Nanoparticles of noble metals have recently attracted much interest due to their potential applications as microelectronics, optoelectronics, catalysis, and information storage. As many chemical and physical properties of nanoparticles considerably depend on their sizes and shapes, synthetic methods and reaction conditions must be deliberately controlled to obtain non-aggregated, homogeneous sized nanoparticles. Among many approaches to prepare the nanoparticles, alkylthiols are favorably used as a stabilizer due to homogeneity of nanoparticle sizes and synthetic diversity to introduce various functional groups.

In this presentation, we report the synchrotron small angle x-ray scattering studies on structures, sizes and size distributions of the as-made silver nanoparticles (SNPs). The analysis results will be discussed with TEM and UV-Vis spectra. SNPs in this work were synthesized by reducing silver salts with strong reductants, and subsequently stabilized by various alkylthiols with different hydrocarbon chain lengths. UV-Vis spectra of SNPs capped with various alkylthiols showed the characteristic surface plasmon bands at ~450 nm. However, the spectral shapes of SNPs with relatively short butanethiols became weaker and asymmetrically broader into longer wavelength region. Their nanostructures were deliberately characterized by small angle x-ray scattering analysis based on hard sphere model and TEM results.