writer：Fei Yuan, Xinjun Zhang, Miao Yang, Wei Wang,* Britt Minch, Günter Lieser and Gerhard Wegner
keywords：Topological transformation; Amphiphilic and truncated-cone-shaped codendrimer
source：期刊
specific source：Soft Matter
Issue time：2007年

Experimental evidence for a topological transformation of aggregates of an amphiphilic codendrimer from sphere to button structures via a toroidal intermediate is reported. The aggregates are produced in organic solvents which consist of water droplets covered by a continuous monolayer of the codendrimer. The transformations occur at a mean curvature which is equal to the spontaneous curvature. At this point, the contribution to Helfrich's bending free energy essentially comes from the Gaussian curvature of the continuous monolayers. Therefore, an aggregate of lower genus will transform to another aggregate of higher genus to further minimize the total free energy.