Nanoscience and Nanotechnology Commons^™

Reducing Leakage Current And Enhancing Polarization In Multiferroic 3d Super-Nanocomposites By Microstructure Engineering, Erik Enriquez, Ping Lu, Leigang Li, Bruce Zhang, Haiyan Wang, Quanxi Jia, Aiping Chen

Physics and Astronomy Faculty Publications and Presentations

Multiferroic materials have generated great interest due to their potential as functional device materials. Nanocomposites have been increasingly used to design and generate new functionalities by pairing dissimilar ferroic materials, though the combination often introduces new complexity and challenges unforeseeable in single-phase counterparts. The recently developed approaches to fabricate 3D super-nanocomposites (3D‐sNC) open new avenues to control and enhance functional properties. In this work, we develop a new 3D‐sNC with CoFe2O4 (CFO) short nanopillar arrays embedded in BaTiO3 (BTO) film matrix via microstructure engineering by alternatively depositing BTO:CFO vertically-aligned nanocomposite layers and single-phase BTO layers. This microstructure engineering method allows …

Twisted Laminar Superconducting Composite: Mgb2 Embedded Carbon Nanotube Yarns, Ujjal Lamichhane, Gamage C. Dannangoda, Mkhitar Hobosyan, R. A. Shohan, A. Zakhidov, Karen S. Martirosyan

Physics and Astronomy Faculty Publications and Presentations

Twisted laminar superconducting composite structures based on multi-wall carbon nanotube (MWCNT) yarns were crafted by integrating magnesium and boron homogeneous mixture into the carbon nanotube (CNT) aerogel sheets. After the ignition of the Mg–B–MWCNT system, under the controlled argon environment, the high exothermic reaction between magnesium (Mg) and boron (B) with stoichiometric ratio produced the MgB2@MWCNT superconducting composite yarns. The process was conducted under the controlled argon environment and uniform heating rate in the differential scanning calorimetry and thermogravimetric analyzer. The XRD analysis confirmed that the produced composite yarns contain nano and microscale inclusions of superconducting phase of MgB2. The …

Modeling And Simulation Of Janus-Like Nanoparticles Formation By Solid-Gas Exothermic Reactions, A. A. Markov, Karen S. Martirosyan

Physics and Astronomy Faculty Publications and Presentations

Theoretical model for the simulation of synthesis of Janus-like particles (JP) consisting two different phases using the Carbon Combustion Synthesis of Oxides (CCSO) is presented. The model includes the variation of sample initial porosity, carbon concentration and oxygen flow rate used to predict the formation of JP features. The two temperature (2T) combustion model of chemically active submicron-dispersed mixture of two phases including ferroelectric and ferromagnetic was implemented and assessed by using the experimentally estimated activation energy of 112±3.3 kJ/mol and combustion temperature. The experimental values allowed to account the thermal and concentration expansion effect along with the dispersion by …

Piezo-Tribo Dual Effect Hybrid Nanogenerators For Health Monitoring, Sk Md Ali Zaker Shawon, Andrew Xu Sun, Valeria Suarez Vega, Brishty Deb Chowdhury, Phong Tran, Zaida D. Carballo, Jim Aica Tolentino, Jianzhi Li, Muhammad Sufian Rafaqut, Serena Danti, Mohammed Jasim Uddin

Electrical and Computer Engineering Faculty Publications and Presentations

Over the years, nanogenerators for health monitoring have become more and more attractive as they provide a cost-effective and continuous way to successfully measure vital signs, physiological status, and environmental changes in/around a person. Using such sensors can positively affect the way healthcare workers diagnose and prevent life-threatening conditions. Recently, the dual piezo-tribological effect of hybrid nanogenerators (HBNGs) have become a subject of investigation, as they can provide a substantial amount of data, which is significant for healthcare. However, real-life exploitation of these HBNGs in health monitoring is still marginal. This review covers piezo-tribo dual-effect HBNGs that are used as …

