Past Hancock Memorial Award Winners
2009
Sponsored by the American Chemical Society, Division of Environmental Chemistry:
Johnathan Gorke, University of Minnesota
“Enzymatic Synthesis in Deep Eutectic Solvents”
Innovation and Benefits. Ionic liquids have been called the “solvents of the future” and, when introduced, were a welcome alternative to hazardous volatile organic solvents. But ionic liquids are costly and require a high level of purity, which limits their widespread use. This research shows that deep eutectic solvents (DES’s) are viable alternatives to ionic liquids and are easy to synthesize.
Johnathan Gorke, a graduate student of Professor Romas Kazlauskas at the University of Minnesota, was selected for his research on enzymatic synthesis in deep eutectic solvents (DES’s). His research demonstrates that DES’s are viable alternatives to volatile organic solvents and ionic liquids. Furthermore, unlike ionic liquids, DES’s can be made from renewable, biodegradable, and non-toxic materials, and have the advantages of being commercially available, low cost, and easy to synthesize.
DES’s are liquids formed by the physical mixtures of ammonium or metal salts such as choline chloride (a vitamin) and hydrogen bond donors such as urea or glycerol (derivable from renewable resources).
Johnathan’s research shows that DES’s are widely applicable to the field of enzyme catalysis in academia and industry. He has demonstrated many types of hydrolase-catalyzed reactions as well as enzymatic reactions from the oxidoreductase family, resulting in comparable or enhanced conversions, selectivity, and activities as in volatile organic solvents. The overall research demonstrates the efficacy and advantages of this promising alternative class of solvents.
Sponsored by the National Institute of Standards and Technology:
Joseph B. Binder, University of Wisconsin-Madison
“Simple Chemical Transformation of Lignocellulosic Biomass and Olefin Metathesis in Aqueous Solvents”
Innovation and Benefits. Most renewable fuels and chemicals are currently made from edible biomass, such as corn, sugarcane, or vegetable oil. But there isn’t enough edible biomass available to produce a significant amount of renewable fuels; plus, it competes with the need to feed people and animals. This research has identified a potentially efficient and economical method to transform inedible biomass into renewable products.
Joseph Binder, a graduate student of Professor Ronald Raines at the University of Wisconsin-Madison, was selected for his research on transforming biomass into valuable chemicals and fuels, and on olefin metathesis reactions using less hazardous, aqueous solvent conditions for new applications including biomolecule modification.
In the first system, Joseph has developed mild conditions to convert lignocellulosic biomass into sugars and into 5-hydroxymethylfurfural (HMF), a bio-based platform chemical that can be used to derive many useful chemical products from renewable, non-petroleum resources. His conditions consist of water, acid, and ionic liquids to dissolve and hydrolyze the typically insoluble lignocellulose, plus a catalyst for conversion of the sugars into HMF.
In the second project, Joseph developed new olefin metathesis catalysts for aqueous reactions, enabling efficient construction of pharmaceuticals, crop protectants, and other chemical products. His unique approach combines solubilizing- and stability-enhancing ligands on the metathesis catalysts. Joseph’s developments have already opened up the field of greener metathesis to new applications including biomaterials such as proteins.
2008
Sponsored by the National Institute of Standards and Technology:
Lallie McKenzie, University of Oregon
“High-Throughput, Low-Waste Synthesis of Well-Defined Nanoparticles in Microcapillary Flow Reactors”
Lallie McKenzie, a student of Professor Jim Hutchison, was selected for her research that has produced well-defined nanoparticles in high-throughput and with low-waste using microcapillary flow reactors and in-line analysis. Widespread usage of nanoparticles is growing in many applications, including catalysis, electronics, medical diagnostics and therapeutics, sensors, and optical devices. Professor Hutchison and his group are at the forefront of incorporating the principles of green chemistry into the early development of nanomanufacturing processes, thereby reducing the environmental impacts and simultaneously enhancing the economic and technological viability of these approaches.
Specialized applications using nanoparticles generally rely on well-defined composition, size, shape, and surface functionality of the nanoparticles, but these properties have been difficult to control and manufacture, especially on a large scale. Lallie’s work has overcome these challenges, demonstrating unprecedented improvements in quality, selectivity, and efficiency through microcapillary flow reactors. For example, she reports new production methods for subnanometer gold particles with higher purity and product selectivity, a four-fold increase in yield, a hundred-fold increase in production rates (up to 8 g/hr), and an 80% reduction in solvent waste for a savings of nearly 6 L per gram of nanoparticles. She also shows that flow synthesis methods can improve process development and production scale-up in industrial settings.
