AL
TGA-MS and related methods also help researchers study the processing of food waste. Scientists used TGA-FTIR and TGA-MS to analyze the pyrolysis—high-temperature breakdown—of chestnut shells, cherry stones, and grape seeds.2
“In order to make available
theoretical groundwork for biomass pyroly- sis, activation energies were calculated with the help of four different model-free kinetic methods,” these researchers wrote. “The re- sults are attributed to the complex reaction schemes which imply parallel, competitive, and complex reactions during pyrolysis.” The team used TGA-MS to study the volatile gases released during pyrolysis, and reported that “the main evolved gases were determined as H2
O, CO2 , and hydrocarbons such as CH4 and
temperature-dependent profiles of the species were obtained.”
Scientists use thermogravimetric analysis to explore the evolution of many processes, such as the curing of siloxane shown here in an argon atmosphere and a heating rate of 10 degrees Celsius per minute. (Image courtesy of EAG Laboratories.)
photonics, and medical devices. If the silox- ane isn’t cured properly, the device can fail. TGA-MS can provide information about curing kinetics and thermal degradation mechanisms that can help manufacturers improve the reli- ability of devices.
This analytical technology can also be used in developing batteries. In lithium-ion batteries, safety is a key concern, because they can leak or even explode. TGA-MS can reveal poten- tially problematic gases created if the battery decomposes under heat.
Many other materials can be studied with TGA-MS. Scientists used TGA-MS and other techniques to study how pre-ceramic poly- mers—polysilazane and polysiloxane—turn into ceramics.1
Mixers
Analog and digital mixers are available for test tube racks, vials, bottles, volumetric flasks and reactor blocks.
They noted that “thermally
induced decomposition of the pre-ceramic polymer is the critical step in the synthesis of polymer derived ceramics (PDCs) and accurate kinetic modeling is key to attaining a complete understanding of the underlying process and to attempt any behavior predictions.” Unravel- ing the kinetics, in this case, required TGA-MS and a numerical process that the scientists described as “a semiempirical deconvolution method based on the Frasier-Suzuki function.”
Recommended for sample preparation and QuEChERS method. Precise control of speed, time and pulsing is available on the digital system.
CONTACT US FOR A
FREE PRODUCT SHOWCASE
glascol.com
800-452-7265 (United States) 812-235-6167 (International) Evaporators
This FlexiVap instrument concentrates chemical and biochemical solutions at an affordable cost. It can now be fitted with our “NEW” Vacuum Manifold. Ideal for auto-sample vials and up to 50mL tubes. Heating up to 100°C.
Pyrolysis is used to decompose other materi- als, such as polyvinyl chloride (PVC). One study showed that adding electric arc–furnace dust reduced the activation energy to pyrolyze PVC
SAMPLE PREP TOOLS
AMERICAN LABORATORY
39
JUNE/JULY 2017
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