Polymer Based Triboelectric Nanogenerator For Cost‐Effective Green Energy Generation And Implementation Of Surface‐Charge Engineering, Diana Lopez, Aminur Rashid Chowdhury, Abu Masa Abdullah, Muhtasim Ul Karim Sadaf, Isaac Martinez, Brishty Deb Chowdhury, Serena Danti, Christopher J. Ellison, Karen Lozano, Mohammed Jasim Uddin

Chemistry Faculty Publications and Presentations

Performance of triboelectric nanogenerators for harvesting mechanical energy from the ambient environment has been limited by structural complexity, cost-effectiveness, and mechanical weakness of materials. Herein, a cost-effective vertical contact separation mode triboelectric nanogenerator using polyethylene (PE) and polycarbonate (PC) in a regular digital versatile disc is reported. This cost-effective nanogenerator with simplified structures is able to generate an open-circuit voltage of 215.3 V and short-circuit current of 80 μA. The effects of the distance of impact and the air gap between the triboelectric layers have also been tested from 3 to 9 cm, and 0.25 to 1 cm, respectively. It …

Fabrication Of Forcespinning® Nanofibers Incorporating Nopal Extract, Cristobal Rodriguez, Victoria Padilla, Karen Lozano, J. Andrew Mcdonald, Luis Materon, Alejandra Chapa, Fariha Ahmad, Carlos Trevino De Leon, Robert Gilkerson

Biology Faculty Publications and Presentations

In this study, nanofibers composed of Opuntia cochenillifera nopal mucilage (N) extract combined with chitosan (CH) and pullulan (PL) (N/CH/PL) were produced via Forcespinning®. The developed nonwoven composite membranes are comprised of long, continuous, and homogenous fibers with fiber average diameter varying between 251±77 nm and 406±127 nm depending on the concentration of N. After crosslinking, the developed membranes were highly stable in water. The water absorption capacity of the N/CH/PL composite nanofiber membranes was shown to be 65% higher when compared to the CH/PL nanofiber membranes. Nopal dipcoated membranes show inhibition of gram-negative Escherichia coli, indicating antibacterial properties. These …

Editorial: Carbon- And Inorganic-Based Nanostructures For Energy Applications, Federico Cesano, M. Jasim Uddin, Yuanbing Mao, Muhammad N. Huda

Chemistry Faculty Publications and Presentations

No abstract provided.

Novel Silica Filled Deep Eutectic Solvent Based Nanofluids For Energy Transportation, Changhui Liu, Hui Fang, Xinjian Liu, Ben Xu, Zhonghao Rao

Chemistry Faculty Publications and Presentations

Liquid range of nanofluids is a crucial parameter as it intensively determines their application temperature scope. Meanwhile, improved thermal conductivity and stability are of great significances and comprise the main fundamental research topics of nanofluids. In this work, 2- butoxy-3,4-dihydropyran (DP), produced from a convenient one-pot three-component reaction in water, was employed as dual lipophilic brusher and metal nanoparticle anchor. It was found that DP was able to enhance the dispersing ability and thermal conductivity of SiO2 nanoparticle filled deep eutectic solvent (DES) based nanofluids simultaneously. The key to the success of this protocol mainly relies on the electrophilic property …

Novel Silica Filled Deep Eutectic Solvent Based Nanofluids For Energy Transportation, Changhui Liu, Hui Fang, Xinjian Liu, Ben Xu, Zhonghao Rao

Mechanical Engineering Faculty Publications and Presentations

Liquid range of nanofluids is a crucial parameter as it intensively determines their application temperature scope. Meanwhile, improved thermal conductivity and stability are of great significances and comprise the main fundamental research topics of nanofluids. In this work, 2-butoxy-3,4-dihydropyran (DP), produced from a convenient one-pot three-component reaction in water, was employed as dual lipophilic brusher and metal nanoparticle anchor. It was found that DP was able to enhance the dispersing ability and thermal conductivity of SiO2 nanoparticle filled deep eutectic solvent (DES) based nanofluids simultaneously. The key to the success of this protocol mainly relies on the electrophilic property and …

