120 results on '"Dale L. Huber"'
Search Results
2. Antibacterial activity of iron oxide, iron nitride, and tobramycin conjugated nanoparticles against Pseudomonas aeruginosa biofilms
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Leisha M. Armijo, Stephen J. Wawrzyniec, Michael Kopciuch, Yekaterina I. Brandt, Antonio C. Rivera, Nathan J. Withers, Nathaniel C. Cook, Dale L. Huber, Todd C. Monson, Hugh D. C. Smyth, and Marek Osiński
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Antibiotic resistance ,Pseudomonas aeruginosa ,Cystic fibrosis ,Biofilm ,Antibacterial agents ,Drug delivery ,Biotechnology ,TP248.13-248.65 ,Medical technology ,R855-855.5 - Abstract
Abstract Background Novel methods are necessary to reduce morbidity and mortality of patients suffering from infections with Pseudomonas aeruginosa. Being the most common infectious species of the Pseudomonas genus, P. aeruginosa is the primary Gram-negative etiology responsible for nosocomial infections. Due to the ubiquity and high adaptability of this species, an effective universal treatment method for P. aeruginosa infection still eludes investigators, despite the extensive research in this area. Results We report bacterial inhibition by iron-oxide (nominally magnetite) nanoparticles (NPs) alone, having a mean hydrodynamic diameter of ~ 16 nm, as well as alginate-capped iron-oxide NPs. Alginate capping increased the average hydrodynamic diameter to ~ 230 nm. We also investigated alginate-capped iron-oxide NP-drug conjugates, with a practically unchanged hydrodynamic diameter of ~ 232 nm. Susceptibility and minimum inhibitory concentration (MIC) of the NPs, NP-tobramycin conjugates, and tobramycin alone were determined in the PAO1 bacterial colonies. Investigations into susceptibility using the disk diffusion method were done after 3 days of biofilm growth and after 60 days of growth. MIC of all compounds of interest was determined after 60-days of growth, to ensure thorough establishment of biofilm colonies. Conclusions Positive inhibition is reported for uncapped and alginate-capped iron-oxide NPs, and the corresponding MICs are presented. We report zero susceptibility to iron-oxide NPs capped with polyethylene glycol, suggesting that the capping agent plays a major role in enabling bactericidal ability in of the nanocomposite. Our findings suggest that the alginate-coated nanocomposites investigated in this study have the potential to overcome the bacterial biofilm barrier. Magnetic field application increases the action, likely via enhanced diffusion of the iron-oxide NPs and NP-drug conjugates through mucin and alginate barriers, which are characteristic of cystic-fibrosis respiratory infections. We demonstrate that iron-oxide NPs coated with alginate, as well as alginate-coated magnetite–tobramycin conjugates inhibit P. aeruginosa growth and biofilm formation in established colonies. We have also determined that susceptibility to tobramycin decreases for longer culture times. However, susceptibility to the iron-oxide NP compounds did not demonstrate any comparable decrease with increasing culture time. These findings imply that iron-oxide NPs are promising lower-cost alternatives to silver NPs in antibacterial coatings, solutions, and drugs, as well as other applications in which microbial abolition or infestation prevention is sought.
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- 2020
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3. Magnetic Nanocomposites and Their Incorporation into Higher Order Biosynthetic Functional Architectures
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John Watt, Aaron M. Collins, Erika C. Vreeland, Gabriel A. Montano, and Dale L. Huber
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Chemistry ,QD1-999 - Published
- 2018
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4. Iron Oxide Nanocrystals for Magnetic Hyperthermia Applications
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Dale L. Huber, Todd C. Monson, Gennady A. Smolyakov, Natalie L. Adolphi, Nathan J. Withers, Nathaniel C. Cook, Antonio C. Rivera, Salomon Maestas, Surabhi Yadav, Dimple Mathew, Yekaterina I. Brandt, Leisha M. Armijo, Hugh D. C. Smyth, and Marek Osiński
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iron oxide nanocrystals ,hyperthermia ,thermotherapy ,ferrofluid ,Chemistry ,QD1-999 - Abstract
Magnetic nanocrystals have been investigated extensively in the past several years for several potential applications, such as information technology, MRI contrast agents, and for drug conjugation and delivery. A specific property of interest in biomedicine is magnetic hyperthermia—an increase in temperature resulting from the thermal energy released by magnetic nanocrystals in an external alternating magnetic field. Iron oxide nanocrystals of various sizes and morphologies were synthesized and tested for specific losses (heating power) using frequencies of 111.1 kHz and 629.2 kHz, and corresponding magnetic field strengths of 9 and 25 mT. Polymorphous nanocrystals as well as spherical nanocrystals and nanowires in paramagnetic to ferromagnetic size range exhibited good heating power. A remarkable 30 °C temperature increase was observed in a nanowire sample at 111 kHz and magnetic field of 25 mT (19.6 kA/m), which is very close to the typical values of 100 kHz and 20 mT used in medical treatments.
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- 2012
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5. Development of Antibody-Tagged Nanoparticles for Detection of Transplant Rejection Using Biomagnetic Sensors
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Kimberly S. Butler, Debbie M. Lovato, Natalie L. Adolphi, Robert Belfon, Danielle L. Fegan, Todd C. Monson, Helen J. Hathaway, Dale L. Huber, T. E. Tessier, H. C. Bryant, Edward R. Flynn, and Richard S. Larson M.D., Ph.D.
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Medicine - Abstract
Organ transplantation is a life-saving procedure and the preferred method of treatment for a growing number of disease states. The advent of new immunosuppressants and improved care has led to great advances in both patient and graft survival. However, acute T-cell-mediated graft rejection occurs in a significant quantity of recipients and remains a life-threatening condition. Acute rejection is associated with decrease in long-term graft survival, demonstrating a need to carefully monitor transplant patients. Current diagnostic criteria for transplant rejection rely on invasive tissue biopsies or relatively nonspecific clinical features. A noninvasive way is needed to detect, localize, and monitor transplant rejection. Capitalizing on advances in targeted contrast agents and magnetic-based detection technology, we developed anti-CD3 antibody-tagged nanoparticles. T cells were found to bind preferentially to antibody-tagged nanoparticles, as identified through light microscopy, transmission electron microscopy, and confocal microscopy. Using mouse skin graft models, we were also able to demonstrate in vivo vascular delivery of T-cell targeted nanoparticles. We conclude that targeting lymphocytes with magnetic nanoparticles is conducive to developing a novel, noninvasive strategy for identifying transplant rejection.
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- 2013
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6. Asymmetric nanoparticle oxidation observed in-situ by the evolution of diffraction contrast
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Agus R Poerwoprajitno, Nitish Baradwaj, Manish Kumar Singh, C Barry Carter, Dale L Huber, Rajiv Kalia, and John Watt
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in-situ ,environmental TEM ,oxidation ,iron oxide nanoparticles ,Ashby-Brown contrast ,Materials of engineering and construction. Mechanics of materials ,TA401-492 ,Physics ,QC1-999 - Abstract
The use of transmission electron microscopy (TEM) to observe real-time structural and compositional changes has proven to be a valuable tool for understanding the dynamic behavior of nanomaterials. However, identifying the nanoparticles of interest typically require an obvious change in position, size, or structure, as compositional changes may not be noticeable during the experiment. Oxidation or reduction can often result in subtle volume changes only, so elucidating mechanisms in real-time requires atomic-scale resolution or in-situ electron energy loss spectroscopy, which may not be widely accessible. Here, by monitoring the evolution of diffraction contrast, we can observe both structural and compositional changes in iron oxide nanoparticles, specifically the oxidation from a wüstite-magnetite (FeO@Fe _3 O _4 ) core – shell nanoparticle to single crystalline magnetite, Fe _3 O _4 nanoparticle. The in-situ TEM images reveal a distinctive light and dark contrast known as the ‘Ashby-Brown contrast’, which is a result of coherent strain across the core – shell interface. As the nanoparticles fully oxidize to Fe _3 O _4 , the diffraction contrast evolves and then disappears completely, which is then confirmed by modeling and simulation of TEM images. This represents a new, simplified approach to tracking the oxidation or reduction mechanisms of nanoparticles using in-situ TEM experiments.
