| 1. |
- Anoshkin, Ilya, et al.
(author)
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Coronene Encapsulation in Single-Walled Carbon Nanotubes : Stacked Columns, Peapods, and Nanoribbons
- 2014
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In: ChemPhysChem. - : Wiley. - 1439-4235 .- 1439-7641. ; 15:8, s. 1660-1665
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Journal article (peer-reviewed)abstract
- Encapsulation of coronene inside single-walled carbon nanotubes (SWNTs) was studied under various conditions. Under high vacuum, two main types of molecular encapsulation were observed by using transmission electron microscopy: coronene dimers and molecular stacking columns perpendicular or tilted (45-608) with regard to the axis of the SWNTs. A relatively small number of short nanoribbons or polymerized coronene molecular chains were observed. However, experiments performed under an argon atmosphere (0.17 MPa) revealed reactions between the coronene molecules and the formation of hydrogen-terminated graphene nanoribbons. It was also observed that the morphology of the encapsulated products depend on the diameter of the SWNTs. The experimental results are explained by using density functional theory calculations through the energies of the coronene molecules inside the SWNTs, which depend on the orientation of the molecules and the diameter of the tubes.
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| 2. |
- Boulanger, Nicolas, et al.
(author)
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Spray deposition of supercapacitor electrodes using environmentally friendly aqueous activated graphene and activated carbon dispersions for industrial implementation
- 2021
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In: ChemElectroChem. - : John Wiley & Sons. - 2196-0216. ; 8:7, s. 1349-1361
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Journal article (peer-reviewed)abstract
- A spray gun machine was used to deposit high‐surface‐area supercapacitor electrodes using green non‐toxic aqueous dispersions based on different kinds of high specific surface area nanostructured carbon materials: activated graphene (a‐rGO) and activated carbon (AC). Tuning the spray conditions and dispersion formulation allowed us to achieve good adhesion to stainless‐steel current collectors in combination with high surface area and a satisfactory mechanical stability of the electrodes. The specific surface area of approximately 2000 m2/g was measured directly on a‐rGO and AC electrodes showing only around a 20 % decrease compared to the precursor powder materials. The performance of the electrodes deposited on stainless‐steel and aluminum current collectors was tested in supercapacitor devices using three electrolytes. The electrodes were tested in an “as‐deposited” state and after post‐deposition annealing at 200 °C. The spray deposition method and post‐deposition annealing are completely compatible with roll‐to‐roll industrial production methods. The a‐rGO demonstrated superior performance compared to AC in supercapacitor electrodes with gravimetric capacitance, energy, and power density parameters, which exceed commercially available analogues. The formulation of the dispersions used in this study is environmentally friendly, as it is based on only on water as a solvent and commercially available non‐toxic additives (graphene oxide, fumed silica, and carbon nanotubes).
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| 3. |
- Chernov, Alexander I, et al.
(author)
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Optical properties of graphene nanoribbons encapsulated in single-walled carbon nanotubes
- 2013
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In: ACS Nano. - : American Chemical Society (ACS). - 1936-0851 .- 1936-086X. ; 7:7, s. 6346-6353
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Journal article (peer-reviewed)abstract
- We report the photoluminescence (PL) from graphene nanoribbons (GNRs) encapsulated in single-walled carbon nanotubes (SWCNTs). New PL spectral features originating from GNRs have been detected in the visible spectral range. PL peaks from GNRs have resonant character, and their positions depend on the ribbon geometrical structure in accordance with the theoretical predictions. GNRs were synthesized using confined polymerization and fusion of coronene molecules. GNR@SWCNTs material demonstrates a bright photoluminescence both in infrared (IR) and visible regions. The photoluminescence excitation mapping in the near-IR spectral range has revealed the geometry-dependent shifts of the SWCNT peaks (up to 11 meV in excitation and emission) after the process of polymerization of coronene molecules inside the nanotubes. This behavior has been attributed to the strain of SWCNTs induced by insertion of the coronene molecules.
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| 4. |
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| 5. |
- Klechikov, Alexey, et al.
