RESEARCH
1. Materials Design:
A. POROUS MATERIALS:
Porous materials such as metal-organic frameworks, covalent organic frameworks (COFs) and porous aromatic frameworks (PAFs) with high levels of permeant porosity have been intensively investigated. When permanent porosity is coupled with the inherent modularity, the resulting materials become relevant to several contemporary challenges related to the environment, energy and human necessities: 1) reduction of energy consumption associated with commodity production (e.g. through improved heterogeneous catalytic processes or through physisorption that will enable improved separation methods and enhanced storage capacity); 2) enabling more efficient, less-polluting means of energy production (e.g. carbon capture) and transportation (e.g. methane or hydrogen storage for vehicular transport) 3) development of electrically conductive porous materials (e.g. for use in physisorptive heat pumps, photocatalysis, environmental sensing, batteries, supercapacitor and solar energy) (4) fabrication of novel membranes that can be feasibly introduced in many technologies (gas separations, molecular sensing and water treatment) (5) discovering new porous nanomaterials that offer opportunities for applications across biology and medicine (drug delivery, bioactive MOF nanoparticles) . In this contribution, we are working on a cutting edge-research of discovering new materials and synthetic/design strategies through metal substitution, isoreticular expansion “changing the linker length”, tuning the linker functionality, control over interpenetration, post-synthetic modification, grafting of active groups, and encapsulation of active species, and their impact on the targeted applications such as gas storage, gas separations, catalysis, energy storage, sensing, and biological applications.
Selected references:
1-Elsaidi, S. K.; Mohamed, M. H.; Banerjee, D.; Thallapally, P. K. Flexibility in Metal Organic Frameworks: A Fundamental Understanding. Coordination Chemistry Reviews 2018, 358, 125-152. https://www.sciencedirect.com/science/article/pii/S0010854517303272
2- Elsaidi, S. K.; Mohamed, M. H.; Simon, C. M.; Braun, E.; Pham, T.; Forrest, K.; Xu, W.; Space, B.; Zaworotko, M. J.; Thallapally, P. K. Effect of Ring Rotation upon Gas Adsorption in SIFSIX-3- M (M = Fe, Ni) Pillared Square Grid Networks. Chemical Science 2017, 8, 2373-2380. http://pubs.rsc.org/en/content/articlelanding/2017/sc/c6sc05012c#!divAbstract
3-Elsaidi, S. K.; Mohamed, M. H.; Loring, J.S.; McGrail, B. P.; Thallapally, P. K. Covalent Coordination Frameworks: A New Route for Synthesis and Expansion of Functional Porous Materials. ACS Applied Materials & Interfaces 2016, 8, 28424.
4-Elsaidi, S. K.; Mohamed, M. H.; Wojtas, L.; Chanthapally, A.; Pham, T.; Space, B.; Vittal, J. J.; Zaworotko, M. J, Putting the squeeze on CH4 and CO2 through control over interpenetration in diamondoid nets. Journal of the American Chemical Society, 2014, 136, 5072
5- Elsaidi, S. K.; Mohamed, M. H.; Wojtas, L.; Cairns, A. J.; Eddaoudi, M.; Zaworotko, M. J. Two-step crystal engineering of porous nets from [Cr3(µ3-O)(RCO2)6] and [Cu3(µ3-Cl)(RNH2)6Cl6] molecular building blocks. Chemical Communications 2013, 49, 8154. http://pubs.rsc.org/en/content/articlelanding/2013/cc/c3cc44133d#!divAbstract
6- Mohamed, M. H.;* Elsaidi, S. K.;* Pham, T.; Forrest, K. A.; Tudor, B.; Wojtas, L.; Space, B.; Zaworotko, M. J. Pillar substitution modulates CO2 affinity in "mmo" topology networks. Chemical Communications 2013, 49, 9809. http://pubs.rsc.org/en/Content/ArticleLanding/2013/CC/C3CC44745F#!divAbstract