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- 2023
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7. Colloidal Er3+-doped LiYF4 nanoparticles for NIR bioimaging
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Mia I. Baca, Shruti I. Gharde, Adreanna G. Rael, Mark V. Reymatias, Erum Jamil, Gennady A. Smolyakov, Sergei A. Ivanov, Winson C. H. Kuo, John D. Watt, Dale L. Huber, and Marek Osinski
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- 2023
8. Nanoscale layers of precise ion-containing polyamides with lithiated phenyl sulfonate in the polymer backbone
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Jinseok Park, Charles P. Easterling, Christopher C. Armstrong, Dale L. Huber, Jared I. Bowman, Brent S. Sumerlin, Karen I. Winey, and Mercedes K. Taylor
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Polymers and Plastics ,Organic Chemistry ,Bioengineering ,Biochemistry - Abstract
Precise polyamide ionomer produces well-defined nanoscale layers.
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- 2022
9. Effect of manganese substitution of ferrite nanoparticles on particle grain structure
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Zichun Yan, Anish Chaluvadi, Sara FitzGerald, Sarah Spence, Christopher Bleyer, Jiazhou Zhu, Thomas M. Crawford, Rachel B. Getman, John Watt, Dale L. Huber, and O. Thompson Mefford
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General Engineering ,General Materials Science ,Bioengineering ,General Chemistry ,Atomic and Molecular Physics, and Optics - Abstract
Manganese substitution induces crystallite shrinkage and loss of saturation magnetization for the manganese ferrite nanoparticles synthesized by thermal decomposition.
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- 2022
10. Editorial: The May 2023 cover paper
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Dale L. Huber
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Mechanics of Materials ,Mechanical Engineering ,General Materials Science - Published
- 2023
11. Strong Anti-Stokes Luminescence from Colloidal LiY1-xYbxF4 Nanoparticles
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Shruti I. Gharde, Mark V. Reymatias, Quang Tin Nguyen, Lillian N. Elam, Mia I. Baca, Sergei A. Ivanov, John D. Watt, Dale L. Huber, Gennady A. Smolyakov, and Marek Osinski
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- 2022
12. Editorial: The January 2023 cover paper
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Dale L. Huber
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Mechanics of Materials ,Mechanical Engineering ,General Materials Science - Published
- 2023
13. Lithium yttrium ytterbium fluoride nanocrystals for laser cooling applications
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Shruti I. Gharde, Mark V. Reymatias, Quang Tin Nguyen, Lillian N. Elam, Sergei A. Ivanov, John D. Watt, Dale L. Huber, and Marek Osinski
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- 2022
14. Phase Behavior of Ternary Polymer Brushes
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Dale L. Huber, Amalie L. Frischknecht, and Chester K. Simocko
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chemistry.chemical_classification ,Materials science ,Polymers and Plastics ,Polymer composition ,Organic Chemistry ,02 engineering and technology ,Polymer ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,Inorganic Chemistry ,chemistry.chemical_compound ,chemistry ,Chemical engineering ,Phase (matter) ,Polymer chemistry ,Materials Chemistry ,Polystyrene ,Methyl methacrylate ,0210 nano-technology ,Ternary operation ,Phase diagram - Abstract
Ternary polymer brushes consisting of polystyrene, poly(methyl methacrylate), and poly(4-vinylpyridine) have been synthesized. These brushes laterally phase separate into several distinct phases and can be tailored by altering the relative polymer composition. Self-consistent field theory has been used to predict the phase diagram and model both the horizontal and vertical phase behavior of the polymer brushes. All phase behaviors observed experimentally correlate well with the theoretical model.
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- 2022
15. In-Situ ETEM Reveals Formation Mechanism of Single Pt Atom on Ru Nanoparticle Electrocatalysts for CO-Resilient Methanol Oxidation
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Agus R Poerwoprajitno, Lucy Gloag, John Watt, Soshan Cheong, Benjamin K Miller, Dale L Huber, and Richard D Tilley
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Instrumentation - Published
- 2022
16. Colloidal synthesis and characterization of ytterbium-doped YLF nanocrystals
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Shruti I. Gharde, Arjun Senthil, Mark V. Reymatias, Aadit Sharma, Ciara R. Murphy, Nathan J. Withers, Gennady A. Smolyakov, Sergei A. Ivanov, John D. Watt, Dale L. Huber, and Marek Osinski
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- 2022
17. Anti-Stokes photoluminescence from LiY1-xYbxF4 nanocrystals
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Arjun Senthil, Shruti I. Gharde, Mark V. Reymatias, Ciara Murphy, Alexander Neumann, Nathan J. Withers, Gennady A. Smolyakov, Sergei A. Ivanov, Dale L. Huber, and Marek Osinski
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- 2022
18. A single-Pt-atom-on-Ru-nanoparticle electrocatalyst for CO-resilient methanol oxidation
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Agus R. Poerwoprajitno, Lucy Gloag, John Watt, Soshan Cheong, Xin Tan, Han Lei, Hassan A. Tahini, Aaron Henson, Bijil Subhash, Nicholas M. Bedford, Benjamin K. Miller, Peter B. O’Mara, Tania M. Benedetti, Dale L. Huber, Wenhua Zhang, Sean C. Smith, J. Justin Gooding, Wolfgang Schuhmann, and Richard D. Tilley
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Process Chemistry and Technology ,Bioengineering ,Biochemistry ,Catalysis - Abstract
Single Pt atom catalysts are key targets because a high exposure of Pt substantially enhances electrocatalytic activity. In addition, PtRu alloy nanoparticles are the most active catalysts for the methanol oxidation reaction. To combine the exceptional activity of single Pt atom catalysts with an active Ru support we must overcome the synthetic challenge of forming single Pt atoms on noble metal nanoparticles. Here we demonstrate a process that grows and spreads Pt islands on Ru branched nanoparticles to create single-Pt-atom-on-Ru catalysts. By following the spreading process by in situ TEM, we found that the formation of a stable single atom structure is thermodynamically driven by the formation of strong Pt–Ru bonds and the lowering of the surface energy of the Pt islands. The stability of the single-Pt-atom-on-Ru structure and its resilience to CO poisoning result in a high current density and mass activity for the methanol oxidation reaction over time. [Figure not available: see fulltext.]
