The 30th International Conference on Advanced Laser Technologies ALT'23
Laser-induced fragmentation of solid and porous Si nanopar in colloidal solutions using molecular dynamics
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S.Yu. Lukashenko1, I.A. Kutlubulatova1'2, M.S. Grigoryeva1, V.A. Dimitreva2, D.S. Ivanov1, A.P. Kanavin1, V.Yu. Timoshenko1,2,3, and I.N. Zavestovskaya1,2
1 P. N. Lebedev Physical Institute of Russian Acad. Sci., Leninskiy Pr. 53, 119991 Moscow, Russia 2 MEPHI, Institute of Engineering Physics for Biomedicine (PhysBio), 115409 Moscow, Russia 3 Lomonosov Moscow State University, Leninskie Gory 1, 119234 Moscow, Russia
email address: [email protected]
Silicon nanoparticles (NPs), due to their high biocompatibility and non-toxicity, are widely used in biomedical technologies [1, 2]. In this case, it is crucial to utilize homogeneous colloidal solutions of nanoparticles with controlled properties. The laser ablation method has emerged as a powerful technique for nanoparticle synthesis. However, controlling the size distribution of the resulting particles has proven challenging [3]. Therefore, subsequent fragmentation of NPs using pulsed laser radiation is often employed to achieve the desired particle characteristics. Nevertheless, the understanding of the underlying mechanisms involved in this process is severely limited. In our work, we use molecular dynamics (MD) modeling to study the mechanism of silicon NP fragmentation under the action of short-pulse laser radiation.
We conducted large-scale parallel MD simulations of the interaction between a 270 fs laser pulse and the colloid solution model at an incident fluence of approximately (1 - 10) J/cm2, with a wavelength of 800 nm. The irradiated volume was represented by a water cube measuring (100 x 100 x 100) nm, in which three solid or three porous nanoparticles of sizes (30, 20, 10) nm were submerged. The simulation accounted for the complete absorption of a Gaussian laser pulse by the NPs, as well as subsequent processes including heating, phase transition, vaporization, nucleation, and aggregation.
We present the kinetics of dispersion of primary NPs and condensation of silicon atoms into secondary NPs. The fragmentation thresholds for solid and porous NPs are estimated and compared. We also discuss the features that can occur during laser ablation of NPs in colloidal solutions of high concentration. The study aims to contribute for revealing the mechanisms involved in laser fragmentation of NPs and to develop experimental conditions for generating NPs with desired properties.
This work was financially supported by Ministry of Science and Higher Education of Russian Federation (project No 075-15-2021-1347).
[1] M. Nikzamir, A. Akbarzadeh, Y. Panahi, "An overview on nanoparticles used in biomedicine and their cytotoxicity", Journal of Drug Delivery Science and Technology 61, 102310-102316 (2021).
[2] L.T. Canham, Handbook of Porous Silicon, Cham: Springer. 2018.
[3] D. Zhang, B. Gokce, S. Barcikowski, Laser Synthesis and Processing of Colloids: Fundamentals and Applications Chem. Rev. 117, 3990-4103 (2017).