7-Mohamed, M. H.;* Elsaidi, S. K.;* Wojtas, L.; Pham, T.; Forrest, K. A.; Tudor, B.; Space, B.; Zaworotko, M. J. Highly Selective CO2 Uptake in Uninodal 6-Connected “mmo” Nets Based upon MO4 2– (M = Cr, Mo) Pillars. Journal of the American Chemical Society 2012, 134, 19556. https://pubs.acs.org/doi/abs/10.1021/ja309452y *Authors contributed equally to this work
PATENTS :
1. Sameh K. Elsaidi, David Hopkinson, Mixed-Matrix Membranes for Post-combustion CO2 Separations (in preparation)
2. Sameh K. Elsaidi, David Hopkinson, New Class of Metallopolymers: Synthesis and Applications (in preparation) 3. Michael J. Zaworotko, Mona H. Mohamed, and Sameh K. Elsaidi, Metal-Organic Materials (MOMs) for Adsorption of Polarizable Gases and Methods of Using MOMs, US 9676807. https://patents.google.com/patent/WO2014074378A1
B. NANOMATERIALS AND NANOCOMPOSITES:
Porous materials synthesized in the nano-size have shown a great potential for many applications such as molecular sensing, catalysis, drug delivery and biomedical applications. Also, porous materials were employed as carrier of the nanoparticles whereas their channels can act as hosts for the nano-particles to endow them unique properties such as stability, recyclability and efficiency. Herein, various MOF-based nanoparticles were synthesized and exploited to form nanocomposite materials that showed a great promise in magnetic separation, water treatment, extraction of rare-earth elements, membrane technologies, gas separations and biological applications.
Our work at PNNL were recognized in different science websites:
Reduced Magnetism in Core–Shell Magnetite@MOF Composites
https://pubs.acs.org/doi/abs/10.1021/acs.nanolett.7b03451
Elsaidi, S. K.; Sinnwell, M.; Banerjee, D.; Devaraj, A.; Kukkadapu, R.; Droubay, T.; Nie, Z.; Kovarik, L.; Manandhar, , S.; Nandasiri, M.; McGrail, B.; Thallapally, P.; Vijayakumar, M. Reduced Magnetism in Core-Shell Magnetite@MOF Composites Nano Letters 2017, 17, 6968-6973.
C. MEMBRANES TECHNOLOGIES:
Membrane technology such as inorganic membranes and organic polymer membranes are promising techniques for separation technologies such as water purification, organic solvent nanofilteration and gas separation because of the low cost and processing feasibility. In the light of this, we are developing a new generation of defect-free self-standing MOF-based Mixed Matrix Membranes (MMMs) and investigating their potential for wide range of applications such as gas separation, sensing, water treatment and detection of toxic compounds. The new membranes will combine the advantages of MOFs in terms of the permanent porosity, inherent modularity, structural diversity and fine-tunability and those of organic polymers such as the facile processability and the mechanical strength.
Patent: . Sameh K. Elsaidi, David Hopkinson, Mixed-Matrix Membranes for Post-combustion CO2 Separations (in preparation)
Selected References:
1-Wu, T.; Lucero, J.; Zong, Z.; Elsaidi, S. K.; Thallapally, P. K.; Carreon, M. A. Microporous crystalline membranes for Kr/Xe Separation: Comparison between AlPO-18, SAPO-34, and ZIF-8. ACS Applied Nano Materials, 2018, 1, 463-470
2-Wu, T.; Feng, X.; Elsaidi, S. K.; Thallapally, P. K.; Carreon, M. A. Zeolitic Imidazolate Framework-8 (ZIF-8) Membranes for Kr/Xe Separation. Industrial & Engineering Chemistry Research 2017, 56, 1682- 1686. https://pubs.acs.org/doi/abs/10.1021/acs.iecr.6b04868
3- Zong, Z.; Elsaidi, S. K.; Thallapally, P. K.; Carreon, M. A. Highly Permeable AlPO-18 Membranes for N2/CH4 Separation. Industrial & Engineering Chemistry Research 2017, 56, 4113-4118. https://pubs.acs.org/doi/abs/10.1021/acs.iecr.7b00853
4- Feng, X.; Zong, Z.; Elsaidi, S. K; Jasinski, J. B.; Thallapally, P. K.; Carreon, M. A. Kr/Xe Separation over a Chabazite Zeolite Membrane. Journal of the American Chemical Society 2016, 138, 9791.
