Attempts to Study a Water Evaporation Retardation by Soluble Surfactants
✍ Scribed by K. Lunkenheimer; M. Zembala
- Publisher
- Elsevier Science
- Year
- 1997
- Tongue
- English
- Weight
- 154 KB
- Volume
- 188
- Category
- Article
- ISSN
- 0021-9797
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✦ Synopsis
Taking this into account we tried to investigate whether The effect of a soluble surfactant adsorption layer on the water soluble surfactant adsorption layers could also produce meaevaporation was studied using an osmometric method. It was surable effects of a water evaporation hindrance and, if so, proved that Knauer's osmometer after appropriate modification to correlate them with their adsorption properties. of the measuring cell can be successfully used for a qualitative detection of the evaporation retardation. The osmometric behavior MATERIALS of the system was explained taking into account the adsorption properties of the surfactants and the heat effects accompanying Commercial products were used as received. The following the evaporation process. A measurable evaporation hindrance was surfactant systems were studied. (i) nonionics-n-decanol registered only in case of sodium salts of myristic and palmitic acids at concentrations (close to the solubility limit) at which (Fluka) and n-decyl-b-D-glucopyranoside (Sigma); (ii) catdensely packed adsorption layers are formed. At the same time ionics-n-hexadecyltrimethylammonium bromide (CTAB) the latent heat of evaporation may cause a freezing of the higher (Fluka); (iii) anionics-sodium salts of the following fatty density adsorption layer which is formed on the supersaturated acids (Sigma); n-decanoic (capric (CA)), n-dodecanoic solution drop. ᭧ 1997 Academic Press (lauric (LA)), n-tetradecanoic (myristic (MA)), n-hexa-Key Words: evaporation retardation; soluble surfactant adsorpdecanoic (palmitic (PA)), and perfluorodecanoic (PFD) acid tion.
(Sigma); and sodium dodecyl sulfate (SDS) (Merck and Fluka).
Supporting electrolytes (NaCl, NaBr) were added to keep 1 To whom correspondence should be addressed.
solution suspended on both thermistors give zero tempera-363