scholarly journals Structural and chemical characterization of modified graphenes for hydrogen storage

2018 ◽  
Author(s):  
◽  
Joseph Schaeperkoetter
Keyword(s):  
Hydrogen Storage ◽  
Photoelectron Spectroscopy ◽  
Performance Metrics ◽  
Storage Systems ◽  
Structural Response ◽  
Chemical Characterization ◽  
Structural Data ◽  
Hydrogen Fuel Cell ◽  
Substitutional Doping

The automotive industry is already showing signs of moving beyond a century long dependence on petroleum. The tens of billions of dollars in the electric vehicle (EV) consumer market are a powerful demonstration of this transition. Hydrogen fuel cell electric vehicles also offer a clean alternative to petroleum and have advantages to EVs in some transportation sectors. To grow the hydrogen economy, significant progress must be made in hydrogen storage systems. Adsorbent based storage systems have the potential to lower the pressure requirements while simultaneously improving the storage capacity of these systems. The research presented in this dissertation focuses on the development and characterization of new adsorption storage systems based upon modified graphene. Early work involved substitutional doping of activated carbon with boron to alter the surface chemistry of the adsorbing surface with the goal of improving adsorption strength. Boron-doped samples were characterized with X-ray Photoelectron Spectroscopy to correlate specific boron chemistries to adsorption performance metrics. A maximum of 2% substitutional doping was observed. Later work focused on framework materials built up from graphene oxide and benzene diboronic acid (GOFs). GOFs are an ideal material to study the structural response of an adsorbent during adsorption due to their layered structure and relatively well-defined pore geometry. To study GOF's adsorption-induced structural response, we built a computer-controlled gas handing system for in situ neutron diffraction measurements at the University of Missouri Research Reactor. For the first time, supercritical adsorption-induced structural change was observed. Through correlation of adsorption and structural data, we are able to predict the rate of expansion in GOF based on the critical temperature and vdW diameter of the adsorbate molecule.

Multi-Field Characterization of Single Wall Nano-Tube Composites for Hydrogen Storage

2005 ◽  
Author(s):  
John G. Michopoulos ◽  
Sam G. Lambrakos ◽  
Nick E. Tran
Keyword(s):  
Hydrogen Storage ◽  
Objective Function ◽  
Storage Systems ◽  
Chemical Reactivity ◽  
Linear Optimization ◽  
Optimization Methods ◽  
Design Parameters ◽  
Spatio Temporal ◽  
Extensive Experimental Data

The goal of the present work is three fold. Firstly to create the forward continuum model of a multi-species diffusing system under simultaneous presence of chemical reactivity and temperature as the general case of all hydrogen storage systems. Secondly, cast the problem of hydrogen storage in a pragmatic product-design context where the appropriate design parameters of the system are determined via appropriate optimization methods that utilize extensive experimental data encoding the behavior of the system. Thirdly, demonstrate this methodology on characterizing certain systemic parameters. Thus, the context of the work presented is defined by a data-driven characterization of coupled heat and mass diffusion models of hydrogen storage systems from a multiphysics perspective at the macro length scale. In particular, a single wall nanotube (SWNT) based composite is modeled by coupled partial differential equations representing spatio-temporal evolution of distributions of temperature and hydrogen concentration. Analytical solutions of these equations are adopted for an inverse analysis that defines a non-linear optimization problem for determining the parameters of the model by objective function minimization. Experimentally acquired and model produced data are used to construct the system’s objective function. Simulations to demonstrate the applicability of the methodology and a discussion of its potential extension to multi-scale and manufacturing process optimization are also presented.

XPS Studies of the Interactions of Biocells with Various Silicon Based Surfaces

1995 ◽  
Vol 414 ◽  
Author(s):  
S. Seal ◽  
S. Krezoski ◽  
T. L. Barr ◽  
D. H. Petering
Keyword(s):  
Surface Chemistry ◽  
Tumor Cells ◽  
Photoelectron Spectroscopy ◽  
Freeze Drying ◽  
Chemical Characterization ◽  
Chrysotile Asbestos ◽  
X Ray ◽  
Silicon Based ◽  
Rat Tumor

AbstractSiliceous materials are the principal components of Earth's crust and also have become key ingredients of modem technology. Recently, we have expanded our chemical characterization of complex silicates (e.g., framework [1] and sheet types [2]) to include studies of their interaction with select biocells [3,4]. It is becoming apparent that the surface chemistry of these silicates, and perhaps that of silica itself, plays a key role in the oft resulting cell pathogenesis, thus enhancing the value of further investigations with X-ray photoelectron spectroscopy. The present research describes the unique growth of Ehrlich (murine or rat tumor) cells on Sio and SiO2 wafers, and also on select seaentine silicates (such as chrysotile asbestos). Tbese growth studies were followed by both cell/silicate separations and unique freeze drying [3,4]. XPS examination at select stages discovered cell induced alterations in the Si, O, Mg and particularly Fe chemistry of the silicon based systems as well as corresponding changes in the cell chemistry. Many of these features were confirmed by atomic absorption spectroscopy.