Evaluating The Rheological And Tribological Behaviors Of Coconut Oil Modified With Nanoparticles As Lubricant Additives, Vicente Cortes, Javier A. Ortega

Mechanical Engineering Faculty Publications and Presentations

In metal-forming processes, the use of lubricants for providing desirable tribological conditions at the tool–workpiece interface is critical to increase the material formability and prolonging tool life. Nowadays, the depletion of crude oil reserves in the world and the global concern in protecting the environment from contamination have renewed interest in developing environmentally-friendly lubricants derived from alternative sources such as vegetable oils. In the present study, the rheological and tribological behavior of coconut oil modified with nanoparticle additives was experimentally evaluated. Two different nanoparticle additives were investigated: Silicon dioxide (SiO₂) and copper oxide (CuO). For the two conditions, …

Electrical Properties And Electromagnetic Interference Shielding Effectiveness Of Interlayered Systems Composed By Carbon Nanotube Filled Carbon Nanofiber Mats And Polymer Composites, Claudia A. Ramirez-Herrera, Homero Gonzalez, Felipe De La Torre, Laura Benitez, Jose G. Cabanas-Moreno, Karen Lozano

Mechanical Engineering Faculty Publications and Presentations

The demand for multifunctional requirements in aerospace, military, automobile, sports, and energy applications has encouraged the investigation of new composite materials. This study focuses on the development of multiwall carbon nanotube (MWCNT) filled polypropylene composites and carbon nanofiber composite mats. The developed systems were then used to prepare interlayered composites that exhibited improved electrical conductivity and electromagnetic interference (EMI) shielding efficiency. MWCNT-carbon nanofiber composite mats were developed by centrifugally spinning mixtures of MWCNT suspended in aqueous poly(vinyl alcohol) solutions. The developed nanofibers were then dehydrated under sulfuric acid vapors and then heat treated. Interlayered samples were fabricated using a nanoreinforced …

Development Of Antimicrobial Chitosan Based Nanofiber Dressings For Wound Healing Applications, Lee Cremar, Jorge Gutierrez, Jennifer Martinez, Luis A. Materon, Robert Gilkerson, Fenghua Xu, Karen Lozano

Mechanical Engineering Faculty Publications and Presentations

Objective(s): Chitosan based composite fine fibers were successfully produced via a centrifugal spinning technology. This study evaluates the ability of the composites to function as scaffolds for cell growth while maintaining an antibacterial activity.

Materials and Methods: Two sets of chitosan fiber composites were prepared, one filled with anti-microbial silver nanoparticles and another one with cinnamaldeyhde. Chitosan powder was dissolved in trifluoroacetic acid and dichloromethane followed by addition of the fillers. The fiber output was optimized by configuring the polymer weight concentration (7, 8, and 9 w/w% chitosan) and applied angular velocity (6000-9000 RPM) within the spinning process.

Results: …

Forcespinning: A New Method For The Mass Production Of Sn/C Composite Nanofiber Anodes For Lithium Ion Batteries, Victor Agubra, Luis Zuniga, David De La Garza, Luis Gallegos, Madhab Pokhrel, Mataz Alcoutlabi

Chemistry Faculty Publications and Presentations

The development of nanostructured anode materials for rechargeable Lithium-ion Batteries has seen a growing interest. We herein report the use of a new scalable technique, Forcespinning (FS) to produce binder-free porous Sn/C composite nanofibers with different Sn particle size loading. The preparation process involves the FS of Sn/PAN precursor nanofibers and subsequently stabilizing in air at 280 °C followed by carbonization at 800 °C under an inert atmosphere. The Sn/C composite nanofibers are highly flexible and were directly used as binder-free anodes for lithium-ion batteries. The produced Sn/C composite nanofibers showed an improved discharge capacity of about 724 mA …

Slip-Jump Model For Carbon Combustion Synthesis Of Complex Oxide Nanoparticles, A. A. Markov, Mkhitar A. Hobosyan, Karen S. Martirosyan

