TY  - JOUR
AU  - Tomašević-Ilić, Tijana
AU  - Škoro, Nikola
AU  - Jovanović, Đorđe
AU  - Puač, Nevena
AU  - Spasenović, Marko
PY  - 2023
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/7210
AB  - Graphene films prepared from solution and deposited by Langmuir–Blodgett self-assembly technique (LBSA) were treated with radio-frequency (13.56 MHz) nitrogen plasma in order to investigate the influence of the time of nitrogen plasma exposure on the work function, sheet resistance, and surface morphology of LBSA graphene films. Kelvin probe force microscopy and sheet resistance measurements confirm nitrogen functionalization of our films, with the Fermi level shifting in a direction that indicates binding to a pyridinic and/or pyrrolic site. Upon 1 min of nitrogen plasma exposure, the sheet resistance decreases and there is no obvious difference in film morphology. However, plasma exposure longer than 5 min leads to the removal of graphene flakes and degradation of graphene films, in turn, affecting the flake connectivity and increasing film resistance. We show that by changing the exposure time, we can control the work function and decrease sheet resistance, without affecting surface morphology. Controllability of the plasma technique has an advantage for graphene functionalization over conventional doping techniques such as chemical drop-casting. It allows for the controllable tuning of the work function, surface morphology, and sheet resistance of LBSA graphene films, which is substantial for applications in various optoelectronic devices.
PB  - MDPI
T2  - Condensed Matter
T1  - Plasma-Assisted Nitrogen Doping of Langmuir–Blodgett Self-Assembled Graphene Films
VL  - 8
IS  - 2
SP  - 34
DO  - 10.3390/condmat8020034
ER  - 

@article{
author = "Tomašević-Ilić, Tijana and Škoro, Nikola and Jovanović, Đorđe and Puač, Nevena and Spasenović, Marko",
year = "2023",
abstract = "Graphene films prepared from solution and deposited by Langmuir–Blodgett self-assembly technique (LBSA) were treated with radio-frequency (13.56 MHz) nitrogen plasma in order to investigate the influence of the time of nitrogen plasma exposure on the work function, sheet resistance, and surface morphology of LBSA graphene films. Kelvin probe force microscopy and sheet resistance measurements confirm nitrogen functionalization of our films, with the Fermi level shifting in a direction that indicates binding to a pyridinic and/or pyrrolic site. Upon 1 min of nitrogen plasma exposure, the sheet resistance decreases and there is no obvious difference in film morphology. However, plasma exposure longer than 5 min leads to the removal of graphene flakes and degradation of graphene films, in turn, affecting the flake connectivity and increasing film resistance. We show that by changing the exposure time, we can control the work function and decrease sheet resistance, without affecting surface morphology. Controllability of the plasma technique has an advantage for graphene functionalization over conventional doping techniques such as chemical drop-casting. It allows for the controllable tuning of the work function, surface morphology, and sheet resistance of LBSA graphene films, which is substantial for applications in various optoelectronic devices.",
publisher = "MDPI",
journal = "Condensed Matter",
title = "Plasma-Assisted Nitrogen Doping of Langmuir–Blodgett Self-Assembled Graphene Films",
volume = "8",
number = "2",
pages = "34",
doi = "10.3390/condmat8020034"
}

Tomašević-Ilić, T., Škoro, N., Jovanović, Đ., Puač, N.,& Spasenović, M.. (2023). Plasma-Assisted Nitrogen Doping of Langmuir–Blodgett Self-Assembled Graphene Films. in Condensed Matter
MDPI., 8(2), 34.
https://doi.org/10.3390/condmat8020034

Tomašević-Ilić T, Škoro N, Jovanović Đ, Puač N, Spasenović M. Plasma-Assisted Nitrogen Doping of Langmuir–Blodgett Self-Assembled Graphene Films. in Condensed Matter. 2023;8(2):34.
doi:10.3390/condmat8020034 .

Tomašević-Ilić, Tijana, Škoro, Nikola, Jovanović, Đorđe, Puač, Nevena, Spasenović, Marko, "Plasma-Assisted Nitrogen Doping of Langmuir–Blodgett Self-Assembled Graphene Films" in Condensed Matter, 8, no. 2 (2023):34,
https://doi.org/10.3390/condmat8020034 . .

