Related Experiment Video
Updated: Jul 6, 2026

Raman and IR Spectroelectrochemical Methods as Tools to Analyze Conjugated Organic Compounds
Published on: October 12, 2018
Conformational Structure of Triblock Copolymers by FT-Raman and FTIR Spectroscopy
1Young Scientist Laboratory of Separation Science and Engineering, Institute of Chemical Metallurgy, Academia Sinica, Beijing, 100080, China
Abstract:
Fourier transform Raman (FT-Raman) and Fourier transform infrared (FTIR) spectra of poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) (PEO-PPO-PEO) triblock copolymers as pure solids or liquids and in aqueous solutions have been examined. The qualitative features in Raman and FTIR spectra of these copolymers have been presented. The Raman and FTIR spectra of PEO-PPO-PEO triblock copolymers are very sensitive to the structural and conformational changes. It shows that the relative intensities of several peaks in Raman spectra are dependent on the PPO/PEO ratios and the conformation of the copolymers. From Raman and FTIR spectra, Pluronic F68 and F88 assume helical structures with a few trans conformers. Other block copolymers exhibit that the disordered structure increases with increasing PPO/PEO ratio. Comparison of Raman spectra of PEO-PPO-PEO triblock copolymers as pure solids or liquids with those in aqueous solutions has been presented. Copyright 1999 Academic Press.
Related Concept Videos
¹H NMR of Conformationally Flexible Molecules: Temporal Resolution
UV–Vis Spectroscopy of Conjugated Systems
One of the factors influencing λmax is the extent of conjugation in the...
¹H NMR of Conformationally Flexible Molecules: Variable-Temperature NMR
IR Frequency Region: Fingerprint Region
The...
Raman Spectroscopy: Overview
However, a small fraction of the scattered light exhibits a frequency shift due to the exchange of energy between the incident photons and the...
Raman Spectroscopy Instrumentation: Overview
The monochromatic laser source, typically using visible or near-infrared radiation, generates a highly focused beam of light. This light interacts with the molecules of the sample, scattering some of the light. Liquid and gaseous samples are usually tested in ordinary glass capillaries, while solids can be analyzed as powders packed in capillaries or as potassium...