(author)
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Graphene decorated with metal nanoparticles : Hydrogen sorption and related artefacts
- 2017
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In: Microporous and Mesoporous Materials. - : Elsevier BV. - 1387-1811 .- 1873-3093. ; 250, s. 27-34
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Journal article (peer-reviewed)abstract
- Hydrogen sorption by reduced graphene oxides (r-GO) is not found to increase after decoration with Pd and Pt nanoparticles. Treatments of metal decorated samples using annealing under hydrogen or air were tested as a method to create additional pores by effects of r-GO etching around nanoparticles. Increase of Specific Surface Area (SSA) was observed for some air annealed r-GO samples. However, the same treatments applied to activated r-GO samples with microporous nature and higher surface area result in breakup of structure and dramatic decrease of SSA. Our experiments have not revealed effects which could be attributed to spillover in hydrogen sorption on Pd or Pt decorated graphene. However, we report irreversible chemisorption of hydrogen for some samples which can be mistakenly assigned to spillover if the experiments are incomplete.
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| 6. |
- Klechikov, Alexey, et al.
(author)
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Hydrogen storage in high surface area graphene scaffolds
- 2015
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In: Chemical Communications. - : Royal Society of Chemistry. - 1359-7345 .- 1364-548X. ; 51:83, s. 15280-15283
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Journal article (peer-reviewed)abstract
- Using an optimized KOH activation procedure we prepared highly porous graphene scaffold materials with SSA values up to 3400 m2 g−1 and a pore volume up to 2.2 cm3 g−1, which are among the highest for carbon materials. Hydrogen uptake of activated graphene samples was evaluated in a broad temperature interval (77–296 K). After additional activation by hydrogen annealing the maximal excess H2 uptake of 7.5 wt% was obtained at 77 K. A hydrogen storage value as high as 4 wt% was observed already at 193 K (120 bar H2), a temperature of solid CO2, which can be easily maintained using common industrial refrigeration methods.
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| 7. |
- Luzan, Serhiy, et al.
(author)
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Hydration of graphite oxide in electrolyte and non-electrolyte solutions
- 2011
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In: The Journal of Physical Chemistry C. - Washington DC : American Chemical Society (ACS). - 1932-7447 .- 1932-7455. ; 115:50, s. 24611-24614
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Journal article (peer-reviewed)abstract
- Pressure induced insertion of liquid media was studied for graphite oxide (GO) immersed in excess amounts of aqueous copper acetate and sucrose solutions and compared to previous experiments with GO immersed in solute-free water media. Compression of GO in copper acetate solution resulted in significant enhancement of high pressure anomaly compared to pure water: interlayer distance reached 17.4 Å at 2.3 GPa while for pure water the maximal observed layer separation was 13.08 Å. Compression of GO in sucrose solution was found to be very similar to compression in solute-free water. These results confirm that copper ions can be pressure-inserted into GO structure while the expansion of structure is attributed to osmotic swelling. Sucrose dissolves in water in molecular form (nonelectrolyte) which results in weaker absorption into the GO structure and the absence of osmotic swelling. Pressure induced insertion of various solutions into the GO structure could possibly be promising for synthesis of new graphite intercalation materials or graphene-related composites.
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| 8. |
- Luzan, Serhiy, 1985-, et al.
(author)
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Reaction of C60 with Hydrogen gas : In Situ monitoring and pathways
- 2011
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In: The Journal of Physical Chemistry C. - : American Chemical Society (ACS). - 1932-7447 .- 1932-7455. ; 115:23, s. 11484-11492
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Journal article (peer-reviewed)abstract
- Kinetics and pathways of C60 reaction with hydrogen gas were studied in a broad temperature interval and over extended periods of time. Specifically, hydrogenation was monitored in situ at high temperature and high hydrogen pressure conditions using the gravimetric method. The shape of gravimetric curve was found to depend on hydrogenation temperature: at 350–400 °C saturation of the sample weight was achieved, whereas at 420–440 °C the sample weight reached the maximum and decreased upon prolonged hydrogenation. The weight decrease is due to fullerene cage fragmentation with formation of light hydrocarbons evaporating from the sample. Hydrogenation products were studied by X-ray diffraction, MALDI TOF and APPI FT-ICR mass spectrometry, liquid chromatography, and elemental analysis. Hydrogenation pathways (from C60H18 up to C60H56) and possible mechanisms of hydrogenation-induced fragmentation of fulleranes are discussed.
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| 9. |
- Martin, Natalia M., et al.
