Research Topics

    My research area is inorganic materials chemistry.  I am interested in the nanoscale design of  new solid-state compounds for optical, electronic, and catalytic applications.  My methodology for the production of these materials involves the intercalation of species (organic dyes, metal nanoparticles, or transition metal complexes) into inorganic hosts.  Below are outlined three projects currently underway.

    All of these projects are done in collaboration with undergraduate students.  During the process of generating new information, the students develop laboratory skills, scientific thinking, use of the chemical literature, and scientific writing and speaking.  In addition to lab work and maintaining a research notebook, each student will: (a)   write a research report, including an introduction section providing background information to the project  (b)   attend professional research seminars 
(c)    Present a research poster to the department.  This semester our research symposium is on Fri, Apr 26.

Self-assembly of Gold/ Zr(HPO4)2 Nanocomposites

    The Zr(HPO4)2 host will be investigated, due to its ease of preparation and modification.  The photochemical and photophysical properties of our materials can be tuned by varying the guest species.  The gold nanoparticles we will be studying have found use in a variety of applications, including catalysts and non-linear optical (NLO) devices.  Gold nanoparticles, also called quantum dots, are so small (10-100 Å) that the metal’s energy levels become quantized, producing an intensely colored compound.  The optical properties of this compound have been utilized for NLO by embedding them in a glass matrix.  Our intercalation methodology has distinctive advantages over glass, including higher loading capacity, greater control of nanoparticle size, and crystallinity.  

Organic Dyes Intercalated into Zr(HPO4)2

    Organic dyes will be intercalated into the same Zr(HPO4)2 host described above.  The organic dyes we will be studying have been used for DNA probes.  In aqueous solution, these dyes absorb light but do not emit.  However, in the presence of DNA, they show strong emission.  The mechanism for producing a fluorescent state is not well understood.  It is known that the dye intercalates into DNA.  Therefore a possible mechanism is that the rigid environment in the DNA enhances fluorescence.  We will look at whether emission is enhanced or not when the dye is in a rigid, inorganic environment. 

Pillared Layered Double Hydroxides

            Layered materials are found in high-technology applications like catalysts and batteries. Improved properties, such as stability and surface area, are possible through pillaring—the intercalating of structural clusters between the slabs of the layered material.  Conventional solid state synthetic routes, involving high temperatures and pressures, tend to yield materials with high stability but low surface area.  Recently, room temperature solution techniques have been developed to modify the structure and properties of solids.  These “soft” chemical methods can access kinetically stable structures normally unavailable and may result in materials with novel properties.

Using combinations of co-precipitation and anion exchange reactions, pillared layered double hydroxides (LDH), such as Co(OH)2 will be synthesized.  The properties of these materials will be tuned by the partial substitution of Co by other metals (e.g. Al3+, Fe3+) and by varying the nature of the pillaring agent.  Intercalation of polyoxometalate anions (POM), which are catalytically active, would yield catalytic materials with improved stability, due to the electrostatic attraction between the pillar and the slab.  In addition, precursor materials for hydrodesulfurization catalysis may be possible by choosing the right polyoxometalate anions (e.g. [Mo7O24]6-).