(7dy) Sustainability through Nanoscience: Green, Smart, and Controllable Synthesis and Characterization of One-Dimensional Metal Nanostructures

I strongly believe there is no firm border between the various fields of engineering and science. This motivates me to pursue my future career in the multidisciplinary field of nanomaterials. I want to contribute to the creation and application of the next generation of green functional nanomaterials for electronic devices, solar cells and photovoltaic. I envision a lab capable of providing these functional nanomaterials for application to many fields such as biosensing, energy, drug delivery, tissue engineering, and food science.

In recent years much attention has been paid to the importance of metal nanoparticles due to their unique physicochemical characteristics, nano-scale size, and surface Plasmon behavior. Among metal nanoparticles, silver nanoparticles (AgNPs) have unique and outstanding shape and size dependent electrical, thermal, optical, catalytical, optoelectronic, anticancer, biosensing, medicinal, antiviral, and biological characteristics which make them exceptional for applications in a variety of fields and disciplines. Palladium (Pd) is well known for its high capacity in hydrogen affinity and corresponding adsorption or absorption that make its nanostructure broadly applicable as a primary catalyst for hydrogenation reactions, petroleum cracking, reduction of automobile pollutants, hydrogen purification, and many electrochemical applications. One dimensional (1D) metal nanostructures are important in several applications where nano spheres are less effective. Green noble nanoparticle syntheses utilizing natural precursors are of great interest because of cost effectiveness, facile reactions, less harmful feedstocks and procedures, and sustainability. However, these new techniques should be optimized not only in terms of scale-up capability, but also with respect to product quality and performance. These green and smart technologies can be achieved by either application of green reagents including the reducing agent, solvent, and capping agent or application of green templates such as plant viruses as biotemplate for their synthesis.

My graduate studies at University of New Hampshire (UNH), and my post-doctoral experiences at Purdue University in chemical engineering have uniquely prepared me to be able to synthesize 1D metal nanostructures with controllable size and morphology for specific practical applications. In my graduate studies I synthesized high aspect ratio silver nanowires (AgNWs) with high yield in both large-scale batch and continuous millifluidic reactors. I investigated both the reaction mechanism and the flow behavior of the reaction mix. The synthesized AgNWs were used to formulate conductive inks adaptable for screen-printing to create conductive patterns. In my postdoc studies I have utilized several methods for green synthesis of 1D Ag and Pd nanostructures. Moreover, my duties as a postdoc include mentoring and supervising the research of undergraduates. We are using wire-shaped plant viruses such as the tobacco mosaic virus (TMV) and barely strip mosaic virus (BSMV) expressed in e-coli in collaboration with synthetic biology and plant pathology laboratories as biotemplates for the synthesis of Pd and Ag nanorods. We are using several green reducing agents such as sugar substitutes and artificially sweeteners with the assistance of various capping agents for synthesis of 1D Pd and Ag nanostructures. We are also utilizing several polymers and compounds containing OH- groups to assess the utility of the OH- group in the reduction of Pd and Ag ions and formation and stabilization of the corresponding nanoparticles.

As an independent scientist and new faculty member I will utilize different millifluidic methods for synthesis of 1D metal nanostructures with the goal of reducing their final cost by an order of magnitude through the application of less expensive water based reducing agent at lower reaction temperature in a continuous manner. These methods will be tailored to control the morphology of the nanostructures for specific practical applications as their characteristics strongly depend on their size and morphology. The reaction mechanisms will be investigated with the assistance of several characterization methods such as mass spectroscopy, X-ray absorption spectroscopy, scanning electron microscopy, transmission electron microscopy, Fourier transfer spectroscopy, and UV-Visible spectroscopy. These detailed fundamental investigations and characterizations will make us able to assess which functional groups in each green reducing agent are responsible for the reduction of specific metal ions, and consequently selection of other green reducing agents offered by nature suitable for green synthesis of a specific metal nanostructures. My lab will be able to provide metal nanostructures with specific morphology for use by other labs and groups for further practical applications. As the commercially available 1D metal nanostructures are expensive, the finding of my research will provide a tool to control the morphology of 1D metal nanostructures in an inexpensive way, and consequently synthesize them with specific dimensions. The result will be increased in efficiency and lower cost of various 1D metal nanostructure based devices including but not limited to sensors, biosensors, nanoelectronics, solar cells, and touch screens. This will affect several research areas such as health care, energy, and food science both technically and scientifically.

I will also address specific applications of metal nanostructures to formulate conductive inks, and more generally film deposition processes including screen printing, doctor blading, spin coating, inkjet printing, and spray coating to create conductive patterns for solar cells and photovoltaic applications. Finally, I will be able to fully characterize these new devices using several electrical characterization techniques.

Teaching Interests:

My teaching philosophy has developed based on my experience in the classroom. As a new faculty member, I will actively try to work closely with students to be sure they grasp not only the details of technical procedures but broader theoretical concepts as well. I also have a strong belief in peer learning, having found that students learn better through interactive participation rather than passive listening. All in all, I believe that my experience and my beliefs have prepared me to implement successful pedagogy by encouraging student curiosity in an open and collaborative environment. I enjoy teaching courses on Introduction to Chemical Engineering, Transport Phenomena, Reaction Kinetics, and Rector Design. I would also be interested in complementing current courses or creating new course material related to topics from my own research, including nanomaterial characterization.