Sponsored by the ACS Division of Environmental Chemistry:
Arsen Simonyan, State University of New York, College of Environmental Sciences and Forestry
“Linear-Dendritic Copolymers as Nano-Reactors for Organic Reactions in Water”
Arsen Simonyan, a student of Professor Ivan Gitsov, was selected for his research on linear-dendritic copolymers as building blocks of nano-reactors, used for conducting organic reactions in water. In these investigations, the non-toxic, biocompatible polymers self-assemble into nano-reactors that facilitate organic reactions: cycloadditions, oxidations and polymerizations of pharmaceutically and industrially valuable substances.
The first strategy employs the well-defined nano-containers for aqueous Diels-Alder reactions of fullerene and other hydrophobic reagents, which may be important for the construction of pharmaceutically-important molecules. Arsen’s results show that the nano-vessels accomplish the reaction in comparable yields, but in water and at room temperature for similar or lesser amounts of time compared to the conventional reactions in organic solvents. The second approach involves the construction of nano-containers from the same linear-dendritic copolymers with embedded biocatalyst, the enzyme laccase. These nanoconstructs enable oxidation and polymerization reactions of hydrophobic compounds of pharmaceutical, biomedical, and industrial interest in water at room temperature. Some of Arsen’s examples include the oxidation of steroids and the formation of macromolecules of biomedical interest, such as polymers containing curcumin and tyrosine. Overall, the environmental benefits are low energy consumption, usage of non-toxic, renewable and recyclable reaction media and catalysts, and simple recovery of reaction products.
2007
Sponsored by the National Institute of Standards & Technology:
Jennifer Haghpanah, Polytechnic University
“Investigating cutinases for the deacetylation of polyvinyl acetate”
Jennifer Haghpanah, a student of Professors Richard Gross and Jin K. Montclare, was selected for her proposal to investigate deacetylation of polyvinyl acetate. Cutinase mediated polyvinyl acetate deacetylation can be used to remove adhesives from textiles and paper forming water-soluble poly(vinylalcohol-acetate) copolymers that are biodegradable. The work aims to understand the structure-activity relationship of cutinase for new applications in polymer technology. She has begun to explore cutinases from different organisms to investigate the following: (1) whether cutinases are selective for deacetylation, (2) what concentrations of enzyme and substrates are preferred for deacetylation, and (3) what are the kinetic parameters of the reaction. Conditions, such as the temperature and pH will be monitored throughout reactions to identify optimal conditions for deacetylation. The proposed work aims to explore the use of protein-engineered biocatalysts for industrially relevant and ecological bio-refined products. Ultimately, Jennifer hopes to explore a wide-range of surface modification reactions by cutinase-catalysis that will provide mild methods to engineer surface chemistry.
Sponsored by the ACS Division of Environmental Chemistry:
Arani Chanda, Carnegie Mellon University
“Applications and Mechanistic Understanding of Fe-TAML® Activators of Peroxide – A Green Oxidation Catalysis System”
Arani Chanda, a student of Professor Terry Collins, was selected for his work on the applications and mechanisms of action of Fe-tetraamido macrocyclic ligand (Fe-TAML®) activators of peroxides. Fe-TAMLs are highly effective small molecule mimics of the peroxidase enzymes that activate peroxides and also dioxygen, offering cleaner and safer methods for a number of industrial processes, including wastewater treatment, chemical decontamination, pulp and paper bleaching, disinfection, and laundry applications. Arani showed that the Fe-TAML/H2O2 system achieves facile in-solution total degradation of fenitrothion and other organophosphorus (OP) pesticides, including a commercial formulation of chlorpyrifos. He also developed an Fe-TAML/H2O2 process for degrading a broad range of recalcitrant nitroaromatic compounds to environmentally acceptable endpoints. Using Fe-TAML/peroxide systems, Arani developed a general model for the simultaneous measurement under operating conditions of both reactivity and catalyst life-times arriving at a unique relative reactivity quotient that provides an important quantitative green design parameter for homogeneous catalysts. Arani was a key researcher in highly collaborative projects that led to the isolation and characterization of a rare FeIV-oxo species and the first FeV-oxo complex — these discoveries help in understanding the mechanisms of action of Fe-TAML/peroxide. Arani used density functional theory (DFT) calculations to further elucidate the structural and electronic properties of these unique species.
