Materials Science and Engineering Commons^™

Investigation Of Thermal Cycle And Hardness Distribution In The Laser Cladding Of Aisi H13 Tool Steel Produced By A High Power Direct Diode Laser, Parisa Farahmand, Prabu Balu, Fanrong Kong, Radovan Kovacevic

Mechanical Engineering Research

Laser cladding (LC) of tool steel has significant application in rapid tooling, and surface coating for worn-out components in different industries. During the LC process, several phase transformations influence the microstructural and mechanical properties of the deposited layer. In order to successfully implement the LC process, it is essential to understand the relationship between the thermal cycle (heating and cooling), phase transformations, and the output quantities of the deposited layer. In this study a direct diode laser with a power of up to 8 kW was used to deposit AISI H13 tool steel on mild steel grade A36 substrate to …

Binding, Transcytosis And Biodistribution Of Anti-Pecam-1 Iron Oxide Nanoparticles For Brain-Targeted Delivery, Mo Dan, David B. Cochran, Robert A. Yokel, Thomas D. Dziubla

Pharmaceutical Sciences Faculty Publications

OBJECTIVE: Characterize the flux of platelet-endothelial cell adhesion molecule (PECAM-1) antibody-coated superparamagnetic iron oxide nanoparticles (IONPs) across the blood-brain barrier (BBB) and its biodistribution in vitro and in vivo.

METHODS: Anti-PECAM-1 IONPs and IgG IONPs were prepared and characterized in house. The binding affinity of these nanoparticles was investigated using human cortical microvascular endothelial cells (hCMEC/D3). Flux assays were performed using a hCMEC/D3 BBB model. To test their immunospecificity index and biodistribution, nanoparticles were given to Sprague Dawley rats by intra-carotid infusion. The capillary depletion method was used to elucidate their distribution between the BBB and brain parenchyma.

RESULTS: Anti-PECAM-1 …

Oil Droplet Behavior At A Pore Entrance In The Presence Of Crossflow: Implications For Microfiltration Of Oil-Water Dispersions, Nikolai V. Priezjev, Tohid Darvishzadeh, Volodymyr V. Taravara

Mechanical and Materials Engineering Faculty Publications

The behavior of an oil droplet pinned at the entrance of a micropore and subject to clossflow-induced shear is investigated numerically by solving the Navier-Stokes equation. We found that in the absence of crossflow, the critical transmembrane pressure required to force the droplet into the pore is in excellent agreement with a theoretical prediction based on the Young-Laplace equation. With increasing shear rate, the critical pressure of permeation increases, and at sufficiently high shear rates the oil droplet breaks up into two segments. The results of numerical simulations indicate that droplet breakup at the pore entrance is facilitated at lower …

Compounds And Methods For Reducing The Occurrence Of Post-Surgical Adhesions, Thomas Dziubla, Eugene Kaplan, John Mark Medley Jr.

Chemical and Materials Engineering Faculty Patents

Compounds and methods for reducing the occurrence of a post-surgical adhesion are provided. The compounds can include acrylic acid groups and ethylene glycol groups, and can be directed to an area of damaged tissue by the incorporation of a fibrin targeting peptide. The compounds can further include a brush-like portion, capable of creating a steric barrier between a damaged tissue or organ and adjacent tissues or organs, and a targeting portion, capable of directing the compounds to a damaged tissue or organ. Methods of detecting damaged tissue and kits are also provided.