D. DISCOVERING NEW DESIGN AND SYNTHETIC STRATEGIES:
Crystal and molecular engineering allows the design and synthesis of new materials with desired and predicted properties. We are developing pioneering crystal/molecular engineering strategies that offer a bottom-up approach to materials design and synthesis based upon selecting molecules or ions in order to achieve a targeted outcome in terms of structure and properties. Two-step reaction is used for the synthesis of porous materials by connecting the previously prepared molecular building blocks, MBBs (in the first step) with a metal or both metal and organic ligand in the second step. We exploited the two-step crytal engineering approach to design a novel class of porous material called Covalent Coordination Frameworks (CCFs) that blooms a new avenue for synthesis of porous materials since it merges the synthetic routes of two well-known classes; metal organic frameworks (MOFs) and covalent organic frameworks (COFs). CCFs have been synthesized by the condensation or Schiff base reaction of the amino-decorated trigonal prismatic coordination molecular building block (CMBB-1) and di-/tri-aldehydes or di-/tri-acid chlorides. This facile and potentially universal approach would inevitably open a feasible path for the synthesis of porous materials under ambient conditions using various simple organic molecules and versatile MBBs with different decorations. This class of porous materials can also militate against constraints of the expansion of many interesting functional porous materials and could lead to synthesis of many novel porous materials that are previously unattainable.
Our work at PNNL were recognized in different science websites:
Fast and easy two-step creates new porous materials
https://www.pnnl.gov/science/highlights/highlight.asp?id=4460
https://www.nanowerk.com/nanotechnology-news/newsid=45009.php
Elsaidi, S. K.; Mohamed, M. H.; Loring, J.S.; McGrail, B. P.; Thallapally, P. K. Covalent Coordination Frameworks: A New Route for Synthesis and Expansion of Functional Porous Materials. ACS Applied Materials & Interfaces 2016, 8, 28424.
RESEARCH
2- Gas storage and separations:
A. CO2 CAPTURE AND SEPARATIONS:
The reducing of the anthropogenic emission of CO2 gas becomes extremely important since the industrial revolution results in a fast increase of CO2 concentration in atmosphere by almost 40%. Typical flue gases produced from the combustion of fossil fuel plants for the electricity generation comprise 3 to 16% CO2 by volume at ambient condition which generate about one-third of the total emission of CO2 gas. Therefore, the U.S. department of energy (DOE) issued a new target for the implementation of carbon dioxide capture at 2009 stated that the CO2 adsorbent material should capture 90% of CO2 through the post-combustion process and a maximum 35% increase for the cost of the electricity generated from coal-fired power stations by 2020. The current technologies for the capture of CO2 from the flue gases involve the using of aqueous alkanolamines which costs approximately $300/ton of captured CO2 that leads to the increase of the electricity cost produced from the fuel-fired power plants by approximately 50% due to their limitations such as the large heat loss (25-40%), solvent loss and corrosion issues. In addition to its involvement in climate change, CO2 is an impurity in many gas streams. Herein, we are interested in developing inexpensive, facile to synthesize, robust and highly selective CO2 adsorbents and membranes for CO2 separation from flue gas (CO2/N2), natural gas (CO2/CH4), biogas (CO2/H2) as well as its direct capture from air.