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- 2022
19. Facettierte verzweigte Nickel‐Nanopartikel mit variierbarer Verzweigungslänge für die hochaktive elektrokatalytische Oxidation von Biomasse
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Dale L. Huber, Priyank V. Kumar, Wolfgang Schuhmann, John Watt, Chen Deng, Christopher E. Marjo, Dawei Wang, Kuang-Hsu Wu, Steffen Cychy, J. Justin Gooding, Agus R. Poerwoprajitno, Lucy Gloag, Richard D. Tilley, Soshan Cheong, Martin Muhler, and Tania M. Benedetti
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Materials science ,General Medicine ,Nuclear chemistry - Published
- 2020
20. Faceted Branched Nickel Nanoparticles with Tunable Branch Length for High‐Activity Electrocatalytic Oxidation of Biomass
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Agus R. Poerwoprajitno, Dale L. Huber, Priyank V. Kumar, Chen Deng, Kuang-Hsu Wu, John Watt, Christopher E. Marjo, Soshan Cheong, Wolfgang Schuhmann, Lucy Gloag, Tania M. Benedetti, Dawei Wang, Martin Muhler, Richard D. Tilley, Steffen Cychy, and J. Justin Gooding
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Materials science ,Surface Properties ,Dispersity ,Metal Nanoparticles ,Biomass ,Nanoparticle ,chemistry.chemical_element ,Branch length ,010402 general chemistry ,Electrocatalyst ,01 natural sciences ,Catalysis ,Nickel ,High activity ,branching mechanisms ,electrocatalysis ,nanoparticle synthesis ,Furaldehyde ,Particle Size ,HMF oxidation ,010405 organic chemistry ,Communication ,General Chemistry ,Nanomaterial-based catalyst ,Communications ,0104 chemical sciences ,Chemical engineering ,chemistry ,ddc:540 ,branched nickel ,Oxidation-Reduction - Abstract
Controlling the formation of nanosized branched nanoparticles with high uniformity is one of the major challenges in synthesizing nanocatalysts with improved activity and stability. Using a cubic‐core hexagonal‐branch mechanism to form highly monodisperse branched nanoparticles, we vary the length of the nickel branches. Lengthening the nickel branches, with their high coverage of active facets, is shown to improve activity for electrocatalytic oxidation of 5‐hydroxymethylfurfural (HMF), as an example for biomass conversion., Branched nickel nanoparticles having controlled branch length are synthesized using a new approach. The branches enable high surface area and surface facets which improve the catalytic activity for biomass electrooxidation.
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- 2020
21. Soft matter and nanomaterials characterization by cryogenic transmission electron microscopy
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Phoebe L. Stewart, John Watt, and Dale L. Huber
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0303 health sciences ,Materials science ,Nanoparticle ,Nanotechnology ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Soft materials ,Nanomaterials ,Characterization (materials science) ,Colloidal nanoparticles ,03 medical and health sciences ,Transmission electron microscopy ,Energy materials ,General Materials Science ,Soft matter ,Physical and Theoretical Chemistry ,0210 nano-technology ,030304 developmental biology - Abstract
Soft matter has historically been an unlikely candidate for investigation by electron microscopy techniques due to damage by the electron beam as well as inherent instability under a high vacuum environment. Characterization of soft matter has often relied on ensemble-scattering techniques. The recent development of cryogenic transmission electron microscopy (cryo-TEM) provides the soft matter community with an exciting opportunity to probe the structure of soft materials in real space. Cryo-TEM reduces beam damage and allows for characterization in a native, frozen-hydrated state, providing direct visual representation of soft structure. This article reviews cryo-TEM in soft materials characterization and illustrates how it has provided unique insights not possible by traditional ensemble techniques. Soft matter systems that have benefited from the use of cryo-TEM include biological-based “soft” nanoparticles (e.g., viruses and conjugates), synthetic polymers, supramolecular materials as well as the organic–inorganic interface of colloidal nanoparticles. Many challenges remain, such as combining structural and chemical analyses; however, the opportunity for soft matter research to leverage newly developed cryo-TEM techniques continues to excite.
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- 2019
22. Luminescence thermometry for detection of optical cooling from colloidal quantum dots embedded in dielectric waveguides
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Nathan J. Withers, Marek Osinski, Dale L. Huber, Gema J. Alas, Landon A. Schmucker, DeYannah J. Walker, Sergei A. Ivanov, Adreanna G. Rael, Alexander Neumann, Arjun Senthil, Shruti I. Gharde, Gennady A. Smolyakov, Rafael A. Castro, John Watt, and Mark V. Reymatias
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Materials science ,Photoluminescence ,Condensed Matter::Other ,business.industry ,Physics::Optics ,Condensed Matter::Mesoscopic Systems and Quantum Hall Effect ,Laser ,Signal ,law.invention ,Condensed Matter::Materials Science ,Phase change ,law ,Optoelectronics ,Colloidal quantum dots ,Luminescence ,Dielectric waveguides ,business - Abstract
We have developed a novel method of pump-probe luminescence thermometry based on the detection of photoluminescence signal phase change versus power of the pumping laser, and applied it to studies of optical cooling from colloidal quantum dots embedded in dielectric waveguides.
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- 2021
23. Perspective: altering structure in a hierarchically assembled magnetic nanocomposite to rapidly tune optical reflection
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Dale L. Huber
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Materials science ,Nanocomposite ,Mechanics of Materials ,Mechanical Engineering ,Solid mechanics ,Perspective (graphical) ,Structure (category theory) ,General Materials Science ,Nanotechnology ,Optical reflection - Published
- 2019
24. Single Pt atoms on Ru nanoparticles for CO-resistant methanol oxidation reaction electrocatalysis
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Nicholas M. Bedford, Wolfgang Schuhmann, Dale L. Huber, Aaron Henson, Lucy Gloag, Tania M. Benedetti, Benjamin K. Miller, J. Justin Gooding, Bijil Subhash, Soshan Cheong, Agus R. Poerwoprajitno, Peter B. O’Mara, John Watt, and Richard D. Tilley
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chemistry.chemical_compound ,chemistry ,Nanoparticle ,Methanol ,Photochemistry ,Electrocatalyst ,Redox - Abstract
Single Pt atom catalysts on non-active carbon supports have been key targets for electrochemical reactions because the high exposure of active Pt leads to record-high activities. PtRu alloy catalysts are the most active for the methanol oxidation reaction (MOR) as the Ru atoms decrease CO poisoning of the active Pt. To combine the exceptional activity of single atom Pt catalysts with the benefits of an active Ru support we must overcome the synthetic challenge of forming single Pt atoms on noble metal nanoparticles. We have developed a concept to grow and spreads Pt islands on faceted Ru branched nanoparticles to make single Pt atom on Ru catalysts. By following the spreading process with in situ TEM, we show that the formation of single atoms is thermodynamically driven by the formation of strong Pt-Ru bonds and a lowering of surface area. The single Pt atom on Ru catalysts successfully limit CO poisoning during MOR to produce record current density and mass activity over time.
