Imaging and measuring size and elasticity of nanoparticles under wet conditions are important because nanoparticles are used in various applications such as vehicles in drug delivery and additives in cosmetics and paints. Conventional techniques allow for average size measurements but individual size and elasticity measurements on a specific particle in liquid would be challenging without the use of atomic force microscopy (AFM).
    In this presentation, we will demonstrate how to take topographic images in liquid and force spectroscopy measurements on the samples comprised of Silica nanoparticles on Mica using AFM. During the demo, we will change cantilevers, set up samples, and demonstrate tip approach into a liquid environment for liquid imaging. Using image analysis software, we will show how to determine the size of the particles from the acquired AFM topography images. We will perform force spectroscopy measurements on and off the nanoparticle to determine differences between loading and unloading curves on the different areas. These differences correlate to characteristic elastic properties of those materials measured under wet conditions.

Presented by Dr. Cynthia Buenviaje-Coggins and Dr. Byong Kim
Applications Laboratory, Park Systems Inc.