Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Nanophotothermolysis of Poly-(vinyl) Alcohol Capped Silver Particles | Nanoscale Res Lett 2008 3 164-167 DOI S11671-008-9131-7 NANO EXPRESS Nanophotothermolysis of Poly- vinyl Alcohol Capped Silver Particles Suraj Kumar Tripathy Received 15 January 2008 Accepted 4 April 2008 Published online 15 April 2008 to the authors 2008 Abstract Laser-induced thermal fusion and fragmentation of poly- vinyl alcohol PVA -capped silver nanoparticles in aqueous medium have been reported. PVA-capped silver nanoparticles with an average size of 15 nm were prepared by chemical reduction technique. The laser-induced photofragmentation of these particles has been monitored by UV-visible spectroscopy and transmission electron microscopy. The morphological changes induced by thermal and photochemical effects were found to influence the optical properties of these nanoparticles. Keywords Nanoparticles PVA Silver Surface plasmon Thermolysis Introduction Ultrafine metal particles in the nanometer regime have various interesting properties compared with bulk metals because of their quantum size effects so they hold promise as advanced materials with new electronic magnetic optical and thermal properties as well as new catalytic properties 1 . Metal nanoparticles NPs are certain to be the building blocks of the next generation of electronic optoelectronic and chemical sensing devices 2 . One of the most important applications of metal NPs is as catalysts 3 . The activity of a catalyst largely depends on the particle size. Several methods have been employed to control the particle size in solution. A common feature of those methods is that the size control is achieved by changing the reaction conditions for example adding surfactants as protective agents changing pH concentration of reactants etc. However once metal NPs are synthesized it is very difficult to break them effectively particularly when their diameter is less than 50 nm. Thus the size-manipulation of metal NPs remained a major challenge for materials scientists and physical chemists. The .