Physics and Astronomy Faculty Publications and Presentations

Carbon Combustion Synthesis of Oxides (CCSO) is a promising method to produce submicron- and nano- sized complex oxides. The CCSO was successfully utilized for producing several complex oxides, a complete theoretical model including the sample porosity, fl ow parameters and reaction energetics is needed to predict the combustion parameters for CCSO. In this work, we studied the ignition temperature and combustion wave axial temperature distribution, activation energy, combustion heat and thermal losses for a typical CCSO synthesis for cylindrical samples of Ni-Zn ferrites with high (>85%) porosity. We developed a two level combustion model of chemically active nano-dispersed mixture, …

A Comparative Study Of Polyurethane Nanofibers With Different Patterns And Its Analogous Nanofibers Containing Mwcnts, Javier Macossay-Torres, Faheem A. Sheikh, Hassan Ahmad, Hern Kim, Gary L. Bowlin

Chemistry Faculty Publications and Presentations

Tissue engineering is a multidisciplinary field that has evolved in various dimensions in recent years. One of the main aspects in this field is the proper adjustment and final compatibility of implants at the target site of surgery. For this purpose, it is desired to have the materials fabricated at the nanometer scale, since these dimensions will ultimately accelerate the fixation of implants at the cellular level. In this study, electrospun polyurethane nanofibers and their analogous nanofibers containing MWCNTs are introduced for tissue engineering applications. Since MWCNTs agglomerate to form bundles, a high intensity sonication procedure was used to disperse …

Fabrication Of Cellulose Fine Fiber Based Membranes Embedded With Silver Nanoparticles Via Forcespinning, Fenghua Xu, Baicheng Weng, Luis A. Materon, Anxiu Kuang, Jorge A. Trujillo, Karen Lozano

Mechanical Engineering Faculty Publications and Presentations

This study presents the successful development of cellulose fiber based membranes embedded with silver nanoparticles. These fine fiber membranes were developed utilizing the Forcespinning (FS) technique followed by alkaline hydrolysis treatment. The fiber morphology, homogeneity and yield were optimized by varying spinning parameters such as polymer concentration and angular velocity of the spinnerets. The structure, thermal and mechanical properties, and water absorption capability of the developed membranes were investigated. The cellulose acetate (CA) present in the membrane was converted to cellulose in the presence of embedded silver nanoparticles by alkaline hydrolysis. The silver nanoparticles embedded cellulose membrane exhibits outstanding water …

Tio 2 Fibers: Tunable Polymorphic Phase Transformation And Electrochemical Properties, Edna Garcia, Qiang Li, Xing Sun, Karen Lozano, Yuanbing Mao

Chemistry Faculty Publications and Presentations

A series of one-dimensional (1D) nanoparticle-assembled TiO2 fibers with tunable polymorphs were prepared via a novel and large scale ForceSpinning® process of titanium tetraisopropoxide (TTIP)/polyvinylpyrrolidone (PVP) precursor fibers followed with a thermal treatment at various calcinations temperatures. The thermal and structural transformations were characterized by thermogravimetric analysis/differential scanning calorimetry, scanning electron microscopy, and X-ray diffraction. The influence of polymorphic phase of the TiO2 fibers on the electrochemical performance in neutral aqueous 1 M Na2SO4 electrolyte was investigated. The polymorphic amorphous/anatase/rutile TiO2 fibers prepared at 450 °C achieved a highest capacitance of 21.2 F g−1 (6.61 mF cm−2) at a current …

Imaging, Spectroscopy, Mechanical, Alignment And Biocompatibility Studies Of Electrospun Medical Grade Polyurethane (Carbothane™ 3575a) Nanofibers And Composite Nanofibers Containing Multiwalled Carbon Nanotubes, Faheem A. Sheikh, Javier Macossay-Torres, Travis Cantu, Xujun Zhang, M. Shamshi Hassan, M. Esther Salinas, Chakavak S. Farhangi, Hassan Ahmad, Hern Kim, Gary L. Bowlin