(author)
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High-temperature reactions of C60 with polycyclic aromatic hydrocarbons
- 2010
-
In: Chemical Physics. - : Elsevier. - 0301-0104 .- 1873-4421. ; 368:1-2, s. 49-57
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Journal article (peer-reviewed)abstract
- Fullerenes are proposed as a precursor for preparation of nanocarbon materials using controlled collapse of cage structure by high temperature reaction with polycyclic aromatic hydrocarbons. The chemical modification of C60 by reaction with anthracene and coronene was studied over a broad temperature interval. The products of the reaction were characterized by X-ray diffraction, and Raman and IR spectroscopy. Mono- and multi-adducts of C60 with anthracene were obtained in the temperature interval 290–400 °C. Above 400 °C the C60 adducts are not stable and decompose back to C60 and anthracene. No chemical adducts of C60 with coronene were found below 500 °C. Above this temperature fullerite structure was found to expand reflecting interaction with coronene melt and vapor. The reactions of C60 with anthracene and C60 with coronene at temperatures above 650 °C resulted in fullerene cage collapse and formation of nanocarbons. These nanocarbons were found to store up to 0.45 wt% of hydrogen at ambient temperatures despite negligible surface area.
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| 10. |
- Nordenström, Andreas, et al.
(author)
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Intercalation of dyes in graphene oxide thin films and membranes
- 2021
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In: The Journal of Physical Chemistry C. - : American Chemical Society (ACS). - 1932-7447 .- 1932-7455. ; 125:12, s. 6877-6885
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Journal article (peer-reviewed)abstract
- Intercalation of dyes into thin multilayered graphene oxide (GO) films was studied by neutron reflectivity and X-ray diffraction. Methylene blue (MB) penetrates the interlayer space of GO in ethanol solution and remains intercalated after the solvent evaporation, as revealed by the expansion of the interlayer lattice and change in chemical composition. The sorption of MB by thin GO films is found to be significantly stronger compared to the sorption of Crystal violet (CV) and Rose bengal (RB). This effect is attributed to the difference in the geometrical shape of planar MB and essentially nonflat CV and RB molecules. Graphite oxides and restacked GO films are found to exhibit different methylene blue (MB) sorptions. MB sorption by precursor graphite oxide and thin spin-coated films of GO is significantly stronger compared to freestanding micrometer-thick membranes prepared by vacuum filtration. Nevertheless, the sorption capacity of GO membranes is sufficient to remove a significant part of the MB from diluted solutions tested for permeation in several earlier studies. High sorption capacity results in strong modification of the GO structure, which is likely to affect permeation properties of GO membranes. Therefore, MB is not suitable for testing size exclusion effects in the permeation of GO membranes. It is not only hydration or solvation diameter but also the exact geometrical shape of molecules that needs to be taken into account considering size effects for penetration of molecules between GO layers in membrane applications.
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| 11. |
- Skrypnychuk, Vasyl, 1986-, et al.
(author)
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Aqueous activated graphene dispersions for deposition of high-surface area supercapacitor electrodes
- 2020
-
In: The Journal of Physical Chemistry Letters. - : American Chemical Society (ACS). - 1948-7185. ; 11:8, s. 3032-3038
-
Journal article (peer-reviewed)abstract
- High-surface area activated graphene has a three-dimensional porous structure that makes it difficult to prepare dispersions. Here we report a general approach that allows the preparation of stable water-based dispersions/inks at concentrations of ≲20 mg/mL based on activated graphene using environmentally friendly formulations. Simple drying of the dispersion on the substrate allows the preparation of electrodes that maintain the high specific surface area of the precursor material (∼1700 m2/g). The electrodes are flexible because of the structure that consists of micrometer-sized activated graphene grains interconnected by carbon nanotubes (CNTs). The electrodes prepared using activated graphene demonstrate performance superior to that of reduced graphene oxide in supercapacitors with KOH and TEA BF4/acetonitrile electrolytes providing specific capacitance values of 180 and 137 F/g, respectively, at a specific current of 1 A/g. The high surface area of activated graphene in combination with the good conductivity of CNTs allows an energy density of 35.6 Wh/kg and a power density of 42.2 kW/kg to be achieved. The activated graphene dispersions were prepared in liter amounts and are compatible with most industrial deposition methods.
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| 12. |
- Sun, Jinhua, et al.
