title: Effects of particle size on far infrared emission properties of tourmaline superfine powders.
abstract: Tourmaline superfine powders with different particle sizes were prepared by grinding, superfine ball milling, and high-speed centrifugation. The powders were characterized by scanning electron microscopy, X-ray diffraction, dynamic contact angle meter and tensiometry, and Fourier transform infrared spectrometry. The results show that tourmaline powders exhibit improved far infrared emission properties as the particle size decreases. The increased surface free energy and proportion of the polar component are considered to play an important role for their properties. The spontaneous polarization is increased, and the dipole moment of tourmaline is stimulated to a high energy level more easily for the chemical bond vibration, so that the energy is apt to emit by transition. In the range of 2000-500 cm(-1), the emissivity values of the samples with D50 size of 2.67 microm and 0.2 microm are 0.973 and 0.991, respectively.
authors.affiliation: Institute of Power Source and Ecomaterials Science, Hebei University of Technology, Box 1055 Tianjin 300130, China.
authors.forename: Junping
authors.initials: J
authors.lastname: Meng
authors.forename: Wei
authors.initials: W
authors.lastname: Jin
authors.forename: Jinsheng
authors.initials: J
authors.lastname: Liang
authors.forename: Yan
authors.initials: Y
authors.lastname: Ding
authors.forename: Kun
authors.initials: K
authors.lastname: Gan
authors.forename: Youde
authors.initials: Y
authors.lastname: Yuan