ABSTRACT
I. INTRODUCTION It has generally been considered that a gaseous monolayer state at very low surface pressure changes to a liquid expanded state, a liquid condensed state, and finally, a solid monolayer state during compression of the monolayer on the water surface. Several authors have proposed that amphiphiles with a large intermolecular aggregation force form crystalline monolayer domains on the water surface at very low surface pressure as well as at zero surface pressure, and that these crystalline domains aggregate with increasing surface pressure [1,2]. Therefore, to understand the aggregation structure of monolayers on the water surface, it is necessary to investigate the aggregation structure of mono layers prepared from amphiphiles with different intermolecular aggregation forces at various surface pressures.