Patent:
Michael J. Zaworotko, Mona H. Mohamed, and Sameh K. Elsaidi, Metal-Organic Materials (MOMs) for Adsorption of Polarizable Gases and Methods of Using MOMs, US 9676807. https://patents.google.com/patent/WO2014074378A1
Selected References:
1-Elsaidi, S. K.; Mohamed, M. H.; Wojtas, L.; Chanthapally, A.; Pham, T.; Space, B.; Vittal, J. J.; Zaworotko, M. J, Putting the squeeze on CH4 and CO2 through control over interpenetration in diamondoid nets. Journal of the American Chemical Society, 2014, 136, 5072. https://pubs.acs.org/doi/abs/10.1021/ja500005k
2- Elsaidi, S. K.; Mohamed, M. H.; Wojtas, L.; Cairns, A. J.; Eddaoudi, M.; Zaworotko, M. J. Two-step crystal engineering of porous nets from [Cr3(µ3-O)(RCO2)6] and [Cu3(µ3-Cl)(RNH2)6Cl6] molecular building blocks. Chemical Communications 2013, 49, 8154. http://pubs.rsc.org/en/content/articlelanding/2013/cc/c3cc44133d#!divAbstract
3- Mohamed, M. H.;* Elsaidi, S. K.;* Pham, T.; Forrest, K. A.; Tudor, B.; Wojtas, L.; Space, B.; Zaworotko, M. J. Pillar substitution modulates CO2 affinity in "mmo" topology networks. Chemical Communications 2013, 49, 9809. http://pubs.rsc.org/en/Content/ArticleLanding/2013/CC/C3CC44745F#!divAbstract
3- Mohamed, M. H.;* Elsaidi, S. K.;* Wojtas, L.; Pham, T.; Forrest, K. A.; Tudor, B.; Space, B.; Zaworotko, M. J. Highly Selective CO2 Uptake in Uninodal 6-Connected “mmo” Nets Based upon MO4 2– (M = Cr, Mo) Pillars. Journal of the American Chemical Society 2012, 134, 19556. https://pubs.acs.org/doi/abs/10.1021/ja309452y *Authors contributed equally to this work
B. XE STORAGE:
The demand for Xe capture and storage continues to grow due to its wide applications ranging from lighting, through laser and space technology to medical devices. Specifically, it is projected a NASA (National Aeronautics & Space Administration) deep space rocket with Xe-ion-thrusters engine will utilize approximately 16 metric ton of Xe, with cost ranging between $81-100 million in today's market price. Apart from ion thrusters, large amount of liquid Xenon is currently used in the particle physic experiments to detect the particles that are thought to constitute dark matter. For instance, XENON1T (dark matter experiment), a largest Xe detector that uses approximately 3500 Kg of liquid Xe under operation temperature of -100 °C. To put this in perspective, the liquid Xe tank requires a volume as big as water tank, which face serious engineering and technological challenges. In order to store such large amounts of Xe, the current technology uses a double insulated stainless steel, which is laborious and very, costly. and not economical. In this context, we develop new solid adsorbents that can store large amounts of Xe at ambient or near-ambient conditions, which would reduce the cost and foot print of the storage media. Given these facts, alternate methods are required to address store Xe storage economically at ambient condition.
Our work at PNNL were recognized in different science websites:
New, Energy Efficient Method To Extract Noble Gases From Air
https://www.acsh.org/news/2016/08/03/new-energy-efficient-method-to-extract-noble-gases-from-air
Xenon Gas Separation and Storage Using Metal-Organic Frameworks
https://www.cell.com/chem/fulltext/S2451-9294(17)30527-2
1-Elsaidi, S. K.; Mohamed, M. H.; Xu, W.; Banerjee, D.; Thallapally, P. K. Ultra-Microporous Material for Efficient Removal of Krypton from Nuclear Reprocessing Facilities. (Submitted to Environmental Science & Technology Letters)
2-Banerjee, D.; Elsaidi, S. K.; Simon, C. M.; Thallapally, P. K. Xenon Gas Separation and Storage using Metal Organic Frameworks, Chem 2018. (Just accepted)
3-Wu, T.; Lucero, J.; Zong, Z.; Elsaidi, S. K.; Thallapally, P. K.; Carreon, M. A. Microporous crystalline membranes for Kr/Xe Separation: Comparison between AlPO-18, SAPO-34, and ZIF-8. ACS Applied Nano Materials, 2018.