A Systematic Study Of Radiation-Induced Segregation In Ferritic–Martensitic Alloys, Janelle P. Wharry, Gary S. Was

Materials Science and Engineering Faculty Publications and Presentations

A systematic approach to measuring radiation-induced segregation (RIS) was used on four ferritic–martensitic (F–M) alloys: T91, HCM12A, HT9, and a Fe–9Cr model alloy, irradiated with 2.0 MeV protons over a range of doses (1–10 dpa) and temperatures (300–700°C). The experimental conditions are established so as to isolate the dependence of RIS on the experimental parameters: temperature, dose and bulk composition. RIS is measured at prior austenite grain boundaries (PAGBs) using the STEM/EDX technique. Chromium is found to enrich at PAGBs in all conditions with the exception being T91 irradiated to 3 dpa at 700°C. The magnitude of enrichment is small …

Magnetic Interaction Reversal In Watermelon Nanostructured Cr-Doped Fe Nanoclusters, Maninder Kaur, Qilin Dai, Mark Bowden, Mark H. Engelhard, Yaqiao Wu, Jinke Tang, You Qiang

Materials Science and Engineering Faculty Publications and Presentations

Cr-doped core-shell Fe/Fe-oxide nanoclusters (NCs) were synthesized at varied atomic percentages of Cr from 0 at. % to 8 at. %. The low concentrations of Cr (%) were selected in order to inhibit the complete conversion of the Fe-oxide shell to Cr₂O₃ and the Fe core to FeCr alloy. The magnetic interaction in Fe/Fe-oxide NCs (~25 nm) can be controlled by antiferromagnetic Cr-dopant. We report the origin of σ-FeCr phase at very low Cr concentration (2 at. %) unlike in previous studies, and the interaction reversal from dipolar to exchange interaction in watermelon-like Cr-doped core-shell NCs.

Physiological Fluid Specific Agglomeration Patterns Diminish Gold Nanorod Photothermal Characteristics, Kristen K. Comfort, Jared W. Speltz, Bradley M. Stacy, Larry R. Dosser, Saber M. Hussain

Chemical and Materials Engineering Faculty Publications

Investigations into the use of gold nanorods (Au-NRs) for biological applications are growing exponentially due to their distinctive physicochemical properties, which make them advantageous over other nanomaterials. Au-NRs are particularly renowned for their plasmonic characteristics, which generate a robust photothermal response when stimulated with light at a wavelength matching their surface plasmon resonance. Numerous reports have explored this nanophotonic phenomenon for temperature driven therapies; however, to date there is a significant knowledge gap pertaining to the kinetic heating profile of Au-NRs within a controlled physiological setting. In the present study, the impact of environmental composition on Au-NR behavior and degree …

Characterisation And Optimisation Of Magnetorheological Elastomers, Jennifer Mcintyre

Doctoral

The primary aim of this research was to optimise the design of magnetorheological elastomers (MREs), composite materials consisting of magnetic particles in an elastomer matrix. In doing so, the understanding of their dynamic behaviour when subjected to stress would be furthered. Plenty of uses have been suggested for these materials which adapt to their environments and can be tuned to suit operating conditions, but very few of these have actually been realised. Characterising their dynamic behaviour is crucial if they are to gain wider use in commercial applications. The first objective of the research was to investigate the factors affecting …

Synthesis Of Pani/Nihcf Nanocomposite Particles And Eqcm Measurement Of Ion Exchange Properties In Solutions Containing Cd2+, Yu-Jiao Yang, Xiao-Gang Hao, Xu-Li Ma, Zhong-De Wang, Zhong-Lin Zhang, Nian-Chen Han

Journal of Electrochemistry

The PANI/NiHCF nanocomposite particles were synthesized on the CNTs-modified Pt substrate by one-step co-polymerization using cyclic voltammetry. Electrochemical quartz crystal microbalance (EQCM) technique was adopted to investigate the polymerization process of the nanocomposite particles and the mechanism of ion exchange in aqueous solution containing Cd²⁺． The morphology and structure of the as-prepared composite particles were characterized by scanning electron microscope (SEM), transmission electron microscope (TEM), and Fourier transform infrared spectroscopy (FT-IR). Combined with cyclic voltammetry (CV) and energy dispersive spectroscopy (EDS), the electrochemical behavior and the mechanism of ion exchange were also investigated in electrolytes of Cd^{2+ …}

A Comparative Study In Pretreatments Of Acid Chemical Wastewater By Electrochemical Oxidation And Ozonation, Han-Shui Liu, Su Yu, Shao-Ping Tong, Chun-An Ma

