Molecular vibrational dynamics in polyvinyl alcohol studied by femtosecond coherent anti-stokes Raman spectroscopy

FTIR spectroscopy characterization and critical comparison of poly(vinyl)alcohol and natural hydroxyapatite derived from fish bone composite for bone-scaffold

“…PVA filament had complex molecular structure. The peak at 2940 𝑐𝑚 −1 representing asymmetric 𝐶𝐻 2 group had faster energy transfer due to shorter distance to its abundant neighboring molecules [19,20] PVA filament with higher peak intensity at this wavenumber suggested more asymmetric 𝐶𝐻 2 group present that formed complex structure in the matrix. PVA filament may be formulated to have rigid structure for 3DP application.…”

Coherent molecular vibrational dynamics of CH2 stretching modes in polyethylene studied by femtosecond-CARS

“…As we set the detection window at the Raman shift of 2850 cm −1 , the two decay components originate from the symmetric and anti‐symmetric CH 2 stretching modes. Based on our previous work on the time‐resolved CARS signals in PVA, where we found out the faster coherent relaxation of anti‐symmetric CH 2 stretching modes than that of the symmetric ones, we assign the fast and slow decay components in PE to the anti‐symmetric and symmetric CH 2 stretching modes, respectively. In addition, we remark that the CARS signal beats between the symmetric and anti‐symmetric modes with the frequency separation of 50 cm −1 are not detected in contrast to the measurements in PVA because, as shown later, the dephasing of the anti‐symmetric modes is so fast for the signal beats to be observed.…”

“…As we previously demonstrated in polyvinyl alcohol (PVA), fs‐CARS technique can measure an ultrafast relaxation of the coherent molecular vibrations in solid phase by the advent of stable and high‐power femtosecond laser system . We consider that the study on the coherent relaxation of molecular vibrations provides important information not only about the energy flow rate and pathways in solid phase, but also about the interaction of the molecular vibration modes to phonons and bath modes.…”

“…In addition, the vibrational motion and energy flow in diacetylene polymers have been probed by coherent anti‐Stokes Raman spectroscopy (CARS), where the analysis of CARS signals provided the time scale of molecular vibration, the nature of coupling to bath modes and dynamics of intermolecular vibrational energy redistribution in diacetylene polymer. The time‐resolved femtosecond CARS (fs‐CARS) technique has been widely utilized as a powerful tool for studying the vibrational dynamics of Raman modes in time domain since 1980s . It is recently applied in single‐molecule sensing by the combination with a plasmonic resonance of nanoparticles …”

Extreme-Pressure Superlubricity of Polymer Solution Enhanced with Hydrated Salt Ions

“…The peak in the range of 3100–3600 cm –1 is assigned to the vibration of O–H, and that in the range of 2800–3000 cm –1 represents the stretching vibration of C–H in PVA. , Furthermore, the peaks of C–O vibration (1099 cm –1 ) and C–C vibration (850 cm –1 ) are also obvious in the spectra. , Figure c shows the Raman spectra of solid PVA and the aqueous PVA/NaCl solution. Evidently, C–C (850 and 1464 cm –1 ), C–O (1104 cm –1 ), C–H (2880–2980 cm –1 ), and O–H (3200–3500 cm –1 ) Raman bands − appeared in the Raman spectrum of solid PVA powder. In the Raman spectrum of the aqueous PVA solution, however, the intensity of the C–C, C–O, and C–H bands is relatively lower, while the O–H band intensity increased compared to that of the solid PVA powder.…”