ABSTRACT
Formation of sponge structure was described for amphiphiles in solution. Experimental evidence for sponge-like structure was showed as a L3 phase on a nonionic surfactant solution,
and moreover effects of ionic additives to L3 phase were described together with some theoretical interpretations for L3 phase. Sponge state may be essentially recognized in the phase diagram for the surfactant-water system. On the contrary, sponge structure of phospholipid NaDMPG was observed as a network structure of bilayer-assembly with and without additive salt. However, sponge-like structure for the phospholipid was absolutely different from that of surfactant solution. Sponge-like structure appeared only at an intermediary state in a region of a phase transition from vesicles to lamellar or vice versa, but no thermodynamically stable state. An intermediary state of phospholipid bilayer-assembly was indicated on the conversion into a new gel state with very slow time aging.
