Related Experiment Video
Updated: Feb 4, 2026

UV-Vis Spectroscopic Characterization of Nanomaterials in Aqueous Media
Published on: October 25, 2021
Novel Rapid Screening of Basic Immobilized Amine Sorbent/Catalyst Water Stability by a UV/Vis/Cu2+ Technique
Walter Christopher Wilfong1, Brian W Kail1, Qiuming Wang2
1Functional Materials Development Division, AECOM/Department of Energy, 626 Cochrans Mill Rd., Pittsburgh, PA, 15236, USA.
Abstract:
Time-consuming thermogravimetric analysis (TGA) decomposition study is a typical practice to assess the stability of fresh and water-treated basic immobilized amine sorbents (BIAS)/catalysts. This work presents a faster and more precise spectroscopic UV/Vis/Cu2+ sorbent screening technique that quantifies aqueous amines washed from the BIAS by using UV-active amine/Cu2+ complexes. Six BIAS-based catalysts, containing different amine species and a crosslinker within silica, were treated with ultrapure water and then analyzed for their CO2 capture performance and amine leach resistance/stability by using TGA (catalysts, approximately 4 h) and UV/Vis/Cu2+ techniques (wash solution, few minutes). A comparative analysis revealed that directly quantifying washed amines with UV/Vis/Cu2+ is 9-127 times more precise than indirect testing of the sorbents by TGA. Similar trends in the H2 O stability profiles of the catalysts [organic content retained values (OCR)] were reported by both analysis methods, allowing UV/Vis/Cu2+ to replace TGA for quantifying unstable leached amines. The UV/Vis/Cu2+ OCR results could be used to predict the CO2 -capture stability profile of the sorbents, confirming the reliability of this technique to rapidly screen catalyst stability and performance.
Related Concept Videos
UV–Vis Spectrum
The UV–Vis spectrum of a molecule is the plot of its absorbance versus wavelength. The plot is drawn by taking molar...
UV–Vis Spectrometers
Basicity of Aliphatic Amines
To measure the basicity of amines, two conventions are generally used. The first defines Kb as the basicity constant for the deprotonation reaction of water by the amine, as presented in Figure 1. Conventionally, lower Kb indicates higher...
Basicity of Aromatic Amines
IR and UV–Vis Spectroscopy of Aldehydes and Ketones
IR and UV–Vis Spectroscopy of Carboxylic Acids
However, the stretching absorptions for the C=O bond vary depending on the structure of carboxylic acids. The C=O bond of the free carboxylic acids shows a higher stretching frequency, 1760 cm−1, while H-bonded carboxylic acids (dimers) exhibit stretching absorptions at a lower frequency,...

