光子学报, 2016, 45 (4): 0414001, 网络出版: 2016-05-11
膨胀石墨制备及其1.064 μm激光消光性能
Preparation and Extinction Behaviour of Expanded Graphite to 1.064 Micrometer Laser
膨胀石墨 消光 激光 两步氧化插层法 膨胀体积 微观形貌 Expanded graphite Extinction Laser Two-step chemical intercalation Expanding volume Micro morphology
摘要
基于两步氧化插层先驱体法制备了不同膨胀体积的膨胀石墨,分析了先驱体、膨胀石墨的微观结构和微观形貌;利用静态测试系统测试了膨胀石墨对1.064 μm激光的消光行为,据此计算了其对1.064 μm激光的质量消光系数,得到了该系数与膨胀体积的依赖关系,并从消光机理进行了原因分析。结果表明:通过控制和优化先驱体合成条件,可以制得膨胀体积高达600 mL·g-1的膨胀石墨;两步插层导致先驱体的层间距(d002)明显大于天然石墨,当其d002从0.359 0 nm 增至0.371 1 nm时,所得膨胀石墨的膨胀体积从267 mL·g-1增至600 mL·g-1;膨胀石墨平均质量消光系数与膨胀体积呈近似线性关系,当膨胀体积由233 mL·g-1增至600 mL·g-1时,该系数从0.20 m2·g-1升至0.48 m2·g-1;膨胀石墨对1.064 μm激光呈非选择性散射,膨胀体积大,导致几何面积大,对1.064 μm激光的散射能力增强;同时,膨胀石墨中出现了更深的孔隙或孔腔,可作为等效黑体增强对入射激光的吸收.
Abstract
A series of Expanded Graphite (EG) with different Expanding Volume (EV) were prepared by the two-step chemical intercalation, and the microstructures and morphologies of the EG particles and their precursors were obtained by X-Ray Diffraction (XRD), Scanning Electron Microscope (SEM) and a stereoscopic microscope, respectively. The extinction behaviour of EG for 1.064 μm laser was measured by a static test, and then the average mass extinction coefficient was calculated and its dependence on EV was obtained and subsequently analyzed by the extinction theory. The results show that EG particles with different EV, especially with an EV of 600 mL·g-1, may be prepared by controlling the synthesis conditions of the precursors, namely graphite intercalation compounds. The average interlayer spacing (d002) of the precursor for EG becomes larger than that of Natural Graphite (NG) due to the two-step intercalation, and the EV of the EG whose precursor’s d002 rises from 0.3590nm up to 0.3711nm, increases from 267 mL·g-1 to 600 mL·g-1. The average mass extinction coefficient of EG depends near-linearly on its EV, and rises from 0.20 m2·g-1 up to 0.48 m2·g-1 while the EV increases from 233 mL·g-1 up to 600 mL·g-1 in the static test. The phenomenon of nonselective scattering occurs when an incident 1.064 μm laser reaches to EG particles, and then the larger is the surface area of an EG particle owing to a higher EV, the stronger is its scattering power to 1.064 μm laser. Meanwhile, much deeper pores and cavities appear with the EV increasing, and may work as equivalent black bodies to improve EG absorption of the incident laser.
李晓霞, 赵纪金, 马德跃, 郭宇翔. 膨胀石墨制备及其1.064 μm激光消光性能[J]. 光子学报, 2016, 45(4): 0414001. LI Xiao-xia, ZHAO Ji-jin, MA De-yue, GUO Yu-xiang. Preparation and Extinction Behaviour of Expanded Graphite to 1.064 Micrometer Laser[J]. ACTA PHOTONICA SINICA, 2016, 45(4): 0414001.