Webinar: Zooming in on the surface — with FTIR

Webinar: Zooming in on the surface — From molecular vibrations through microscopy to mastering material mysteries with FTIR Speaker: Nicodemus Kraufvelin 3rd of April, 2025

Highlights

00:10 The webinar focuses on FTIR microscopy, bridging molecular properties to real-world applications. This session aims to explore the utility of FTIR in material analysis and identification.

06:15 UV and IR spectroscopy differ fundamentally in their absorption mechanisms, with UV focusing on electronic transitions and IR on vibrational states. This distinction leads to different energy levels and wavelengths in each technique.

• The electronic transitions in UV spectroscopy involve moving electrons to a higher energy state, resulting in distinct absorption patterns. This contrasts with the vibrational transitions seen in IR spectroscopy.

-Different measuring modes, such as reflectance and transmittance, are crucial for practical applications in spectroscopy. Reflectance measurements can be particularly useful for sticky or rapidly polymerizing samples. -Attenuated total reflectance (ATR) is a common method in FTIR spectroscopy, allowing sensitive measurements without direct contact.

The technique benefits from multiple reflections enhancing absorption detection.

12:19 Various instruments used for material analysis, focusing on ATR and FDIR spectroscopy. It highlights differences between basic and advanced models, emphasizing their modular capabilities and applications. -The significance of signal strength and absorption in material analysis through spectroscopy is emphasized. Understanding these concepts is crucial for accurate measurements.

-The instruments featured include a basic ATR instrument and an advanced FDIR microscopy system. The latter is highlighted for its versatility in conducting various measurement types. -A demonstration showcases the measurement process, including focusing on a sample and obtaining spectra. This practical application illustrates how to analyze materials effectively.

18:22 The analysis reveals that a shirt contains a blend of cotton and polyester, not pure cotton as initially assumed.

28:09 The analysis of epoxy polymerization shows that after 24 hours, nearly all epoxy rings open, indicating near-completion of the reaction. This data is crucial for understanding the curing process in practical applications.

30:29 The discussion highlights the analysis of weathered versus non-weathered samples using FTIR spectroscopy, focusing on oxidation effects and data interpretation. It emphasizes the importance of accurate measurement techniques for reliable results.

36:35 The cross-section of painted wood in epoxy resin provides a sustainable method for sample preparation in FTIR analysis. This technique allows for easier measurement of complex materials by layering components effectively.

42:40 FTIR mapping is a valuable technique for obtaining molecular information from samples, though it presents challenges due to the need for physical contact with the sample. Proper baseline correction is crucial to avoid misleading results like topographical maps instead of molecular insights. -The importance of sample reflectance is emphasized, as certain operating modes require the sample to be reflective or on a reflective surface for accurate measurements.

This requirement can limit the types of samples that can be analyzed effectively. -Challenges in FTIR mapping include potential issues from sample contact, which can complicate baseline drawing and lead to inaccurate molecular interpretations. Correct baseline adjustments are essential for obtaining reliable data.

-Different methods of dimensionality reduction can enhance the analysis of FTIR data, such as using average absorbance or peak ratios to distinguish materials. These methods provide alternatives to single wave number analysis for more complex samples.

48:45 Principal component analysis is crucial in analyzing samples, particularly in understanding the relationship of components to topographical features. Awareness of potential pitfalls can enhance the accuracy of results. -Using mapping techniques can significantly improve the insights gained from data analysis in various fields, including materials science and environmental studies.

Proper initial processing is essential. -FTIR microscopy offers quick and versatile analysis capabilities, allowing for detailed examination of materials at a microscopic level. It reveals spatial variations in sample composition effectively. -Combining FTIR with other analytical techniques, like mass spectrometry, enhances the ability to identify functional groups and characterize materials accurately.

This synergistic approach improves overall analysis.

54:48 The webinar concluded with appreciation for the attendees' participation and an invitation for feedback through a form and QR code. Future webinars are anticipated after the summer, encouraging continued engagement.