Journal of Electrochemistry

Under the condition of keeping certain acidity, the pretreatment efficiency of an acid chemical wastewater (pH 0.85) by electrochemical oxidation was compared with that by ozonation. The results showed that the electrochemical oxidation pretreatment could obtain a better result than the ozonation at pH 0.85. After the addition of 2 g·L^-1 NaCl and with the electrochemical oxidation pretreatment at 30 mA·cm^-2, the removal rate of chemical oxygen demand (CODCr) reached 43.4%, and the value of biochemical oxygen demand/chemical oxygen demand (BOD₅/COD_Cr) also increased from 0.034 to 0.14 in 20 minutes, indicating significantly improvement …

Electrocatalytic Properties Of The Keggin-Type Co(Ii)-Substituted Heteropolyanion Pw11O39Co(Ii)(H2O)5-, Bin Wang, Chong-Tai Wang, Ying-Jie Hua, Jin-Yuan Liu, Liang-Fei Zheng

Journal of Electrochemistry

The electrochemical properties of the Keggin-type Co(II)-substituted heteropolyanion PW₁₁O₃₉Co(II)(H₂O)^5- (PW₁₁Co), as well as the electrocatalytic properties of PW₁₁Co towards the anodic oxidations of H₂O₂ and CH₃OH were studied using the electrochemical methods such as cyclic voltammetry and AC impedance spectroscopy in this paper. An electrocatalytic mechanism of PW₁₁Co as an anodic medium was also proposed. It was found that PW₁₁Co showed a pair of pseudo-reversible redox peaks at the potentials of 1.367 V/1.266 V, corresponding to the redox responses of …

An Investigation Of Photocatalytic Degradation Reactions Of Pollutants By Combination Of (Photo)Electrochemical Measurements, Wen-Hua Leng, Hong-Qiao Zhu

Journal of Electrochemistry

Semiconductor photocatalysis plays a critical role in the environment protection and future energy development. (Photo)electrochemical measurements are powerful tools for studying the kinetics and mechanism of photocatalytic reactions, since photo-carriers, as reactants of photocatalytic reactions, are involved in the interfacial transfer and recombination of semiconductor/electrolyte interface. This review describes the part of our recent results regarding aqueous photocatalytic decontamination obtained by these methods, and the focus of future work in this field is suggested.

Preparation Of Benzoquinone From Phenol By Electrooxidation, Dong-Fang Niu, Cheng-Kai Yu, Xin-Sheng Zhang

Journal of Electrochemistry

The benzoquinone was prepared from phenol by electrooxidation in an H-type cell with cation exchange membrane, in which lead plates were used both as an anode and a cathode, while H₂SO₄ was used as a supporting electrolyte. The effects of current density, concentration of sulphuric acid, concentrations of benzoquinone in electrolyte and extractant on the yields and efficiencies of electrolysis were investigated. Under the optimized conditions of current density being 4 A·dm^-2, concentration of sulphuric acid 1 mol·L^-1, passed charge 3.2 A·h, the yield and current efficiency of benzoquinone could reach 68% and …

Experimental Design Methodology Applied To The Oxidation Of Quinolines In Aqueous Medium By Electro-Fenton Process, Souhaila Trabelsi Souissi, Nihal Oturan, Nizar Bellakhal, Mehmet A. Oturan

Journal of Electrochemistry

The degradation behavior of 8-hydroxyquinoleine sulfate (8-HQS), a model molecule of quinolines, was studied in an aqueous medium by electro-Fenton process using a carbon felt cathode and a platinum anode. The great oxidation ability of this process is due to a large production of hydroxyl radical (OH) by electrochemically induced Fenton’s reagent (H₂O₂, Fe²⁺). Hydroxyl radicals are very powerful oxidizing agents which react on organics up to complete mineralization. A factorial experimental design was used for determining the operating parameters on the degradation of 8-HQS in an aqueous medium. The results showed that the …