4-Wu, T.; Feng, X.; Elsaidi, S. K.; Thallapally, P. K.; Carreon, M. A. Zeolitic Imidazolate Framework-8 (ZIF-8) Membranes for Kr/Xe Separation. Industrial & Engineering Chemistry Research 2017, 56, 1682-1686.
5-Elsaidi, S. K.; Ongari, D.; Xu, W.; Mohamed, M. H.; Haranczyk, M.; Thallapally, P. K. Xenon Recovery at Room Temperature using Metal Organic Frameworks. Chemistry-A European Journal 2017.
6-Banerjee, D.; Elsaidi, S. K.; Thallapally, P. K. Xe Adsorption and Separation Properties of a Series of Mi-croporous Metal-Organic Frameworks (MOFs) with V-shaped Linkers. J Mater Chem A 2017.
7-Elsaidi, S. K.; Mohamed, M. H.; Simon, C. M.; Braun, E.; Pham, T.; Forrest, K.; Xu, W.; Space, B.; Zaworotko, M. J.; Thallapally, P. K. Effect of Ring Rotation upon Gas Adsorption in SIFSIX-3- M (M = Fe, Ni) Pillared Square Grid Networks. Chemical Science 2017, 8, 2373-2380
8-Feng, X.; Zong, Z.; Elsaidi, S. K; Jasinski, J. B.; Thallapally, P. K.; Carreon, M. A. Kr/Xe Separation over a Chabazite Zeolite Membrane JACS 2016, 138, 9791.
9-Mohamed, M. H.; Elsaidi, S. K.; Pham, T.; Forrest, K.; Schaef, H.; Hogan, A.; Wojtas, L.; Space, B.; Zaworotko, M. J.; Thallapally, P. K. Hybrid Ultramicroporous Materials for Selective Xe Adsorption and Separation. Angewandte Chemie International Edition 2016, 55, 8285.
3- ENERGY APPLICATIONS:
a. CH4 Storage:
Natural gas, NG, which is predominantly methane, is the most abundant source of hydrocarbon fuel and the second largest energy source that offers several advantages over liquid and solid hydrocarbon fuels: 30-40% lower carbon footprint; 60-80% less smog producing pollutants; lower cost. However, the current technologies for storage and transportation of NG, compressed NG and liquefied NG, face considerable hurdles to their more widespread adoption because of the challenges and costs associated with pressurization and cooling, respectively. In addition, NG is typically contaminated with CO2 and H2S, which should be reduced in concentration to “sweeten” NG prior to use. Herein, we develop new technologies for natural gas (NG) storage/purification upon porous adsorbents/membranes
Selected References
1- Elsaidi, S. K.; Mohamed, M. H.; Wojtas, L.; Chanthapally, A.; Pham, T.; Space, B.; Vittal, J. J.; Zaworotko, M. J, Putting the squeeze on CH4 and CO2 through control over interpenetration in diamondoid nets. Journal of the American Chemical Society, 2014, 136, 5072. https://pubs.acs.org/doi/abs/10.1021/ja500005k
2- Pham T.; Forrest k.; Tudor B.; Elsaidi S. K.; Mohamed M. H.; McLaughlin K.; Cioce C. R.; Zaworotko M. J.; Space B. Theoretical Investigations of CO2 and CH4 Sorption in an Interpenetrated Diamondoid Metal Organic Material. Langmuir 2014, 30, 6454. https://pubs.acs.org/doi/abs/10.1021/la500967w
B. RARE-EARTH ELEMENTS SEPARATION:
As the global technology need grows, demand for REEs such as neodymium (in cell phones), cerium, europium, terbium and yttrium (as phosphors in LCD displays) is predicted to increase exponentially. However, REE extraction through conventional mining processes is expensive and feasible at only a few locations worldwide. As a result, there is a significant interest in new methods of extraction of industrially important REEs from unconventional sources such as from coal fly ash, produced water during oil and gas production, uranium ore extraction, and from geothermal wells. We are developing a simple and highly cost-effective nanofluid-based method for extracting REEs that would be an attractive additional revenue for REE extraction. We demonstrated that a magnetic core-shell approach can effectively extract REEs in their ionic form from aqueous solution with up to 99.99% removal efficiency by introducing either chelating group or ion exchange group to the pores of the porous materials. We chose to coat the Fe3O4 magnetic core with highly porous materials such as MOFs where the core-shell nanocomposite can be completely removed from the mixture under an applied magnetic field, offering a practical, and efficient REE-removal process. Easy one-step synthesis process of functionalized porous materials is required to keep the overall cost down, while long term water stability is required for recyclability of the material. These materials also must have fast REE uptake as the contact time will be relatively short (< 5 min) during the exchange process in a commercial operation.
