Naslov
Underwater laser synthesis of nanoparticles

Autori
Krstulović, Nikša

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
Book of Abstract of 20th International Scientific Meeting on Vacuum Science and Technologies / Miran Mozetič, Alenka Vesel - Ljubljana : Infokart, 2013, 11-11

ISBN
978-961-92989-5-4

Skup
20th International Scientific Meeting on Vacuum Science and Technologies

Mjesto i datum
Jeruzalem, Slovenija, 09.05.2013. - 10.05.2013

Vrsta sudjelovanja
Pozvano predavanje

Vrsta recenzije
Nije recenziran

Ključne riječi
Underwater laser synthesis of nanoparticles; underwater laser ablation

Sažetak
Nanoparticles of various materials are today implemented in wide variety of industrial, scientific and medical applications. Biocompatible nanoparticles are used for cell treatment ; as nanobiomarkers, for therapy and diagnostics. Nanoparticles can be synthesized conventionally either using wet chemistry methods or gas phase processes. Nanoparticles prepared in those two ways are often characterize by impurities, agglomerations and precipitation effects. Such drawbacks make those techniques of nanoparticles synthesis very limiting. The laser ablation in liquids appeared to be a solution for many of those problems. The main advantage of this technique is ability to ablate almost any kind of material (metals, magnetic, glass, plastics, single- and multi-component) and absence of impurities (chemicals) which make the final product relatively clean - consisted only of target material. Anyway, over a time the nanoparticles produced by laser ablation in liquids may aggregate (if not charged) and precipitate thus making theirs properties limiting. In this work we will be focused on synthesis of Au and Ag nanoparticles in water by ns laser ablation. Two ways to control nanoparticles properties were proposed. Namely, dual pulse laser scheme for the ablation process (second laser pulse interact with the nanoparticles produced with the first one) and post-dilution of NP colloid sample with pure water (addition of water prevents nanoparticles from collisions avoiding formation of agglomerations and growth in late stage of NP formation). In both cases a certain control of NP size distributions is possible. Laser produced Ag nanoparticles showed great potential for Surface Enhanced Raman Spectroscopy studies. Raman signal was increased by two orders of magnitude when low concentration of tetrakis(4- sulfonatophenyl)porphine molecules were added to Au NP solution. The results are discussed in terms of time delays between pulses (in dual pulse scheme, varied from 0 to 50 ms), size-distributions based on TEM figures and DLS measurements, mass and crater volumes after ablation, Z-potential measurements and measurements of extinction curves (real-time monitoring during experiment and after treatment) extracting data on precipitation and agglomeration of NP’s. The dual pulse laser synthesis of NP’s is compared to conventional post-treatment synthesis. The experiment was performed with Q-switched Nd:YAG lasers irradiating at 1064 nm and 10 Hz.

Izvorni jezik
Engleski

Znanstvena područja
Fizika

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