Chemistry Faculty Publications and Presentations

In the present study, we discuss the electrospinning of medical grade polyurethane (Carbothane™ 3575A) nanofibers containing multi-walled-carbon-nanotubes (MWCNTs). A simple method that does not depend on additional foreign chemicals has been employed to disperse MWCNTs through high intensity sonication. Typically, a polymer solution consisting of polymer/MWCNTs has been electrospun to form nanofibers. Physiochemical aspects of prepared nanofibers were evaluated by SEM, TEM, FT-IR and Raman spectroscopy, confirming nanofibers containing MWCNTs. The biocompatibility and cell attachment of the produced nanofiber mats were investigated while culturing them in the presence of NIH 3T3 fibroblasts. The results from these tests indicated non-toxic behavior …

Imaging, Spectroscopic, Mechanical And Biocompatibility Studies Of Electrospun Tecoflex® Eg 80a Nanofibers And Composites Thereof Containing Multiwalled Carbon Nanotubes, Javier Macossay-Torres, Faheem A. Sheikh, Travis Cantu, Thomas Eubanks, M. Esther Salinas, Chakavak S. Farhangi, Hassan Ahmad, M. Shamshi Hassan, Myung-Seob Khil, Shivani K. Maffi, Hern Kim, Gary L. Bowlin

Chemistry Faculty Publications and Presentations

The present study discusses the design, development and characterization of electrospun Tecoflex® EG 80A class of polyurethane nanofibers and the incorporation of multiwalled carbon nanotubes (MWCNTs) to these materials. Scanning electron microscopy results confirmed the presence of polymer nanofibers, which showed a decrease in fiber diameter at 0.5% wt. and 1% wt. MWCNTs loadings, while transmission electron microscopy showed evidence of the MWCNTs embedded within the polymer matrix. The fourier transform infrared spectroscopy and Raman spectroscopy were used to elucidate the polymer-MWCNTs intermolecular interactions, indicating that the C-N and N-H bonds in polyurethanes are responsible for the interactions with MWCNTs. …

Biodegradable Electrospun Nanofibers Coated With Platelet-Rich Plasma For Cell Adhesion And Proliferation, Luis Diaz-Gomez, Carmen Alvarez-Lorenzo, Angel Concheiro, Maite Silva, Fernando Dominguez, Faheem A. Sheikh, Travis Cantu, Raj Desai, Vanessa L. Garcia, Javier Macossay-Torres

Chemistry Faculty Publications and Presentations

Biodegradable electrospun poly(ε-caprolactone) (PCL) scaffolds were coated with platelet-rich plasma (PRP) to improve cell adhesion and proliferation. PRP was obtained from human buffy coat, and tested on human adipose-derived mesenchymal stem cells (MSC) to confirm cell proliferation and cytocompatibility. Then, PRP was adsorbed on the PCL scaffolds via lyophilization, which resulted in uniform sponge-like coating of 2.85 (s.d. 0.14) mg/mg. The scaffolds were evaluated regarding mechanical properties (Young’s modulus, tensile stress and tensile strain), sustained release of total protein and growth factors (PDGF-BB, TGF-β1 and VEGF), and hemocompatibility. MSC seeded on the PRP-PCL nanofibers showed an increased adhesion and proliferation …

Fabrication Of Yttrium Ferrite Nanoparticles By Solution Combustion Synthesis, A. A. Saukhimov, Mkhitar A. Hobosyan, Gamage C. Dannangoda, N. N. Zhumabekova, S. E. Kumekov

Physics and Astronomy Faculty Publications and Presentations

The ternary oxide system Y-Fe-O presents fascinating magnetic properties that are sensitive to the crystalline size of particles. There is a major challenge to fabricate these materials in nano-crystalline forms due to particle conglomeration during nucleation and synthesis. In this paper we report the fabrication of nano sized crystalline yttrium ferrite by solution combustion synthesis (SCS) where yttrium and iron nitrates were used as metal precursors with glycine as a fuel. The magnetic properties of the product can be selectively controlled by adjusting the ratio of glycine to metal nitrates. Yttrium ferrite nano-powder was obtained by using three concentration of …

