Sonochemical degradation of various lubricating oils investigated using terahertz time-domain spectroscopy

Magnetic field induced reduction of intermolecular force between the normal alkanes

“…1(d), along with a nearly linear fit and nearly B-independent. These results can be understood by using the well-known Lorentz-Lorentz formula, which relates the refractive index of a liquid to its carbon number [12]. Following Scaife, the refractive index for a given chain length should contain two contributions, such as methylene groups and the two methy end-groups.…”

“…The vibrational modes of C5H12-C10H22 are composed of three types in the 0.2-5.5 THz region, namely, skeleton vibration of carbon-carbon (C-C) chain in the yoz plane, swing vibration of C-C chain in the xoy plane, and torsional vibration of methyl group along the y axis [13]. Previously, the absorption peak at 2.2 THz has been obtained in the THz-TDS of n-paraffin crystals (C19H40, C27H56, C29H60, C30H62, and C36H74), liquid paraffin, lube base oils, lubricating oils and many other substances [10][11][12][14][15][16]. Thus, based on these literatures, the recorded 2.2 THz assigned to the B1u mode, corresponds to the intermolecular interaction between the parallel alkane molecules [10,17].…”

“…Terahertz time-domain spectroscopy (THz-TDS) has recently received great attention with the expectation that it will provide new insights into complex polymer systems (such as order-disorder transition of nonadecane, higher order conformation, assignment of intermolecular vibration modes and structural characterization, characterizing polymorphism and crystal transformation of polylactide, etc. ), and several relevant studies have been reported [10][11][12]. In this paper, the magnetic field dependence of the THz optical properties are experimentally characterized using THz-TDS.…”