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Articles 1 - 9 of 9

Full-Text Articles in Materials Chemistry

Synthesis, Characterization, And Enhanced Magnetic Properties Of Iron Carbide Nanomaterials, Brent M. Williams Jan 2017

Synthesis, Characterization, And Enhanced Magnetic Properties Of Iron Carbide Nanomaterials, Brent M. Williams

Theses and Dissertations

Permanent magnets are classified as hard magnetic materials with the main purpose of generating flux for applications such as electric motors, turbines, and hard drives. High coercivity, magnetic remanence, and saturation values with high stability are some of the requirements for permanent magnets. Rare-earth magnets including neodymium and samarium based magnets are known to have superior magnetic properties due to their high magnetocrystalline anisotropy. However, due to the price of rare-earth materials development of alternate permanent magnets composed of inexpensive materials is an ongoing process. Previously cobalt carbide (CoxC) have shown promise as a potential rare-earth free magnet …


Assembly Of Nucleic Acid-Based Nanoparticles By Gas-Liquid Segmented Flow Microfluidics, Matthew L. Capek, Ross Verheul, David H. Thompson Aug 2016

Assembly Of Nucleic Acid-Based Nanoparticles By Gas-Liquid Segmented Flow Microfluidics, Matthew L. Capek, Ross Verheul, David H. Thompson

The Summer Undergraduate Research Fellowship (SURF) Symposium

The development of novel and efficient mixing methods is important for optimizing the efficiency of many biological and chemical processes. Tuning the physical and performance properties of nucleic acid-based nanoparticles is one such example known to be strongly affected by mixing efficiency. The characteristics of DNA nanoparticles (such as size, polydispersity, ζ-potential, and gel shift) are important to ensure their therapeutic potency, and new methods to optimize these characteristics are of significant importance to achieve the highest efficacy. In the present study, a simple segmented flow microfluidics system has been developed to augment mixing of pDNA/bPEI nanoparticles. This DNA and …


Pulse Electrodeposition Of Pd-Ni Alloy Nanoparticles For Electrocatalytic Oxidation Of Formic Acid, Fang-Zu Yang, Jun-Pei Yue, Zhong-Qun Tian, Shao-Min Zhou Feb 2014

Pulse Electrodeposition Of Pd-Ni Alloy Nanoparticles For Electrocatalytic Oxidation Of Formic Acid, Fang-Zu Yang, Jun-Pei Yue, Zhong-Qun Tian, Shao-Min Zhou

Journal of Electrochemistry

The Pd-Ni alloy nanoparticles with nickel atomic contents of 12.0%, 16.4% and 22.6% were successfully electrodeposited from a Pd-Ni alloy electrolyte by square wave pulse plating. The alloy nanoparticles were in the spherical shape with a diameter of 50 ~ 80 nm. As the growth potential of the alloy was negatively shifted, the nickel content of the alloy was increased, and the size of the nanoparticles was almost the same, whereas the number, the degree of crosslinking and the real active area of the nanoparticles were increased. As the nickel content of the alloy nanoparticles increased, the peak current for …


Controllable Synthesis Of Dispersed Spherical Fe3O4 Nanoparticles As Lithium-Inserted Materials, Hong-Li Zou, Wei-Shan Li Dec 2013

Controllable Synthesis Of Dispersed Spherical Fe3O4 Nanoparticles As Lithium-Inserted Materials, Hong-Li Zou, Wei-Shan Li

Journal of Electrochemistry

Dispersed spherical Fe3O4 nanoparticles were synthesized by a hydrothermal method. The influences of odecyl trimethyl ammonium bromide (DTAB) concentration on the morphology and particle size of the as-prepared Fe3O4 were studied. Electrochemical performance of the as-prepared sample as anode materials of lithium ion battery was investigated. It is found that the as-prepared sample exhibits superior rate performance and cycle performance. The nano-sized materials provide structural stability and favor the transfer of lithium ions.


Phenomena Characterization Of Energy Materials By X-Ray Absorption Spectroscopy, Ming-Yao Cheng, Chun-Jen Pan, Ju-Hsiang Cheng, Bing-Joe Hwang Aug 2010

Phenomena Characterization Of Energy Materials By X-Ray Absorption Spectroscopy, Ming-Yao Cheng, Chun-Jen Pan, Ju-Hsiang Cheng, Bing-Joe Hwang

Journal of Electrochemistry

The aim of this review is to introduce the characterization of energy materials by X-ray absorption spectroscopy (XAS) . This technique allows us to probe changes in the valance state and the local environment of the targeted element in the active material; thereby,leading to a better understanding of its electrochemical behavior,and hopefully showing the way to improved performance. Here,electrocatalysts for fuel cells and active electrode materials for Li-ion batteries are taken as the examples that illustrate the capability of XAS and allow observation and theory to be correlated with electrochemical phenomena.