Fluid Dynamic Modeling Of Nano-Thermite Reactions, Karen S. Martirosyan, Maxim Zyskin, Charles M. Jenkins, Yasuyuki Horie

Physics and Astronomy Faculty Publications and Presentations

This paper presents a direct numerical method based on gas dynamic equations to predict pressure evolution during the discharge of nanoenergetic materials. The direct numerical method provides for modeling reflections of the shock waves from the reactor walls that generates pressure-time fluctuations. The results of gas pressure prediction are consistent with the experimental evidence and estimates based on the self-similar solution. Artificial viscosity provides sufficient smoothing of shock wave discontinuity for the numerical procedure. The direct numerical method is more computationally demanding and flexible than self-similar solution, in particular it allows study of a shock wave in its early stage …

An Integrated Multidisciplinary Nanoscience Concentration Certificate Program For Stem Education, Karen S. Martirosyan, Mikhail M. Bouniaev, Malik Rakhmanov, Ahmed Touhami, Nazmul Islam, Davood Askari, Tarek Trad, Dmitri Litvinov, Sergey E. Lyshevski

Physics and Astronomy Faculty Publications and Presentations

Integration of nanoscience and nanotechnology curricula into the College of Science, Mathematics, and Technology (CSMT) at the University of Texas at Brownsville (UTB) is reported. The rationale for the established multidisciplinary Nanoscience Concentration Certificate Program (NCCP) is to: (i) develop nanotechnology-relevant courses within a comprehensive Science, Engineering and Technology curriculum, and, to offer students an opportunity to graduate with a certificate in nanoscience and nanotechnology; (ii) to contribute to students' success in achieving student outcomes across all college's majors, and, improve the breath, depth and quality of science, technology, engineering and mathematics (STEM) graduates' education; (iii) through NCCP, recruit certificate- …

Nitroxide-Functionalized Graphene Oxide From Graphite Oxide, Yazmin I. Avila-Vega, Cesar C. Leyva-Porras, Marcela Mireles, Manuel Quevedo-Lopez, Javier Macossay-Torres, Jose Bonilla-Cruz

Chemistry Faculty Publications and Presentations

A facile method for preparing functionalized graphene oxide single layers with nitroxide groups is reported herein. Highly oxidized graphite oxide (GO=90.6%) was obtained, slightly modifying an improved Hummer’s method. Oxoammonium salts (OS) were investigated to introduce nitroxide groups to GO, resulting in a one-step functionalization and exfoliation. The mechanisms of functionalization/exfoliation are proposed, where the oxidation of aromatic alcohols to ketone groups, and the formation of alkoxyamine species are suggested. Two kinds of functionalized graphene oxide layers (GOFT1 and GOFT2) were obtained by controlling the amount of OS added. GOFT1 and GOFT2 exhibited a high interlayer spacing (d0001 = 1.12nm), …

Experimental Study Of Nanofiber Production Through Forcespinning, Simon Padron, Arturo Fuentes, Dumitru Caruntu, Karen Lozano

Mechanical Engineering Faculty Publications and Presentations

A newly developed method of producing nanofibers, called forcespinning, has proven to be a viable alternative to mass produce nanofibers. Unlike electrospinning, the most common method currently being employed (which draws fibers through the use of electrostatic force), forcespinning utilizes centrifugal forces which allow for a host of new materials to be processed into nanofibers (given that electric fields are not required) while also providing a significant increase in yield and ease of production. This work presents a detailed explanation of the fiber formation process. The study is conducted using high speed photography to capture the jet initiation process at …