Basic Principles And Applications Of Secm In Metal Corrosion, Fa-He Cao, Yan Xia, Wen-Juan Liu, Lin-Rong Chang, Jian-Qing Zhang

Journal of Electrochemistry

Scanning electrochemical microscopy (SECM) is chemical microscopy with higher spatial resolution. After 24 years of development, SECM has been widely applied in mapping and kinetics study of heterogeneous electron transfer in localized processes at solid-liquid or liquid-liquid interfaces. The fundamentals and recent advances of SECM in corrosion applications are described, including SECM mapping and kinetics on localized corrosion of metal or coating. Research work of SECM in corrosion by our group is also introduced. Future applications of SECM in corrosion are highlighted.

Applications Of Spectroscopic Ellipsometry In Corrosion Investigation, Ling-Jie Li, Yu-Ling He, Jing-Lei Lei, Sheng Tao Zhang

Journal of Electrochemistry

As a highly-sensitive and non-destructive in situ technique, spectroscopic ellipsometry has been widely applied in corrosion investigation to acquire the dynamic information of the “electrode-medium” interface during corrosion. This paper lays out some representative demonstrations in several established optical models used to interpret data obtained with spectroscopic ellipsometry in corrosion investigation. In addition, the latest trends in development of this technique are analyzed.

Corrosion Behavior Of A High Strength Low Alloy Steel Under Hydrostatic Pressure In Deep Ocean, Hai-Jing Sun, Li Liu, Ying Li

Journal of Electrochemistry

The corrosion behavior of a high strength low alloy steel (HSLA steel) in 3.5% NaCl solution under hydrostatic pressure (HP) in deep ocean has been investigated by performing weight loss measurement, obtaining potentiodynamic polarization curve and emplying electrochemical impedance spectroscopy (EIS) using the set up for simulation of deep sea environment in laboratory. The results were compared with that at atmospheric pressure and the influence of HP was emphatically discussed. The results revealed identical corrosion mechanism for HSLA steel at 3.5 × 10⁶ Pa and 1 × 10⁵ Pa. Howevere, the development of such a corrosion process was …

Corrosion Resistance Of Low Pressure Cold Sprayed Al Coating On Q235 Steel In Seawater, Xiang-Bo Li, Li-Kun Xu, Shan-Guang Qiu, Jia Wang, Guo-Sheng Huang, Cai-Chang Dong

Journal of Electrochemistry

Taking aluminium (Al) powder mixed with 10% (by volume) of Al₂O₃ powder as raw materials, the Al coating was prepared on the Q235 carbon steel substrate using a portable low pressure cold spraying equipment. Through the measurements of the corrosion potential and potentiodynamic polarization, the electrochemical corrosion behavior of the low pressure cold sprayed Al coating in seawater was studied in comparison with those of the Al coatings deposited with high pressure cold spray and thermal spray processes. At the same time, the surface and cross-section morphologies of these coatings were observed with scanning electron microscope. The …

Corrosion Behavior Of Zinc Covered With Thin Electrolyte Layers Under External Electric Field, Xu-Jie Yuan, Jun-Xi Zhang, Shi-Ming Zhang, Tian Tan, Qi-Meng Chen

Journal of Electrochemistry

The corrosion behavior of zinc covered with thin electrolyte layers (TELs) under an application of external electric field was investigated by performing corrosion potential and cathodic polarization current measurements. The results showed that the Ecorr and ic values first increased and then decreased with the increase of electrolyte layer thickness. Pure zinc exhibited the maximum corrosion potential as the TELs increased to 400 μm under the controls of cathodic process and corrosion products. The application of external electric field resulted in either a negative shift in corrosion potential of zinc or an increase of cathodic current. The effect of external …

A Clamped Dual-Ridged Waveguide Measurement System For The Broadband, Nondestructive Characterization Of Sheet Materials, Milo W. Hyde Iv, Michael J. Havrilla

