Although controlling the primary structure of synthetic polymers is itself a great challenge, the potential of sequence control for tailoring hierarchical structures remains to be exploited, especially in the creation of new and unconventional phases. A series of model amphiphilic chain-like giant molecules was designed and synthesized by interconnecting both hydrophobic and hydrophilic molecular nanoparticles in precisely defined sequence and composition to investigate their sequence-dependent phase structures. Not only compositional variation changed the self-assembled supramolecular phases, but also specific sequences induce unconventional phase formation, including Frank-Kasper phases. The formation mechanism was attributed to the conformational change driven by the collective hydrogen bonding and the sequence-mandated topology of the molecules. These results show that sequence control in synthetic polymers can have a dramatic impact on polymer properties and self-assembly.

A series of multi-headed giant surfactants based on polystyrene (PS)-polyhedral oligomeric silsesquioxane(s) (POSS) conjugates, with a different number and topology of POSS heads, are found to self-assemble into different supramolecular structures including vesicles, cylindrical and spherical micelles in H2O/DMF mixed solvents. The transitions among different morphologies can be rationally controlled by tuning the number and topology of POSS heads, as well as the macromolecular concentration.

We synthesized a series of novel degradable alternating copolyesters composed of diglycolic anhydride (DGA) and two epoxides, epoxymethoxytriethylene glycol (ETEG) and a photoactive crosslinking agent epoxy benzophenone (EBP). After UV crosslinking, soaking the films in a good solvent (tetrahydrofuran) removed uncrosslinked material, and the resulting film gel fractions were calculated. These network films were then degraded in buffer solutions of varying pH values. The degradation of networks with lower gel fraction (fewer crosslinks) was faster and followed first-order kinetics. In contrast, the denser network degraded slower and followed zeroth-order kinetics. The lower gel fraction networks possess a higher swelling ratio and resist bovine serum albumin (BSA) adsorption better by entropic shielding and faster degradation. In comparison, higher gel fraction networks with higher EBP mole fractions adsorb more BSA due to hydrophobic interactions and slower degradation.

Two triarmed organic–inorganic hybrid materials based on carboxylic acid-functionalized polyhedral oligomeric silsesquioxane (APOSS) with/without PS linkers are designed and synthesized (tri-PS-APOSS and tri-APOSS). They can both self-assemble into hollow spherical nanostructures in water/organic mixed solvents, as confirmed by light scattering and TEM techniques, yet they possess completely different mechanisms and driving forces. With the PS linkers, the hybrid forms bilayer vesicles similar to surfactants; while without the PS linkers, the hybrid behaves like hydrophilic macroions and assembles into single-layered, vesicle-like “blackberry”-type structure. Consequently, the trend of the assembly size in response to the change of the solvent polarity is different for the two scenarios. This work shows a simple, universal approach of controlling the mechanism and product of the self-assembly process via minor adjustment of the organic–inorganic hybrid structures.