Gold is a noble metal that is inert and shows little reactivity. The resistance of gold to corrosion has been known to humans for millennia and is reflected in the use of gold in jewellery and currency. Nanosized gold particles are used as a catalyst in im-portant chemical reactions, such as the oxidation of hydrogen and carbon monoxide. The release of gold for metallurgical recovery from gold deposits is dependent on the nature and particle size of the gold-bearing mineral, the textural association of gold with gangue and economically recoverable sulphides. Lately, gold nanoparticles have been of high interest because of their potential application in electrochemistry, in medicine and in some nanodevices. The reasons for the high reactivity of gold nano-particles are assumed to be hidden in their atomic structure. Different synthesis methods for preparation of nanosized gold particles have been used, such as photo-reduction, chemical reduction in aqueous solutions and thermal decomposition in or-ganic solvents. Chemical synthesis of gold nanoparticles with well-controlled shapes, sizes and structures is becoming a practical reality by using colloid chemistry. This study provides the newest information regarding the synthesis of gold nanoparticles via the ultrasonic spray pyrolysis method and reduction in aqueous solution. Ultra-sonic spray pyrolysis (USP) is the mostly used method for the synthesis of particles with controlled and uniform particle size because of easy powder morphology control and the availability of cheap precursor solutions. In the USP process a metal-containing solution is cold atomized forming an aerosol. Special attention is given in this paper to the formation of Gold nanoparticles from gold auric acid solution using sodium citrate as the reducing agent in an aqueous solution under atmospheric and high pressure. A key feature of the non-spherical nanoparticles is that their optical properties vary dramatically with their physical dimensions. In contrast to gold nanospheres, their resonance frequency is tuneable over a wide range from blue to near-infrared and enables one to set the surface plasmon resonance to a wavelength or spectral re-gion specific to a particular application. Together with the high degree of biocompati-bility of gold, these structures show potential in a wide variety of biological applica-tions. It is confirmed that gold nanoparticles play a role in cancer diagnosis and therapy. To improve early cancer detection, researchers are developing in vivo biomedical imaging techniques with a resolution which can distinguish between healthy and malignant tissue.
B.04 Guest lecture
COBISS.SI-ID: 16906774Performed lectures at RWTH Aachen institution: •To check and optimize the technology of ultrasonic spray pyrolisis for production of shape memory NiTi nanoparticles; •To explain the phenomena and growth mechanisms of nanoparticles , that will be made by USP method with aim to control the selected shape of particles; •To characterize the microstructure and to determine the grade of metastability as a function of process parameters; Gained experiences during the staff training: •To acquire the knowledge in the field of the technology of ultrasonic spray pyrolisis in the production of nanoparticles; •To gain the knowledge in the field of characterization the microstructure and knowledge of thermodynamic stability of nanoparticles
B.05 Guest lecturer at an institute/university
COBISS.SI-ID: 17118230Nanostructured materials and their application have been attracted much attention in the last decades. Due to extended research in this area, various nanomaterials and endless application of them is known today. This led to rising demand for methods suitable for big scale nanomaterials production, especially when it comes to ones with target morphology, complex composition, multicomponent and coated materials. In this paper a report of first results on scale up of Ultrasonic Spray Pyrolysis (USP) process is presented, which is relatively inexpensive and quite versatile technique for nanoparticle production based on an aerosol process. It is possible to produce fine metallic, oxidic, composite nanoparticles of precisely controlled morphology and defined chemical compositions from water solution using different metal salts and their mixtures. In the first trial on big scale USP equipment nano Ag powder was produced.
F.13 Development of new production methods and tools or processes
COBISS.SI-ID: 17117206