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Materials Characterization

Density

Micromeritics Accupyc II 1340

Helium pycnometry measures true (absolute) and skeletal (apparent) volume and density.  

These terms are defined as follows:

Faculty Experts: 
Bazilevskaya, Katya

Mercury Porosimetry

Mercury porosimetry is used to measure the porosity of a material by applying controlled pressure to a sample immersed in mercury.  External pressure is required for mercury to penetrate into the pores of a material due to high contact angle of mercury.  The amount of pressure required to intrude into the pores is inversely proportional to the size of the pores.  The larger the pore the smaller the pressure needed to penetrate into the pore.  The mercury porosimeter generates volume and pore size distributions from the pressure versus intrusion data generated by the instrument using the Was

Faculty Experts: 
Anderson, Julie

Zeta Potential

Description

The zeta potential of the sample will determine whether the particles within a liquid will tend to flocculate (stick together) or not.

Electrophoretic Light Scattering (ELS) is a technique used to measure the electrophoretic mobility of particles in dispersion, or molecules in solution. This mobility is often converted to Zeta potential to enable comparison of materials under different experimental conditions. The fundamental physical principle is that of electrophoresis.

Faculty Experts: 
Bazilevskaya, Katya

X-Ray Scattering

X-ray Scattering

Faculty Experts: 
Wonderling, Nichole
Jones, Beth

X-Ray Photoelectron Spectroscopy (XPS/ESCA)

This technique is based on the Photoelectric Effect. When a material is irradiated with x-rays, photoelectrons are subsequently ejected from atoms in the near surface. The kinetic energy of an emitted photoelectron is equal to the difference between the photon energy, and the binding energy of the electron (K.E. = hν - B.E.). The technique is inherently surface sensitive because the x-ray energy is low (<1,500 eV). The majority of the signal detected originates from the outer 1-10 nm of a sample.

Faculty Experts: 
Shallenberger, Jeff
Bojan, Vincent

Ultraviolet-Visible Spectroscopy (UV-Vis-NIR)

Measurements in the ultraviolet/visible region (UV-VIS) cover wavelengths from about 200 nm to 800 nm. The absorption of ultraviolet or visible radiation by a molecule leads to transitions among the electronic energy levels of the molecule. It is ideal for characterizing the optical and electronic properties of various materials such as: films, powders, monolithic solids, and liquids.

Faculty Experts: 
Stapleton, Joshua

Time of Flight Secondary Ion Mass Spectrometry

TOF-SIMS

Time of Flight Secondary Ion Mass Spectrometry (TOF-SIMS) is a surface characterization technique which is based upon the liberation and identification of ions that are sputtered from a sample’s surface. This method is extremely surface sensitive since most of the liberated material comes from the top-most surface layers, yet it also has the capability to selectively etch away material and perform in-depth analysis. The data provide molecular and elemental information about the sample.

Faculty Experts: 
Bojan, Vincent

Thermal Analysis

Thermogravimetric Analysis (TGA)

Thermogravimetric Analysis (TGA) measures changes in weight of a sample with increasing temperature. Measurements are used primarily to determine the composition of materials and to predict their thermal and oxidative stability. Also the technique is used to estimate the lifetime of a product, decomposition kinetics, moisture/volatile content, melting point, glass transition, heat capacity, crystallinity and purity.

Faculty Experts: 
Bazilevskaya, Katya

Transmission Electron Microscopy (TEM)

In a transmission electron microscope (TEM), a thin specimen (ideally ≤ 100 nm) is exposed to a high-energy (typically 60 - 300 keV) electron beam. Images generally contain contrast that may be due to crystallinity, atomic mass, or thickness variations within the sample. Crystallographic information can also be obtained from diffraction patterns. We can also collect elemental and chemical state maps via analysis of 1) emitted x-rays (Energy Dispersive Spectroscopy – EDS) or 2) the energy loss of electrons that have gone through the specimen (Electron Energy Loss Spectroscopy – EELS).

Faculty Experts: 
Grey, Jennifer
Wang, Ke

Surface Area

Surface Area is helpful to determine how materials react to other materials, or how they dissolve or burn. In order to determine surface area a sample contained in a tube is pretreated by evacuation, including heat, vacuum and some flowing gas to remove contaminants from the surface. The material is then cooled to cryogenic temperatures. An adsorptive is added to the material at controlled pressure increments. After each dose of adsorptive, the pressure is equilibrated and the quantity adsorbed is calculated.

Faculty Experts: 
Bazilevskaya, Katya

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