Charge And Discharge Behaviour Of Li-Ion Batteries At Various Temperatures Containing Licoo2 Nanostructured Cathode Produced By Ccso, Y. Y. Mamyrbayeva, R. E. Beissenov, Mkhitar A. Hobosyan, S. E. Kumekov, Karen S. Martirosyan

Physics and Astronomy Faculty Publications and Presentations

There are technical barriers for penetration market requesting rechargeable lithium-ion battery packs for portable devices that operate in extreme hot and cold environments. Many portable electronics are used in very cold (-40 °C) environments, and many medical devices need batteries that operate at high temperatures. Conventional Li-ion batteries start to suffer as the temperature drops below 0 °C and the internal impedance of the battery increases. Battery capacity also reduced during the higher/lower temperatures. The present work describes the laboratory made lithium ion battery behaviour features at different operation temperatures. The pouch-type battery was prepared by exploiting LiCoO2 cathode material …

Reactive Self-Heating Model Of Aluminum Spherical Nanoparticles, Karen S. Martirosyan, Maxim Zyskin

Physics and Astronomy Faculty Publications and Presentations

Aluminum-oxygen reaction is important in highly energetic and high pressure generating systems. Recent experiments with nanostructured thermites suggest that oxidation of aluminum nanoparticles occurs in a few microseconds. Such rapid reaction cannot be explained by a conventional diffusion-based mechanism. We present a rapid oxidation model of a spherical aluminum nanoparticle, using Cabrera-Mott moving boundary mechanism, and taking self-heating into account. In our model, electric potential solves the nonlinear Poisson equation. In contrast with the Coulomb potential, a “double-layer” type solution for the potential and self-heating leads to enhanced oxidation rates. At maximal reaction temperature of 2000 C, our model predicts …

Modeling And Simulation Of Pressure Waves Generated By Nano-Thermite Reactions, Karen S. Martirosyan, Maxim Zyskin, Charles M. Jenkins, Yasuyuki Horie

Physics and Astronomy Faculty Publications and Presentations

This paper reports the modeling of pressure waves from the explosive reaction of nano-thermites consisting of mixtures of nanosized aluminum and oxidizer granules. Such nanostructured thermites have higher energy density (up to 26 kJ/cm3) and can generate a transient pressure pulse four times larger than that from trinitrotoluene (TNT) based on volume equivalence. A plausible explanation for the high pressure generation is that the reaction times are much shorter than the time for a shock wave to propagate away from the reagents region so that all the reaction energy is dumped into the gaseous products almost instantaneously and thereby a …

A Simple Approach For Synthesis, Characterization And Bioactivity Of Bovine Bones To Fabricate The Polyurethane Nanofiber Containing Hydroxyapatite Nanoparticles, Faheem A. Sheikh, M. A. Kanjwal, Javier Macossay-Torres, N. A. M. Barakat, H. Y. Kim

Chemistry Faculty Publications and Presentations

In the present study, we had introduced polyurethane (PU) nanofibers that contain hydroxyapatite (HAp) nanoparticles (NPs) as a result of an electrospinning process. A simple method that does not depend on additional foreign chemicals had been employed to synthesize HAp NPs through the calcination of bovine bones. Typically, a colloidal gel consisting of HAp/PU had been electrospun to form nanofibers. In this communication, physiochemical aspects of prepared nanofibers were characterized by FE-SEM, TEM and TEM-EDS, which confirmed that nanofibers were well-oriented and good dispersion of HAp NPs, over the prepared nanofibers. Parameters, affecting the utilization of the prepared nanofibers in …

Ferromagnetic Resonance On Ni Nanowire Arrays, Mircea Chipara, Ralph Skomski, Roger D. Kirby, David J. Sellmyer

Physics and Astronomy Faculty Publications and Presentations

Ferromagnetic resonance investigations on Ni nanowires are reported. The angular dependence of the resonance line position is analyzed within a thermodynamic approach that includes shape anisotropy (ellipsoids of revolution), magnetocrystalline anisotropies (cubic and uniaxial), and dipole–dipole interactions. The results are supported by hysteresis loops, obtained on the same sample.