Our work at PNNL were recognized in different science websites:
Extraction of Rare Earth Elements using Magnetite@MOF Composites
https://www.pnnl.gov/science/highlights/highlight.asp?id=4883
https://www.pnnl.gov/science/highlights/highlight.asp?id=4883
Elsaidi, S. K.; Sinnwell, M. A.; Devaraj, A.; Droubay, T. C.; Nie, Z.; Murugesan, V.; McGrail, B. P.; Thallapally, P. K. Extraction of Rare Earth Elements using Magnetite@MOF Composites. Journal of Materials Chemistry A 2018, 6, 18438.
RESEARCH
4- National Security:
A. XE SEPARATION FROM NUCLEAR REPROCESSING PLANTS:
Nuclear energy is considered an emission free, high-energy density source with minimal land-use requirements. However, any future expansion of civilian nuclear energy will require efficient management of used nuclear fuel (UNF). Major challenge during the reprocessing of the UNF is the release of volatile radionuclides that must be captured and subsequently stored for an extended period of time. While methods such as cryogenic distillation and fluorocarbon based absorption have been proposed and tested, solid state adsorbents are considered better alternatives in terms of cost and engineering control to capture these volatile radionuclides including 85Kr. However, due to the presence of Xe during the reprocessing of the UNF, adsorbent materials such as MOFs are found to be more Xe-philic. To address this challenge, we developed a two-bed breakthrough method which leads to enhanced adsorption and separation of 85Kr.
Our work at PNNL were recognized in different science websites:
New, Energy Efficient Method To Extract Noble Gases From Air
https://www.acsh.org/news/2016/08/03/new-energy-efficient-method-to-extract-noble-gases-from-air
Xenon Gas Separation and Storage Using Metal-Organic Frameworks
https://www.cell.com/chem/fulltext/S2451-9294(17)30527-2
1-Elsaidi, S. K.; Mohamed, M. H.; Xu, W.; Banerjee, D.; Thallapally, P. K. Ultra-Microporous Material for Efficient Removal of Krypton from Nuclear Reprocessing Facilities. (Submitted to Environmental Science & Technology Letters)
2-Banerjee, D.; Elsaidi, S. K.; Simon, C. M.; Thallapally, P. K. Xenon Gas Separation and Storage using Metal Organic Frameworks, Chem 2018. (Just accepted)
3-Wu, T.; Lucero, J.; Zong, Z.; Elsaidi, S. K.; Thallapally, P. K.; Carreon, M. A. Microporous crystalline membranes for Kr/Xe Separation: Comparison between AlPO-18, SAPO-34, and ZIF-8. ACS Applied Nano Materials, 2018.
4-Wu, T.; Feng, X.; Elsaidi, S. K.; Thallapally, P. K.; Carreon, M. A. Zeolitic Imidazolate Framework-8 (ZIF-8) Membranes for Kr/Xe Separation. Industrial & Engineering Chemistry Research 2017, 56, 1682-1686.
5-Elsaidi, S. K.; Ongari, D.; Xu, W.; Mohamed, M. H.; Haranczyk, M.; Thallapally, P. K. Xenon Recovery at Room Temperature using Metal Organic Frameworks. Chemistry-A European Journal 2017.
