A hybrid model, which combines the characteristic features of the Pace—Datyner molecular model with those of the Kulkarni—Stern free-volume model, was developed to assess the effect of temperature, penetrant concentration, and polymer crystallinity on penetrant diffusivity. To address these competing issues, new materials will be needed with the appropriate properties. In addition samples with increased filler content 20% demonstrated also, apart from the delaminated, well-organized intercalated regions. Growth behavior was controlled by appropriate manipulation of the precursor mixture without altering hydrothermal temperature. In the case of skin samples, the observed low-pressure hysteresis was attributed to the existence of constrictions, which hinder the access of gas molecules to certain micropores. A strong effect of the reaction temperature was found on nanotube growth leading to an optimal value of 750 °C, while for a reaction duration longer than 5 min the growth rate was continuously suppressed, the nanotube size distribution was broaden, and the formation of amorphous carbon was favored. More specific, the carbon hollow fiber morphology was investigated by scanning electron microscopy.
The metal ion-binding capacity of the prepared hybrids was examined by means of batch Cd2+ ion adsorption experiments. The E-mail message field is required. Carbon and activated carbon hollow fiber membranes were prepared from an asymmetric co-polyimide precursor through the application of common pyrolytic carbonization procedures followed by carbon dioxide activation. This striking performance is attributed to the synergistic action of the combination of the two different metals that coexist on the surface as well as the enhancing role of the graphene support. This book provides an introduction to the fascinating world of diffusion in microporous solids.
As a next step, the pore structure and liquid flow properties of standard core samples Berea sandstone were examined by combining nitrogen and mercury porosimetry as well as permeability measurements. The hybrid nanotubes are stable under extreme pH conditions due to particle protection provided by the graphitic shell. Thermogravimetric analysis was used to investigate the weight loss during the carbonization process. Through the use of rapid thermal processing, the structure debilitation could be partially avoided. It is should be noted that this value is the average radii The Open-Access Journal for the Basic Principles of Diffusion Theory, Experiment and Application The purpose of this work is the utilization of the selective π-complexation interactions exhibited between certain metal cations and the double bond of the olefins, in order to develop membrane materials for a continuous propane—propylene separation process. The contents of this title are based on topics to be discussed by invited lecturers, which deal with periodic mesoporous organosilicas, stability and catalytic activity of aluminosilicate mesostructures, electron microscopy studies of ordered materials, imprinted polymers and highly porous metal-organic frameworks.
He has received a total funding from over 50 European and national programs of the order of 12 million Euros. It was found that both Ag- and Cu- based monometallic graphene composites significantly suppress bacterial growth, yet the Ag-based ones exhibit higher activity compared to their Cu-based counterparts. Having successfully replaced elements used in traditional, pollution-prone, energy-consuming separation processes, nanoporous materials play an important role in chemical processing. Local density profiles as well as angular distributions of molecular axes within the pores are examined and discussed. Such chemical modification included grafting two different types of silanes onto the external surface and pores of gamma-alumina, followed by chemical bonding of the alginate with the characteristic groups of the silane molecules involved.
This book offers a coverage to a wide selection of subjects ranging from modelling and material design to the preparation and use of nanoporous catalysts, adsorbents and membranes. Organized into well-focused sections written by internationally known experts, this book includes case studies, end-of-chapter problems, and illustrative video presentations of basic principles. La Biblioteca richiedente è tenuta al rispetto della vigente normativa sul Diritto d'Autore e in particolare, ma non solo, a consegnare al richiedente un'unica copia cartacea del presente documento, distruggendo ogni eventuale copia digitale ricevuta. Nanoporous Materials: Advanced Techniques for Characterization, Modeling, and Processing outlines existing and expected innovations in the combination of characterization and modeling techniques used to distinguish, monitor, and control the evolution of properties in nanoporous sorbents, catalysts, and membranes during their synthesis and utilization in several important energy processes. On the other hand the similarity of pore size distributions of all samples, pointed out that the pore microstructure, derived from similar phenol—formaldehyde resins, is not affected by the powder size of the precursor. Organized into well-focused sections written by internationally known experts, this book includes case studies, end-of-chapter problems, and illustrative video presentations of basic principles.
Sorption kinetic measurements were carried out at temperatures up to 80°C and pressures up to 80 atm. Responsibility: edited by Nick Kanellopoulos. When SnCl2 was used instead of Cu2+salts in aqueous phase, aredox reaction seemed to take place, resulting in greater surface roughness. Llewellyn The Combination of In Situ and Ex Situ Techniques for Monitoring and Controlling the Evolution of Nanostructure of Nanoporous Materials, G. The results suggest that the formation of the selective layer on the fibers is independent from the initial orientation of the asymmetric polyimide precursor. Due to the surface reactive functionalities the activated carbon is considered not only as filler, influenced on the sorption properties of the composition, but also as a physicochemical modifier of the polyurethane matrix. Growth of few-layer graphene using ferrocene as precursor by chemical vapor deposition is reported.
Silvestre-Albero Fundamental Approach to Supercritical Hydrogen Adsorptivity of Nanoporous Carbons, S. This proceedings volume reflects the current trends and advances in the field of nanomaterials, which will certainly continue to attract the attention of materials scientists around the globe. It was concluded that the adsorbed water on the Vycor® surface, in combination with the presence of residual water in the solvent, facilitated the formation of bulky, but not continuous organosilane entities, which were generated by the silane polymerization. Saboungi Studying Diffusion and Mass Transfer at the Microscale, C. The second section addresses modeling and scale transition from and to nanoscale processes, and the third section presents applications in the environmental and energy sectors. Finally, a number of parameters necessary for the optimization of the process are discussed.
Thus, a book dedicated to both these material needs as well as the various applications is very timely. His research interests are pore structure characterization nanoporous membrane and carbon nanotube systems and their evaluation of their performance using combination of in-situ and ex-situ techniques. Composite specimen produced by either casting from water suspension and compression moulding, were submitted to mechanical characterisation with the aim of selecting formulations enabling promising practical exploitation. Usually, for gas molecules with kinetic diameters lower than 4 Å the permeance are in accordance with the order of their kinetic diameters. The introduction of polyaniline into the polyimide matrix, results in a great enhancement in fiber permeability 60—600 times possibly due to increase of the total free volume due to the introduction of shorter polyaniline molecules in the matrix, allowing larger quantities of gases to pass through the composite membrane. The developed nanostructured catalyst exhibits enhanced activity at lower temperatures in comparison to that reported for other Rh-based catalytic systems, while data about feed composition effects and carbon support depletion provided operating conditions that suppress N 2 O formation and extent the catalyst lifetime. Saboungi Studying Diffusion and Mass Transfer at the Microscale, C.
The Sips equation provided the best fit with the experimental results, indicating sorption sites heterogeneity for the material. Silvestre-Albero Fundamental Approach to Supercritical Hydrogen Adsorptivity of Nanoporous Carbons, S. In situ monitoring of growth evolution was achieved by a microbalance system connected on-line to the reaction zone. The membrane quality was inspected through pervaporation measurements consisting of a liquid hydrocarbon feed of n-heptane and 1,3,5-triisopropylbenzene. Given the large spectrum of applications separations, catalysis, etc. The experimental work described in this study gives an example for the monitoring of the compositional evolution of phase separating compact-glass precursors of porous glasses. La Biblioteca fornitrice garantisce di aver effettuato copia del presente documento assolvendo direttamente ogni e qualsiasi onere correlato alla realizzazione di detta copia.