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Updated: May 21, 2026

Interfacial Molecular-level Structures of Polymers and Biomacromolecules Revealed via Sum Frequency Generation Vibrational Spectroscopy
Published on: August 13, 2019
Quantifying weak intermolecular interactions at soft matter interfaces with sum frequency generation vibrational
Jing Lai1, Haowen Lu1, Shuji Ye2
1Hefei National Research Center for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui 230026, China.
Abstract:
Understanding weak interfacial interactions and their synergistic effects in soft matter is crucial for controlling physicochemical processes. However, detecting and quantifying these interactions remains challenging. This review highlights how sum frequency generation vibrational spectroscopy (SFG-VS) addresses this challenge through three primary approaches. First, we discuss methods based on vibrational peak frequencies and their applications. Second, we introduce techniques that utilize vibrational peak intensity ratios. Notably, measuring Fermi resonance signals can assess the overall weak interactions within a system, while analyzing intensity variations in the bend-libration combination bands of interfacial water molecules helps distinguish between changes in water-water and solute-water interactions. Finally, we examine femtosecond time-resolved infrared pump-probe techniques. In this approach, the relaxation rate of vibrational excitations-governed by the strength of intermolecular energy transfer-reveals both primary and secondary variations in different interactions. The review concludes by summarizing current challenges in characterizing weak interactions and outlining key directions for future research.
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