Affiliation:
1. China Research Institute of Daily Chemical Industry , No. 34 Wenyuan Road , Taiyuan 030001 , P. R. China
2. Jinzhong University , No. 199 Wenhua Road , Jinzhong 030619 , P. R. China
Abstract
Abstract
In this paper, sodium oleyl sulphate (SOS) was successfully synthesised by reacting octyl alcohol (OA) with gaseous sulphur trioxide (SO3) as a sulphating reagent in a falling film reactor. The structure was determined by Fourier transform infrared (FTIR) and proton nuclear magnetic resonance (1HNMR) spectroscopy. The dynamic adsorption and aggregation behaviour of SOS was systematically investigated to reveal the relationship between the structure and properties of SOS. The physicochemical properties of SOS were determined by measuring the equilibrium surface tension, dynamic surface tension and dynamic contact angle, respectively. A laser particle size analyser and a transmission electron microscope (TEM) were used to analyse the aggregation behaviour of SOS. Compared to sodium dodecyl sulphate (SDS) and sodium n-octadecyl sulphate (C18H37OSO3Na), which have a similar structure to SOS, the increase in hydrophobic chain size and tighter molecular packing enabled by the polar head conformation caused a decrease in CMC and an increase in surface activity. The efficiency of the surface activity was controlled by a mixed diffusion kinetic adsorption mechanism. Moreover, SOS in aqueous solution showed efficient wettability on the surface of the low-energy paraffin film at concentration above the CMC. In addition, SOS molecules can spontaneously form spheroidal aggregates with increasing concentration, and the size of the aggregates increased with the concentration.
Subject
Condensed Matter Physics,General Chemical Engineering,General Chemistry
Reference44 articles.
1. Chang, C., Franses, E. I. Adsorption dynamics of surfactants at the air/water interface: a critical review of mathematical models, data, and mechanisms. Colloids Surf. A. Physicochem. Eng. Asp. 1995, 100, 1–45; https://doi.org/10.1016/0927-7757(94)03061-4.
2. Yada, S., Suzuki, T., Hashimoto, S., Yoshimura, T. Adsorption dynamics of homogeneous polyoxypropylene-polyoxyethylene alkyl ether nonionic surfactants at the air/water interface. J. Mol. Liq. 2018, 255, 208–214; https://doi.org/10.1016/j.molliq.2018.01.150.
3. Rehbinder, P. A. Über die Abhängigkeit der Oberflächenaktivität und der Oberflächenspannung der Lösungen von der Temperatur und Konzentration. Z. Phys. Chem. 1924, 111U, 447–464; https://doi.org/10.1515/zpch-1924-11130.
4. Rehbinder, P. A. Über Grenzflächenaktivität bzw. –Energie an Verschiedenen Grenzflächen und deren Spezifisches Adsorptionsvermögen. Biochem. Z. 1927, 187, 19–31.
5. Adam, N. K., Brown, R. C., Murray, R. C., Ramsden, W., Lottermoser, A. General discussion. Trans. Faraday Soc. 1935, 31, 204–208; https://doi.org/10.1039/TF9353100200.