The catalyst solution may include a dye or other colorimetric substance for visualizing {HEAD ~ the layer} of {TAIL ~ catalyst solution} on the substrate 
of
The catalyst solution may include a dye or other colorimetric substance for visualizing { HEAD ~ the layer } of { TAIL ~ catalyst solution } on the substrate
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH