ts a hectic early spring day at the Advanced Analysis Facility on the UWM campus. Director Andrei Skliarov is to depart the next day for a trip to his native Russia, and he and researcher Steven Hardcastle are scrambling to identify trace components in a sample brought in by an industrial client. To solve the mystery, Skliarov dashes around a large room, between a scanning electron microscope, a Fourier Transform Infrared spectrometer, a light microscope, and several computer monitors, all the while discussing possibilities in his thick Russian accent, talking half to the client and half to himself.
Unlike other facilities in Wisconsin, which focus on specific areas, the AAF houses a broad spectrum of analytical tools, providing the flexibility to answer a wide variety of questions in materials analysis, trace components analysis, and molecular structure analysis.
Its never one-layer polymer layers, Skliarov says. Its very complex structure: sometimes two, three, five layers that have different propertiesoptical and electrical properties.
Another example they mention is touchscreen technology, which is seen in industrial and financial applications, as well as video games. Very tricky technology involved, Skliarov says. When you hear what they do, you get amazed.
Prominent area businesses the AAF has worked for include label and signage manufacturer Brady Corporation, engine manufacturer Briggs & Stratton, automotive and facility management control designer Johnson Controls, SC Johnson, Miller Brewing, Aldridge Chemical, Benz Oil, Oshkosh Truck, and many others.
Skliarov and Hardcastle generally work in the material sciencesphysics, chemistry, materialsbut have found themselves exploring other areas as well.
We do not limit ourselves, Skliarov says. Were pushed by other people to use our knowledge in physics and chemistry, physical chemistry, and chemical physics.
A lot of times, Hardcastle chimes in, we ourselves arent sure what technique is the best to get answers. So we look at different techniques until we find out specifically how to solve the customers problem.
The AAF is also a critical resource for campus researchers. In the past, the facilities have offered internship opportunities for students, and current users include materials professors Carolyn Aita, Tery Barr, Lian Li, and Pradeep Rohatgi; Associate Professor Vladislav Yakovlev and Professor Prasenjit Guptasarma in physics; and professors Dennis Bennett and Wilfred Tysoe in chemistry.
AAF materials analysis instruments
Electron Spectroscopy for Chemical Analysis (ESCA) or X-Ray Photoelectron Spectroscopy
Sample is irradiated with a mono-energetic X-ray beam, causing photoelectrons to be emitted from the sample. An energy analyzer determines the kinetic energy and thus binding energy of the emitted photoelectrons, from which the elemental identity, chemical state, and quantity of an element can be determined. Elemental and chemical information is collected from the top 0.5 to 1.0 nanometer of a surface. Information provided about surface layers or thin film structures is useful in different applications including: polymer modification, catalysis, corrosion, adhesion, semiconductors, electronics packaging, magnetic media, and thin film coatings.
Scanning Electron Microscopy (SEM)/Electron Probe (EP)
Gas Chromatography/Mass Spectrometry (GC/MS)
Combines the ability of gas chromatography (GC) to separate compounds from a complex mixture with the ability of mass spectroscopy (MS) to identify those compounds, and accurately determine the amounts present. Data is recorded by a computerized system that also analyzes the information obtained and controls the instruments. GC/MS is very sensitive, and can identify samples containing femtogram quantities of compounds. It can analyze a wide range of samples and can be used by entities such as environmental agencies, medical and forensic labs, and the control boards for athletics and horse racing.
Fourier Transform Infrared Spectroscopy/FTIR
Raman Microscopic Spectroscopy
Raman Spectroscopy also measures the molecular vibrations, but uses a different physical property than FTIR. Raman uses a laser (UV to Visible to IR wavelengths are possible) to excite a sample and then measures the shift in wavelengths (very small) as a result. Water does not give a Raman signal, wet samples and suspensions in water can be studied easily. In addition, inorganic samples can be studied with better results than FTIR. The lateral resolution in the case of Laser Raman Microscopy is mainly determined by the optical lenses used and can easily be less than 2 micrometers.