Khabarov Kirill, Nouraldeen Messan, Tikhonov Sergei, Lizunova Anna, Seraya Olesya, Filalova Emiliia, Ivanov Victor
Moscow Institute of Physics and Technology, National Research University, 141701 Dolgoprudny, Russia.
Materials (Basel). 2021 Dec 29;15(1):227. doi: 10.3390/ma15010227.
In this paper, we investigated the interaction of nanosecond pulsed-periodic infrared (IR) laser radiation at a 50 and 500 Hz repetition rate with aerosol platinum (Pt) and silver (Ag) nanoparticles agglomerates obtained in a spark discharge. Results showed the complete transformation of Pt dendrite-like agglomerates with sizes of 300 nm into individual spherical nanoparticles directly in a gas flow under 1053 nm laser pulses with energy density 3.5 mJ/cm. Notably, the critical energy density required for this process depended on the size distribution and extinction of agglomerates nanoparticles. Based on the extinction cross-section spectra results, Ag nanoparticles exhibit a weaker extinction in the IR region in contrast to Pt, so they were not completely modified even under the pulses with energy density up to 12.7 mJ/cm. The obtained results for Ag and Pt laser sintering were compared with corresponding modification of gold (Au) nanoparticles studied in our previous work. Here we considered the sintering mechanisms for Ag, Pt and Au nanoparticles agglomerates in the aerosol phase and proposed the model of their laser sintering based on one-stage for Pt agglomerates and two-stage shrinkage processes for Au and Ag agglomerates.
在本文中，我们研究了重复频率为50Hz和500Hz的纳秒脉冲周期红外（IR）激光辐射与在火花放电中获得的气溶胶铂（Pt）和银（Ag）纳米颗粒团聚体之间的相互作用。结果表明，在能量密度为3.5mJ/cm的1053nm激光脉冲作用下，尺寸为300nm的树枝状Pt团聚体在气流中直接完全转变为单个球形纳米颗粒。值得注意的是，该过程所需的临界能量密度取决于团聚体纳米颗粒的尺寸分布和消光。基于消光截面光谱结果，与Pt相比，Ag纳米颗粒在红外区域表现出较弱的消光，因此即使在能量密度高达12.7mJ/cm的脉冲作用下，它们也没有被完全改性。将获得的Ag和Pt激光烧结结果与我们之前工作中研究的金（Au）纳米颗粒的相应改性进行了比较。在这里，我们考虑了气溶胶相中Ag、Pt和Au纳米颗粒团聚体的烧结机制，并基于Pt团聚体的一级和Au及Ag团聚体的二级收缩过程提出了它们的激光烧结模型。
