石墨/硝酸钾配比对其反应性光声特性的影响

Effect of reagent ratio of graphite to potassium nitrate on reactive photoacoustic characteristics

为了研究药剂配比对石墨/硝酸钾反应性光声特性的影响,采用动态光声测试技术和差示扫描量热技术进行了研究,在波长1.06μm、脉冲宽度为54μs的Nd∶YAG脉冲激光作用下,同一配比的石墨/硝酸钾体系中,激光能量越大光声信号越强;不同配比药剂在同一激光能量下光声强度不同。石墨/硝酸钾质量比为25/75(3#样品)时,光声信号最强;为30/70(4#样品)时,光声信号较弱。考察药剂达到光声信号峰值所用时间,发现同一样品随着激光能量增大都呈现先增大后减小的趋势。结果表明,C/KNO3的配比不同,化学反应不同,热分析结果与光声实验结果可以相互印证。

In order to study the effect of the pharmacy ratio of graphite to potassium on the reactive photoacoustic spectrum, the dynamic photoacoustic detection technology and differential scanning calorimetry （DSC）were used for analysis. When the samples were irradiated by an Nd： YAG pulse laser （wavelength of 1.06 μm, pulse width of 54μs） , the greater the laser energy, the stronger the photoaeoustic signal. The photoacoustic signal changed when the ratio of samples were different. The photoaeoustic signal became the strongest when the ratio of the sample （3# sample ） was 25/75, while the ratio was 30/70 （4# sample） , the photoacoustie signal was weak. After studying the time needed to achieve the photoacoustic signal peak, it found that when laser energy increased, the time first increased and then decreased. The results show that the different proportion of C and KNO3 arousing different chemical reaction. Thermal analysis results conform to the photoacoustic experimental results.