Balkus, Kenneth J.
Permanent URI for this collectionhttps://hdl.handle.net/10735.1/4257
Kenneth Balkus is a Professor of inorganic and materials chemistry and a Fellow of the American Chemical Society. His current research focuses on nanoporous metal oxides, including "zeolites and related molecular sieves as well as layered materials."
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Item Synthesis and Characterization of a Holmium 2,2′-bipyridine-5,5′-dicarboxylate MOF: Towards the Construction of a Suitable Holmium Carrier(Pergamon-Elsevier Science Ltd, 2019-02) Vizuet, Juan P.; Lewis, Abigail L.; McCandless, Gregory T.; Balkus, Kenneth J.; 0000-0003-1142-3837 (Balkus, KJ); Vizuet, Juan P.; Lewis, Abigail L.; McCandless, Gregory T.; Balkus, Kenneth J.Based on the 2,2′-bipyridine-5,5′-dicarboxylic acid ligand (H₂bpdc), a new metal-organic framework using holmium as the coordinating metal site was synthesized through a solvothermal reaction. The 3D compound {[Ho₂(bPdc)₃(DMF)₂] · 2(DMF)}ₙ (1) was characterized by single crystal X-ray diffraction, FTIR, TGA and PXRD. The coordination between H₂bpdc, the solvent, and holmium (CN = 7) allows for the construction of a MOF containing potentially free metal sites and uncoordinated N-donor sites. These features make this MOF an attractive holmium carrier for radiotherapeutic applications.Item Biphenyl-Bridged Wrinkled Mesoporous Silica Nanoparticles for Radioactive Iodine Capture(Cambridge Univ Press, 2019-02-11) Brown, Alexander T.; Lin, Jason; Thomas, Milana C.; Chabal, Yves J.; Balkus, Kenneth J.; 0000-0003-0291-2081 (Brown, AT); Brown, Alexander T.; Lin, Jason; Thomas, Milana C.; Chabal, Yves J.; Balkus, Kenneth J.The capture of volatile radioactive iodine-129 is an important process for nuclear fission. Biphenyl-bridged wrinkled mesoporous silica shows similar performance for iodine sequestration to commercial Ag-mordenite and avoids the use of expensive silver The biphenyl-wrinkled mesoporous silica nanoparticles function as a scaffold for biphenyl groups and also as a fluorescent indicator for the loading of iodine. The nanoparticles have a surface area of 973 m²/g and the biphenyl molecules form an electron charge-transfer complex with iodine. Iodine was loaded into the biphenyl-bridged wrinkled mesoporous silica (BUMS) at 19 ± 0.2 % loading by mass.Item Nanocast Carbon Microsphere Flowers from a Lanthanum-Based Template(Elsevier Science B.V., 2018-09-11) Brown, Alexander T.; Thomas, Milana C.; Chabal, Yves J.; Balkus, Kenneth J.; 0000-0001-5926-0200 (Fischetti, MV); 0000-0003-1142-3837 (Balkus, KJ); Brown, Alexander T.; Thomas, Milana C.; Chabal, Yves J.; Balkus, Kenneth J.Hollow carbon microsphere flowers were nanocast from glucose, acrylamide, and acetylene sources. Carbon growth was catalyzed by a lanthanum graft copolymer template using wet acetylene. The resulting spherical shape is beneficial for 3-D porosity, and has a highly graphitic content as indicated by raman spectroscopy (I_{D} :I_{G} = 0.99). The carbon has a high surface area of 1000 m²/g, as well as strong π-π stacking of aromatic carbons.Item Transition from a 1D Coordination Polymer to a Mixed-Linker Layered MOF(American Chemical Society) Vizuet, Juan P.; Howlett, Thomas S.; Lewis, Abigail L.; Chroust, Zachary D.; McCandless, Gregory T.; Balkus, Kenneth J.; 0000-0003-1142-3837 (Balkus, KJ); Vizuet, Juan P.; Howlett, Thomas S.; Lewis, Abigail L.; Chroust, Zachary D.; McCandless, Gregory T.; Balkus, Kenneth J.A novel copper(II) metal-organic framework (MOF) has been synthesized by modifying the reaction conditions of a 1D coordination polymer. The 1D polymer is built by the coordination between copper and 2,2′-(1H-imidazole-4,5-diyl)di-1,4,5,6-tetrahydropyrimidine (H-L1). The geometry of H-L1 precludes its ability to form extended 3D framework structures. By adding 1,4-benzenedicarboxylic acid (H 2 BDC), a well-studied linker in MOF synthesis, we achieved the transition from a 1D polymer chain into porous 2D layered structures. Hydrogen bonding between L1 and BDC directs the parallel stacking of these layers, resulting in a 3D structure with one-dimensional channels accessible by two different pore windows. The preferred growth orientation of the crystal produces prolonged channels and a disparity in pore size distribution. This in turn results in slow diffusion processes in the material. Furthermore, an isoreticular MOF was prepared by substituting the BDC