Challenges in Observing the Formation of Colloidal, Self-Assembled Monolayers with In Situ Electron Microscopy in Liquid

Abstract

Our goal is to develop liquid-phase electron microscopy (LPEM) for observing colloidal assembly processes in situ. Direct imaging methods could possibly elucidate some of the nanoscale interactions that are not well described by models such as Derjaguin-Landau-Verwey-Overbeek-theory [1]. Here, we have made attempts to study a simple system exhibiting colloidal self-assembly, namely the formation of a colloidal self-assembled monolayer (SAM) of positively charged silica nanopar-ticles (SiONP) on the silicon nitride (SiN) membrane used as liquid cell window. Visualisation could bring new insight to the colloidal organization and create a deeper understanding for observing colloidal interactions with the LPEM in general. The special interest now would be how the process develops from random surface adsorption [2] towards denser monolayer.