TY  - JOUR
AU  - Stojadinović, Sanja
AU  - Jovančićević, Branimir
AU  - Šajnović, Aleksandra
AU  - Golumbenau, Mariana
AU  - Almasan, Roxana
AU  - Jovanović, Đorđe
AU  - Brceski, Ilija
PY  - 2021
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/4006
AB  - The Techirghiol Lake, located on the Romanian coast of the Black Sea, is a hypersaline lake. In this environment, a unique ecosystem in Europe has developed with the specific capacity of producing mud by the decomposition of flora and fauna under the microbial activity (saprogenic sludge), which is used for therapeutic purposes.
In this study, hydrocarbon compositions of the Techirghiol Lake mud are investigated in order to determine the origin and type of organic matter (OM). All samples are characterized by a high abundance of n-alkanes, short and high chain alkenes, pimarane, phyllocladane, indicating that OM was mainly derived from phytoplankton, filamentous green alga Cladophora vagabunda, Cyanobacteria, submerged/floating macrophytes, terrestrial and emergent plants. The terrestrial origin of organic matter is probably related to a significant input by wind or rivers. Typical oil distributions of terpanes and steranes biomarkers clearly indicate that the muds of Techirghiol Lake, in addition to native organic matter, contain a relatively low contribution of petroleum type pollutants, as well as PAH compounds of pyrogenic origin. 
The relatively high abundance of 1-chloroalkenes, which in some samples represent the most abundant compounds in the total distribution of hydrocarbons, together with isoprenoid thiophenes indicate the local presence of significant amounts of chloride and sulphur species in the water column or surface sediment.
PB  - Parlar Scientific Publications
T2  - Fresenius Environmental Bulletin
T1  - Organic-geochemical characteristics of the mud from the Techirghiol Lake, Romania
UR  - https://hdl.handle.net/21.15107/rcub_cherry_4898
ER  - 

@article{
author = "Stojadinović, Sanja and Jovančićević, Branimir and Šajnović, Aleksandra and Golumbenau, Mariana and Almasan, Roxana and Jovanović, Đorđe and Brceski, Ilija",
year = "2021",
abstract = "The Techirghiol Lake, located on the Romanian coast of the Black Sea, is a hypersaline lake. In this environment, a unique ecosystem in Europe has developed with the specific capacity of producing mud by the decomposition of flora and fauna under the microbial activity (saprogenic sludge), which is used for therapeutic purposes.
In this study, hydrocarbon compositions of the Techirghiol Lake mud are investigated in order to determine the origin and type of organic matter (OM). All samples are characterized by a high abundance of n-alkanes, short and high chain alkenes, pimarane, phyllocladane, indicating that OM was mainly derived from phytoplankton, filamentous green alga Cladophora vagabunda, Cyanobacteria, submerged/floating macrophytes, terrestrial and emergent plants. The terrestrial origin of organic matter is probably related to a significant input by wind or rivers. Typical oil distributions of terpanes and steranes biomarkers clearly indicate that the muds of Techirghiol Lake, in addition to native organic matter, contain a relatively low contribution of petroleum type pollutants, as well as PAH compounds of pyrogenic origin. 
The relatively high abundance of 1-chloroalkenes, which in some samples represent the most abundant compounds in the total distribution of hydrocarbons, together with isoprenoid thiophenes indicate the local presence of significant amounts of chloride and sulphur species in the water column or surface sediment.",
publisher = "Parlar Scientific Publications",
journal = "Fresenius Environmental Bulletin",
title = "Organic-geochemical characteristics of the mud from the Techirghiol Lake, Romania",
url = "https://hdl.handle.net/21.15107/rcub_cherry_4898"
}

Stojadinović, S., Jovančićević, B., Šajnović, A., Golumbenau, M., Almasan, R., Jovanović, Đ.,& Brceski, I.. (2021). Organic-geochemical characteristics of the mud from the Techirghiol Lake, Romania. in Fresenius Environmental Bulletin
Parlar Scientific Publications..
https://hdl.handle.net/21.15107/rcub_cherry_4898

Stojadinović S, Jovančićević B, Šajnović A, Golumbenau M, Almasan R, Jovanović Đ, Brceski I. Organic-geochemical characteristics of the mud from the Techirghiol Lake, Romania. in Fresenius Environmental Bulletin. 2021;.
https://hdl.handle.net/21.15107/rcub_cherry_4898 .

Stojadinović, Sanja, Jovančićević, Branimir, Šajnović, Aleksandra, Golumbenau, Mariana, Almasan, Roxana, Jovanović, Đorđe, Brceski, Ilija, "Organic-geochemical characteristics of the mud from the Techirghiol Lake, Romania" in Fresenius Environmental Bulletin (2021),
https://hdl.handle.net/21.15107/rcub_cherry_4898 .