Monolayer properties and spontaneous Z-type Langmuir-Blodgett multilayers of 2-(heneicosa-2,4-diynoxycarbonyl)benzoic acid

Abstract

The monolayer properties of two diacetylene phthalates, - 2-(heneicosa-2,4-diynoxycarbonyl)benzoic acid and 2-(heptadeca-2,4-diynoxycarbonyl) benzoic acid - which are surfactants of different hydrocarbon chain lengths, at the air-aqueous solution interface have been examined using subphases containing CdCl2 and a polyelectrolyte, poly(diallyldimethylammonium chloride). The headgroup on the longer chain phthalate appears to reorientate at a critical point as the monolayer is continuously compressed from high to low areas on a CdCl2 subphase. This does not occur on the polyelectrolyte subphase. The apparent reorientation process was found to be highly sensitive to the monolayer compression rat..