Optimization and comprehensive characterization of metal hydride based hydrogen storage systems using in-situ Neutron Radiography

2016 ◽  
Vol 328 ◽  
pp. 567-577 ◽  
Author(s):  
S. Börries ◽  
O. Metz ◽  
P.K. Pranzas ◽  
J.M. Bellosta von Colbe ◽  
T. Bücherl ◽  
...  
Keyword(s):  
Hydrogen Storage ◽  
Metal Hydride ◽  
Storage Systems ◽  
Neutron Radiography ◽  
Comprehensive Characterization

Modified Carbon Cryogel-Ammonia Borane Nanocomposites for Hydrogen Storage

2007 ◽  
Vol 1042 ◽  
Author(s):  
Saghar Sepehri ◽  
Betzaida Batalla Garcia ◽  
Qifeng Zhang ◽  
Guozhong Cao
Keyword(s):  
Hydrogen Storage ◽  
Photoelectron Spectroscopy ◽  
Ammonia Borane ◽  
Scanning Calorimetry ◽  
Dehydrogenation Kinetics ◽  
Carbon Cryogel ◽  
Nitrogen Doped Carbon ◽  
Kinetics Of ◽  
Catalytic Effects

AbstractThis paper reports the synthesis and characterization of coherent Boron/Nitrogen –doped –carbon cryogels- ammonia borane nanocomposites for hydrogen storage. Resorcinol formaldehyde derived doped carbon cryogels (CC) were obtained via chemical modification.CC- ammonia-borane nanocomposites were made by incorporation of ammonia borane (AB), in CCs. Nitrogen sorption analysis, scanning electron microscopy, and X-ray photoelectron spectroscopy, are used to investigate the structure and morphology of the modified CCs. Differential scanning calorimetry is used to study the dehydrogenation of coherent doped-CC-AB nanocomposites. Modified CCs show higher mesoporosity, and more homogeneous porous structure compared to undoped CCs. Also, dehydrogenation kinetics of nanocomposites is enhanced as compared to neat AB. Possible nanoscale and catalytic effects of nanocomposites in improved dehydrogenation kinetics are discussed.

scholarly journals Covalent Functionalization of Graphene Oxide with Fructose, Starch, and Micro-Cellulose by Sonochemistry

Polymers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 490
Author(s):  
María Montserrat Cruz-Benítez ◽  
Pablo Gónzalez-Morones ◽  
Ernesto Hernández-Hernández ◽  
José Roberto Villagómez-Ibarra ◽  
Javier Castro-Rosas ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Photoelectron Spectroscopy ◽  
Organic Molecules ◽  
Chemical Characterization ◽  
Covalent Bond ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ultrasound Waves ◽  
Short Time

In this work, we report the synthesis of graphene oxide (GO) nanohybrids with starch, fructose, and micro-cellulose molecules by sonication in an aqueous medium at 90 °C and a short reaction time (30 min). The final product was washed with solvents to extract the nanohybrids and separate them from the organic molecules not grafted onto the GO surface. Nanohybrids were chemically characterized by Fourier-transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and Raman spectroscopy and analyzed by thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and X-ray diffraction (XRD). These results indicate that the ultrasound energy promoted a chemical reaction between GO and the organic molecules in a short time (30 min). The chemical characterization of these nanohybrids confirms their covalent bond, obtaining a grafting percentage above 40% the weight in these nanohybrids. This hybridization creates nanometric and millimetric nanohybrid particles. In addition, the grafted organic molecules can be crystallized on GO films. Interference in the ultrasound waves of starch hybrids is due to the increase in viscosity, leading to a partial hybridization of GO with starch.

scholarly journals Chemical characterization of red cells from the black sea urchin Arbacia lixula by X-ray photoelectron spectroscopy

RSC Advances ◽  
2021 ◽  
Vol 11 (43) ◽  
pp. 27074-27083
Author(s):  
Patrizia Pagliara ◽  
Daniela Chirizzi ◽  
Maria Rachele Guascito
Keyword(s):  
Immune Response ◽  
Sea Urchin ◽  
Photoelectron Spectroscopy ◽  
Chemical Characterization ◽  
Antimicrobial Activities ◽  
The Black Sea ◽  
Coelomic Fluid ◽  
X Ray ◽  
Arbacia Lixula

Red spherula cells from sea urchin coelomic fluid have attracted great interest for their specific and intriguing properties, such as antimicrobial activities and immune response, that probably tie in with their red characteristic pigments.

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