Nucleation dynamics around single microabsorbers in water heated by nanosecond laser irradiation
Nucleation dynamics around single microabsorbers in water heated by nanosecond laser irradiation
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DOI：
10.1063/1.2740348
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发表时间：
2007-06-01
影响因子：
3.2
通讯作者：
Brinkmann, Ralf
中科院分区：
文献类型：
--
作者：
Neumann, Joerg;Brinkmann, Ralf
含有微吸收剂和纳米吸收剂的悬浮液被短激光脉冲照射，用于医学、生物技术和其他领域的多种程序。气泡成核和动力学的详细知识是必不可少的，这是由热量从吸收器传递到周围的透明水引起的，这对于理解微观尺度上发生的潜在过程是必不可少的。在532 nm波长的激光脉冲照射下，我们研究了吸收微米级黑色素颗粒（视网膜色素上皮黑素体）周围的快速相变现象，包括温度、加热速率、压力产生、气泡成核和初始气泡生长。黑素体以10(10)K/s的速率加热。平均气泡成核温度为136℃。通过时间分辨显微镜观察初始气泡膨胀。气泡形成的膨胀速度范围从1.5倍阈值辐射下的10m /s到8.5倍阈值辐射下的85 m/s。膨胀速度在研究范围内随辐照量的增加几乎呈线性增加。(c) 2007年美国物理学会。
Suspensions containing micro- and nanoabsorbers, which are irradiated by short laser pulses, are used for a manifold of procedures in medicine, biotechnology, and other fields. Detailed knowledge of the bubble nucleation and dynamics, which is induced by the heat transfer from the absorber to the surrounding transparent water, is essential for understanding the underlying processes occurring on a microscopic scale. We investigated the rapid phase change phenomena including temperature, heating rates, pressure generation, bubble nucleation, and initial bubble growth around absorbing micron-sized melanin particles (retinal pigment epithelial melanosomes) during irradiation with 12 ns (full width at half maximum) laser pulses at a wavelength of 532 nm. The melanosomes were heated at rates in the order of 10(10) K/s. A mean bubble nucleation temperature of 136 degrees C was found. The initial bubble expansion was observed by time-resolved microscopy. The expansion velocities range from 10 m/s at 1.5-fold to 85 m/s at 8.5-fold threshold radiant exposure for bubble formation, respectively. The expansion velocity increases in the investigated range almost linearly with the applied radiant exposure. (c) 2007 American Institute of Physics.