- Published
- 2021
25. Unravelling Magnetic Nanochain Formation in Dispersion for In Vivo Applications
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Sergei A. Ivanov, Thomas Brückel, Ulrich Rücker, Emmanuel Kentzinger, Tanvi Bhatnagar-Schöffmann, Sascha Ehlert, Vanessa Leffler, Asma Qdemat, Antonio Cervellino, Rafal E. Dunin-Borkowski, Artem Feoktystov, Lester C. Barnsley, Dale L. Huber, Michael T. Wharmby, Nileena Nandakumaran, Mikhail Feygenson, and Lisa Sarah Fruhner
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Materials science ,Biocompatibility ,Dispersity ,Nanotechnology ,02 engineering and technology ,Reverse Monte Carlo ,Neutron scattering ,010402 general chemistry ,Ferric Compounds ,01 natural sciences ,chemistry.chemical_compound ,General Materials Science ,Particle Size ,Magnetite Nanoparticles ,Scattering ,Mechanical Engineering ,021001 nanoscience & nanotechnology ,0104 chemical sciences ,chemistry ,Mechanics of Materials ,ddc:660 ,Magnetic nanoparticles ,0210 nano-technology ,Dispersion (chemistry) ,Iron oxide nanoparticles - Abstract
Advanced materials 33(24), 2008683 (2021). doi:10.1002/adma.202008683, Self‐assembly of iron oxide nanoparticles (IONPs) into 1D chains is appealing, because of their biocompatibility and higher mobility compared to 2D/3D assemblies while traversing the circulatory passages and blood vessels for in vivo biomedical applications. In this work, parameters such as size, concentration, composition, and magnetic field, responsible for chain formation of IONPs in a dispersion as opposed to spatially confining substrates, are examined. In particular, the monodisperse 27 nm IONPs synthesized by an extended LaMer mechanism are shown to form chains at 4 mT, which are lengthened with applied field reaching 270 nm at 2.2 T. The chain lengths are completely reversible in field. Using a combination of scattering methods and reverse Monte Carlo simulations the formation of chains is directly visualized. The visualization of real‐space IONPs assemblies formed in dispersions presents a novel tool for biomedical researchers. This allows for rapid exploration of the behavior of IONPs in solution in a broad parameter space and unambiguous extraction of the parameters of the equilibrium structures. Additionally, it can be extended to study novel assemblies formed by more complex geometries of IONPs., Published by Wiley-VCH, Weinheim
- Published
- 2021
26. Synthesis and Functionalization of Magnetic Particles
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Dale L. Huber and Erika C. Vreeland
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chemistry.chemical_classification ,Materials science ,chemistry ,Surface modification ,Magnetic nanoparticles ,Nanotechnology ,Polymer - Abstract
Magnetic nanoparticles are a complex mix including a magnetic inorganic core that is typically 30 nm or smaller and surrounding organic species bound to the surface, all of which is typically dispersed in a solvent. Creating this structure in a well-controlled and reproducible manner is a topic that has been studied in great detail for the past few decades. This chapter will introduce the various materials and techniques utilized in creating these structures. The enormity of this topic requires a selective approach, and many topics are discussed in summary form, though references are provided for further reading on these topics. Emphasis is placed on the most common and promising approaches to forming and functionalizing magnetic nanoparticles for application in biotechnology. This means that the bulk of text is dedicated to chemical synthesis of magnetic nanoparticles as well as the surface functionalization of those particles with organic small molecules or polymers with or without further reactive or recognition sites.
- Published
- 2020
27. Magnetic Tunability in RE-DOBDC MOFs via NO
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Susan E, Henkelis, Dale L, Huber, Dayton J, Vogel, Jessica M, Rimsza, and Tina M, Nenoff
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The magnetic susceptibility of NO
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- 2020
28. Synthesis and characterization of near-infrared PbSe/SnS colloidal core-shell quantum dots
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Nathan J. Withers, Rafael A. Castro, Gema J. Alas, Dale L. Huber, Gennady A. Smolyakov, Adreanna G. Rael, Arjun Senthil, DeYannah J. Walker, Shruti I. Gharde, Sergei A. Ivanov, Mark V. Reymatias, and Marek Osinski
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chemistry.chemical_compound ,Materials science ,chemistry ,Quantum dot ,Chalcogenide ,Tin selenide ,chemistry.chemical_element ,Nanotechnology ,Lead sulfide ,Tin ,Zinc sulfide ,Lead selenide ,Cadmium sulfide - Abstract
Colloidal quantum dots (QDs) emitting in the near-infrared (NIR) spectrum are of interest for many biomedical applications, including bioimaging, biosensing, drug delivery, and photodynamic therapy. However, a significant limitation is that QDs are typically highly cytotoxic, containing materials such as indium arsenide (InAs), cadmium, or lead, which makes prospects for their FDA approval for human treatment very unlikely. Previous work on QDs in the NIR has focused on indium arsenide or cadmium chalcogenide cores coated with cadmium sulfide shells or zinc sulfide shells. Lead-based nanoparticles, such as lead selenide (PbSe) or lead sulfide (PbS) are also popular materials used for NIR emission. However, these nanoparticles have also been shown to be cytotoxic. Coating these Pb-based QDs with a biocompatible shell consisting of tin chalcogenides, such as tin sulfide (SnS) or tin selenide (TnSe), could be a reasonable alternative to improve their biocompatibility and reducing their cytotoxicity. In this paper, we report on our recent studies of PbSe-core QDs with Sn-containing shells, including synthesis, structural characterization, and investigation of optical properties. Characteristics of these QDs synthesized under different conditions are described. We conclude that their synthesis is challenging and still requires further work to avoid shell oxidation.
- Published
- 2020
29. Synthesis and characterization of colloidal CdSexS1-x/ZnS quantum dots
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Arjun Senthil, Nathan J. Withers, Marek Osinski, Adreanna G. Rael, John Watt, Sergei A. Ivanov, Shruti I. Gharde, Dale L. Huber, DeYannah J. Walker, Dominic Bosomtwi, Nhi Nguyen, Mark V. Reymatias, and Gema J. Alas
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Colloid ,Materials science ,Photoluminescence ,Absorption spectroscopy ,Chemical engineering ,Quantum dot ,Zeta potential ,Quantum yield ,Spectroscopy ,Characterization (materials science) - Abstract
CdSexS1-x/ZnS quantum dots (QDs) can cover a broader spectral range than the commonly used CdSe/ZnS QDs and are potentially useful as biomarkers for tagging cell lines such as HeLa, A549, and MCF-7 due to their high photoluminescence intensity and stability in solution. So far, there have been few studies of colloidal CdSexS1-x/ZnS QDs that would simultaneously investigate changes in a) the molar composition of QD cores, and b) the shell thickness, as well as the effects of these changes on the photoluminescence and quantum yield properties of the QDs. CdSeyS1-y QDs and CdSexS1-x/ZnS core/shell QDs were synthesized via a previously reported and modified hot-injection procedure and via a telescoping one-pot synthesis based on the modified hot-injection procedure. Size, morphology, composition, and colloidal stability of these QD core/shell systems is reported with data obtained from TEM, XRD, TGA, DSC, DLS, and zeta potential techniques. Optical characterization is described using data collected from UV-Vis absorption spectrophotometry and photoluminescence spectroscopy.
- Published
- 2020
30. ADMET polymerization in affordable, commercially available, high boiling solvents
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Angel Moreno, Chester K. Simocko, Zachary W. Romero, Jolie M. Lucero, and Dale L. Huber
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chemistry.chemical_classification ,Bulk polymerization ,General Chemical Engineering ,General Engineering ,General Physics and Astronomy ,Polymer ,Polyethylene ,Diethyl phthalate ,chemistry.chemical_compound ,Monomer ,chemistry ,Polymerization ,Propylene carbonate ,General Earth and Planetary Sciences ,Organic chemistry ,General Materials Science ,General Environmental Science ,Acyclic diene metathesis - Abstract
Acyclic diene metathesis polymerization is a powerful technique for creating polymers with precise placement of functional groups. However, due to the need to use high vacuum or other methods to remove the volatile ethylene byproduct and drive the reaction forward, traditional solvents are not feasible. Here we demonstrate the use of three cheap, commercially available solvents as a medium for ADMET polymerizations: propylene carbonate, diethyl phthalate, and dioctyl phthalate. We have shown that by using these solvents, we can increase the molecular weights of ADMET-synthesized polyethylene by over 450% as compared to the bulk polymerization as well as reduce polymerization times from 72 h down to 24 and polymerize challenging, solid monomers.