(author)
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A Molecular Pillar Approach To Grow Vertical Covalent Organic Framework Nanosheets on Graphene : Hybrid Materials for Energy Storage
- 2018
-
In: Angewandte Chemie International Edition. - : John Wiley & Sons. - 1433-7851 .- 1521-3773. ; 57:4, s. 1034-1038
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Journal article (peer-reviewed)abstract
- Hybrid 2D–2D materials composed of perpendicularly oriented covalent organic frameworks (COFs) and graphene were prepared and tested for energy storage applications. Diboronic acid molecules covalently attached to graphene oxide (GO) were used as nucleation sites for directing vertical growth of COF-1 nanosheets (v-COF-GO). The hybrid material has a forest of COF-1 nanosheets with a thickness of 3 to 15 nm in edge-on orientation relative to GO. The reaction performed without molecular pillars resulted in uncontrollable growth of thick COF-1 platelets parallel to the surface of GO. The v-COF-GO was converted into a conductive carbon material preserving the nanostructure of precursor with ultrathin porous carbon nanosheets grafted to graphene in edge-on orientation. It was demonstrated as a high-performance electrode material for supercapacitors. The molecular pillar approach can be used for preparation of many other 2D-2D materials with control of their relative orientation.
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| 13. |
- Szabó, Tamás, et al.
(author)
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Stability and dye inclusion of graphene oxide/polyelectrolyte layer-by-layer self-assembled films in saline, acidic and basic aqueous solutions
- 2017
-
In: Carbon. - : Elsevier. - 0008-6223 .- 1873-3891. ; 111, s. 350-357
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Journal article (peer-reviewed)abstract
- We demonstrate that a simple spectrophotometric method can be efficiently applied for the characterization of structural and chemical stability and adsorption properties of composite graphene oxide (GO) films in various solutions. The immersion stability of GO layer-by-layer (LbL) self-assembled with a polycation into ultrathin multilayered films was studied in water and in concentrated salty, acidic and basic solutions by UV-visible spectroscopy. These films were found to retain both their chemical stability and physical integrity in water, salt and HCl solutions with a slight rearrangement of the nanoscale structure as shown by the change in their visible spectrum. However, immersion into NaOH solutions above molar concentration led to the deconstruction of the multilayer structure by base-induced deoxygenation of GO. The adsorption of methylene blue on polymer/GO LbL films of various thicknesses revealed that the multilayers are largely impermeable towards this cationic dye.
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| 14. |
- Talyzin, Alexandr, 1969-, et al.
(author)
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Brodie vs Hummers graphite oxides for preparation of multi-layered materials
- 2017
-
In: Carbon. - : Elsevier. - 0008-6223 .- 1873-3891. ; 115, s. 430-440
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Journal article (peer-reviewed)abstract
- Graphite oxides synthesized by one and two step Brodie oxidation (BGO) and Hummers (HGO) methods were analyzed by a variety of characterization methods in order to evaluate the reasons behind the difference in their properties. It is found that the Brodie method results in a higher relative amount of hydroxyl groups and a more homogeneous overall distribution of functional groups over the planar surface of the graphene oxide flakes. The higher number of carbonyl and carboxyl groups in HGO, detected by several methods, including XPS, NMR and FTIR, unavoidably results in defects of the graphene "skeleton", holes and overall disruption of the carbon-carbon bond network, stronger deviation from planar flake shape and poor ordering of the graphene oxide layers. It is also suggested that functional groups in HGO are less homogeneously distributed over the flake surface, forming some nanometer-sized graphene areas. The presence of differently oxidized areas on the GO surface results in inhomogeneous solvation and hydration of HGO and effects of inter- and intra-stratification. The proposed interpretation of the data explains the higher mechanical strength of multi-layered BGO membranes/papers, which are also less affected by humidity changes, thus providing an example of a membrane property superior to that of HGO. (C) 2016 Published by Elsevier Ltd.
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| 15. |
- Talyzin, Alexandr, 1969-, et al.
(author)
-
Coronene Fusion by Heat Treatment : Road to Nanographenes
- 2011
-
In: The Journal of Physical Chemistry C. - Washington : American Chemical Society (ACS). - 1932-7447 .- 1932-7455. ; 115:27, s. 13207-13214
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Journal article (peer-reviewed)abstract
- The reactions of coronene dehydrogenation and fusion upon heat treatment in the temperature range of 500-700 degrees C were studied using XRD, TEM, Raman, IR, and NEXAFS spectroscopy. The formation of a coronene dimer (dicoronylene) was observed at temperatures 530-550 degrees C; dicoronylene can easily be separated using sublimation with a temperature gradient. An insoluble and not sublimable black precipitate was found to form at higher temperatures. Analysis of the data shows that dimerization of coronene is followed at 550-600 degrees C by oligomerization into larger molecules. Above 600 degrees C amorphization of the material and formation of graphitic nanoparticles was observed. Coronene fusion by annealing is proposed as a road to synthesis of larger polycyclic aromatic hydrocarbons and nanographenes.
