CURVATURE DETERMINATION OF SPINODAL INTERFACE IN A CONDENSED MATTER SYSTEM

Laser scanning confocal microscopy has been used to study the time evo lution of a three dimensional spatially bicontinuous structure of a ph ase-separated polymer blend undergoing the late stage of spinodal deco mposition, as a model example of condensed matter systems. Bath the me an and Gaussian curvatures of the interface between two coexisting pha ses have been directly measured for the first time from the reconstruc ted 3D image. The Gaussian curvature is negative, clearly demonstratin g that the interface of the bicontinuous structure is anticlastic, whi le the mean curvature is close to zero. Self-similar growth of the str ucture is inferred from the time evolution of the average radius of cu rvature of the interface.