Pyrocarbon Matrices at the Nanoscale: Characterization – Atomistic Models - Properties – PyroMaN

Task 1: Preparation of samples of various pyrocarbons (thick, thin slices, powders) & characterization (density, X-ray, Raman, neutrons …)
Task 2: Electronic microscopy : (HR)TEM-LF, DF imaging, EELS
Task 3 : Image analysis of HRTEM-LF images, and 2D/3D inference, ie 3D synthesis from 2D data
Task 4 : Image-Guided Atomistic Reconstruction (IGAR) to obtain numerical models and prevision of structural and physical properties
Task 5 : Structure-property relationship

Expected output:
(i) An exhaustive database of pyrocarbons and their properties,
(ii) Atomistic and mesoscopic models of pyrocarbons, adapted to the computational evaluation of their physical & chemical properties,
(iii) New tools for TEM data interpretation (texture and image analysis) and for atomistic reconstruction
The main expected results are a better knowledge of the materials structure, and of their structure/property relationships.

Dense carbons are of particular importance in thermostructural materials, like carbon fibers, Carbon/Carbon Composites, nuclear graphites, etc ..., which are related to applications in aerospace and nuclear-- fusion and fission – technologies. This work is expected to bring guidelines to engineers in designing more efficient materials

Publications & communications of the project (06/2012): 2 articles, 5 international conferences (1 invited), 4 national conferences

Publications & communications around the project (2009-2012) : 4 articles, 9 proceedings (3 referenced), 16 international conferences (2 invited & 6 posters), 8 national conferences (3 posters).

This project aims to describe quantitatively the spatial arrangement of carbon atoms
in pyrocarbons, which are dense, anisotropic forms of carbon of high added value containing both order and disorder through several length scales, and to provide structure-property relationships through
a fully computational approach of the properties as compared to experimental data.
The work plan is divided in five tasks.
First, samples will be prepared and experimental data will be acquired by several methods, especially by X-ray and neutron scattering experiments.
Second, a thorough characterization by TEM and derived tools (HRTEM, EELS, EXELFS, SAED) will be made.
The third step is to apply image analysis and synthesis tools, in order to produce from 2D lattice-fringe HRTEM images some 3D blocks with similar properties.
The fourth step consists in (i) performing atomistic reconstructions, which are primarily guided by the 3D images from task 3, as well as by any other experimental data from tasks 1 & 2, and (ii) computing physical and chemical properties from these reconstructions.
The last task will be to collect the results and to provide a comprehensive overview of the
structure-properties relationships in this class of materials.