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| 16. |
- Talyzin, Alexandr, 1969-
(author)
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Feasibility of H2–THF–H2O clathrate hydrates for hydrogen storage applications
- 2008
-
In: International journal of hydrogen energy. - : Elsevier. - 0360-3199 .- 1879-3487. ; 33:1, s. 111-115
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Journal article (peer-reviewed)abstract
- Hydrogen storage capacity of hydrogen clathrate hydrates H-2-THF-H2O was directly measured using gravimetric method. The amount of hydrogen stored in a bulk piece of ice was below 0.1 wt% even after prolonged exposure to hydrogen at 150 bar. It is confirmed that fine dispersion of material is required to improve kinetics of hydrogen uptake. To achieve a fine dispersion of ice grains, it is proposed to use rather common light framework materials with size of pore sizes of about 200-300 mu m as a support media. The samples dispersed in foamed polyurethane showed measurable hydrogen uptake at 135 bar H-2 pressure and release. However, the amount of stored hydrogen was found maximum on the level of 0.2 wt%.
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| 17. |
- Talyzin, Alexandr, 1969-, et al.
(author)
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Hydrogenation, Purification, and Unzipping of Carbon Nanotubes by Reaction with Molecular Hydrogen : Road to Graphane Nanoribbons
- 2011
-
In: ACS Nano. - : American Chemical Society (ACS). - 1936-0851 .- 1936-086X. ; 5:6, s. 5132-5140
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Journal article (peer-reviewed)abstract
- Reaction of single-walled carbon nanotubes (SWNTs) with hydrogen gas was studied in a temperature interval of 400-550 degrees C and at hydrogen pressure of 50 bar. Hydrogenation of nanotubes was observed for samples treated at 400-450 degrees C with about 1/3 of carbon atoms forming covalent C-H bonds, whereas hydrogen treatment at higher temperatures (550 degrees C) occurs as an etching. Unzipping of some SWNTs Into graphene nanoribbons is observed as a result of hydrogenation at 400-550 degrees C Annealing in hydrogen gas at elevated conditions for prolonged periods of time (72 h) is demonstrated to result also in nanotube opening, purification of nanotubes from amorphous carbon, and removal of carbon coatings from Fe catalyst particles, which allows their complete elimination by acid treatment.
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| 18. |
- Talyzin, Alexandr, 1969-, et al.
(author)
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Pressure-induced insertion of liquid acetone into the graphite oxide structure
- 2010
-
In: The Journal of Physical Chemistry C. - : American Chemical Society (ACS). - 1932-7447 .- 1932-7455. ; 114:11, s. 7004-7006
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Journal article (peer-reviewed)abstract
- An expansion of the graphite oxide structure due to pressure-induced insertion of acetone solvent was observed upon compression at 0.9 GPa. However, conversion into the expanded high-pressure phase is not complete, with the high-pressure and the ambient-pressure phases coexisting even at pressures up to 4.5 GPa. The phase transformation is not correlated with the solidification point of acetone, a behavior similar to that of the graphite oxide/alcohol systems and unlike that of the previously studied graphite oxide/water system. It can be concluded that pressure-induced insertion of solvent into the graphite oxide structure occurs not only for protic solvents (water, methanol, ethanol) but also for aprotic polar solvents (acetone).
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| 19. |
- Talyzin, Alexandr, 1969-, et al.
(author)
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Synthesis of Graphene Nanoribbons Encapsulated in Single-Walled Carbon Nanotubes
- 2011
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In: Nano letters (Print). - : American Chemical Society (ACS). - 1530-6984 .- 1530-6992. ; 11:10, s. 4352-4356
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Journal article (peer-reviewed)abstract
- A novel material, graphene nanoribbons encapsulated in single-walled carbon nanotubes (GNR@SWNT), was synthesized using confined polymerization and fusion of polycyclic aromatic hydrocarbon (PAH) molecules. Formation of the GNR is possible due to confinement effects provided by the one-dimensional space inside nanotubes, which helps to align coronene or perylene molecules edge to edge to achieve dimerization and oligomerization of the molecules into long nanoribbons. Almost 100% filling of SWNT with GNR is achieved while nanoribbon length is limited only by the length of the encapsulating nanotube. The PAH fusion reaction provides a very simple and easily scalable method to synthesize GNR@SWNT in macroscopic amounts. First-principle simulations indicate that encapsulation of the GNRs is energetically favorable and that the electronic structure of the encapsulated GNRs is the same as for the free-standing ones, pointing to possible applications of the GNR@SWNT structures in photonics and nanoelectronics.
