Nonphotochemical Laser-Induced Nucleation of Potassium Halides: Effects of Wavelength and Temperature
Nonphotochemical Laser-Induced Nucleation of Potassium Halides: Effects of Wavelength and Temperature
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DOI：
10.1021/cg300750c
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发表时间：
2012-09
影响因子：
3.8
通讯作者：
M. R. Ward;A. Alexander
中科院分区：
文献类型：
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作者：
M. R. Ward;A. Alexander
用波长为532和1064 nm的纳秒激光脉冲研究了KCl和KBr的非光化学激光诱导成核（NPLIN）。成核的样品的数量与用激光照射的数量的比率（f）遵循对峰值功率密度的非线性依赖性，其在较高的入射功率下接近f = 1，我们用泊松函数拟合。成核样品所需的阈值功率在532 nm处比在1064 nm处低，并且我们观察到当暴露于给定激光功率下的532 nm脉冲时，更高比例的样品成核。与KCl相比，我们看到KBr样品在两个波长下成核的分数较高，阈值较低。在两个不同温度（23和33 °C）下用1064 nm脉冲射击的相等过饱和度的KCl样品显示，33 °C样品明显更不稳定成核。在33 °C下成核的样品与在23 °C下成核的样品的比率为2.11 ± 0.47。一个经典的成核模型的基础上激活的亚临界…
Nonphotochemical laser-induced nucleation (NPLIN) of KCl and KBr has been studied using nanosecond laser pulses with wavelengths of 532 and 1064 nm. The ratio of the number of samples nucleated to the number irradiated with the laser (f) follows a nonlinear dependence on peak power density that approaches f = 1 at higher incident powers, which we fit with a Poisson function. The threshold power required to nucleate samples is lower at 532 than at 1064 nm, and we observe that a higher fraction of samples nucleate when exposed to 532 nm pulses at a given laser power. In comparison to KCl, we see higher fractions of KBr samples nucleate and lower threshold values at both wavelengths. Samples of KCl of equal supersaturation at two different temperatures (23 and 33 °C) shot with 1064 nm pulses show that the 33 °C samples are significantly more labile to nucleation. The ratio of samples nucleated at 33 °C compared to those at 23 °C was 2.11 ± 0.47. A classical nucleation model based on activation of subcritical...