Researchers at the University of Huddersfield have combined differential scanning calorimetry (DSC) with thermomicroscopy to reveal detailed energy changes in specific materials.
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In this first-ever study that uses DSC thermomicroscopy to exploit the benefits of simultaneously analyzing rubidium nitrate and polyethylene oxidation using both methods, researchers from the Thermal Methods Research Unit (TMRU ) from the University of Huddersfield used the Optical
Linkam Scientific Instruments’ DSC450 system for obtaining detailed information on the properties of a wide range of materials, including industrial polymers and pharmaceuticals.
Polymers play a vital role in saving energy and resources in applications such as healthcare, pharmaceuticals and the production of packaging materials, and current research strongly emphasizes their potential. to support renewable energy technologies. As the pharmaceutical industry comes under increasing pressure to bring new drugs to market quickly and affordably, managing a successful launch program is becoming increasingly difficult, and the industry must continue to find new ways to optimize the drug discovery and development process.
Thermal analysis methods such as thermomicroscopy allow researchers to closely observe optical and physical transitions as a material progresses through a reaction or phase change, ultimately enabling optimization of materials. in their end use. Coupling thermomicroscopy with DSC adds the ability to measure energy changes during the reaction simultaneously, on the same sample.
Research at TMRU used a Linkam heat flux DSC plate embedded in a hot stage, combined with a T96 temperature controller to study phase transitions in the oxidation of rubidium nitrate and polyethylene over a temperature range of – 150 to 450°C. The results demonstrated the advantages of obtaining simultaneous optical data – both images and light intensity measurements – with DSC, allowing the detection of small enthalpy changes.
Figure 1: Analysis of rubidium nitrate using the DSC450 (Linkam Scientific). Differential scanning calorimetry (DSC) (bottom) and region of interest (ROI) (top) intensity profiles are plotted against temperature. Selected micrographs (labeled a, b) are linked to DSC and ROI profiles. Reproduced from reference 1 under the Creative Commons Attribution 4.0 License http://creativecommons.org/licenses/by/4.0/.
Figure 2: Oxidative induction test in progress on a sample of ultra-high molecular weight polyethylene (UHMWPE). The DSC profile (blue solid line) and the temperature program (red dashed line) were plotted against time. The vertical line indicates when the gas changes from N2 to air. Selected micrographs (labeled t0 and a–c) are linked to the DSC profile. Reproduced from reference 1 under the Creative Commons Attribution 4.0 License. http://creativecommons.org/licenses/by/4.0/.
Duncan Stacey, Director of Sales and Marketing, Linkam Scientific Instruments commented: “We are only at the beginning of discovering the potential of DSC combined with thermomicroscopy. Recent developments in high-quality digital microscopes and improved computing power open up new and exciting potential for the in-depth study, via this method,
of materials that are used in our daily lives. By observing phase changes such as solid-solid transitions, fusion reactions and decomposition, we can discover new ways to improve the performance and energy profile of materials in application.
Dr Gareth Parkes, Reader in Forensic and Analytical Chemistry at TMRU, added: “Understanding how materials behave under different conditions and at carefully controlled temperatures helps to optimize their use in different applications. Simultaneous thermal analysis sheds new light on the complex thermal processes of certain materials because the optical image allows the interpretation of often complex DSC profiles thanks to the possibility of obtaining optical and enthalpy information on a single sample.iv
“The precise temperature control of the Linkam DSC450, especially at low temperatures, proved to be an excellent tool in our research. We are now moving forward to determine if the DSC450 can support studying the thermal conductivity of a material by optical means, which opens up exciting new research potential.