SEM Cross-sections

The images shown are representative of a cross-section area we took with the fibers embedded in PDMS.  In order to image this, we made a PDMS substrate with carbon fibers and then collected a 500 nm colloidal array on top.  Next, that sample was turned 90 and embedded in more PDMS.  Afterwards, the "composite" of the substrate embedded with PDMS was cut for a cross-section area.  This was done to hold the fibers in place and not allow them to move.  When we cut the samples for a cross section with no embedding, the fibers would move out of the substrate.  Alternatively, when we repeated this embedding in epoxy, there were adhesion problems and the fibers would transfer to the epoxy.  Below are three images of the same fiber from several angles.

The problem with this method of embedding in PDMS is that the PDMS creates better adhesion to the colloids than the carbon fiber and thus they are stripped off the surface.  However, we have not be able to get the cross section on the PDMS substrate without embedding.  Unlike the fabrics, the individual fibers do not remain still when the cutting occurs.