Skip to Main content Skip to Navigation
Theses

Sessile Droplets of Salt Solutions on Inert and Metallic Surfaces : Influence of Salt Concentration Gradients on Evaporation and Corrosion Behaviour

Abstract : In this thesis we investigate the evaporation behaviour of sessile droplets of aqueous saline solutions on planar inert and metallic surfaces and characterise the corrosion phenomenon for iron surfaces. First we study the evaporation behaviour of sessile salty droplets on inert surfaces for a wide range of salt concentrations, relative humidities, droplet sizes and contact angles. Our study reveals the range of validity of the well-accepted diffusion-controlled evaporation model and highlights the impact of salt concentration (surface tension) gradients driven Marangoni flows on the evaporation behaviour and the subsequent salt deposit patterns. Furthermore we study the spatial-temporal evolution of sessile droplets from saline solutions on metallic surfaces. In contrast to the simple, generally accepted Evans droplet model, we show that the corrosion spreads ahead of the macroscopic contact line with a peripheral film. The three-phase contact line is destabilized by surface tension gradients induced by ionic composition change during the course of the corrosion process and migrations of cations towards the droplet perimeter. Finally we investigate the corrosion behaviour under drying salty sessile droplets on metallic surfaces. The corrosion process, in particular the location of anodic and cathodic activities over the footprint droplet area is correlated to the spatial distribution of the salt inside the drying droplet.
Document type :
Theses
Complete list of metadatas

Cited literature [162 references]  Display  Hide  Download

https://tel.archives-ouvertes.fr/tel-01992174
Contributor : Abes Star :  Contact
Submitted on : Thursday, January 24, 2019 - 11:58:22 AM
Last modification on : Tuesday, September 8, 2020 - 6:19:42 AM

File

52822_SOULIE_2015_archivage_co...
Version validated by the jury (STAR)

Identifiers

  • HAL Id : tel-01992174, version 1

Citation

Virginie Soulié. Sessile Droplets of Salt Solutions on Inert and Metallic Surfaces : Influence of Salt Concentration Gradients on Evaporation and Corrosion Behaviour. Material chemistry. Université Montpellier; Universität Potsdam, 2015. English. ⟨NNT : 2015MONTS129⟩. ⟨tel-01992174⟩

Share

Metrics

Record views

91

Files downloads

77