Diffuse Reflectance Infrared Spectroscopy
Diffuse Reflectance Infrared Spectroscopy - Related Videos
10:31
Diffuse Reflectance Infrared Spectroscopic Identification of Dispersant/Particle Bonding Mechanisms in Functional Inks
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Cited by 11 •
2015
Formulation of stable, functional inks is critical to expanding the applications of additive manufacturing. In turn, knowledge of the mechanisms of dispersant/particle bonding is required for effective ink formulation. Diffuse Reflectance Fourier Transform Infrared Spectroscopy (DRIFTS) is presented as a simple, inexpensive way to gain insight into these mechanisms.
08:11
Infrared Spectroscopy
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2023
Source: Vy M. Dong and Zhiwei Chen, Department of Chemistry, University of California, Irvine, CA This experiment will demonstrate the use of infrared (IR) spectroscopy (also known as vibrational spectroscopy) to elucidate the identity of an unknown compound by identifying the functional group(s) present. IR spectra will be obtained on an IR spectrometer using the attenuated total reflection (ATR) sampling technique with a neat sample of the unknown.
06:50
Diffuse Reflectance Spectroscopy: Getting the Capillary Refill Test Under One's Thumb
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Cited by 4 •
2017
This protocol describes how the use of diffuse polarization spectroscopy can improve the clinical usefulness of the capillary refill test. We suggest a more detailed analysis of the course of the capillary refill in healthy volunteers using diffuse reflectance spectroscopy videos and new informatic endpoints.
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Attenuated Total Reflectance (ATR) Infrared Spectroscopy: Overview
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2024
Attenuated total reflectance (ATR) infrared spectroscopy is a powerful analytical technique used to study the composition of materials. It is widely employed in chemistry, materials science, forensic science, and other fields where sample characterization is required. ATR has several advantages over traditional transmission IR spectroscopy, including the requirement of little to no sample preparation and the ability to analyze a wide range of samples. The ATR process begins by directing a beam...
03:04
A Fourier Transform Infrared Spectroscopy Technique to Study Peptide Self-Assembly
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2025
This video demonstrates the self-assembly of amyloid peptides into a beta sheet-rich supramolecular structure using Fourier transform infrared spectroscopy. An infrared beam is passed through a crystal with a high refractive index, and energy absorption across the interface of the crystal and the sample is recorded. The secondary structures of the sample proteins are identified by analyzing their characteristic absorption peaks at specific regions of the infrared spectrum, which aids in...
FAQs
The measured signal results from infrared radiation entering the material, scattering through it, and being selectively absorbed by molecular vibrations. Wavelengths associated with particular absorptions are therefore altered in the diffusely reflected radiation. Interpreting these spectral changes allows chemists to associate observed features with chemical bonds and functional groups within the analyzed solid.
Powders and rough surfaces can be difficult to examine with conventional transmission measurements, which may require a suitable sample form for light to pass through. DRIFTS instead collects radiation returned from the sample after internal scattering and absorption. This makes the technique practical for heterogeneous solids whose physical form complicates transmission analysis.
Gas flow and temperature are important controllable conditions when DRIFTS monitors a surface reaction. Changing the gas environment can alter the chemical species interacting with the surface, while temperature changes can affect the reaction state. Recording spectra under controlled variations helps relate spectral changes to evolving chemistry at the material surface.
Spectral features are interpreted through the molecular vibrations that produce selective infrared absorption. Because different chemical bonds and functional groups absorb at characteristic wavelengths, changes in the spectrum can indicate changes in the material's chemical state. This makes the method useful for following chemical transformations rather than only identifying an initial solid.
A practical measurement begins with placing the powder, rough solid, or other suitable material so its surface can interact with incident infrared radiation. The instrument records the radiation diffusely reflected after penetration, scattering, and absorption within the sample. The resulting spectrum is then examined for absorption features linked to chemical bonds and functional groups.
Chemists may choose DRIFTS when the sample is a powder, rough solid, or another material for which transmission measurements are difficult. The technique requires little sample preparation and is minimally destructive, supporting rapid analysis without substantially altering the material. These practical advantages are especially relevant when the original solid form must be preserved.
DRIFTS is particularly relevant to heterogeneous catalysts, minerals, polymers, and pharmaceutical solids. In catalyst research, controlled gas flow and temperature allow surface reactions to be monitored, while analyses of minerals, polymers, and pharmaceutical solids use the spectral response to examine their chemical bonds and functional groups. Its broad utility comes from combining solid-state analysis with limited preparation.