Abstract

Published values for the spreading pressures of lipids at the air/water interface are inconsistent. As part of a collaborative programme to establish criteria for surface manometry a detailed study was made of the spreading pressures for tetradecanoic, pentadecanoic and hexadecanoic acid crystals prepared from melts and solutions. The spreading pressures vary considerably for a given acid. The removal of solvents from recrystallised acids and the solubilities of chosen crystal samples in hexane were measured. The spreading pressures were then correlated for the various crystal preparations. Optical and scanning electron microscopy were used to characterise crystal geometries, and the crystallographic forms were determined by X-ray diffraction. It was established that solvent retention in the crystals can lower the spreading pressure, and that crystals with microscopic points and edges show high spreading pressures. The results can be interpreted simply by thermodynamic arguments. Data on the effect of temperature on the spreading pressures and solubilities are also presented, and the enthalpies of spreading and solution are calculated.

Full Text
Paper version not known

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 call

Disclaimer: 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.