Author: Michael Mead Lerner
Publisher:
ISBN:
Category :
Languages : en
Pages : 270
Book Description
Preparation and Characterization of Graphite Fluorometallate Salts and Graphite Fluorides by Chemical and Electrochemical Methods
Energy Research Abstracts
Graphite Intercalation with Fluoroanions by Chemical and Electrochemical Methods
Author: Bahar Ozmen Monkul
Publisher:
ISBN:
Category : Graphite fluorides
Languages : en
Pages : 338
Book Description
New acceptor-type graphite intercalation compounds (GICs) containing perfluoroalkyl anions have been synthesized by using both chemical and electrochemical methods and characterized by elemental and thermogravimetric analyses. Investigation into these graphite intercalation compounds can provide novel materials and a detailed understanding of their properties. GICs of composition Cx[FB(C2F5)3]·[delta]F are prepared for the first time by the intercalation of fluoro-tris(pentafluoroethyl)borate anion, [FB(C2F5)3]−, under ambient conditions in aqueous (48 %) hydrofluoric acid containing the oxidant K2[MnF6].Powder-XRD data indicate that products are pure stage 2 and physical mixture of stage 2 and stage 3 after 1 h to 20 h reaction times. The calculated basal repeat distance, Ic, is 1.20 nm for stage 2 and 1.54-1.56 nm for stage 3 GICs, corresponding to gallery heights of di= 0.86-0.89 nm. In addition, stage 2 GIC of Cx[FB(C2F5)3]·[delta]CH3NO2 having di=0.84 nm is prepared by electrochemical oxidation of graphite in a nitromethane electrolyte. The elemental analyses of these complex GICs required that a new sample digestion protocol be developed. After digestion, the fluoride amounts in these GIC samples were analyzed by using ion-selective fluoride combination electrode. The method developed is able to provide fluoride anion content in GICs without interference from the decomposition products of [FB(C2F5)3]- anion. For the boron analyses the same digestion procedure above is used and the B contents were determined by ICP-AES. For Cx[FB(C2F5)3]·[delta]F, both compositional parameters x and [delta] are obtained from the results of elemental B and F analyses. For the chemically prepared GICs at 1 h to 20 h, calculated x values were in the range of 51-56 and the calculated [delta] values increased with reaction time from approx. 0-2. Combining B analysis and TGA mass loss gives a composition of x=44 and [delta]= 0.37 for the electrochemically prepared GIC of Cx[FB(C2F5)3]·[delta]CH3NO2. Energy minimized structure for the isolated borate anion and powder XRD data show that the borate anions adopt a "lying-down" orientation where the long axes of [FB(C2F5)3]- intercalate anions are parallel to the encasing graphene sheets. The same electrochemical synthesis strategy is also used for the preparation of a new acceptor-type GIC containing the cyclo-hexafluoropropane-1,3-bis(sulfonyl)amide anion, [CF2(CF2SO2)2N]−. The gallery heights of 0.85-0.86 nm are determined by powder X-ray diffraction for stage 2 and 3 products. These GICs are obtained by electrochemical oxidation of graphite in a nitromethane electrolyte. GICs containing the linear anion, [(CF3SO2)2N]− are also prepared in order to compare the gallery heights and the electron charge distributions that helps to understand the GIC stabilities within the graphene sheets. The compositions of GICs containing [CF2(CF2SO2)2N]− are determined by thermogravimetric, fluorine and nitrogen elemental analyses. GICs of composition Cx[(C2F5)3PF3] are prepared for the first time by the intercalation of tris(pentafluoroethyl trifluorophosphate (FAP) anion, [(C2F5)3PF3]− by electrochemical oxidation of graphite. Powder-XRD data indicate that products are of stages 2-4 with gallery heights of 0.82-0.86 nm. These GICs are characterized by the same methods using TGA and F ion selective probe analyses.
