Partnerships for Research and Education in Materials

The 2012 Pre-Freshmen Bridge Summer Science Program students conducted an interdisciplinary high altitude balloon research project. The research project involved eight teams of students working on original research projects.Two teams worked on materials science research, two teams on sustainable energy materials, and one team each on platform design, robotics, video documentary and behavior. The goal, which was accomplished, was to launch this payload of different research projects to the edge of space and collect data.Three of the teams presented their data at the NSF Emerging Researchers National undergraduate student conference.

Recent experimental work has demonstrated production of quasi free-standing graphene by gold intercalation. The intercalation weakens the coupling of adjacent graphene layers and yields Dirac fermion behavior of monolayer graphene.

Recent experimental work has demonstrated production of quasi free-standing graphene by methane intercalation. The intercalation weakens the coupling of adjacent graphene layers and yields Dirac fermion behaviour of monolayer graphene.

The PREM Nano Exhibición is presented in collaboration with Humacao’s Casa Roig Museum from March to December 2013. The basic exhibit was awarded to PREM by NISENet. Additional modules on “Nano, Stained Glasses and Materials in Historical Casa Roig” are being developed with the participation of students from local schools.

CVD Graphene was synthesized at PENN.
A Field Effect Transistor was fabricated at UPRH .
No lithography was used (i.e. no harsh chemicals used) to define the source and drain electrodes, instead a TEM grid was used as a shadow mask. This is new to graphene based device fabrication.
The device was tested in vacuum under UV irradiation
We found that it was possible to dope graphene with no change in the charge mobility (see top figure).
The process was reversible.

NSF-JSU-UCSB PREM members arranged summer program for K12 minority participants, to help local science students in their mission of enhancing scientific literacy to wider audiences.

This program is very popular in Jackson, MS and it helps to raise the number of STEM minority students every year

JSU & UT San Antonio team members have reported the development of multifunctional popcorn shape iron magnetic core- gold plasmonic shell nanotechnology-driven approach for targeted magnetic separation & enrichment, label-free surface enhanced Raman spectroscopy detection, and selective photothermal destruction of MDR Salmonella DT104. Our result shows that magnetic core–plasmonic shell popcorn shape nanoparticle based assay is rapid, takes about 30 minutes from bacterium binding to separation, enrichment, selective detection and photothermal killing.

Functionalization of Au and Ag nanoparticles with thiol molecules has been a topic of high interest, due to their peculiar and unique properties of their organic-metal interfaces. Thiols are well-known ligand molecules because they are able to form a self-assembled monolayer on the metal nanoparticle surface through a strong metal-sulfur covalent bond. Therefore the control of the adsorption and the appearance of structural changes on ligand passivated gold or silver nanoparticles are of primary importance.

Rare-earth doped nanoparticles (NPs) are known to have exceptional optical properties such as strong absorption and sharp emission lines. Since the optical properties are due to the f-f electron transitions, these nanoparticles do not photobleach like organic dyes or blink like quantum dots. Through the process known as upconversion, rare-earth ions can convert multiple lower energy photons into higher energy ones. We utilize this to engineer our NPs to absorb near-infrared light (980 nm) and emit in the visible (550 nm, 660 nm) and NIR (800 nm). Also, these NPs do not require high energy densities such as conventional two-photon processes and can be excited with pulsed and continuous sources, making them ideal for biomedical purposes. The 980 nm excitation for ytterbium and erbium co-doped systems, such as the KMgF3: Yb/Er and NaGdF4: Yb/Er NPs used herein, is advantageous due to the low scattering and absorption of tissue in this region.

Oxidative stress is a critical process in biological systems, involved in both normal and pathological functions; thus it is a commonly measured endpoint. Current methods for measuring oxidative stress are affected by artifacts, such as auto-oxidation. We are developing a new measurement approach based on the aggregation of functionalized gold NP in the presence of reactive oxygen species.