- Published
- 2020
31. Anti-Stokes photoluminescence and optical cooling of CdSeS/ZnS colloidal quantum dots embedded in dielectric waveguides
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Dominic Bosomtwi, Adreanna G. Rael, Nathan J. Withers, Yuliya Kuznetsova, Gema J. Alas, Alexander Neumann, Hosuk Lee, DeYannah J. Walker, Gennady A. Smolyakov, Sergei A. Ivanov, Shruti I. Gharde, Troy A. Hutchins-Delgado, Sami A. Nazib, Marek Osinski, Dale L. Huber, Arjun Senthil, and Mark V. Reymatias
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Photoluminescence ,Materials science ,Condensed Matter::Other ,business.industry ,Physics::Optics ,Condensed Matter::Mesoscopic Systems and Quantum Hall Effect ,Laser ,Semiconductor laser theory ,law.invention ,Condensed Matter::Materials Science ,law ,Quantum dot ,Laser cooling ,Optoelectronics ,Thin film ,Luminescence ,business ,Waveguide - Abstract
Anti-Stokes photoluminescence from colloidal CdSeS/ZnS quantum dots (QDs) is observed. The QDs were inserted into the core of wider-bandgap SiO2/Si3N4/SiO2 structure by thin film deposition and confirmed as promising nanoemitters for laser cooling due to efficient anti-Stokes emission. The nanoemitters were optically pumped by semiconductor lasers coupled to the waveguides using free-space optics. A direct evidence of local optical cooling in the waveguide structure has been demonstrated with a luminescence thermometry based on the detection of photoluminescence signal phase change versus power of the pumping laser, using a lock-in amplifier.
- Published
- 2020
32. Design and Evaluation of Nano-Composite Core Inductors for Efficiency Improvement in High- Frequency Power Converters
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John Watt, Eric Langlois, Dale L. Huber, Todd C. Monson, Jason C. Neely, and Matthew McDonough
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010302 applied physics ,Materials science ,Buck converter ,business.industry ,Energy conversion efficiency ,02 engineering and technology ,Converters ,021001 nanoscience & nanotechnology ,Inductor ,01 natural sciences ,Magnet ,0103 physical sciences ,Optoelectronics ,Ferrite (magnet) ,0210 nano-technology ,business ,Relative permeability ,Superparamagnetism - Abstract
This paper evaluates the performance of a novel nano-composite core inductor. In this digest, a brief explanation of the superparamagnetic magnetite nanoparticle core is given along with magnetic characterization results and simulated design parameters and dimensions. A nearly flat relative permeability (μ r ) of around 5 is measured for the magnetic material to 1 MHz. A synchronous buck converter with nano-composite inductor was constructed and evaluated; the converter demonstrates a 1% improvement in conversion efficiency at higher currents (4% reduction in electrical losses), compared to an identical circuit with a benchmark commercial ferrite inductor.
- Published
- 2020
33. Antibacterial activity of iron oxide, iron nitride, and tobramycin conjugated nanoparticles against Pseudomonas aeruginosa biofilms
- Author
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Yekaterina I. Brandt, Marek Osinski, Todd C. Monson, Leisha M. Armijo, Antonio C. Rivera, Stephen J. Wawrzyniec, Dale L. Huber, Michael Kopciuch, Nathaniel C. Cook, Hugh D. C. Smyth, and Nathan J. Withers
- Subjects
Cystic Fibrosis ,Antibiotic resistance ,Pharmaceutical Science ,Medicine (miscellaneous) ,02 engineering and technology ,medicine.disease_cause ,Ferric Compounds ,Applied Microbiology and Biotechnology ,chemistry.chemical_compound ,Tobramycin ,Magnetite Nanoparticles ,Drug Carriers ,0303 health sciences ,biology ,Biofilm ,Pseudomonas ,021001 nanoscience & nanotechnology ,Anti-Bacterial Agents ,3. Good health ,lcsh:R855-855.5 ,Pseudomonas aeruginosa ,Molecular Medicine ,Drug Therapy, Combination ,0210 nano-technology ,Antibacterial activity ,Iron oxide nanoparticles ,medicine.drug ,lcsh:Medical technology ,Silver ,Alginates ,Surface Properties ,lcsh:Biotechnology ,Biomedical Engineering ,Bioengineering ,Microbial Sensitivity Tests ,Iron-oxide nanoparticles ,Zero-valent iron nanoparticles ,Microbiology ,Magnetite ,03 medical and health sciences ,Minimum inhibitory concentration ,lcsh:TP248.13-248.65 ,medicine ,Humans ,Pseudomonas Infections ,Agar diffusion test ,Particle Size ,030306 microbiology ,Research ,Alginate ,biology.organism_classification ,Magnetic Fields ,Antibacterial agents ,chemistry ,Biofilms ,Drug Design ,Drug delivery - Abstract
Background Novel methods are necessary to reduce morbidity and mortality of patients suffering from infections with Pseudomonas aeruginosa. Being the most common infectious species of the Pseudomonas genus, P. aeruginosa is the primary Gram-negative etiology responsible for nosocomial infections. Due to the ubiquity and high adaptability of this species, an effective universal treatment method for P. aeruginosa infection still eludes investigators, despite the extensive research in this area. Results We report bacterial inhibition by iron-oxide (nominally magnetite) nanoparticles (NPs) alone, having a mean hydrodynamic diameter of ~ 16 nm, as well as alginate-capped iron-oxide NPs. Alginate capping increased the average hydrodynamic diameter to ~ 230 nm. We also investigated alginate-capped iron-oxide NP-drug conjugates, with a practically unchanged hydrodynamic diameter of ~ 232 nm. Susceptibility and minimum inhibitory concentration (MIC) of the NPs, NP-tobramycin conjugates, and tobramycin alone were determined in the PAO1 bacterial colonies. Investigations into susceptibility using the disk diffusion method were done after 3 days of biofilm growth and after 60 days of growth. MIC of all compounds of interest was determined after 60-days of growth, to ensure thorough establishment of biofilm colonies. Conclusions Positive inhibition is reported for uncapped and alginate-capped iron-oxide NPs, and the corresponding MICs are presented. We report zero susceptibility to iron-oxide NPs capped with polyethylene glycol, suggesting that the capping agent plays a major role in enabling bactericidal ability in of the nanocomposite. Our findings suggest that the alginate-coated nanocomposites investigated in this study have the potential to overcome the bacterial biofilm barrier. Magnetic field application increases the action, likely via enhanced diffusion of the iron-oxide NPs and NP-drug conjugates through mucin and alginate barriers, which are characteristic of cystic-fibrosis respiratory infections. We demonstrate that iron-oxide NPs coated with alginate, as well as alginate-coated magnetite–tobramycin conjugates inhibit P. aeruginosa growth and biofilm formation in established colonies. We have also determined that susceptibility to tobramycin decreases for longer culture times. However, susceptibility to the iron-oxide NP compounds did not demonstrate any comparable decrease with increasing culture time. These findings imply that iron-oxide NPs are promising lower-cost alternatives to silver NPs in antibacterial coatings, solutions, and drugs, as well as other applications in which microbial abolition or infestation prevention is sought.