Faculty Publications

A novel two-port probe which uses dual-ridged waveguides for the nondestructive, broadband characterization of sheet materials is presented. The new probe is shown to possess approximately 2 to 3 times the bandwidth of traditional coaxial and rectangular/circular waveguide probe systems while maintaining the structural robustness characteristic of rectangular/circular waveguide probe systems. The theoretical development of the probe is presented, namely, by applying Love’s equivalence theorem and enforcing the continuity of transverse fields at the dual-ridged waveguide apertures, a system of coupled magnetic field integral equations is derived. The system of coupled magnetic field integral equations is solved using the method …

Cellulose Nanocrystals As A Material For Microencapsulation, Lauren C. Kennedy, Congwang Ye, Colton Steiner, Carlos Martinez

The Summer Undergraduate Research Fellowship (SURF) Symposium

Cellulose is an abundant, biodegradable, and inexpensive renewable polymer that is light in weight with high mechanical strength (Habibi, Lucia, Rojas 2010). Full fibers of cellulose have been used in many products such as plastics and textiles for over a century and a half, but recently, modern extraction techniques have made it possible to investigate uses for minuscule cellulose fibers (Habibi, Lucia, Rojas 2010). Through acid hydrolysis, cellulose fibers become rod-like nanostructures with a high aspect ratio that are known as Cellulose Nanocrystals (CNCs) (Habibi, Lucia, Rojas 2010). Since CNCs are biodegradable and derive from a renewable resource, finding ways …

Next Generation Crystal Viewing Tool, Zach Schaffter, Gerhard Klimeck

The Summer Undergraduate Research Fellowship (SURF) Symposium

The science and engineering community is limited when it comes to crystal viewing software tools. Each tool lacks in a different area such as customization of structures or visual output. Crystal Viewer 2.0 was created to have all of these features in one program. This one tool simulates virtually any crystal structure with any possible material. The vtkvis widget offers users advanced visual options not seen in any other crystal viewing software. In addition, the powerful engine behind Crystal Viewer 2.0, nanoelectronic modeling 5 or (NEMO5), performs intensive atomic calculations depending on user input. A graphical user interface, or GUI, …

Efficiently Dispersing Carbon Nanotubes In Polyphenylene Sulfide, Kevin M. Sommer, R. Byron Pipes

The Summer Undergraduate Research Fellowship (SURF) Symposium

Thermal plastics are replacing conventional metals in the aerospace, sporting, electronics, and other industries. Thermal plastics are able to withstand relatively high temperatures, have good fatigue properties, and are lighter than metals. Unfortunately, they are not very electrically conductive. However, adding carbon nanotubes to thermal plastics such as polyphenylene sulfide (PPS) can drastically increase the plastic's conductivity at a low weight percent of nanotubes called the percolation threshold. The percolation threshold is the point where adding a little more carbon nanotubes brings together the network of nanotubes and greatly increases the conductivity. We need to learn how to increase the …

Nanohub - Crystal Viewer 2.0, Kevin Margatan, Gerhard Klimeck

The Summer Undergraduate Research Fellowship (SURF) Symposium

nanoHUB is an online compilation of tools for simulations. Equipped with 3-D simulations and a capability to solve very complex calculations, nanoHUB provides its users worldwide with various tools to help them finish their assignments. One of the tools available is called a Crystal Viewer Tool, an advanced crystal visualization tool. This tool allows users to generate various crystal types including their every single detail. Currently, a newer version, called Crystal Viewer 2.0, is being tested prior to its release. However, this tool is lacking some important features and a GUI that is not as user friendly as expected. The …

Prediction Of Fiber Orientation In Compression Molded Parts Of Short-Fiber-Reinforced Thermoplastics, Anshuman Jagtap, R Byron Pipes, Chris Schwall, Ethan Brubaker

The Summer Undergraduate Research Fellowship (SURF) Symposium

Short Fiber molded thermoplastics like poly ether ketone ketone (PEKK) have the potential to be used to build reinforcement structures for next generation air crafts. Because of the anisotropic properties of these fibers, it is necessary to know the orientation of fibers in molded parts to determine the strength of parts. The goal of the project is to prepare samples that will be used to determine the spatial distribution of fibers as a function of the parts thickness and for comparison with computer generated models to test for accuracy. Using a full factorial method the effects of four key control …

