Precise structural control is critical for scientists to harness the optical, electrical, magnetic, chemical and biological properties of nanomaterials and nanomedicines. The research in the Zhang group will focus on applying organic and polymer chemistry to control the behavior of inorganic (metal) ions, clusters, and nanoparticles. A central thematic building block in our research is endohedral metallofullerenes (EMFs), which are fullerene cages with metal atoms encapsulated inside. Meanwhile, we are broadly interested in working with synthetic polymers, biomacromolecules, inorganic nanoparticles, as we aim to develop functional materials taking advantage of the electric, optical, chemical and mechanical properties from a wide selection of compositions.
Research Area #1: molecularly exact nanocomposites enabled by metallofullerenes
Nanocomposites can provide new properties not achievable with their single constituent, and the spatial configuration of the constituents is essential for the composite properties. It has been especially challenging to place metal ions or clusters into long-range ordered arrays at molecular precision. The Zhang group will graft EMF molecules with organic functional ligands as “molecular nanocomposite” (MNC) building blocks to build well-defined mesoscale assemblies. We will also control the physical characteristic of the composite material by varying the ligand size, shape, chemical composition, binding group and the stoichiometric number between individual constituents, and thereby develop a series of functional materials and design rule for EMF assembly.
Research Area #2: Biocompatible metallofullerene derivatives with accurate molecular design
EMFs provide an ideal template for lanthanide-based nanomedicine as the carbon cage is robust to confine the toxic metal ions but still reactive enough to allow functionalization. The limitation for current EMF based medicine is the hydrophilic groups were introduced chiefly to ensure water solubility, giving a mixture of products with batch-to-batch variations and limited control over their metabolic behavior. My group will create a platform to develop various molecularly exact biocompatible EMF derivatives. The assembly and biological behavior of the EMF derivatives will be tuned via multiple control handles provided by the functional ligands.
Research Area #3: Framework-templated assembly of inorganic nanostructures
Top-down lithography has provided useful templates to arrange the order of inorganic materials. However, next-generation consumer products require ordering inorganic matter at 1-5 nm scale, which is very challenging for lithographical templating. On a paradigm shift, I will build the template via bottom-up assembly approach. My group will build well-defined and rigid supramolecular organic frameworks to host inorganic materials including metallofullerene, nanocrystals and quantum dots. Then we will crosslink the inorganic materials to fix their relative locations and simultaneously dissolve and recover the organic framework template for next cycle.