- Published
- 2020
34. Finite element modeling of nanoscale-enabled microinductors for power electronics
- Author
-
Dale L. Huber, John Watt, Eric Langlois, and Todd C. Monson
- Subjects
010302 applied physics ,Materials science ,Form factor (electronics) ,business.industry ,Buck converter ,Mechanical Engineering ,020208 electrical & electronic engineering ,02 engineering and technology ,Condensed Matter Physics ,Inductor ,01 natural sciences ,Finite element method ,Power (physics) ,Magnetic core ,Mechanics of Materials ,Power electronics ,0103 physical sciences ,0202 electrical engineering, electronic engineering, information engineering ,Optoelectronics ,General Materials Science ,business ,Power density - Abstract
This article focuses on the finite element modeling of toroidal microinductors, employing first-of-its-kind nanocomposite magnetic core material and superparamagnetic iron nanoparticles covalently cross-linked in an epoxy network. Energy loss mechanisms in existing inductor core materials are covered as well as discussions on how this novel core material eliminates them providing a path toward realizing these low form factor devices. Designs for both a 2 µH output and a 500 nH input microinductor are created via the model for a high-performance buck converter. Both modeled inductors have 50 wire turns, less than 1 cm3 form factors, less than 1 Ω AC resistance, and quality factors, Q’s, of 27 at 1 MHz. In addition, the output microinductor is calculated to have an average output power of 7 W and a power density of 3.9 kW/in3 by modeling with the 1st generation iron nanocomposite core material.
- Published
- 2018
35. Gram scale synthesis of Fe/FexOycore–shell nanoparticles and their incorporation into matrix-free superparamagnetic nanocomposites
- Author
-
Dale L. Huber, Grant C. Bleier, Bradley G. Hance, Todd C. Monson, Bierner Jessica Anne, Zachary W. Romero, and John Watt
- Subjects
Nanostructure ,Nanocomposite ,Materials science ,Mechanical Engineering ,Composite number ,Nanoparticle ,02 engineering and technology ,Epoxy ,equipment and supplies ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,0104 chemical sciences ,Chemical engineering ,Mechanics of Materials ,Permeability (electromagnetism) ,Covalent bond ,visual_art ,visual_art.visual_art_medium ,General Materials Science ,0210 nano-technology ,human activities ,Superparamagnetism - Abstract
Significant reductions recently seen in the size of wide-bandgap power electronics have not been accompanied by a relative decrease in the size of the corresponding magnetic components. To achieve this, a new generation of materials with high magnetic saturation and permeability are needed. Here, we develop gram-scale syntheses of superparamagnetic Fe/FexOy core–shell nanoparticles and incorporate them as the magnetic component in a strongly magnetic nanocomposite. Nanocomposites are typically formed by the organization of nanoparticles within a polymeric matrix. However, this approach can lead to high organic fractions and phase separation; reducing the performance of the resulting material. Here, we form aminated nanoparticles that are then cross-linked using epoxy chemistry. The result is a magnetic nanoparticle component that is covalently linked and well separated. By using this ‘matrix-free’ approach, we can substantially increase the magnetic nanoparticle fraction, while still maintaining good separation, leading to a superparamagnetic nanocomposite with strong magnetic properties.
- Published
- 2018
36. Reversible Magnetic Agglomeration: A Mechanism for Thermodynamic Control over Nanoparticle Size
- Author
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Dale L. Huber, John Watt, Judith Maria Lavin, Grant C. Bleier, and Chester K. Simocko
- Subjects
chemistry.chemical_classification ,Steric effects ,Materials science ,Precipitation (chemistry) ,Economies of agglomeration ,Nucleation ,Nanoparticle ,General Chemistry ,02 engineering and technology ,General Medicine ,equipment and supplies ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Catalysis ,0104 chemical sciences ,chemistry ,Pulmonary surfactant ,Chemical physics ,Magnetic nanoparticles ,0210 nano-technology ,human activities ,Alkyl - Abstract
We present a method for the synthesis and precise size control of magnetic nanoparticles in a reversible magnetic agglomeration mechanism. In this approach, nanoparticles nucleate and grow until a critical susceptibility is reached, in which magnetic attraction overcomes dispersive forces, leading to agglomeration and precipitation. This phase change in the system arrests nanoparticle growth and gives true thermodynamic control over the size of nanoparticles. We then show that increasing the alkyl chain length of the surfactant, and hence increasing steric stabilization, allows nanoparticles to grow to larger sizes before agglomeration occurs. Therefore, simply by choosing the correct surfactant, the size and magnetic properties of iron nanoparticles can be tailored for a particular application. With the continuous addition of the precursor solution, we can repeat the steps of nucleation, growth, and magnetic agglomeration indefinitely, making the approach suitable for large scale syntheses.
- Published
- 2018
37. Magnetic Nanocomposites and Their Incorporation into Higher Order Biosynthetic Functional Architectures
- Author
-
Aaron M. Collins, John Watt, Gabriel A. Montaño, Dale L. Huber, and Erika C. Vreeland
- Subjects
Materials science ,General Chemical Engineering ,Chlorosome ,02 engineering and technology ,macromolecular substances ,010402 general chemistry ,01 natural sciences ,behavioral disciplines and activities ,Article ,lcsh:Chemistry ,Pigment ,chemistry.chemical_compound ,Amphiphile ,Copolymer ,Bifunctional ,chemistry.chemical_classification ,Nanocomposite ,Ethylene oxide ,technology, industry, and agriculture ,General Chemistry ,Polymer ,021001 nanoscience & nanotechnology ,0104 chemical sciences ,Chemical engineering ,chemistry ,lcsh:QD1-999 ,visual_art ,visual_art.visual_art_medium ,0210 nano-technology - Abstract
A magnetically active Fe3O4/poly(ethylene oxide)-block-poly(butadiene) (PEO-b-PBD) nanocomposite is formed by the encapsulation of magnetite nanoparticles with a short-chain amphiphilic block copolymer. This material is then incorporated into the self-assembly of higher order polymer architectures, along with an organic pigment, to yield biosynthetic, bifunctional optical and magnetically active Fe3O4/bacteriochlorophyll c/PEO-b-PBD polymeric chlorosomes.
