Size-quantised cadmium sulfide particles in Langmuir–Blodgett films: film thermal stability

Abstract

The fabrication of particles in Langmuir–Blodgett films of cadmium icosanoate and nonacosa-10,12-diynoate is followed using a quartz crystal microbalance. The mass changes accompanying the exposure of the film to hydrogen sulfide are consistent with a chemical reaction in the film which also produces the acid form of the surfactant. Film thermal stability is greatly reduced after the particles are formed, a result also consistent with formation of the more volatile acid form. The extent of film removal by heating/outgassing suggests that particles are capped by adsorbed icosano or diynoic acid. It is likely that this capping plays a role in particle growth control.