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Effects of confinement in meso-porous silica and carbon nano-structures; Etude des effets de confinement dans la silice mesoporeuse et dans certaines nanostructures carbonees

Abstract

Physico-chemical properties of materials can be strongly modified by confinement because of the quantum effects that appear at such small length scales and also because of the effects of the confinement itself. The aim of this thesis is to show that both the nature of the confining material and the size of the pores and cavities have a strong impact on the confined material. We first show the effect of the pore size of the host meso-porous silica on the temperature of the solid-solid phase transition of silver selenide, a semiconducting material with enhanced magnetoresistive properties under non-stoichiometric conditions. Narrowing the pores from 20 nm to 2 nm raises the phase transition temperature from 139 C to 146 C. This result can be explained by considering the interaction between the confining and confined materials as a driving force. The effects of confinement are also studied in the case of hydrogen and deuterium inside cavities of organized carbon nano-structures. The effects that appear in the adsorption/desorption cycles are much stronger with carbon nano-horns as the host material than with C60 pea-pods and single-walled carbon nano-tubes. (author)
Authors:
Publication Date:
Jul 15, 2006
Product Type:
Thesis/Dissertation
Report Number:
FRNC-TH-6923
Resource Relation:
Other Information: TH: These science des materiaux; 255 refs; Also available from Service commun de la documentation de l'Universite d'Orleans. Section Sciences, 9, Rue de Saint-Amand, 45072 - Orleans Cedex 2 (France)
Subject:
08 HYDROGEN; CARBON COMPOUNDS; HYDROGEN STORAGE; NANOTUBES; POROSITY; RESEARCH PROGRAMS; SILICA; SILVER SELENIDES; X-RAY DIFFRACTION
OSTI ID:
21000780
Research Organizations:
Orleans Univ., 45 (France)
Country of Origin:
France
Language:
French
Other Identifying Numbers:
TRN: FR0702466025646
Availability:
Available from INIS in electronic form
Submitting Site:
FRN
Size:
174 pages
Announcement Date:
Apr 11, 2008

Citation Formats

Leon, V. Effects of confinement in meso-porous silica and carbon nano-structures; Etude des effets de confinement dans la silice mesoporeuse et dans certaines nanostructures carbonees. France: N. p., 2006. Web.
Leon, V. Effects of confinement in meso-porous silica and carbon nano-structures; Etude des effets de confinement dans la silice mesoporeuse et dans certaines nanostructures carbonees. France.
Leon, V. 2006. "Effects of confinement in meso-porous silica and carbon nano-structures; Etude des effets de confinement dans la silice mesoporeuse et dans certaines nanostructures carbonees." France.
@misc{etde_21000780,
title = {Effects of confinement in meso-porous silica and carbon nano-structures; Etude des effets de confinement dans la silice mesoporeuse et dans certaines nanostructures carbonees}
author = {Leon, V}
abstractNote = {Physico-chemical properties of materials can be strongly modified by confinement because of the quantum effects that appear at such small length scales and also because of the effects of the confinement itself. The aim of this thesis is to show that both the nature of the confining material and the size of the pores and cavities have a strong impact on the confined material. We first show the effect of the pore size of the host meso-porous silica on the temperature of the solid-solid phase transition of silver selenide, a semiconducting material with enhanced magnetoresistive properties under non-stoichiometric conditions. Narrowing the pores from 20 nm to 2 nm raises the phase transition temperature from 139 C to 146 C. This result can be explained by considering the interaction between the confining and confined materials as a driving force. The effects of confinement are also studied in the case of hydrogen and deuterium inside cavities of organized carbon nano-structures. The effects that appear in the adsorption/desorption cycles are much stronger with carbon nano-horns as the host material than with C60 pea-pods and single-walled carbon nano-tubes. (author)}
place = {France}
year = {2006}
month = {Jul}
}