Au-nanoparticle synthesis via ultrasonic spray pyrolysis with a separate evaporation zone

• Published in: Materiali in tehnologije
• Main Authors: Friedrich, Bernd, Rudolf, Rebeka, Majerič, Peter
• Format: Report
• Language: English
• Published: Inštitut za kovinske materiale in tehnologije 2017
• Subjects: nanotehnology; ultrasonic spray pyrolysis; gold; aerosol; TEM microscopy; nanotehnologija; ultrazvočna razpršilna piroliza; zlato; TEM-mikroskopija; info:eu-repo/classification/udc/669.21:620.3:537.533.35; Cono; sami
• Online Access: https://dk.um.si/IzpisGradiva.php?id=59280; https://dk.um.si/Dokument.php?id=109785&dn=; https://dk.um.si/Dokument.php?id=91349&dn=; https://plus.si.cobiss.net/opac7/bib/18972438?lang=sl

Some experiments were conducted in connection with the gold-nanoparticle production in an effort to produce a more accurate model for determining the gold-nanoparticle synthesis with a modified ultrasonic spray pyrolysis (USP). As previous experi- ments with gold nanoparticles yielded nanoparticles of various shapes (spherical, triangular, cylindrical, etc.), a focus on synthesizing only spherical nanoparticles is underway, as a mixture of different shapes is difficult to characterize and utilize. One of the factors for the particle formation is droplet evaporation. In an attempt to produce the optimum conditions for droplet evaporation with the solvent diffusion and precipitation, a separate furnace and a separate reaction-gas inlet were used. This modification separates the evaporation stage from the reaction stage, compared to the standard USP set-up. Using relatively low temperatures, from 60 °C up to 140 °C, for the evaporation stage provides for more time and better conditions for the diffusion of the solvent into the center of a droplet and a higher probability of forming a spherical particle. Prispevek opisuje sintezo nanodelcev zlata, ki smo jo izvedli z modificirano ultrazvočno razpršilno pirolizo (USP) s ciljem postavitve čim bolj realnega teoretičnega modela. Pri prejšnjih eksperimentih sinteze nanodelcev zlata smo dobili nanodelce različnih oblik (sferične, trikotne, cilindrične, itd.), zato smo se pri tej raziskavi osredinili na izdelavo sferičnih nanodelcev. Morfološko različni nanodelci so ovira ne samo pri karakterizaciji, ampak tudi kasneje pri sami uporabi. Pri sintezi nanodelcev ima velik vpliv na končno morfologijo izhlapevanje kapljic aerosola. Za zagotovitev razmer za izhlapevanje kapljic, ki omogočajo nastanek sferičnih nanodelcev, smo v procesu USP uporabili ločeno ogrevalno območje in ločen vnos reakcijskega plina. Ta modifikacija namreč ločuje stopnjo izhlapevanja od stopenj reakcij za nastanek nanodelcev. Nižja temperatura v fazi izhlapevanja (med 60 °C in 140 °C) omogoča boljše razmere za difuzijo topljenca do središča kapljice in večjo verjetnost nastanka sferičnih nanodelcev.