Skip to Main content Skip to Navigation
Theses

Linking Adhesive Properties and Pore Organisation of Silicone Emulsions Obtained by Reactive Blending

Abstract : Macro-cellular polymers are highly searched-for materials thanks to their rich physical properties. These arise from the internal structuration of the material, in which discrete cells of gas or liquid are tightly packed within a continuous polymeric solid. The size and organization of these cells have an important influence on the overall material properties. The influence of the properties of spheres on their final packing morphology has led to numerous studies usually dealing with either hard frictional or soft frictionless grains, which are the two extremes of the spectrum of possible systems. An important question remains as to what happens for systems which are in-between these extremes, i.e. highly deformable grains presenting a frictional surface. To tackle this problem, we work with a model system of ultra-stable emulsions which consist of PEG (polyethyleneglycol) drops which are dispersed in a continuous phase of PDMS (polydimethylsiloxane). Coalescence of the drops is prohibited by a reactive blending approach which creates a solid-like skin around the PEG drops upon contact with the PDMS. This skin creates adhesion and friction between the drops. To study the influence of the skin properties on the sedimentation of the drops, we characterize the final drop packing under gravity using absorption contrast X-Ray. We show that the presence of friction and adhesion at the interface makes the liquid drops pack unconventionally regarding density and organization compared to classic surfactant stabilized emulsions. We then investigated the adhesive properties of the solid emulsions i.e. elastomers containing liquid drops in their substructure, using a probe-tack test. We studied the impact of the drop size and density on the increase of the bulk's dissipations of energy which enhance the adhesive properties of the material.
Complete list of metadatas

https://tel.archives-ouvertes.fr/tel-01712248
Contributor : Abes Star :  Contact
Submitted on : Monday, February 19, 2018 - 11:57:07 AM
Last modification on : Wednesday, October 14, 2020 - 4:00:35 AM
Long-term archiving on: : Monday, May 7, 2018 - 7:32:59 PM

File

76071_GIUSTINIANI_2017_diffusi...
Version validated by the jury (STAR)

Identifiers

  • HAL Id : tel-01712248, version 1

Collections

Citation

Anaïs Giustiniani. Linking Adhesive Properties and Pore Organisation of Silicone Emulsions Obtained by Reactive Blending. Soft Condensed Matter [cond-mat.soft]. Université Paris Saclay (COmUE), 2017. English. ⟨NNT : 2017SACLS379⟩. ⟨tel-01712248⟩

Share

Metrics

Record views

541

Files downloads

266