urldate = {2021-01-06},
journal = {Nanomaterials},
volume = {11},
issue = {2025},
abstract = {The present work reports on the detailed electro-thermal evaluation of a highly water dispersible, functionalized reduced graphene oxide (f-rGO) using inkjet printing technology. Aiming in the development of printed electronic devices, a flexible polyimide substrate was used for the structures’ formation. A direct comparison between the f-rGO ink dispersion and a commercial graphene inkjet ink is also presented. Extensive droplet formation analysis was performed in order to evaluate the repeatable and reliable jetting from an inkjet printer under study. Electrical characterization was conducted and the electrical characteristics were assessed under different temperatures, showing that the water dispersion of the f-rGO is an excellent candidate for application in printed thermal sensors and microheaters. It was observed that the proposed f-rGO ink presents a tenfold increased temperature coefficient of resistance compared to the commercial graphene ink (G). A successful direct interconnection implementation of both materials with commercial Ag-nanoparticle ink lines was also demonstrated, thus allowing the efficient electrical interfacing of the printed structures. The investigated ink can be complementary utilized for developing fully printed devices with various characteristics, all on flexible substrates with cost-effective, few-step processes.},
keywords = {flexible temperature sensors, graphene, inkjet-printed sensors, printed temperature sensors, Reduced graphene oxide},
pubstate = {published},
tppubtype = {article}
}
The present work reports on the detailed electro-thermal evaluation of a highly water dispersible, functionalized reduced graphene oxide (f-rGO) using inkjet printing technology. Aiming in the development of printed electronic devices, a flexible polyimide substrate was used for the structures’ formation. A direct comparison between the f-rGO ink dispersion and a commercial graphene inkjet ink is also presented. Extensive droplet formation analysis was performed in order to evaluate the repeatable and reliable jetting from an inkjet printer under study. Electrical characterization was conducted and the electrical characteristics were assessed under different temperatures, showing that the water dispersion of the f-rGO is an excellent candidate for application in printed thermal sensors and microheaters. It was observed that the proposed f-rGO ink presents a tenfold increased temperature coefficient of resistance compared to the commercial graphene ink (G). A successful direct interconnection implementation of both materials with commercial Ag-nanoparticle ink lines was also demonstrated, thus allowing the efficient electrical interfacing of the printed structures. The investigated ink can be complementary utilized for developing fully printed devices with various characteristics, all on flexible substrates with cost-effective, few-step processes.
2019
2.
Georgitsopoulou, S.; Petrai, O.; Georgakilas, V.
Highly conductive functionalized reduced graphene oxide Journal Article
In: Surfaces and Interfaces, vol. 16, pp. 152-156, 2019, ISSN: 2468-0230.
Abstract | Links | BibTeX | Tags: 1, 3 dipolar cycloaddition, Carbon nanostructures, Conductive inks, Graphene oxide, Reduced graphene oxide
@article{Georgitsopoulou2019,
title = {Highly conductive functionalized reduced graphene oxide},
author = {S. Georgitsopoulou and O. Petrai and V. Georgakilas },
doi = {https://doi.org/10.1016/j.surfin.2019.05.010},
issn = {2468-0230},
year = {2019},
date = {2019-09-01},
urldate = {2019-09-01},
journal = {Surfaces and Interfaces},
volume = {16},
pages = {152-156},
abstract = {Graphene oxide (GO) is a derivative of graphene that is formed by the exfoliation of graphite oxide; product of graphite treatment with strong oxidants [1], [2], [3], [4]. GO nanosheets are decorated by epoxy and hydroxyl groups at the bulk and carboxylates mainly at the edges, while small isolated aromatic areas complete the surface [4], [5], [6]. The hydrophilic character of GO, due to the oxygen groups, induces high dispersibility in water or other polar solvents such as ethanol or dimethylformamide (DMF) [6], [7]. On the other hand, due to the very low aromatic character, GO is practically non conductive. 1,3 dipolar cycloaddition of azomethine ylide on GO in DMF was followed by a simultaneous reduction of GO. The as prepared functionalized reduced graphene oxide showed excellent stability in water and high electrical conductivity.},
keywords = {1, 3 dipolar cycloaddition, Carbon nanostructures, Conductive inks, Graphene oxide, Reduced graphene oxide},
pubstate = {published},
tppubtype = {article}
}
Graphene oxide (GO) is a derivative of graphene that is formed by the exfoliation of graphite oxide; product of graphite treatment with strong oxidants [1], [2], [3], [4]. GO nanosheets are decorated by epoxy and hydroxyl groups at the bulk and carboxylates mainly at the edges, while small isolated aromatic areas complete the surface [4], [5], [6]. The hydrophilic character of GO, due to the oxygen groups, induces high dispersibility in water or other polar solvents such as ethanol or dimethylformamide (DMF) [6], [7]. On the other hand, due to the very low aromatic character, GO is practically non conductive. 1,3 dipolar cycloaddition of azomethine ylide on GO in DMF was followed by a simultaneous reduction of GO. The as prepared functionalized reduced graphene oxide showed excellent stability in water and high electrical conductivity.
