Evaporation of Sessile Droplets of Polyelectrolyte/Surfactant Mixtures on Silicon Wafers

Colloids and Interfaces

Victor M. Starov¹  Eduardo Guzmán²  Francisco Ortega²  Andrew Akanno²  Sara Llamas²  Ramón G. Rubio²  Lionel Perrin³  Manuel G. Velarde⁴ 

[1] Chemical Engineering Department, Loughborough University, Epinal Way, LE11 3TU Loughborough, UK;Departamento de Química Física, Facultad de Ciencias Químicas, Universidad Complutense, Ciudad Universitaria s/n, 28040 Madrid, Spain;Institut Lumière Matière, Claude Bernard University Lyon 1, Bâtiment Alfred Kastler - 4ème Etage Domaine Scientifique de La Doua, 10 Rue Ada Byron, 69622 Villeurbanne CEDEX, France;Instituto Pluridisciplinar, Universidad Complutense, Paseo Juan XXIII 1, 28040 Madrid, Spain;

关键词: spreading;    evaporation;    polyelectrolyte;    surfactant;    sessile droplet;    contact angle.;   

DOI  :  10.3390/colloids5010012

来源: DOAJ

【 摘 要 】

The wetting and evaporation behavior of droplets of aqueous solutions of mixtures of poly(diallyldimethylammonium chloride) solution, PDADMAC, with two different anionic surfactants, sodium laureth sulfate, SLES, and sodium N-lauroyl N-methyl taurate, SLMT, were studied in terms of the changes of the contact angle θ and contact length L of sessile droplets of the mixtures on silicon wafers at a temperature of 25 °C and different relative humidities in the range of 30–90%. The advancing contact angle θ_a was found to depend on the surfactant concentration, independent of the relative humidity, with the mixtures containing SLES presenting improved wetting behaviors. Furthermore, a constant droplet contact angle was not observed during evaporation due to pinning of the droplet at the coffee-ring that was formed. The kinetics for the first evaporation stage of the mixture were independent of the relative humidity, with the evaporation behavior being well described in terms of the universal law for evaporation.

【 授权许可】

Unknown