linker by 2,6-naphthalenedicarboxylic acid (H₂NDC). © 2019 American Chemical Society.Item Fabrication and Characterization of Aging Resistant Carbon Molecular Sieve Membranes for C₃ Separation Using High Molecular Weight Crosslinkable Polyimide, 6FDA-DABA(Elsevier B.V.) Karunaweera, Chamaal; Musselman, Inga H.; Balkus, Kenneth J.; Ferraris, John P.; Karunaweera, C.; Musselman, Inga H.; Balkus, Kenneth J.; Ferraris, John P.Although propylene/propane separation remains a challenge for industrial processes, carbon molecular sieve membranes (CMSMs) have the potential to replace traditional separation methods. A high molecular weight crosslinkable polyimide was utilized to fabricate CMSMs, which showed pure gas permeabilities in excess of 400 barrers with propylene/propane selectivities as high as 25. Mixed gas (C₃H₈:C₃H₆ 50:50) measurements yielded a propylene permeability of 257 barrers and a selectivity of 20. CMSMs from thermally precrosslinked polymer precursors demonstrated a 98% propylene permeability retention after aging for 20 days under vacuum. Active gas flow conditions resulted in slightly lower permeability retention (92.5%) after 15 days of testing. ©2019 Elsevier B.V.Item Novel Binder-Free Electrode Materials for Supercapacitors Utilizing High Surface Area Carbon Nanofibers Derived from Immiscible Polymer Blends of PBI/6FDA-DAM:DABA(Royal Society of Chemistry, 2018-06-01) Abeykoon, Nimali C.; Garcia, Velia; Jayawickramage, Rangana A.; Perera, Wijayantha; Cure, Jeremy; Chabal, Yves J.; Balkus, Kenneth J.; Ferraris, John P.; 0000 0000 4239 3958 (Chabal, YJ); 0000-0002-3225-0093 (Ferraris, JP); Abeykoon, Nimali C.; Garcia, Velia; Jayawickramage, Rangana A.; Perera, Wijayantha; Cure, Jeremy; Chabal, Yves J.; Balkus, Kenneth J.; Ferraris, John P.Carbon nanofibers with high surface area have become promising electrode materials for supercapacitors because of their importance in increasing energy density. In this study, a high free volume polymer, 6FDA-DAM:DABA (6FDD) was blended with polybenzimidazole (PBI) in different ratios to obtain different compositions of PBI/6FDD immiscible polymer blends. Freestanding nanofiber mats were obtained via electrospinning using blend precursors dissolved in N,N-dimethylacetamide (DMAc). Subsequently, carbonization, followed by CO₂ activation at 1000 °C was applied to convert the fiber mats into porous carbon nanofibers (CNFs). The addition of 6FDD shows significant effects on the microstructure and enhancement of the surface area of the CNFs. The obtained CNFs show specific surface area as high as 3010 m² g⁻¹ with pore sizes comparable to those of the electrolyte ions (PYR₁₄TFSI). This provides good electrolyte accessibility to the pore of the carbon materials resulting in enhanced energy density compared to the CNFs obtained from pure PBI. Electrodes derived from PBI:6FDD (70 : 30) exhibited outstanding supercapacitor performance in coin cells with a specific capacitance of 142 F g⁻¹ at the scan rate of 10 mV s⁻¹ and energy density of 67.5 W h kg⁻¹ at 1 A g⁻¹ (58 W h kg⁻¹ at 10 A g⁻¹) thus demonstrating promising electrochemical performance for high performance energy storage system.Item Chemoradiotherapeutic Wrinkled Mesoporous Silica Nanoparticles for use in Cancer Therapy(Amer Inst Physics, 2014-10-30) Munaweera, Imalka; Koneru, Bhuvaneswari; Shi, Yi; Di Pasqua, Anthony J.; Balkus, Kenneth J., Jr.; 0000 0001 3751 138X (Balkus, KJ)Over the last decade, the development and application of nanotechnology in cancer detection, diagnosis, and therapy have been widely reported. Engineering of vehicles for the simultaneous delivery of chemo-and radiotherapeutics increases the effectiveness of the therapy and reduces the dosage of each individual drug required to produce an observable therapeutic response. We here developed a novel chemoradiotherapeutic 1,2-dioleoyl-sn-glycero-3-phosphocholine lipid coated/uncoated platinum drug loaded, holmium-containing, wrinkled mesoporous silica nanoparticle. The materials were characterized with TEM, FTIR, ¹H NMR, energy dispersive x-ray, inductively coupled plasma-mass spectrometry, and zeta potential measurements. In vitro platinum drug release from both lipid coated and uncoated chemoradiotherapeutic wrinkled mesoporous silica are reported. Various kinetic models were used to analyze the release kinetics. The radioactivity of the chemoradiotherapeutic nanocarriers was measured after neutron-activation.