- Published
- 2018
38. Controlling anisotropy in stereolithographically printed polymers
- Author
-
Dale L. Huber
- Subjects
chemistry.chemical_classification ,Materials science ,chemistry ,Polymer science ,Mechanics of Materials ,Mechanical Engineering ,Solid mechanics ,General Materials Science ,Polymer ,Anisotropy - Published
- 2018
39. Magnetic Nanoparticles: Unravelling Magnetic Nanochain Formation in Dispersion for In Vivo Applications (Adv. Mater. 24/2021)
- Author
-
Vanessa Leffler, Lisa Sarah Fruhner, Artem Feoktystov, Ulrich Rücker, Asma Qdemat, Lester C. Barnsley, Mikhail Feygenson, Nileena Nandakumaran, Sergei A. Ivanov, Thomas Brückel, Sascha Ehlert, Antonio Cervellino, Rafal E. Dunin-Borkowski, Dale L. Huber, Tanvi Bhatnagar-Schöffmann, Michael T. Wharmby, and Emmanuel Kentzinger
- Subjects
Materials science ,Condensed matter physics ,Mechanics of Materials ,Mechanical Engineering ,Dispersion (optics) ,Magnetic nanoparticles ,General Materials Science ,Neutron scattering - Published
- 2021
40. Generation-After-Next Power Electronics: Ultrawide-bandgap devices, high-temperature packaging, and magnetic nanocomposite materials
- Author
-
Dale L. Huber, Lee Rashkin, Jason C. Neely, and Robert Kaplar
- Subjects
Materials science ,business.industry ,Band gap ,020208 electrical & electronic engineering ,Wide-bandgap semiconductor ,Energy Engineering and Power Technology ,Gallium nitride ,02 engineering and technology ,Converters ,021001 nanoscience & nanotechnology ,chemistry.chemical_compound ,Semiconductor ,chemistry ,Control and Systems Engineering ,Power module ,Power electronics ,0202 electrical engineering, electronic engineering, information engineering ,Silicon carbide ,Electronic engineering ,Optoelectronics ,Electrical and Electronic Engineering ,0210 nano-technology ,business - Abstract
A new generation of power electronic conversion systems is being enabled by wide-bandgap (WBG) devices. Applications in both the civilian and defense sectors are already beginning to benefit from the improved size, weight, and power (SWaP) now being demonstrated in power converters utilizing silicon carbide (SiC) and/or gallium nitride (GaN) switches, and numerous manufacturers are offering various types of switching devices fabricated from these two WBG semiconductors.
- Published
- 2017
41. Magnetically Recoverable Pd/Fe 3 O 4 Core–Shell Nanowire Clusters with Increased Hydrogenation Activity
- Author
-
John Watt, Paul G. Kotula, and Dale L. Huber
- Subjects
inorganic chemicals ,Materials science ,Inorganic chemistry ,Magnetic separation ,Iron oxide ,Nanowire ,chemistry.chemical_element ,02 engineering and technology ,General Chemistry ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Heterogeneous catalysis ,01 natural sciences ,0104 chemical sciences ,Nanomaterials ,Catalysis ,chemistry.chemical_compound ,chemistry ,Chemical engineering ,0210 nano-technology ,Acetophenone ,Palladium - Abstract
Core-shell nanostructures are promising candidates for the next generation of catalysts due to synergistic effects which can arise from having two active species in close contact, leading to increased activity. Likewise, catalysts displaying added functionality, such as a magnetic response, can have increased scientific and industrial potential. Here, Pd/Fe3 O4 core-shell nanowire clusters are synthesized and applied as hydrogenation catalysts for an industrially important hydrogenation reaction: the conversion of acetophenone to 1-phenylethanol. During synthesis, the palladium nanowires self-assemble into clusters which act as a high-surface-area framework for the growth of a magnetic iron oxide shell. This material demonstrates excellent catalytic activity due to the presence of palladium while the strong magnetic properties provided by the iron oxide shell enable facile catalyst recovery.
- Published
- 2017
42. In-situ Electron Microscopy to Inform Superior Magnetic Nanocomposites
- Author
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Dale L. Huber, John Watt, and Timothy Dreier
- Subjects
Nanocomposite ,Materials science ,Nanotechnology ,Instrumentation ,In situ electron microscopy - Published
- 2020
43. Synthesis and characterization of colloidal ZnTe/ZnS quantum dots
- Author
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Arjun Senthil, Marek Osinski, Sergei A. Ivanov, Nathan J. Withers, Gavin P. Gonzales, Gema J. Alas, and Dale L. Huber
- Subjects
chemistry.chemical_compound ,Photoluminescence ,Materials science ,chemistry ,Quantum dot ,Chalcogenide ,Indium phosphide ,Nanoparticle ,Nanotechnology ,Luminescence ,Biosensor ,Visible spectrum - Abstract
Colloidal quantum dots (QDs) emitting in the visible spectrum are of interest for many biomedical applications, including bioimaging, biosensing, drug delivery, and photodynamic therapy. However, a significant limitation is that QDs typically contain cadmium, which is highly cytotoxic and makes prospects for their FDA approval for human treatment very unlikely. Previous work on biocompatible QDs has focused on indium phosphide and zinc oxide as alternative materials for QDs. However, these nanoparticles have also been shown to be cytotoxic. High-efficiency luminescent ZnTe-based QDs could be a reasonable alternative to Cd-containing QDs. We started our recent studies of ZnTe core, zinc chalcogenide shell QDs with synthesis, structural characterization, and investigation of optical properties of ZnTe/ZnSe colloidal QDs that displayed a blue-green photoluminescence under UV excitation. In this paper, the characteristics of ZnTe/ZnS QDs are compared to those of ZnTe/ZnSe QDs. We conclude that ZnTe/ZnS QDs are appealing candidates for various biomedical applications instead of the currently prominent alternative: cadmium-chalcogenide core QDs.
- Published
- 2019
44. Highly stable multi-anchored magnetic nanoparticles for optical imaging within biofilms
- Author
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Tamara L. McNealy, Dale L. Huber, Roland Stone, Olin Thompson Mefford, Todd C. Monson, Mariah J. Austin, Benjamin D. Fellows, T.R. Tzeng, Yash S. Raval, Bin Qi, Terri F. Bruce, B. Jenkins, and David J. Trebatoski
- Subjects
Materials science ,Biocompatibility ,Nanoparticle ,Nanotechnology ,Legionella pneumophila ,Polyethylene Glycols ,Biomaterials ,Mice ,Colloid and Surface Chemistry ,Animals ,Fluorescent Dyes ,chemistry.chemical_classification ,Biofilm ,Polymer ,equipment and supplies ,Fluorescence ,Dihydroxyphenylalanine ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Magnetic hyperthermia ,Microscopy, Fluorescence ,chemistry ,Biofilms ,Click chemistry ,Nanoparticles ,Magnetic nanoparticles ,Cattle - Abstract
Magnetic nanoparticles are the next tool in medical diagnoses and treatment in many different biomedical applications, including magnetic hyperthermia as alternative treatment for cancer and bacterial infections, as well as the disruption of biofilms. The colloidal stability of the magnetic nanoparticles in a biological environment is crucial for efficient delivery. A surface that can be easily modifiable can also improve the delivery and imaging properties of the magnetic nanoparticle by adding targeting and imaging moieties, providing a platform for additional modification. The strategy presented in this work includes multiple nitroDOPA anchors for robust binding to the surface tied to the same polymer backbone as multiple poly(ethylene oxide) chains for steric stability. This approach provides biocompatibility and enhanced stability in fetal bovine serum (FBS) and phosphate buffer saline (PBS). As a proof of concept, these polymer-particles complexes were then modified with a near infrared dye and utilized in characterizing the integration of magnetic nanoparticles in biofilms. The work presented in this manuscript describes the synthesis and characterization of a nontoxic platform for the labeling of near IR-dyes for bioimaging.
