To see or not to see: imaging surfactant coated nano-particles using HIM and SEM.
Nano-particles are of great interest in fundamental and applied research. However, their accurate visualization is often difficult and the interpretation of the obtained images can be complicated. We present a comparative scanning electron microscopy and helium ion microscopy study of cetyltrimethylammonium-bromide (CTAB) coated gold nano-rods. Using both methods we show how the gold core as well as the surrounding thin CTAB shell can selectively be visualized. This allows for a quantitative determination of the dimensions of the gold core or the CTAB shell. The obtained CTAB shell thickness of 1.0 nm-1.5 nm is in excellent agreement with earlier results using more demanding and reciprocal space techniques.
Physics of Interfaces and Nanomaterials, MESA+ Institute for Nanotechnology, University of Twente, PO Box 217, 7500AE Enschede, The Netherlands.
Gregor
G
Hlawacek
Imtiaz
I
Ahmad
Mark A
MA
Smithers
E Stefan
ES
Kooij
Helium ion microscopy; Nano-particles; Scanning electron microscopy