B. L. and, D. Cadenhead
2000
Citations
0
Influential Citations
8
Citations
Journal
Langmuir
Abstract
The bipolar/monopolar conformational transitions of the hydroxyoctadecanoic acids (HOAs) [6-hydroxy-9-hydroxy- and 12-hydroxyoctadecanoic acid (6HOA, 9HOA, and 12HOA)] plus those of the methyl and ethyl esters of 12HOA have been studied using classical surface pressure (Π)/area per molecule (A) isotherms and fluorescence microscopy techniques. Most studies were carried out using identical compressional rates (5 A2 mol-1 min-1) and identical amounts of a fluid-phase soluble fluorescent probe 1-palmitoyl-2-[6-(7-nitro-2-1-3-benzoxadiazol-4-yl)amino] caproyl phosphatidylcholine (NBD-PC); however, the effect of both compressional rate and probe concentration was investigated. For 6HOA, condensed-phase domains are roughly diamond-shaped with both nucleation and apparent crystal growth being observed. Larger, essentially hexagonal, crystals were observed for 9HOA. For 12HOA the extent of nucleation was much greater, producing elongated needlelike crystals quite different from either 6- or 9HOA. This difference ...