2018
1.
Belessi, V.; Petridis, D.; Steriotis, T.; Spyrou, K.; Manolis, G. K.; Psycharis, V.; Georgakilas, V.
Simultaneous reduction and surface functionalization of graphene oxide for highly conductive and water dispersible graphene derivatives Journal Article
In: SN Applied Sciences, vol. 1, iss. 77, 2018.
Abstract | Links | BibTeX | Tags: Conductive inks, Gravure, Printed electronics, Reduced graphene oxide, Surface functionalization
@article{Belessi2018,
title = {Simultaneous reduction and surface functionalization of graphene oxide for highly conductive and water dispersible graphene derivatives},
author = {V. Belessi and D. Petridis and T. Steriotis and K. Spyrou and G. K. Manolis and V. Psycharis and V. Georgakilas },
doi = {https://doi.org/10.1007/s42452-018-0077-9},
year = {2018},
date = {2018-12-03},
urldate = {2018-12-03},
journal = {SN Applied Sciences},
volume = {1},
issue = {77},
abstract = {A simple and effective preparation method for the simultaneous reduction and functionalization of graphene oxide (rGO) by 2,4-diamino benzene sulfonic acid has been developed. The derivatives exhibit excellent conductivity and high dispersibility in various solvents. The successful preparation of rGO and the presence of the sulfonated aromatic diamine on rGO surface has been confirmed by infrared and X-ray photoelectron spectroscopy, while, the analysis by micro-Raman spectroscopy indicated that the reduction/functionalization alters the lattice structure of GO by the increment the defect density when the 2,4-diamino benzene sulfonic acid is used. Moreover, the study of the dried products by X-ray diffraction spectroscopy suggested the turbostratic restacking of the exfoliated rGO into graphite-like nanostructures. The obtained derivative of simultaneous reduction and functionalization of GO was used for the preparation of highly conductive water-based gravure ink, which in turn, was successfully applied in printing on various flexible substrates, demonstrating its great potentiality in graphene-based flexible and printed electronics applications.},
keywords = {Conductive inks, Gravure, Printed electronics, Reduced graphene oxide, Surface functionalization},
pubstate = {published},
tppubtype = {article}
}
A simple and effective preparation method for the simultaneous reduction and functionalization of graphene oxide (rGO) by 2,4-diamino benzene sulfonic acid has been developed. The derivatives exhibit excellent conductivity and high dispersibility in various solvents. The successful preparation of rGO and the presence of the sulfonated aromatic diamine on rGO surface has been confirmed by infrared and X-ray photoelectron spectroscopy, while, the analysis by micro-Raman spectroscopy indicated that the reduction/functionalization alters the lattice structure of GO by the increment the defect density when the 2,4-diamino benzene sulfonic acid is used. Moreover, the study of the dried products by X-ray diffraction spectroscopy suggested the turbostratic restacking of the exfoliated rGO into graphite-like nanostructures. The obtained derivative of simultaneous reduction and functionalization of GO was used for the preparation of highly conductive water-based gravure ink, which in turn, was successfully applied in printing on various flexible substrates, demonstrating its great potentiality in graphene-based flexible and printed electronics applications.