Publisher:
ISBN:
Category : Graphite fluorides
Languages : en
Pages : 338
Book Description
New acceptor-type graphite intercalation compounds (GICs) containing perfluoroalkyl anions have been synthesized by using both chemical and electrochemical methods and characterized by elemental and thermogravimetric analyses. Investigation into these graphite intercalation compounds can provide novel materials and a detailed understanding of their properties. GICs of composition Cx[FB(C2F5)3]·[delta]F are prepared for the first time by the intercalation of fluoro-tris(pentafluoroethyl)borate anion, [FB(C2F5)3]−, under ambient conditions in aqueous (48 %) hydrofluoric acid containing the oxidant K2[MnF6].Powder-XRD data indicate that products are pure stage 2 and physical mixture of stage 2 and stage 3 after 1 h to 20 h reaction times. The calculated basal repeat distance, Ic, is 1.20 nm for stage 2 and 1.54-1.56 nm for stage 3 GICs, corresponding to gallery heights of di= 0.86-0.89 nm. In addition, stage 2 GIC of Cx[FB(C2F5)3]·[delta]CH3NO2 having di=0.84 nm is prepared by electrochemical oxidation of graphite in a nitromethane electrolyte. The elemental analyses of these complex GICs required that a new sample digestion protocol be developed. After digestion, the fluoride amounts in these GIC samples were analyzed by using ion-selective fluoride combination electrode. The method developed is able to provide fluoride anion content in GICs without interference from the decomposition products of [FB(C2F5)3]- anion. For the boron analyses the same digestion procedure above is used and the B contents were determined by ICP-AES. For Cx[FB(C2F5)3]·[delta]F, both compositional parameters x and [delta] are obtained from the results of elemental B and F analyses. For the chemically prepared GICs at 1 h to 20 h, calculated x values were in the range of 51-56 and the calculated [delta] values increased with reaction time from approx. 0-2. Combining B analysis and TGA mass loss gives a composition of x=44 and [delta]= 0.37 for the electrochemically prepared GIC of Cx[FB(C2F5)3]·[delta]CH3NO2. Energy minimized structure for the isolated borate anion and powder XRD data show that the borate anions adopt a "lying-down" orientation where the long axes of [FB(C2F5)3]- intercalate anions are parallel to the encasing graphene sheets. The same electrochemical synthesis strategy is also used for the preparation of a new acceptor-type GIC containing the cyclo-hexafluoropropane-1,3-bis(sulfonyl)amide anion, [CF2(CF2SO2)2N]−. The gallery heights of 0.85-0.86 nm are determined by powder X-ray diffraction for stage 2 and 3 products. These GICs are obtained by electrochemical oxidation of graphite in a nitromethane electrolyte. GICs containing the linear anion, [(CF3SO2)2N]− are also prepared in order to compare the gallery heights and the electron charge distributions that helps to understand the GIC stabilities within the graphene sheets. The compositions of GICs containing [CF2(CF2SO2)2N]− are determined by thermogravimetric, fluorine and nitrogen elemental analyses. GICs of composition Cx[(C2F5)3PF3] are prepared for the first time by the intercalation of tris(pentafluoroethyl trifluorophosphate (FAP) anion, [(C2F5)3PF3]− by electrochemical oxidation of graphite. Powder-XRD data indicate that products are of stages 2-4 with gallery heights of 0.82-0.86 nm. These GICs are characterized by the same methods using TGA and F ion selective probe analyses.
Graphite Fluorides & Carbon Fluoride Compounds
Author: Tsuyoshi Nakajima
Publisher: Springer
ISBN:
Category : Science
Languages : en
Pages : 192
Book Description
Publisher: Springer
ISBN:
Category : Science
Languages : en
Pages : 192
Book Description
Energy Research Abstracts
Author:
Publisher:
ISBN:
Category : Power resources
Languages : en
Pages : 908
Book Description
Includes all works deriving from DOE, other related government-sponsored information and foreign nonnuclear information.
Publisher:
ISBN:
Category : Power resources
Languages : en
Pages : 908
Book Description
Includes all works deriving from DOE, other related government-sponsored information and foreign nonnuclear information.
Molten Salt Technology
Author: David G. Lovering
Publisher: Springer
ISBN: 1475717245
Category : Education
Languages : en
Pages : 536
Book Description
Publisher: Springer
ISBN: 1475717245
Category : Education
Languages : en
Pages : 536
Book Description
Government Reports Announcements & Index
Author:
Publisher:
ISBN:
Category : Government publications
Languages : en
Pages : 1130
Book Description
Publisher:
ISBN:
Category : Government publications
Languages : en
Pages : 1130
Book Description
American Doctoral Dissertations
Author:
Publisher:
ISBN:
Category : Dissertation abstracts
Languages : en
Pages : 728
Book Description
Publisher:
ISBN:
Category : Dissertation abstracts
Languages : en
Pages : 728
Book Description
Index to American Doctoral Dissertations
Author:
Publisher:
ISBN:
Category : Dissertations, Academic
Languages : en
Pages : 1252
Book Description
Publisher:
ISBN:
Category : Dissertations, Academic
Languages : en
Pages : 1252
Book Description
Inorganic Solid Fluorides
Author: Paul Hagenmuller
Publisher:
ISBN:
Category : Science
Languages : en
Pages : 654
Book Description
Inorganic Solid Fluorides: Chemistry and Physics deals with the chemical and physical properties of inorganic solid fluorides and covers topics ranging from methods used in the preparation of fluorides to the crystal chemistry of fluorides and transition metal oxyfluorides. Defects in solid fluorides are also discussed, along with fluorine intercalation compounds of graphite and high oxidation states in fluorine chemistry. This book is comprised of 21 chapters and begins with an overview of general trends related to fluorides, including bonding problems and economic implications of fluorides.
Publisher:
ISBN:
Category : Science
Languages : en
Pages : 654
Book Description
Inorganic Solid Fluorides: Chemistry and Physics deals with the chemical and physical properties of inorganic solid fluorides and covers topics ranging from methods used in the preparation of fluorides to the crystal chemistry of fluorides and transition metal oxyfluorides. Defects in solid fluorides are also discussed, along with fluorine intercalation compounds of graphite and high oxidation states in fluorine chemistry. This book is comprised of 21 chapters and begins with an overview of general trends related to fluorides, including bonding problems and economic implications of fluorides.