We are a synthetic materials chemistry group, developing new materials for environmental and energy applications. The projects are interdisciplinary and utilize a variety of solid and liquid based characterization techniques.
Current Projects
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Cationic Materials for Pollutant Trapping
We discover new inorganic and metal-organic materials that bear cationic charge. The open space inside these covalently extended crystalline hosts contain anions that can be exchanged for environmentally hazardous anions, both inorganic and organic. The exchange must occur in water and be selective, high capacity and reversible for reusing the material. The goal is to replace current methods of treating wastewater and underground plumes contaminated by toxic species such as chromium-6, perchlorate and radioactive elements. We have published a long list of new crystal structures, most recently SLUG-65. A current focus is on the structure-directing and trapping of toxic perfluorinated anions such as PFOS and PFOA, the so-called "forever" chemicals. |
This project is supported by the National Science Foundation, Partnerships for Innovation, Technology Translation Program (Grant Number 2044692) as well the Division of Chemical, Bioengineering, Environmental, and Transport Systems (CBET), Environmental Engineering, Grant Opportunities for Academic Liaison with Industry (GOALI) Program (Grant Number 1603754).
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Green Hydrogen Made Easy
We discovered a new method of hydrogen generation using a gallium-rich aluminum composite. Aluminum nanoparticles form in the gallium and generate hydrogen at ambient conditions upon the addition of water. Commercial aluminum can be used, including post-consumer aluminum foil that is usually discarded. |
Characterization of the Ga-Al composite by electron microscopy illustrate that the gallium acts to dissolve the aluminum oxide coating of the aluminum. The pristine bare nanoparticles are then available for continuous water splitting and on-demand hydrogen generation. The water splitting reaction requires no applied potential and functions at room temperature/pressure and neutral pH to rapidly generate 130 mL of hydrogen per gram of alloy within minutes. Any available source of water can be used including wastewater, commercial beverages or even ocean water, with no generation of chlorine gas. Equally crucial, the gallium remains intact, allowing it to be collected and reused indefinitely. The Ga-Al alloy is stable under cyclohexane for at least a year so can be prepared ahead of time. The societal impact of our project is potentially vast. We are optimizing the system for performance, with the goal of a functional prototype for larger scale.
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Biodiesel Made Easy
We discovered a new method of biodiesel production that could have direct widespread impact in renewable energy. Better methods are desperately needed in order for biodiesel to become an economically viable energy source. Current biodiesel is too expensive, relying on KOH or NaOH that gives rise to soap that is costly to separate and reduced the biodiesel yield to ca. 60%. |
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A catalyst such as iron oxide or palladium must be heated to 60-100 C to induce formation of the methoxide that allows for transesterification of triglyceride (TG).
Our method is base- and catalyst-free, converting vegetable oils into high-value, carbon neutral biodiesel fatty acid methyl esters (FAMEs). We can use commercial waste oil or virgin cooking oil (e.g. soybean, corn, olive, coconut or animal fat). The reaction uses a boron-based compound in methanol. Our method represents a major advancement in biodiesel production by avoiding base and water, and thus soapy diesel, also increasing our yield to an average of 85%. Only 40 C is required and product recovery is facile: the FAME is simply decanted. The residual glycerol-boron by-product is crystalline and can be recycled. The reaction does not need a refinery, so can be carried out on-site, possibly allowing farmers to fuel their own equipment. The customer base of biodiesel and its societal impact are potentially vast.
Past Projects
Mesoporous Materials for Desulfurization of Jet Fuel
We are studying the removal of sulfur compounds from jet fuel. We have recently reported mesoporous nanoparticles made of silica that show record uptake of sulfur for the fuel known as JP-8. We load the pores of the host with silver, which has a high propensity for sulfur. We are about to submit a paper on a related material that shows excellent uptake but also reversibility so it can be used indefinitely.
We are studying the removal of sulfur compounds from jet fuel. We have recently reported mesoporous nanoparticles made of silica that show record uptake of sulfur for the fuel known as JP-8. We load the pores of the host with silver, which has a high propensity for sulfur. We are about to submit a paper on a related material that shows excellent uptake but also reversibility so it can be used indefinitely.
Biomaterials: Mesoporous Materials for the Eradication of Drug-Resistant Bacteria
This project is in collaboration with the Mascharak group. It also employs mesoporous silica nanoparticles, as depicted in the figure to the left. The pores are loaded with photoactive inorganic complexes developed by the Mascharak group, who then study the release of NO and CO for the eradication of bacterial strains that are drug resistant.
This project is in collaboration with the Mascharak group. It also employs mesoporous silica nanoparticles, as depicted in the figure to the left. The pores are loaded with photoactive inorganic complexes developed by the Mascharak group, who then study the release of NO and CO for the eradication of bacterial strains that are drug resistant.
Swollen Polymers and Elastomers as an Inorganic Growth Medium
Porous polymer gels such as polyacrylamide used in electrophoresis are used as a sacrificial template for making macroporous inorganic materials, with controlled porosity and composition. These macroporous materials are potentially useful for many applications such as as separation media or battery electrodes.
Porous polymer gels such as polyacrylamide used in electrophoresis are used as a sacrificial template for making macroporous inorganic materials, with controlled porosity and composition. These macroporous materials are potentially useful for many applications such as as separation media or battery electrodes.
PDMS Membranes for Li Air Batteries
This project is in collaboration with Yardney, Inc. We create a polymer coating for their air batteries, where the elastomer known as polydimethylsiloxane is oxygen permeable but protects the interior battery from atmospheric moisture.
This project is in collaboration with Yardney, Inc. We create a polymer coating for their air batteries, where the elastomer known as polydimethylsiloxane is oxygen permeable but protects the interior battery from atmospheric moisture.
Self-Assembled Monolayers (SAMs) for Molecular Electronic Devices
We deposit Au or Ag on a PDMS stamp with surface relief. Contact to the top of a alkanedithiol SAM transfered the Ag to the thiol terminated surface, leading to a metal-insulator-metal junction. The PDMS is flexible about the contact, leading to micro/nanofabrication possibilities. The junctions were also investigated for their capacitance and sensing properties.
SAM-Ceramic Composite Bilayer Protective Coatings
This project was in collaboration with Professor Junghyun Cho at SUNY Binghamton. We have several patents on this approach, where a self-assembled monolayer is used as a buffer layer between the semiconductor substrate and the ceramic coating to increase the resistance of the underlying device to thermal cracking.
This project was in collaboration with Professor Junghyun Cho at SUNY Binghamton. We have several patents on this approach, where a self-assembled monolayer is used as a buffer layer between the semiconductor substrate and the ceramic coating to increase the resistance of the underlying device to thermal cracking.
