Tseng Kuo-Hsiung, Lin Yur-Shan, Chang Chaur-Yang, Chung Meng-Yun
Department of Electrical Engineering, National Taipei University of Technology, Taipei 10608, Taiwan.
Nanomaterials (Basel). 2020 May 29;10(6):1044. doi: 10.3390/nano10061044.
This study developed a micro-electrical discharge machining (micro-EDM) system for producing TiO nanocolloids. When a proportional-integral-derivative controller designed using the Ziegler-Nichols method was adopted to control the interelectrode gap, TiO nanocolloids were obtained from spark discharges generated between two titanium wires immersed in deionized water. For a pulse on time-off time of 40-40 μs and a colloid production time of 100 min, TiO nanocolloids were produced that had an absorbance of 1.511 at a wavelength of 245 nm and a ζ potential of -47.2 mV. They had an average particle diameter of 137.2 nm, and 64.2% of particles were smaller than 91.28 nm. The minimum particles were spherical. The characteristics of colloids confirmed that the micro-EDM system can produce TiO nanocolloids with excellent suspension stability. The colloid production method proposed in this study has the advantages of low equipment cost and no dust diffusion in the process environment. These advantages can improve the competitiveness of the electric spark discharge method for high-quality TiO nanoparticle production. The colloids produced in this study did not contain elements other than titanium and oxygen, and they may prevent secondary environmental pollution.
本研究开发了一种用于生产TiO纳米胶体的微电火花加工（micro-EDM）系统。当采用基于齐格勒-尼科尔斯方法设计的比例积分微分控制器来控制电极间隙时，通过浸没在去离子水中的两根钛丝之间产生的火花放电获得了TiO纳米胶体。对于40 - 40 μs的脉冲导通时间-关断时间和100分钟的胶体生产时间，制备出的TiO纳米胶体在245 nm波长处的吸光度为1.511，ζ电位为-47.2 mV。它们的平均粒径为137.2 nm，64.2%的颗粒小于91.28 nm。最小的颗粒呈球形。胶体的特性证实了微电火花加工系统能够生产出具有优异悬浮稳定性的TiO纳米胶体。本研究提出的胶体生产方法具有设备成本低且加工环境中无粉尘扩散的优点。这些优点可以提高电火花放电法生产高质量TiO纳米颗粒的竞争力。本研究中制备的胶体除了钛和氧之外不含有其他元素，并且它们可能防止二次环境污染。
