MVC 3 Awards Gallery

“TiO2 PARTICLES“

Payam Khodaparast, Graduate student, Materials Science and Engineering 

Scientific Process: The sample is an in-situ TiO2/Polystyrene composite made by polycondenstation reaction of TiO2 precurser (TiBuO4) and water in Polystyrene solution in 60°C. After TiO2 particles are made in polymer solution, the solution is casted into a film and dried. The image is taken from the fractured surface of the film after breaking it in liquid nitrogen. The image clearly shows the advantage of in-situ technique in achieving individual dispersion of TiO2 particles in the matrix. By controlling reaction parameters like PH and temperature, size of the individual particles can be changed from micron to nanomaters. In this sample weak interfacial interaction between TiO2 particles and Polystyrene matrix is the reason of separation of some particles from the matrix at the time of fracture and the resulting holes left from places, particles have been located before. TiO2 in particle shape can be used to improve dielectric properties of polymeric matrices.

FIRST PLACE

“MAGNETITE PARTICLE“

Eric Fitterling, Undergraduate Student, Materials Science and Engineering 

Scientific Process: This image was taken using an ESEM and was part of my undergraduate senior thesis research. The particle is composed mostly of magnetite with a smaller amount of wüstite and hematite present. It was produced from an iron oxide melt, solidified using a melt-atomization technique. Inside of many of the large pores, there were triangular growths indicative of the {111} close pack oxygen plane that is present in the spinel crystal lattice. Small lobes are visible all around these growths and growing off of them. It is presumed that the triangular growths extend into the solid part of the proppant and are the primary arms of dendrites. The lobes are believed to be secondary dendritic arms that grow off of the primary triangular growths. This indicates that supercooling occurred at the pore interface during solidification and thus, the dendrites grew into the pore.

SECOND PLACE

“B4C NANOWIRES’“

Melisa Steighner, Graduate Student, Materials Science and Engineering

Scientific Process: Theoretical predictions of boron and boron-based nanofilaments reveal unique physical and mechanical properties. The B4C nanowires in this image were fabricated through chemical vapor deposition (CVD) inducing a vapor-liquid-solid (VLS) growth mechanism from a powder mixture of Ni, NO3, B, and C placed inside an alumina boat in a furnace at 1100oC. The nanowires were found on the TEM to be single crystalline with diameters less than 50 nm. In the near future, tensile experiments utilizing Raman spectroscopy will be carried out on these nanowires in order to fully understand their mechanical properties.

THIRD PLACE

“S-RADEL POLYMER“

Timothy Tighe, Post Doc, Materials Science and Engineering 

Scientific Process: A commercially available Radel polymer was sulfonated (S-Radel) and cast into a thin membrane for evaluation in a vanadium redox flow battery (VRFB). The S-Radel membranes exhibited good battery performance up to 40 cycles, and then steadily declined. SEM, along with chemical analysis of the membrane, was conducted to better understand the changes occurring in the membrane during battery operation. This is an image after 50 cycles in the VRFB in an area where a piece of the surface had peeled back exposing the interior membrane.

FIRST PLACE

“MEMS DEVICE“

Flavio Griggio, Graduate Student, Materials Science and Engineering

Scientific Process: The image shows the stack of several materials on a silicon wafer. Different colors were used to represent different materials. PbZr0.52Ti0.48O3 (PZT) as the active piezoelectric layer is the amaranth layer with the typical columnar structure of thin films deposited via sol-gel method. The blue layers are relative to the Pt layers used for electrical contacts. The thin light bright yellow layer is the TiOx layer used to promote adhesion between the Pt and SiO2 (saturated orange) layer. The amber layer is the Si wafer. Specifically, the image shows the results of the isotropic etch of the Si wafer to partially release the PZT film from the substrate. These devices were fabricated to be tested under-water, as a new prototype MEMS based ultrasound transducer array with a diaphragm resonating geometry. 

SECOND PLACE

“PZT CRYSTAL“

Stephen Poterala, Graduate Student, Materials Science and Engineering 

Scientific Process: Well dispersed, uniform PZT powders are useful as templates for the production of textured PZT ceramics. Well-formed, 1-2 μm crystals are the most desirable, and can be grown by dissolution-precipitation from (Na,K)Cl, KF, or PbO-based fluxes. Larger PZT crystals, such as this one, are a byproduct of this process – they result from excessive evaporation of the flux during long growth cycles. This crystal measures 60 x 70 x 100 μm, and was grown from a KF-based flux. 

THIRD PLACE

“ND:YAG Q-SWITCHED LASER“

Benjamin Hall, Undergraduate Student, Energy Engineering/Laser-Materials Interaction

Scientific Process: The high peak power of the Q-switched laser’s 40ns pulses ablates the aluminum with only minor thermal effects. Quickly scanning the 355nm beam across the surface of the foil induces a thermal gradient from the surface to the base of the material. Because of aluminum’s high coefficient of thermal expansion, the irradiated path tries to expand but cannot because the material below it is still cool. The resultant compressive force exceeds the aluminum’s yield strength and causes plastic deformation. As it cools it contracts, bending upwards.