Dynamic properties of the polyethylene glycol molecules on the oscillating solid-liquid interface

► QCM is used for investigating the dynamic properties of the PEG molecules on the solid-liquid interface oscillating at MHz. ► The number-average molecular weights (Mn) of the PEG molecules are systematically varied over 4 orders of magnitude. ► The value of ΔF slope against Mn indicates the Debye process. ► The resonant length of the PEG molecule moving with the oscillating plate of 9 MHz is estimated at 54.2 Å.