It is well established that matter behaves in a different manner at the nanoscale compared with their bulk counterparts. Mostly, this is due to confinement of electron, increased surface to volume ratio, composition, etc.; therefore, the study of matter at the nanoscale is of crucial relevance to continue the development of nano-devices that surrounds our everyday life.

Abrasive wear induced by the slow flow of concentrated slurry is encountered in many industrial problems. In this work, using a combination of experiment and theory, the coupled issues of the rheology of a concentrated solids-laden liquid and the boundary wear generated as it flows in confined domain in the geometry of simple shear are demonstrated. An experiment is performed with different abrasive particles, specimen materials and under different test conditions such as abrasive concentration and angular velocity. Using the von Mises yield criterion the load at which the plastic yield begins and boundary wear becomes observable is determined. In order to reveal the morphology of the surface, scanning electron microscopy (SEM) were used.

The structure transitions from staggered to loose double chain configuration as the voltage is ramped down at constant magnetic field. As the voltage is ramped back up the structure reforms and the staggered character begins to re-emerge.

Molecular dynamics simulations are used to study the dynamics of drop splashing on a solid surface. In agreement with experiment, we observe that splashes occur only in the presence of vapor. We are investigating how the flow in the vapor produces the stress which tears the drop into fragments, and the effects of surface wettability patterns on the final state.

Numerical simulations of the deformation of a droplet in viscous fluid under shear flow are performed with the Lattice Boltzmann method (LBM) based on the Cahn-Hilliard diffuse interface approach. The Degree of confinement between two parallel walls, which is defined as the ration between drop diameter 2R and the wall separation H and can play an important role and affect the dynamics of droplet deformation, is studied by decreasing the distance between the walls.

Surfactant molecules of Tau-3PDP and Phs-3PDP self-assemble into fractal patterns when placed on an air-water interface. These fractal crystals can subsequently be coated with various metallic films and used in electronic devices. Several labs are currently trying to unlock the potential of self-assembled organic molecules to define complex templates for the rapid processing of nanoscale electronic devices, where exceptionally high surface areas can be accessed in a bottom-up fashion. Before putting the structures to use, an understanding of how to control the growth of the crystals is required. Using Brewster Angle Microscopy coupled to a Langmuir trough we have been able to control the complexity (or fractal dimension) of self-assembled crystals through changes in temperature. The image analysis shows higher fractal dimensions at lower temperatures. We are currently trying to use the fractals as a template by reducing gold on the interface.

The self-assembly dynamics of our two-dimensionally confined organic films defines the composite nanostructure. Mimicking biology, highly organized templates lead to polycrystallinity, and sparse films lead to large single crystals, but films on the phase envelope lead to complex composites.

We have developed new state of the art density matrix renormalization group (DMRG) and transport codes, which can deal with large electron systems with interaction. Right two figures represent some results we obtained with our collaborators.

On the right side, top panel shows our quantum phase diagram for Haldane honeycomb model with spin orbit interaction. It shows that using gate voltage V one can tune into quantum Hall effect (QAHE) by splitting quantum spin Hall effect (QSHE) for system without time reversal symmetry. Bottom panel shows the entanglement gap extrapolates to finite value at thermodynamic limit demonstrating topological order of the 5/2 system.

Electrical transport measurements on a suspended ultra-low-disorder graphene nanoribbon (GNR) with nearly atomically smooth edges have been carried out by Zhixian Zhou and co-workers at Wayne State University that reveal a high mobility exceeding 3000 cm2 V−1 s−1 and an intrinsic band gap.

In 2011, Gallaudet University joined the Howard, Hopkins Prince Georges Community College PREM.
Three Gallaudet students were mentored by Prof. Paul Sabila in summer research at Howard in Jason Matthews’ research group.
In addition to research, the students took part in nanotechnology training together with hearing students.
They were trained to use advanced instrumentation including electron and atomic force microscopes and lithographic equipment in the Howard Nanofabrication Facility together with their fellow hearing students.