tailieunhanh - báo cáo hóa học: " Nonlinear thermo-optical properties of twolayered spherical system of gold nanoparticle core and water vapor shell during initial stage of shell expansion"

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: Nonlinear thermo-optical properties of twolayered spherical system of gold nanoparticle core and water vapor shell during initial stage of shell expansion | Pustovalov and Astafyeva Nanoscale Research Letters 2011 6 448 http content 6 1 448 o Nanoscale Research Letters a SpringerOpen Journal NANO EXPRESS Open Access Nonlinear thermo-optical properties of twolayered spherical system of gold nanoparticle core and water vapor shell during initial stage of shell expansion Victor K Pustovalov1 and Liudmila G Astafyeva2 Abstract Nonlinear thermo-optical properties of two-layered spherical system of gold nanoparticle core and water vapor shell created under laser heating of nanoparticle in water were theoretically investigated. Vapor shell expansion leads to decreasing up to one to two orders of magnitude in comparison with initial values of scattering and extinction of the radiation with wavelengths 532 and 633 nm by system while shell radius is increased up to value of about two radii of nanoparticle. Subsequent increasing of shell radius more than two radii of nanoparticle leads to rise of scattering and extinction properties of system over initial values. The significant decrease of radiation scattering and extinction by system of nanoparticle-vapor shell can be used for experimental detection of the energy threshold of vapor shell formation and investigation of the first stages of its expansion. PACS . . BF Background Metal nanoparticles NPs and other nanostructures are widely used in nanotechnology physical chemistry catalysis biology and laser nanomedicine for different purposes during past 10 years 1-15 also see the references in these papers . The determination of sizes concentrations and placements of NPs in different media is carried out by different methods-transmission electron microscopy small-angle X-ray scattering laser scanning microscopy optical diagnostics etc. 1-15 . In many cases optical detection and diagnostics of NPs via scattering have the advantages in comparison with others and can be carried out on the base of detection of radiation scattered from NPs placed in