Jen-taut Yeh,1, 2,* Wei Wei1,
Han-hsing Hsiung 2and
Tao Jiang1
2 Graduate
Taipei, Taiwan
E-mail: jyeh@tx.ntust.edu.tw
Abstract
The releasing properties of negative air ions of tourmaline contained polypropylene (PP) composite films under varying testing conditions were investigated in this study. It is interesting to note that the average concentrations of negative air ions (Cion-) emitted from PP/tourmaline film specimens tested at varying conditions reach a maximum value as the tourmaline contents present in PP/tourmaline film specimens (i.e. PPc5 specimen) approach the 5 wt% optimum value. A beneficial temperature effect on conductivity and Cion- values of the tourmaline contained water solutions and PP/tourmaline specimens were found, respectively. Moreover, all Cion- values of PP/tourmaline film specimens tested at dynamic impact mode are significantly higher than those of the corresponding specimens tested at static mode but the same temperature. In fact, the Cion- value of the PPc5 film specimens tested at 90°C and dynamic impact mode reaches about 300 particles / cc, which is about 10 times more than that of pure PP film specimen tested at 25°C and static mode. In order to understand these interesting negative air ion properties of PP/tourmaline film specimens, wide angle X-ray diffraction, energy dispersive X-rays analysis of the tourmaline powders and SEM morphology analysis of the PP/tourmaline film specimens were performed. Possible reasons to account for the interesting negative air ion properties of the PP/tourmaline film specimens are discussed.