Other Materials Science and Engineering Commons^™

Influence Of Carbon Nanofillers On The Curing Kinetics Of Epoxy-Amine Resin, Luigi Vertuccio, Salvatore Russo, Marialuigia Raimondo, Khalid Lafdi, Liberata Guadagno

Chemical and Materials Engineering Faculty Publications

The cure kinetics of an epoxy resin based on the tetrafunctional epoxy precursor N,N′-tetraglycidyl methylene dianiline-(TGMDA) hardened with 4,4-diaminodiphenyl sulfone is investigated. The influence of carbon nanofillers (carbon nanotubes, carbon nanofibers, and graphene based nanoparticles) on the cure kinetic is studied. Kinetic analysis is performed by dynamic and isothermal differential scanning calorimetry (DSC).

In dynamic experiments, the activation energy was computed using an advanced isoconversional method while under isothermal conditions, the Kamal’s model of diffusion control was applied to simulate the systems throughout the curing process. The isothermal analysis shows that the introduction of the diluent decreases, …

The Role Of Biological Fluid And Dynamic Flow In The Behavior And Cellular Interactions Of Gold Nanoparticles, Emily K. Breitner, Saber M. Hussain, Kristen K. Comfort

Chemical and Materials Engineering Faculty Publications

Background: Due to their distinctive physicochemical properties, nanoparticles (NPs) have proven to be extremely advantageous for product and application development, but are also capable of inducing detrimental outcomes in biological systems. Standard in vitro methodologies are currently the primary means for evaluating NP safety, as vast quantities of particles exist that require appraisal. However, cell-based models are plagued by the fact that they are not representative of complex physiological systems. The need for a more accurate exposure model is highlighted by the fact that NP behavior and subsequent bioresponses are highly dependent upon their surroundings. Therefore, standard in vitro models …

Electromagnetic Induction By Ferrofluid In An Oscillating Heating Pipe, John Gabriel Monroe, Erick S. Vasquez, Zachary S. Aspin, Keisha B. Walters, Matthew J. Berg, Scott M. Thompson

Chemical and Materials Engineering Faculty Publications

No abstract provided.

Analysis Of Particle Transport And Deposition Of Micron-Sized Particles In A 90° Bend Using A Two-Fluid Eulerian–Eulerian Approach, Erick S. Vasquez, Keisha B. Walters, D. Keith Walters

Chemical and Materials Engineering Faculty Publications

Two-phase flows involving dispersed particle and droplet phases are common in a variety of natural and industrial processes, such as aerosols, blood flow, emulsions, and gas-catalyst systems. For sufficiently dilute particle/aerosol phases, a simplified one-way coupling is often assumed, in which the continuous primary phase is unaffected by the presence of the dispersed secondary phase and standard CFD methods can be applied. To predict the transport and deposition of the particle phase, typically a Lagrangian particle-tracking or Eulerian one-fluid/two-phase drift-flux approach is used. Here, a full two-fluid Eulerian modeling approach is presented for coarse particles (>1 μm), in which …

Optimization Of Graphene-Based Materials Outperforming Host Epoxy Matrices, Liberata Guadagno, Marialuigia Raimondo, Luigi Vertuccio, Marco Mauro, Gaetano Guerra, Khalid Lafdi, Biagio De Vivo, Patrizia Lamberti, Giovanni Spinelli, Vincenzo Tucci

Chemical and Materials Engineering Faculty Publications

The degree of graphite exfoliation and edge-carboxylated layers can be controlled and balanced to design lightweight materials characterized by both low electrical percolation thresholds (EPT) and improved mechanical properties. So far, this challenging task has been undoubtedly very hard to achieve.

The results presented in this paper highlight the effect of exfoliation degree and the role of edge-carboxylated graphite layers to give self-assembled structures embedded in the polymeric matrix. Graphene layers inside the matrix may serve as building blocks of complex systems that could outperform the host matrix. Improvements in electrical percolation and mechanical performance have been obtained by a …

Computational Multiscale Modeling And Characterization Of Piezoresistivity In Fuzzy Fiber Reinforced Polymer Composites, Xiang Ren, Josh Burton, Gary D. Seidel, Khalid Lafdi

Chemical and Materials Engineering Faculty Publications

In this paper, the piezoresistive response (i.e. the change of resistance under the application of strain) of polymer composites reinforced by a novel material known as fuzzy fibers is characterized by using single tow piezoresistive fragmentation tests and modeled by using a 3D computational multiscale model based on the finite element analysis. In the characterization work, the fuzzy fiber tow is embedded in a dog-bone specimen infused by epoxy, with resistance and displacement measured simultaneously to obtain its piezoresistive response. An approximately linear and stable piezoresistive response is observed within the fuzzy fiber tow region yielding gauge factors on average …

The Future Of Carbon-Based Scaffolds In Foot And Ankle Surgery, Jarema S. Czarnecki, Khalid Lafdi, Panagiotis A. Tsonis

Chemical and Materials Engineering Faculty Publications

Autologous grafts have been the gold standard in tissue replacement and the most accurate means of recapitulating both the biological and mechanical properties of tissue. However, autologous grafts have had complications and drawbacks. Skin grafting, a prime example of an autologous tissue graft, has been limited by the size of graft, availability, and secondary donor site morbidity. Use of cadaveric tissues circumvents several limitations of autologous grafts; however, sterilization processes used to reduce the risk of disease transmission potentially weaken tissues and eliminate living cells and some growth factors from scaffolds, making them suboptimal tissue replacements. Chemical cross-linkage of tissue …

Temporally And Spatially Resolved Plasma Spectroscopy In Pulsed Laser Deposition Of Ultra-Thin Boron Nitride Films, Nicholas R. Glavin, Christopher Muratore, Michael L. Jespersen, Jianjun Hu, Timothy S. Fisher, Andrey A. Voevodin

Chemical and Materials Engineering Faculty Publications

Physical vapor deposition (PVD) has recently been investigated as a viable, alternative growth technique for two-dimensional materials with multiple benefits over other vapor deposition synthesis methods. The high kinetic energies and chemical reactivities of the condensing species formed from PVD processes can facilitate growth over large areas and at reduced substrate temperatures. In this study, chemistry, kinetic energies, time of flight data, and spatial distributions within a PVD plasma plume ablated from aboron nitride (BN) target by a KrF laser at different pressures of nitrogen gas were investigated. Time resolved spectroscopy and wavelength specific imaging were used to identify and …

Effects Of Disorder State And Interfacial Layer On Thermal Transport In Copper/Diamond System, Vikas Sinha, Jaime J. Gengler, Christopher Muratore, Jonathan E. Spowart

Chemical and Materials Engineering Faculty Publications

The characterization of Cu/diamond interface thermal conductance (h_c) along with an improved understanding of factors affecting it are becoming increasingly important, as Cu-diamond composites are being considered for electronic packaging applications. In this study, ∼90 nm thick Cu layers weredeposited on synthetic and natural single crystal diamond substrates. In several specimens, a Ti-interface layer of thickness ≤3.5 nm was sputtered between the diamond substrate and the Cu top layer. The h_c across Cu/diamond interfaces for specimens with and without a Ti-interface layer was determined usingtime-domain thermoreflectance. The h_c is ∼2× higher for similar interfacial layers on …