Rhett C. Smith, Ph.D. - US grants

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).

This CAREER award by the Organic and Macromolecular Chemistry Program in the Chemistry Division at the National Science Foundation supports Professor Rhett C. Smith at Clemson University to develop and study two exciting new classes of materials featuring remarkably well-defined and tunable molecular-level organization of organic and hybrid organic/organometallic pi-systems. The unique, shape-persistent scaffolds he will employ ensure specific alignment of adjacent pi-systems. The mode of inter-pi-system interaction enforced will in turn predispose each material to idealized performance in a given technological application (i.e. some modes are ideal for photovoltaics, others for light emitting devices). In addition to their great potential for highly coveted technologies such as lightweight solar cells, thorough characterization of the opto/electronic properties of these materials will reveal fundamental insights into how molecular-level organization dictates performance and elucidate how privileged material combinations act synergistically, thus forwarding rational design strategies for next generation technologies. The molecular scaffolds that are employed include novel oxacyclophane constructs and light-harvesting phosphines used for organometallic polymers.

This work will also have a broader impact on science education through a variety of synergistic activities. The overarching aim of these educational activities is to increase awareness and participation in physical science. These efforts involve a service learning program, outreach and the development of polymer science courses guided by modern education theory and learning models. New course materials include projects-based polymer laboratory modules designed to mimic the graduate school research experience for undergraduates. Undergraduate research mentoring is also a key component of the educational plan. This award will support salary for undergraduates in the summer, and for their travel to conferences, better preparing these young scientists for careers in research.

Planning Grant for an I/UCRC for Energy Harvesting Materials and Systems

0856032 Virginia Polytechnic Institute and State University; Daniel Inman
0856046 Clemson University; Stephen Foulger
0855891 University of Texas, Dallas; Bruce Gnade

The proposal seeks a planning grant for a new multi-university Center for Energy Harvesting Materials and Systems to focus on recovery (harvesting) of unused energy from various sources such as radio and television towers, satellites and various portable electronics. Virginia Polytechnic Institute (VT), Clemson University (CU) and the University of Texas, Dallas (UTD) are collaborating to establish the proposed center, with VT as the lead institution. The research plan includes developing new products and designs in the following areas: Energy Harvesting for Vibration Measurement, PiezoCell and Panels for Harvesting Wind Energy, VLSI Circuit Design, Materials for "Self-Powered" Position and Speed Sensors and Electrical Energy Storage, Micro-Scale Thermal to Electric Energy Conversion, Magnetic to Electric Energy Conversion in Ocean Environments, On-Chip Energy Source Using Indium Nitride Quantum Dot Solar Cells, Piezoelectric Cantilevers Based Energy Harvesters, and Roll-to-Roll Printing of Organic Energy Harvesters. VT, CU and UTD plan to use the NSF planning grant fund to hold a meeting with prospective industrial partners, and to develop an initial research agenda for CEHMS of sufficient commercial interest that attendees will be willing to invest in and sustain the Center.

The proposed Center has the potential to improve sustainability and profitability of US manufacturing firms by developing new technologies that will reduce energy consumption and harvest energy that is normally wasted. Industrial members will benefit from the research conducted at the Center in areas of materials synthesis, thin-film deposition, energy conversion devices, micro/nano electronics, electrochemical storage systems, sensor development, system design, integrated hybrid architectures, computational and theoretical modeling, and nano-scale fabrication techniques. Students and faculty members of CEHMS will gain valuable experience by interaction with industry partners.

Agricultural and petroleum companies produce a tremendous amount of byproducts that is both costly to dispose of and potentially environmentally damaging. This NSF award supports research to develop new chemistry to combine waste from these key American industries and to turn these waste materials into polymers/plastics that are useful for consumer products. By developing novel approaches to recyclable polymers/plastics that are affordable and sustainable, this project aims to benefit society by significantly (1) reducing the environmental damage caused by using non-sustainable plastics, (2) reducing the cost of consumer products in many different markets, and (3) decreasing the amount of waste for which agricultural companies and petroleum refineries pay for disposal. K-12 teachers are offered opportunities to learn about sustainable chemistry to use in lessons in K-12 science classes. To increase participation in science, technology, engineering and mathematics fields, this project provides research opportunities to technical and predominantly undergraduate college students and educational activities to engage underrepresented and economically disadvantaged students.

Polymeric organic and inorganic wastes (POIWs) generated by agricultural and petroleum refining processes have been explored as additives for conventional construction materials, but such products are merely physically blended materials, which are inherently prone to multiple, inescapable environmental deterioration pathways, including fragmentation, leaching, corrosion, and biological degradation. This research is developing chemistry to form covalent bonds between these POIWs and the components of traditional macromolecular compounds to confer upon them significantly greater strength and environmental durability. The objective is being pursued by covalently crosslinking agricultural waste-derived polymeric materials (such as lignocellulosic materials) with petroleum refining waste-derived materials (e.g., sulfur).

With the support of the Macromolecular, Supramolecular and Nanochemistry Program in the Division of Chemistry, Professor Rhett Smith of Clemson University will research ways to recycle agricultural and plastic waste, two underutilized and environmentally detrimental waste streams that represent critical barriers to a sustainable economy. The proposed research aims to benefit society by (1) elucidating new, sustainable ways to recycle plastic waste, (2) allowing access to sustainable products made from plant-derived material instead of from petroleum, and (3) alleviating environmental damage of plastic waste in the environment. This work will also benefit society through sustainability education. Resources on green and sustainable chemistry will be made available online where they may be accessed for free worldwide. This project will also help to improve participation in science, technology, engineering and mathematics degrees by engaging students from historically underserved and underrepresented groups.<br/><br/>This work seeks to establish thio-cracking as a mechanism for chemical recycling/upcycling of plastic and agricultural waste. The thio-cracking approach being pursued involves the reaction of waste materials with elemental sulfur to yield organics and organosulfur compounds. Mixtures so derived are expected to be amenable to desulfurization to give new organic feedstocks. One aim of the research is to establish reactivity pathways between sulfur and functionalities found in target waste compounds including polyethylene terephthalate, polycarbonates, and lignin. These studies will involve the study of reactions of authentic waste materials and of small molecular model compounds. The anticipated reactivity will facilitate the formation of C–S bonds as sulfur will react with radical/radical-reactive species formed in the course of the thermal decomposition of organics at temperatures below 350 °C. This work aims to unveil fundamentally important mechanisms and microstructures resulting from C–S bond-formation and yield new organosulfur polymers. This work further seeks to provide one-pot protocols to convert plastics and biomass into new polymers and small molecular derivatives at significantly lower energy cost than required for many current chemical recycling strategies. This research has the potential to contribute to society by enabling waste reservoirs to be reclaimed for value-added applications, with this approach to recycling drawing upon the thermal reversibility of S–S bond formation.<br/><br/>This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.