Synthesis of low density foam shells for inertial confinement fusion experiments
type: Dataset
description: This work deals with the fabrication process of low density foam shells and the sharp control of their shape (diameter, thickness, density, sphericity, non-concentricity). During this PhD we focused on the non-concentricity criterion which has to be lower than 1%. The shells are synthesized using a microencapsulation process leading to a double emulsion and followed by a thermal polymerization at 60°C. According to the literature, three major parameters, the density of the three phases, the deformations of the shells along the process and the kinetics of the polymerization have a direct influence on the shells non-concentricity. The results obtained showed that when the density gap between the internal water phase and the organic phase increases, the TMPTMA shells non-concentricity improves. A density gap of 0.078 g.cm-3 at 60°C, leads to an average non-concentricity of 2.4% with a yield of shells of 58%. It was also shown that the synthesis process can be considered as reproducible. While using the same internal water phase, equivalent non-concentricity results are obtained using either a straight tube, a tube with areas of constriction or a short wound tube. The time required to fix the shell’s shape is at least 20 minutes with thermal polymerization. So, it seems that the time spent by the shells inside the rotating flask allows the centering of the internal water phase inside the organic phase, whatever the circulation process used. In order to get higher polymerization rates and to avoid destabilization phenomena, we then focused our study on photopolymerization. When the synthesis is performed using a UV lamp with an efficient light intensity, the shells have a slightly higher thickness than the shells synthesized by thermal polymerization. Moreover, a really higher yield, around 80%, is achieved with UV polymerization. However, the average non-concentricity of the shells synthesized lays around 20%, which is really high compared to the 2.4% average non-concen…
identifier: NNT: 2011DIJOS033
issued: 2026-05-20T13:54:08.199821
language: en
modified: 2026-05-20T13:54:08.199827
contact point: Organization
  fn: CCSD
keyword: chimothechemical-sciencesother
keyword: densite
keyword: density
keyword: dispersion
keyword: double-emulsion
keyword: emulsion-double
keyword: infoeu-reposemanticsdoctoralthesis
keyword: microballon
keyword: microencapsulation
keyword: non-concentricite
keyword: non-concentricity
keyword: photopolymerisation
keyword: photopolymerization
keyword: polymerisation-radicalaire
keyword: radical-polymerization
keyword: shell
keyword: theses
keyword: trimethylolpropane-trimethacrylate
landing page: https://theses.hal.science/tel-00692058

Synthesis of low density foam shells for inertial confinement fusion experiments
type: Distribution
format: HTML
issued: 2026-05-20T13:54:08.207409
modified: 2026-05-20T13:54:08.148816
access URL: https://theses.hal.science/tel-00692058

test_moissonnage_selune
type: Agent