tailieunhanh - Báo cáo " Synthesis and characterisation of metallic nanoparticles "

Sphere-like gold nanoparticles have been prepared by chemical reduction method and by using X-ray irradiation, while rod-like gold nanoparticles were synthesized according to the seed-mediated growth method and by sonoelectrochemistry. Sphere-like gold nanoparticles have diameter of 20 - 60 nm, while rod-like gold nanoparticles have aspect ratio from 2 to 4. | VNU Journal of Science Mathematics - Physics 25 2009 221-230 Synthesis and characterisation of metallic nanoparticles Nguyen Hoang Luong1 Nguyen Ngoc Long1 Le Van Vu1 Nguyen Hoang Hai1 Luu Manh Quynh1 Phan Tuan Nghia2 Nguyen Thi Van Anh2 Center for Materials Science Hanoi University of Science Vietnam National University Hanoi 334 Nguyen Trai Thanh Xuan Hanoi Vietnam 2Key Laboratory for Enzyme and Protein Technology Hanoi University of Science Vietnam National University Hanoi 334 Nguyen Trai Thanh Xuan Hanoi Vietnam Received 2 December 2009 Abstract. Sphere-like gold nanoparticles have been prepared by chemical reduction method and by using X-ray irradiation while rod-like gold nanoparticles were synthesized according to the seed-mediated growth method and by sonoelectrochemistry. Sphere-like gold nanoparticles have diameter of 20 - 60 nm while rod-like gold nanoparticles have aspect ratio from 2 to 4. In UV-vis spectra the absorption bands related to surface plasmon resonance were observed. CoPt nanoparticles with the size of 5 - 20 nm have been prepared by electrodeposition while FePt nanoparticles with the size of 5 - 10 nm were synthesized by sonoelectrodeposition. After annealing these magnetic nanoparticles showed a high coercivity. The metallic nanoparticles were functionalized for trial of application in biomedicine. Keywords Gold nanoparticles CoPt nanoparticles FePt nanoparticles Optical properties Magnetic properties. 1. Introduction Metallic nanoparticles NPs are very attractive because of their size- and shape-dependent properties see for instance 1 . For example gold nanospheres have a characteristic red colour but anisotropic gold nanorods have a changed dramatically colour. The colour is due to the collective oscillation of the electrons in the conduction band known as the surface plasmon oscillation 1 2 . The oscillation frequency is usually in the visible region for gold and silver giving rise to the strong surface plasmon resonance absorption. .