Self-assembly of Rigid Sphere-Rod Amphiphiles

We report the self-assembly behavior of rigid sphere-rod amphiphiles composed of spherical Keggin molecular clusters as the solvophilic block and rod-like oligo-fluorene (OF) as the solvophobic block. In comparison to the traditional flexible amphiphiles, such rigid amphiphiles form the condensed hydrophobic domain to minimize the interfacial energy by interdigitating the rigid rods. By designing multiple series of rigid sphere-rod amphiphiles, we have identified multiple parameters which are critical for the solution behaviors of such rigid amphiphiles: 1) inherent parameters like the length of the hydrophobic domain, the side chain length, the side chain sequence, geometry, and the architectures of the molecules; and 2) external parameters like the solvent polarity, temperature, and the ionic strength, have been proven to play a critical role in their self-assembly behaviors. With the consideration of system energy and the local packing, the effects of those parameters on the self-assembly behaviors of rigid amphiphiles become more and more clear. All these studies decode the self-assembly behaviors of rigid sphere-rod amphiphiles and help us to understand the rules to regulate their self-assembly.