- Published
- 2015
45. Phase-sensitive small-angle neutron scattering experiment
- Author
-
Andrew Gomez, Erika C. Vreeland, Charles F. Majkrzak, Erik Brok, Dale L. Huber, and Kathryn Krycka
- Subjects
Materials science ,Spin polarization ,Phase sensitive ,neutron scattering ,General Physics and Astronomy ,core-shell nanoparticle ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Molecular physics ,Small-angle neutron scattering ,biomolecules ,0104 chemical sciences ,Phase (matter) ,0210 nano-technology - Published
- 2018
46. Synthesis and characterization of colloidal ZnTe nanocrystals and ZnTe/ZnSe quantum dots
- Author
-
Gavin P. Gonzales, Arjun Senthil, Gema J. Alas, Alejandro Sandoval, Christina Minetos, Sergei A. Ivanov, Dale L. Huber, Nathan J. Withers, Gennady A. Smolyakov, and Marek Osinski
- Subjects
Colloid ,Materials science ,Nanocrystal ,Quantum dot ,Semiconductor materials ,Nanoparticle ,Nanotechnology ,Luminescence ,Biosensor ,Characterization (materials science) - Abstract
Quantum dots (QDs) emitting in the visible are of interest for many biomedical applications, including bioimaging, biosensing, drug targeting, and photodynamic therapy. However, a significant limitation is that QDs typically contain cadmium, which makes prospects for their FDA approval very unlikely. Previous work has focused on InP and ZnO as alternative semiconductor materials for QDs. However, these nanoparticles have also been shown to be cytotoxic. High-efficiency luminescent ZnTe-based QDs could be a reasonable alternative to Cd-containing QDs. In this paper, we present preliminary results of our recent studies of ZnTe-based QDs, including their synthesis, structural characterization, and optical properties.
- Published
- 2018
47. Effects of iron-oxide nanoparticles on compound biofilms of streptococcus gordonii and fusobacterium nucleatum
- Author
-
Nikita Jaiswal, Christina Minetos, Nathan J. Withers, Arjun Senthil, Gema J. Alas, Gennady A. Smolyakov, Sergei A. Ivanov, Marek Osinski, Jane Q. Nguyen, and Dale L. Huber
- Subjects
Periodontitis ,biology ,Biofilm ,Streptococcus gordonii ,biology.organism_classification ,Dental plaque ,medicine.disease ,Microbiology ,stomatognathic diseases ,chemistry.chemical_compound ,Gingivitis ,stomatognathic system ,chemistry ,medicine ,Fusobacterium nucleatum ,medicine.symptom ,Iron oxide nanoparticles ,Bacteria - Abstract
The human mouth is a host of a large gamut of bacteria species, with over 700 of different bacteria strains identified. Most of these bacterial species are harmless, some are beneficial (such as probiotics assisting in food digestion), but some are responsible for various diseases, primarily tooth decay and gum diseases such as gingivitis and periodontitis. Dental plaque has a complicated structure that varies from patient to patient, but a common factor in most cases is the single species of bacterium acting as a secondary colonizer, namely Fusobacterium nucleatum, while the actual disease is caused by a variety of tertiary colonizers. We hypothesize that destruction of a compound biofilm containing Fusobacterium nucleatum will prevent tertiary colonizers (oral pathogens) from establishing a biofilm, and thus will protect the patient from developing gingivitis and periodontitis. In this paper, we report on the effects of exposure of compound biofilms of a primary colonizer Streptococcus gordonii combined with Fusobacterium nucleatum to iron oxide nanoparticles as possible bactericidal agent.
- Published
- 2018
48. Effect of Seed Age on Gold Nanorod Formation: A Microfluidic, Real-Time Investigation
- Author
-
Rachel S. Anderson, Dale L. Huber, Bradley G. Hance, and John Watt
- Subjects
Gold nanorod ,Ostwald ripening ,Materials science ,Small-angle X-ray scattering ,General Chemical Engineering ,Microfluidics ,food and beverages ,Nanotechnology ,General Chemistry ,symbols.namesake ,Microfluidic chip ,Chemical engineering ,Yield (chemistry) ,Materials Chemistry ,symbols ,Nanorod - Abstract
We report a real time investigation into the effect of seed age on the growth of gold nanorods using a microfluidic reaction apparatus. Through small-angle X-ray scattering (SAXS) and ultraviolet–visible spectroscopy (UV–vis) analysis, we observe the seeds aging in accordance with Ostwald ripening. A seed solution is then aged in situ and continuously injected into a microfluidic chip to initiate rod growth. We track nanorod formation in real time using in-line ultraviolet–visible and near-infrared (UV–vis–NIR) monitoring and observe a dramatic decrease in yield with increasing seed age. We then demonstrate that, by diluting the gold seed solution immediately following synthesis, the rate of aging can be reduced and nanorods synthesized continuously, in good yield. These findings suggest ultrasmall, catalytically active seeds, which are rapidly lost due to ripening and are critical for the formation of gold nanorods.
- Published
- 2015
49. Greater than the sum: Synergy and emergent properties in nanoparticle–polymer composites
- Author
-
Steven C. Hayden, Millicent A. Firestone, and Dale L. Huber
- Subjects
chemistry.chemical_classification ,Materials science ,Composite number ,Nanoparticle ,Nanotechnology ,Polymer ,Condensed Matter Physics ,Soft materials ,chemistry ,Energy materials ,Polymer composites ,General Materials Science ,Physical and Theoretical Chemistry ,Hybrid material ,Nanoscopic scale - Abstract
The ongoing pursuit of multifunctional soft materials that can impact a wide range of technological challenges, ranging from information processing to energy storage and transducing devices, has resulted in the development of hybrid materials composed of nanoparticles (NPs) dispersed in polymers. Beyond the simple preparation of composites that have the additive value of the individual components, this review discusses recent work and trends in composites that exhibit novel synergistic or emergent properties arising from combining the components. In particular, we highlight recent examples of composites in which NP assembly within polymers leads to enhancement or changes of the NP properties and how introducing NPs into a polymer can cause significant changes in the polymer’s intrinsic properties.
- Published
- 2015
50. Enhanced Nanoparticle Size Control by Extending LaMer’s Mechanism
- Author
-
Todd C. Monson, Gretchen Bronwyn Schober, Bradley G. Hance, Ana C. Bohórquez, Benjamin D. Fellows, Andrew D. Price, Carlos Rinaldi, Dale L. Huber, Nicholas S. Hudak, John Watt, Mariah J. Austin, Lorena Maldonado-Camargo, and Erika C. Vreeland
- Subjects
Stages of growth ,Magnetite Nanoparticles ,Materials science ,General method ,Magnetic hyperthermia ,General Chemical Engineering ,Particle growth ,Materials Chemistry ,Nanoparticle ,Nanotechnology ,General Chemistry ,Particle size ,Steady state (chemistry) - Abstract
The synthesis of well-defined nanoparticle materials has been an area of intense investigation, but size control in nanoparticle syntheses is largely empirical. Here, we introduce a general method for fine size control in the synthesis of nanoparticles by establishing steady state growth conditions through the continuous, controlled addition of precursor, leading to a uniform rate of particle growth. This approach, which we term the “extended LaMer mechanism” allows for reproducibility in particle size from batch to batch as well as the ability to predict nanoparticle size by monitoring the early stages of growth. We have demonstrated this method by applying it to a challenging synthetic system: magnetite nanoparticles. To facilitate this reaction, we have developed a reproducible method for synthesizing an iron oleate precursor that can be used without purification. We then show how such fine size control affects the performance of magnetite nanoparticles in magnetic hyperthermia.
- Published
- 2015
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