Khabarov Kirill, Nouraldeen Messan, Tikhonov Sergei, Lizunova Anna, Efimov Alexey, Ivanov Victor
Moscow Institute of Physics and Technology, National Research University, 141701 Dolgoprudny, Russia.
Lebedev Physical Institute, Russian Academy of Sciences, 119991 Moscow, Russia.
Nanomaterials (Basel). 2021 Oct 13;11(10):2701. doi: 10.3390/nano11102701.
This study investigates the processes of interaction of nanosecond pulsed-periodic laser radiation with the flow of aerosol agglomerates of gold nanoparticles synthesized in a spark discharge. Nanoparticles in a gas flow are spatially separated nano-objects whose interaction with each other and with the walls of an experimental cell was insignificant. Therefore, the energy absorbed by nanoparticles was used only for their own heating with further shape and size modification and on heat transfer to the surrounding gas. In the research, we used laser radiation with wavelengths of 527 and 1053 nm at pulse energies up to 900 µJ and pulse repetition rates up to 500 Hz. The dynamics of changes in the nanoparticles size during their sintering process depending on the laser pulses energy is characterized by an S-shaped shrinkage curve. Complete sintering of the initial agglomerates with their transformation into spherical nanoparticles is achieved by a series of impacting laser pulses. The result of nanoparticles' laser modification is largely determined by the pulse energy and the efficiency of the nanoparticles' radiation absorption.
本研究调查了纳秒脉冲周期激光辐射与在火花放电中合成的金纳米颗粒气溶胶团聚体流的相互作用过程。气流中的纳米颗粒是空间分离的纳米物体，它们彼此之间以及与实验腔室壁的相互作用微不足道。因此，纳米颗粒吸收的能量仅用于自身加热，进而改变形状和尺寸，并将热量传递给周围气体。在该研究中，我们使用了波长为527和1053 nm的激光辐射，脉冲能量高达900 µJ，脉冲重复频率高达500 Hz。纳米颗粒在烧结过程中尺寸变化的动力学取决于激光脉冲能量，其特征为S形收缩曲线。通过一系列冲击激光脉冲可实现初始团聚体的完全烧结，并将其转变为球形纳米颗粒。纳米颗粒的激光改性结果在很大程度上取决于脉冲能量和纳米颗粒的辐射吸收效率。