2006
Ke Min, Carnegie Mellon University
"Atom Transfer Radical Polymerization in Aqueous Dispersed Media "
Ke Min, under the guidance of Professor Krzysztof Matyjaszewski at Carnegie Mellon University, was selected for the her research to extend a valuable polymerization technique, atom transfer radical polymerization (ATRP), to economically viable and environmentally benign aqueous dispersed media, which have found extensive application in industry and are applicable to a diverse choice of hydrophobic monomers. In particular, a new initiation technique, named as Activators Generated by Electron Transfer (AGET), was recently developed and successfully employed in ATRP in aqueous dispersed media. AGET ATRP has been carried out in miniemulsion for preparation of homopolymers, block copolymers, gradient copolymers, star copolymers, polymer brushes and polymer composites. An extension of AGET ATRP allowed the first successful microemulsion ATRP to be conducted, resulting in production of a translucent microlatex. This led to development of the first successful ab-initio emulsion ATRP performed using a “two-stage” emulsion approach, where a microemulsion ATRP was initiated before addition of the second monomer. Especially, AGET ATRP can be carried out in the presence of a limited amount of air, thereby reducing inadvertent volatile organic compound emissions. Furthermore, recently an important extension of AGET technique, Activators ReGenerated by Electron Transfer (ARGET), has been employed in ATRP and the catalyst concentration has been dramatically decreased to only a few parts per million by using environmentally benign reducing agents.
2005
Anindya Ghosh, Carnegie Mellon University
"The Design, Synthesis and Application of Green Catalytic Oxidation Systems"
Anindya Ghosh, under the guidance of Professor Terry Collins at Carnegie Mellon University, was selected for the design, synthesis and application of green catalytic oxidation systems using Fe-tetraamido macrocyclic ligand (Fe-TAML®) activators and hydrogen peroxide. The Fe-TAML®/hydrogen peroxide system behaves like peroxidases, oxidizing many organic molecules, and offering a cleaner and safer method for a number of industrial processes, including wastewater treatment, pulp and paper bleaching, and laundry applications. Anindya’s research included the elucidation of mechanism details and decomposition routes of the Fe-TAML® activators, the design and synthesis of novel Fe-TAML® complexes, and the application of Fe-TAML® activators as oxidation catalysts. Anindya demonstrated, for the first time, that ferric iron [Fe(III)] is able to activate dioxygen via coordination chemistry in a homogeneous solution. In addition, Anindya’s work provided new understanding of how TAML® catalysts degrade under acidic pH. By following Professor Collins’ iterative design approach, Anindya was able to synthesize modified Fe-TAML® activators that successfully oxidize organic molecules in acidic regimes. Anindya also contributed to studies on the catalytic decomposition of chlorophenols and other organic pollutants by the Fe-TAML®/hydrogen peroxide system.
2004
Amy S. Cannon, University of Massachusetts Boston
"The Environmentally Benign Synthesis of Materials for Dye-Sensitized Solar Cells"
Amy Cannon, under the guidance of Professor John Warner, was selected for designing an environmentally benign, efficient, and inexpensive Titanium Dioxide Dye-Sensitized Solar Cell (DSSC). Titanium dioxide solar cells are typically constructed at high temperatures (400-500 °C), in an energy-intensive process that limits the choice of substrate. Amy found that adding catalytic amounts of trimesic acid to titanium dioxide permits the films to coalesce at ambient temperatures, producing films with the same physical characteristics as those prepared by traditional methods. Amy is also investigating a series of spiropyrans as possible co-sensitizers to prevent back electron transfer in DSSCs, thereby improving efficiency. Amy's research projects will advance the development of sustainable methods of manufacturing DSSCs.
2003
Due to the exceptional qualifications of the applicants, two students were selected to receive the 2003 Hancock Award.
Richard P. Swatloski, University of Alabama
"Greener Dissolution of Cellulose: Can Ionic Liquids Compete with N-Methylmorpholine-N-Oxide in the Lyocell Process?"
Richard Swatloski works in the field of ionic liquids under the guidance of Professor Robin Rogers. Rick discovered that homogeneous solutions of cellulose in ionic liquids could be prepared without significant cellulose degradation and at high cellulose concentrations. This is significant because applications of cellulose, nature's most abundant renewable organic material, have been limited due to the insolubility of the material in all but a few common solvents. Using ionic liquids to dissolve and reconstitute cellulose reduces VOC emissions and other waste streams, decreases energy requirements, and expands the potential applications for cellulose.
