To understand the mechanism of surface processing using atmospheric-pressure non-equilibrium plasma jets, we measured the vibrational and rotational temperatures in the plasmas by optical emission spectroscopy. Plasma was excited using a high-frequency pulsed power supply, using a gas mixture of Ar (20 L⁄min) and N2 (0.1 to 0.5 L⁄min) as the plasma gas, and changing the flow rate of N2 gas at an input power of 100 W and plasma frequencies of 5 and 10 kHz. The measured vibrational and rotational temperatures in plasma were approximately 0.18 to 0.26 eV and 0.21 to 0.28 eV, respectively. We also carried out a plasma surface processing of polyethylene naphthalate film to measure the changes in water contact angle before and after the processing. We found a monotonic decrease in the contact angle of the processed polyethylene naphthalate film as plasma rotational temperature increased. It is concluded that the hydrophilicity of the polyethylene naphthalate surface increases with plasma rotational temperature.
Structural analysis of high density Deuterium absorbed Pd particles of 5 nm size dispersed in ZrO2 has been carried out using XAFS (X-ray Absorption Fine Structure) techniques. X-ray absorption spectra around the Pd K-absorption edge were observed and absorption edge were observed and K analyzed. The Pd-Pd bonding distance in the free Pd lattice of the 5nm cluster was enlarged by 0.08 - 0.09 Å during absorption of deuterium, and it completely reverted to its original state with the release of deuterium while maintaining the crystal lattice symmetry. These changes provided evidence that deuterium locates not on the surface of the Pd particle, but rather within the Pd crystal lattice. XANES (X-ray Absorption Near Edge Structure) spectra clearly indicated that the valency of Pd atom did not change on absorbing Deuterium atoms, resulting in no reaction of the absorbed Deuterium atoms with Pd atoms. The hydrogen dispersion mechanism was also discussed quantum-mechanically through electron-lattice interaction, and the possible models of deuterium position in the Pd lattice were also discussed. The 5nm-cluster of Pd was not supported by any oxygen or zirconium ion in ZrO2, but the cluster floated in hole by the repulsion of each electron of Pd and ZrO2. Finally, a new approach to seek after the Deuterium position from X-ray absorption spectra is proposed.