Bulk and Adsorbed Monolayer Phase Behavior of Binary Mixtures of Undecanoic Acid and Undecylamine: Catanionic Monolayers

DOI: 10.1021/la1048198

Authors: Chenguang Sun (University of Cambridge) , Michael Bojdys (University of Liverpool) , Stuart Clarke (University of Cambridge) , Lee Harper (University of Cambridge) , Andrew Jefferson (University of Cambridge)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Langmuir , VOL 27 (7) , PAGES 3626–3637

State: Published (Approved)
Published: February 2011

Abstract: Differential scanning calorimetry (DSC) and X-ray powder diffraction (PXRD) have been used to determine the phase behavior of the binary mixtures of undecanoic acid (A) and undecylamine (B) in the bulk. In addition, we report DSC data that indicates very similar behavior for the solid monolayers of these materials adsorbed on the surface of graphite. The two species are found to form a series of stoichiometric complexes of the type AB, A2B, and A3B on the acid rich side of the phase diagram. Interestingly, no similar series of complexes is evident on the amine rich side. As a result of this complexation, the solid monolayers of the binary mixtures exhibit a very pronounced enhancement in stability relative to the pure adsorbates.

Subject Areas: Chemistry


Instruments: I11-High Resolution Powder Diffraction