Nicolay V. Tsarevsky, Carnegie Mellon University
"Atom Transfer Radical Polymerization in Aqueous Systems: Possibilities and Limitations"
Nicolay Tsarevsky, under the guidance of Professor Krzysztof Matyjaszewski, has investigated atom transfer radical polymerization (ATRP) in aqueous systems. Radical polymerization is the preferred method for preparing hydrophilic polymers, compounds with applications in water purification and drug delivery. Controlling molecular weight and avoiding competing side reactions are challenges in radical polymerization reactions. Nick identified reaction conditions that eliminate these side reactions, making ATRP applicable to aqueous systems and producing well-defined hydrophilic polymeric materials, such as block copolymers.
2002
Bianca R. Sculimbrene, Boston College
Bianca R. Sculimbrene, under the guidance of Professor Scott J. Miller at Boston College , was selected for her work employing a biomimetic approach to the synthesis of polyfunctional molecules. Bianca’s research uses small peptides as catalysts that emulate the selectivity of enzymes found in nature. Specifically, Bianca has used a pentapeptide catalyst to selectively monophosphorylate a triol in the synthesis of D-myo-Inositol-1-Phosphate (I-1-P). The high enantioselectivity and diastereoselectivity of the synthesis minimize the need for protecting groups, which have been widely used in previous syntheses of inositol phosphates. Using this biomimetic approach, I-1-P was synthesized in five steps from inositol in 40% overall yield. The target molecule, I-1-P, is involved in signal transduction pathways and is implicated in the treatment of manic depression with lithium. An efficient, selective synthesis of I-1-P will facilitate an understanding of the biological mechanism and may lead to better treatments for manic-depression. Bianca’s research is an important step in the discovery of enzyme-like small molecule catalysts and advances the goal of developing synthetic strategies with a reduced dependence on the use of protecting groups.
2001
Richard A. Brown Jr., University of California-Davis
Richard A. Brown, Jr., under the guidance of Professor Philip Jessop at the University of California, Davis, was selected for his work in conducting reactions in alternative reaction media and exploring the effect of alternative media on selectivity. Much of Dick’s research has focused on reactions run in supercritical fluids and ionic liquids. These alternative solvents offer potential environmental benefits over conventional organic solvents: most supercritical fluids are non-flammable and exhibit low toxicity, while ionic liquids are non-volatile. In addition, increasing selectivity minimizes the number of byproducts formed and decreases the need for subsequent purification steps. One example of Dick’s work is the catalytic hydrogenation of tiglic acid in an ionic liquid, [bmim]PF6. The reaction exhibits high enantiomeric excess and conversion, and the catalyst/ionic liquid solution can be re-used with increasing enantioselectivity. In addition to this and other specific applications, a clearer understanding of the relationship between supercritical fluid pressure and selectivity is possible as a result of Dick’s research.
2000
Scott M. Reed, University of Oregon
“Development of Green Laboratory Experiments: Teaching Green Chemistry in the Organic Laboratory”
Working on a fellowship from the Department of Education, Scott Reed, under the direction of Professor Jim Hutchison, chose to adapt green methods of chemistry for an introductory organic chemistry laboratory course. “An Environmentally Benign Synthesis of Adipic Acid” was adapted from a recent article in Science. This experiment utilizes green reagents (hydrogen peroxide as the oxidant), solvents (water) and methods (phase transfer catalysis, catalyst recycling), to provide an alternative route to an important commodity chemical that avoids use of nitric acid and production of ozone-damaging nitrous oxide, thereby teaching students first-hand many of the essential principles of green chemistry. In order for the field of green chemistry to expand to its full potential it is essential that the next generation of chemists be trained in the growing set of methods, techniques, and principles unique to green chemistry. While many chemistry courses now cover environmental issues as a part of their curriculum, few integrate such concepts into their laboratory sections. The lack of available experiments has been a major obstacle to providing a greener organic laboratory curriculum.
1999
W. Clayton Bunyard, University of North Carolina-Chapel Hill
W. Clayton Bunyard, under the direction of Professor Joseph M. DeSimone, focused on a more environmentally-benign synthesis of perfluoropolyethers, as well as new applications for these specialty polymers. The new synthesis employs carbon dioxide as the solvent, eliminating the traditional use of ozone-depleting CFCs. PFPEs show potential as non-toxic, fouling-release coatings for commercial shipping and military fleets. Fouling-release coatings provide a minimally adhesive surface to the ship that prevents marine organisms from attaching. In contrast, traditional antifouling coatings release a toxic compound that kills marine organisms and may accumulate in both water and aquatic life. Environmental benefits are realized through the improved synthesis and novel application.