The additive is either an ionic additive or {HEAD ~ an amine additive} which forms {TAIL ~ an ionic ammonium type salt} in the acidic precursor solution 
The additive is either an ionic additive or { HEAD ~ an amine additive } which forms { TAIL ~ an ionic ammonium type salt } in the acidic precursor solution
OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH