Characterization of nanoparticles synthesized in the presence of polysaccharides: The search for the needle in the haystack
Our laboratory has established a general procedure to synthesize various types of nanoparticles (NPs) in the presence of polysaccharides (PS). The PS stabilizes the NPs leading to colloidal NP/PS combinations that are readily dispersed in water and could find potential uses in myriad industrial, medical, or environmental applications. However, the synthesis and subsequent stabilization of the NPs requires the presence of fairly high amounts of PS (often more than 90% w/w) leading to NP end products that prove very difficult to characterize (e.g., determine chemical identity, size or morphology). For this research, we have synthesized Au and UO2(OH)2 NPs using various types of PS and attempted to characterize them using UV/Vis spectroscopy, dynamic light scattering (DLS), powder X-ray diffraction (XRD), gel permeation chromatography (GPC) and transmission electron microscopy (TEM). All these techniques provide, at a minimum, a relative ranking of the NPs based upon their particle size. The main focus of this research was to determine whether the various techniques are in agreement with each other so that lesser more robust techniques can be used in place of transmission electron microscopy as a definitive determination of NP size. The experimental data shows that "disagreements" are common, most likely because some techniques measure the size of the inorganic core particle, ignoring coating, while other techniques measure the size of the PS/NP colloidal combination.
Ashley N Bradley,
"Characterization of nanoparticles synthesized in the presence of polysaccharides: The search for the needle in the haystack"
ETD Collection for Tennessee State University.