Abstract
Abstract The surface pressure of mixed monolayers of octadecylammonium chloride and tetradecanoic acid has been measured as a function of mean area per film molecule at various compositions and temperatures. It has been observed that the transition pressure from expanded to condensed state of either constituent decreases with the addition of the other one. This behavior has been called a negative azeotropy in the two-dimensional state in contrast to the positive azeotropy observed for the ethyl heptadecanoate–tetradecanoic acid system. By applying the thermodynamic treatment, the phase diagram has been constructed and the apparent molar entropy and energy associated with the phase transition have been calculated. The results support the view that the negative azeotropic transformation in the mixed monolayer is brought about by the mutual interaction between octadecylammonium chloride and tetradecanoic acid molecules which is stronger than that between the same kind of molecules.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