6-Banerjee, D.; Elsaidi, S. K.; Thallapally, P. K. Xe Adsorption and Separation Properties of a Series of Mi-croporous Metal-Organic Frameworks (MOFs) with V-shaped Linkers. J Mater Chem A 2017.
7-Elsaidi, S. K.; Mohamed, M. H.; Simon, C. M.; Braun, E.; Pham, T.; Forrest, K.; Xu, W.; Space, B.; Zaworotko, M. J.; Thallapally, P. K. Effect of Ring Rotation upon Gas Adsorption in SIFSIX-3- M (M = Fe, Ni) Pillared Square Grid Networks. Chemical Science 2017, 8, 2373-2380
8-Feng, X.; Zong, Z.; Elsaidi, S. K; Jasinski, J. B.; Thallapally, P. K.; Carreon, M. A. Kr/Xe Separation over a Chabazite Zeolite Membrane JACS 2016, 138, 9791.
9-Mohamed, M. H.; Elsaidi, S. K.; Pham, T.; Forrest, K.; Schaef, H.; Hogan, A.; Wojtas, L.; Space, B.; Zaworotko, M. J.; Thallapally, P. K. Hybrid Ultramicroporous Materials for Selective Xe Adsorption and Separation. Angewandte Chemie International Edition 2016, 55, 8285.
B. REMOVAL OF RADIOACTIVE ANIONS FROM NUCLEAR WASTE STREAMS:
Although a trace amount of technetium is naturally present in the atmosphere because of the spontaneous fission of the uranium isotopes, the major source of radioactive 99Tc is the production of weapon grade plutonium (239Pu) during irradiated uranium fuel cell reprocessing. The so-formed 99Tc can be found mainly as 99TcO4- in legacy nuclear waste. The presence of large amounts of 99TcO4- in stored nuclear waste is an environmental and public health concern mainly due to the long half-life and environmental mobility of 99TcO4- as it has high water solubility. Moreover, the high volatility of 99TcO4- in the waste stream causes major operational inefficiencies during vitrification (used for long-term storage purpose of nuclear waste) processes. Efficient and cost-effective removal of radioactive pertechnetate anions from legacy nuclear waste is a key challenge to mitigate long-term nuclear waste storage issues. Traditional materials such as resins and layered double hydroxides (LDHs) were evaluated for their pertechnetate or its non-radioactive surrogate perrhenate removal capacity, but there is room for improvement in terms of capacity, selectivity and kinetics. The modular nature of the porous materials allows us to design highly promising candidates for perrhenate removal in the presence of other competing anions.
Banerjee, D.; Elsaidi, S. K.; Nie, Z.; Li, B.; Aguila, B.; Ma, S.; Thallapally, P. K. Removal of Pertechnetate related Oxyanion using Functionalized Hierarchical Porous Frameworks from Solution. Chemistry A European Journal 2016, 22, 17581.
5- BIOLOGICAL APPLICATIONS:
Xenon is known to be a very efficient anesthetic gas but its cost prohibits the wider use in medical industry and other potential applications. It has been shown that Xe recovery and recycle from anesthetic gas mixture can significantly reduce its cost as anesthetic. The current technology uses series of adsorbent columns followed by low temperature distillation to recover Xe, which is expensive to use in medical facilities. Herein, we propose much efficient and simpler system to recover and recycle Xe from simulant exhale anesthetic gas mixture at room temperature using porous adsorbents and membranes. A closed system containing novel sorbent/membrane for portable breathing units for medical industry provides an opportunity to recycle and reuse Xe efficiently that offers distinct cost-advantage for the widespread use of Xe as new source of anesthetic gas.
Elsaidi, S. K.; Ongari, D.; Xu, W.; Mohamed, M. H.; Haranczyk, M.; Thallapally, P. K. Xenon Recovery at Room Temperature using Metal Organic Frameworks. Chemistry-A European Journal 2017, 23, 10758. https://onlinelibrary.wiley.com/doi/full/10.1002/chem.201702668