Photoelectrochemical Properties Of Tio_2 Nanoparticles, Jie Qu, Ying Li, Qi-Wei Jiang, Xue-Ping Gao Feb 2009

Photoelectrochemical Properties Of Tio_2 Nanoparticles, Jie Qu, Ying Li, Qi-Wei Jiang, Xue-Ping Gao

Journal of Electrochemistry

The protonated titanate nanoparticles were obtained at room temperature and subsequently calcined at different temperatures(300 ℃,400 ℃,500 ℃,600 ℃ and 700 ℃) in air.The obtained products were characterized by XRD,TEM and UV-Vis.It is found that the grain sizes of TiO2 nanoparticles calcined at 300 ℃ were about 20 nm,and increased gradually with the temperature rise.Photoelectric performance was measured with I~V curve and electrochemical impedance spectroscopy(EIS).The TiO2 nanoparticles obtained at 500 ℃ showed the best photoelectrochemical properties with a photovoltaic conversion efficiency of 6.39%,which is much higher than those at other temperatures.In addition,it is also demonstrated that the charge transfer resistance …


Rhodium Nanoparticle Shape Dependence In The Reduction Of No By Co, James Russell Renzas, Yawen Zhang, Wenyu Huang, Gabor Somoraji Jan 2009

Rhodium Nanoparticle Shape Dependence In The Reduction Of No By Co, James Russell Renzas, Yawen Zhang, Wenyu Huang, Gabor Somoraji

Wenyu Huang

The shape dependence of the catalytic reduction of nitric oxide by carbon monoxide on rhodium nanopoly- hedra and nanocubes was studied from 230 to 270 ° C. The nanocubes are found to exhibit higher turnover frequency and lower activation energy than the nanopolyhedra. These trends are compared to previous studies on Rh single crystals.


Electrodeposition Of Nano-Sb-Zn Alloy In Acetamide-Urea-Nabr-Kbr Melt, Peng Liu, Xin-Ai Guo, Ye-Xiang Tong, Qi-Qin Yang Aug 2006

Electrodeposition Of Nano-Sb-Zn Alloy In Acetamide-Urea-Nabr-Kbr Melt, Peng Liu, Xin-Ai Guo, Ye-Xiang Tong, Qi-Qin Yang

Journal of Electrochemistry

The electroreduction of Zn(II) and Sb(III) in acetamide-urea-NaBr-KBr(343 K) were studied by cyclic volatmmetry.The reduction of Zn(II) or Sb(III) to the metals is an irreversible process.The transfer coefficient of Zn(II)+2e→Zn and Sb(III) +3e→Sb were calculated to be 0.231 and 0.319,the diffusion coefficient of Zn(II) and Sb(III) in the melt were determined as 1.70 10~(-6) and 3.21 10~(-6) cm~(2)· s~(-1) respectively.The Zn-Sb films with different Zn content from 29.67 at% to 97.34 at% were electrodeposited in acetamide-urea-NaBr-KBr melt at 343 K by controlling the deposition potential and the Zn(II)/Sb(III) molar ratio.The morphology of Zn-Sb film was observed by SEM.Zn-Sb film comprises …


Photothermal Reshaping Of Prismatic Au Nanoparticles In Periodic Monolayer Arrays By Femtosecond Laser Pulses, Wenyu Huang, Wei Qian, Mostafa A. El-Sayed Jan 2005

Photothermal Reshaping Of Prismatic Au Nanoparticles In Periodic Monolayer Arrays By Femtosecond Laser Pulses, Wenyu Huang, Wei Qian, Mostafa A. El-Sayed

Wenyu Huang

Prismatic goldnanoparticles in the periodic monolayer arrays prepared with nanosphere lithography technique can be reshaped with femtosecond laser pulses at different powers and wavelengths. As the power density of 400 nm femtosecond laser increases, the prismatic particle tips begin to round and the overall particle shape changes from a prism to a sphere with a tripodal intermediate. The formation of the tip-rounded nanoprisms is probably due to the dewetting properties of gold on quartz surface and the low melting temperature at the tips. The formation of the tripodal nanoparticles is attributed to the inhomogeneous heating and lattice rearrangement of the …