Fractal Study of Mesoporous Structure in Water Molecular Condensed System

Bis-(4-stearoylaminophenyl) ether (BSADE) can aggregate and self-assemble in water. Transmission electron microscopy (TEM) indicated that the morphology of BSADE aggregates in water was entanglement and thin fiber-like, and that a three dimensional network structure was formed. Water molecules were entrapped in this three dimensional network structure and formed a new type of condensed system (so-called water molecular gel). Water molecular gel is a typical mesoporous material which can be characterized by the fractal dimension D. Using gas adsorption method along with measurement of porosity and specific surface area, the fractal dimension D of the complicated pores was 2.1-2.2 for this water molecular gel. Using viscosity method and the Cayley fractal tree, the fractal dimension D of the fiber-like three dimensional network was determined to be 1.98. The formation process of water molecular gel can be described as nucleation followed by a repeated growing and branching cycle.