Structure and porosity of lamellar systems under high pressure : the case of expanded graphite and expanded vermiculite
type: Dataset
contact point: Organization
  fn: CCSD
keyword: pression
keyword: vermiculite
keyword: porosity
keyword: lamellar
keyword: porosite
keyword: diffusion-aux-petits-angles
keyword: lamellaire
keyword: pressure
keyword: theses
keyword: fractal
keyword: physcondcm-genphysics-physicscondensed-matter-cond-matother-cond-matother
keyword: small-angle-scattering
keyword: infoeu-reposemanticsdoctoralthesis
keyword: fractale
keyword: graphite
landing page: https://theses.hal.science/tel-00936814
description: The porous structure of expanded graphite and expanded vermiculite has been studied insitu under uniaxial stress. The properties of a porous material being related to the matrix and to theporosity, the in situ evolution under of the crystalline structure (of the matrix) under high pressurehave been first investigated using diamond anvil cell. The equation of state of expanded vermiculitehas been established. This first part of this work allowed giving a particular insight to the study of theunsolved high pressure phase of graphite. Combining Raman scattering data and calculations, a newstructure, called Z-Carbon, has been proposed. Thanks to the specific technical developments of thiswork, the porosities of expanded graphite and expanded vermiculite based systems have been studiedin situ under uniaxial stress. The used of fractal model in data analysis allowed following the evolutionof the fractal dimension and of the apparent specific surface The studied samples were made ofcompressed forms of expanded graphite and expanded vermiculite in which the basal plane of thecrystallites have a preferential orientation. The uniaxial stress was taken perpendicular and parallel tothis preferential direction. The porous structure of the expanded graphite sample was found to undergoan irreversible collapse of the pores or a cracks and creation and propagation. Additional electrical andporosity measurements supported the proposed models. In the expanded vermiculite based systems,the crack apparition was observed under uniaxial stress.
identifier: NNT: 2012LYO10234
issued: 2026-05-07T05:41:53.259311
language: fr
modified: 2026-05-07T05:41:53.259316

Structure and porosity of lamellar systems under high pressure : the case of expanded graphite and expanded vermiculite
type: Distribution
access URL: https://theses.hal.science/tel-00936814
format: HTML
issued: 2026-05-07T05:41:53.261827
modified: 2026-05-07T05:41:53.245262

test_moissonnage_selune
type: Agent