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| 20. |
- Talyzin, Alexandr, 1969-, et al.
(author)
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Temperature dependent structural breathing of hydrated graphite oxide in H2O
- 2011
-
In: Carbon. - : Elsevier. - 0008-6223 .- 1873-3891. ; 49:6, s. 1894-1899
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Journal article (peer-reviewed)abstract
- Hydration of graphite oxide by excess of water was studied in the temperature interval 295–230 K. A structural breathing effect is found for fully hydrated graphite oxide near the water solidification/melting point. Expansion of hydrated graphite oxide structure due to insertion of additional water occurs upon cooling down from ambient temperature to the point of water media freezing. Cooling down below the point of water medium solidification results in stepwise contraction of graphite oxide interlayer distance by ∼25% due to partial withdrawal of water from the hydrated structure. Heating back from 230 K to ambient temperature results in graphite oxide structure expansion due absorption of water from medium, thus making a reversible cycle. The effect of structure breathing is important for any chemical treatments performed with graphite oxide in solution, e.g. graphite oxide functionalizationand conversion into graphene-related materials.
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| 21. |
- You, Shujie, et al.
(author)
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Effect of synthesis method on solvation and exfoliation of graphite oxide
- 2013
-
In: Carbon. - : Elsevier BV. - 0008-6223 .- 1873-3891. ; 52, s. 171-180
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Journal article (peer-reviewed)abstract
- Graphite oxides (GOs) synthesized by Brodie’s and Hummers’ methods are significantly different with respect to hydration, solvation and exfoliation properties. Hummers GO is more easily intercalated by liquid water and alcohols, exhibiting osmotic type of swelling. In contrast, Brodie GO shows crystalline swelling in alcohol solvents with step-like insertion of methanol or ethanol monolayers. However, the stronger hydration and easier dispersion in water observed for Hummers GO do not correlate with better dispersion of graphene powder obtained by thermal exfoliation. Higher surface area graphene powder was obtained by exfoliation of Brodie GO, while the temperature of its exfoliation is about 75 C higher than that for the studied sample of Hummers GO. It is suggested that higher exfoliation temperature and better crystallinity of GO are important factors for preparation of graphene powder using thermal exfoliation.
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| 22. |
- You, Shujie, et al.
(author)
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Enormous lattice expansion of hummers graphite oxide in alcohols at low temperatures
- 2013
-
In: ACS Nano. - : American Chemical Society (ACS). - 1936-0851 .- 1936-086X. ; 7:2, s. 1395-1399
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Journal article (peer-reviewed)abstract
- A structural study of swelling of Hummers graphite oxide (H-GO) in excess of liquid alcohols was performed as a function of temperature using synchrotron X-ray diffraction and revealed a strong “negative thermal expansion” effect. The increase of the distance between graphene oxide layers is explained by insertion of additional solvent upon cooling of the H-GO/solvent system. The interlayer distance of H-GO is found to increase gradually upon temperature decrease, reaching 19.4 and 20.6 Å at 140 K for methanol and ethanol, respectively. The gradual expansion of the H-GO lattice upon cooling corresponds to insertion of at least two additional solvent monolayers and can be described as osmotic swelling. This phenomenon is distinctly different from the solvation of Brodie graphite oxide (B-GO), which was found earlier to exhibit crystalline swelling: single-step insertion of an additional solvent monolayer at low temperatures. The enormous structural expansion of H-GO at low temperatures is suggested to be useful for solution-based intercalation of graphite oxide with relatively large molecules and the synthesis of various composite materials.
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| 23. |
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| 24. |
- You, Shujie, et al.
(author)
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Solvation of graphite oxide in water-methanol binary polar solvents
- 2012
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In: Physica status solidi. B, Basic research. - : Wiley. - 0370-1972 .- 1521-3951. ; 249:12, s. 2568-2571
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Journal article (peer-reviewed)abstract
- The phase transition between two solvated phases was studied by DSC for graphite oxide (GO) powders immersed in water–methanol mixtures of various compositions. GO forms solid solvates with two different compositions when immersed in methanol. Reversible phase transition between two solvate states due to insertion/desertion of methanol monolayer occurs upon temperature variations. The temperature point and the enthalpy (DH) of the phase transition are maximal for pure methanol and decrease linearly with increase of water fraction up to 30%.
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