Particle size and crystallinity of silicon nanoparticles were determined by analyzing the optical extinction spectra of colloidal suspensions. Experimental results from these colloids were anaiyzed using Mie theory in...Particle size and crystallinity of silicon nanoparticles were determined by analyzing the optical extinction spectra of colloidal suspensions. Experimental results from these colloids were anaiyzed using Mie theory in connection with effective medium theory, in order to determine particle sizes and their internal structure with the simple technique of optical transmission spectroscopy. By modeling an effective refractive index for the particles, the crystalline volume fraction can be extracted from extinction spectra in addition to information about the size. The crystalline volume fraction determined in this way were used to calibrate the ratio of the Raman cross sections for nanocrystalline and amorphous silicon, which was found to be σc./σa = 0.66展开更多
There is no doubt about the potential technological significance of nanofluids. The promising application areas have been identified as effective heat transfer fluids, contrast agents in magnetic resonance imaging, ma...There is no doubt about the potential technological significance of nanofluids. The promising application areas have been identified as effective heat transfer fluids, contrast agents in magnetic resonance imaging, magnetohyperthermia treatment, precursors to high performance nanocomposites and ordered nanostructures. However, commercial applications are rare, in part due to the limited understanding of the nanofluid fundamentals such as colloid stability, phase diagrams and rheology. This paper intends to provide a brief overview of the scientific disciplines that are important to nanofluids, and the interconnection among different disciplines in order to gain a perspective on the future development of this intriguing area.展开更多
文摘Particle size and crystallinity of silicon nanoparticles were determined by analyzing the optical extinction spectra of colloidal suspensions. Experimental results from these colloids were anaiyzed using Mie theory in connection with effective medium theory, in order to determine particle sizes and their internal structure with the simple technique of optical transmission spectroscopy. By modeling an effective refractive index for the particles, the crystalline volume fraction can be extracted from extinction spectra in addition to information about the size. The crystalline volume fraction determined in this way were used to calibrate the ratio of the Raman cross sections for nanocrystalline and amorphous silicon, which was found to be σc./σa = 0.66
基金The Dow Chemical Companyfor its support of the writing of this manuscript
文摘There is no doubt about the potential technological significance of nanofluids. The promising application areas have been identified as effective heat transfer fluids, contrast agents in magnetic resonance imaging, magnetohyperthermia treatment, precursors to high performance nanocomposites and ordered nanostructures. However, commercial applications are rare, in part due to the limited understanding of the nanofluid fundamentals such as colloid stability, phase diagrams and rheology. This paper intends to provide a brief overview of the scientific disciplines that are important to nanofluids, and the interconnection among different disciplines in order to gain a perspective on the future development of this intriguing area.