Testing Self Healing Properties In Polymers, Hamsini Gopalakrishna, John Blendell

The Summer Undergraduate Research Fellowship (SURF) Symposium

Mussels and barnacles have the ability to stick to underwater surfaces with the help of a cross-linked protein structure. Reduction in the plastic consumption can be achieved by using toughened polymers. Synthesized cross-linking polymers can be used for underwater adhesion by mimicking the protein structure used by mussels and barnacles. One such polymer is poly(3,4-dihydroxystyrene-co-styrene) having enhanced toughness. Traditionally, blister tests measure the adhesion between a substrate to a surface but this was modified to serve as the driving force to drive crack propagation in controlled flaws. The modified blister tests were carried out on polystyrene (PS) samples. Once the …

Silver Oxide-Graphene Sensor For Hydrogen Peroxide, Austin D. Scherbarth, L Stanciu

The Summer Undergraduate Research Fellowship (SURF) Symposium

A nonenzymatic, amperometric sensor for Hydrogen Peroxide (H₂O₂) was designed by drop coating glassy carbon electrodes (GCEs) with Silver Oxide (Ag₂O). Combining Ag₂O with Graphene Oxide and a polymer, PEDOT, was also attempted in order to increase stability and electrochemical properties. Using metal oxides along with Graphene Oxide for sensors has been done quite a bit, but Ag₂O itself has not been research extensively. So, in order to produce the best H₂O₂ sensor, the configuration of all components had to be optimized. Three different Ag₂O …

Intermetalic Growth Rate In Transient Liquid Phase Sintering Of Pb-Free Solder Interconnects, Shuqing Zhang, John Blendell

The Summer Undergraduate Research Fellowship (SURF) Symposium

Following the electron devices are widely used in daily life, Pb-free solder alloy, as the replacement of Pb solder joint material, needs extensive researches to observe the properties for using and simulation purpose. Solder are used as the joint to connect two work pieces in printed wiring board of electronics. Most lead-free solders comprise tin (Sn) as the majority component, and nominally pure b-Sn is the majority phase in the microstructure of these solders. The most important thing for solder joint that researchers care about is its life cycle. Due to the incomplete of the mechanical profile of Pb-free solder …

Characterization Of Lead-Free Piezo-Ceramics, Hanhan Zhou, John Blendell

The Summer Undergraduate Research Fellowship (SURF) Symposium

Lead zirconate titanate (PZT) has been the most commonly used piezoelectric material due to its high piezoelectric performance under varied operating conditions. However, it has been noticed that the lead component is toxic, causing some environmental issues and a lead free substitute material was introduced. The substituted environmental friendly piezoelectric material, Ba(Zr0.2Ti0.8)O3–x(Ba0.7Ca0.3)TiO3 (BZT-xBCT) system that can fulfill the need of high piezoelectricity has been developed. The research was conducted to characterize the BZT-xBCT system with five different compositions (x=0.06, 0.08, 0.1, 0.12 and 0.14).. XRD was applied to examine the crystal structure of the samples before and after poling and …

Characterization Of Hardness And Elastic Modulus Of A Pharmaceutical Material For Multiple Crystal Orientations, Alexis L. Mertz, David F. Bahr

The Summer Undergraduate Research Fellowship (SURF) Symposium

Nanoindentation has made it possible to test material properties of extremely brittle molecular crystals, which include many pharmaceuticals. An antifungal, griseofulvin, is tested to determine differences in hardness and elastic modulus for different crystal orientations. Hardness and elastic modulus are determined by nanoindentation on single crystals that are rotated in 15° intervals. There are differences in hardness at rotation degrees of 45°, 60°, and 75° from the 0° orientation and differences in elastic modulus at rotation degrees of 15°, 60°, and 75° from the 0° orientation. It is also found that the elastic modulus and hardness values of the 75° …