The carbodiimide can promote {TAIL ~ the formation} of crosslinks between {HEAD ~ carboxylate and amine groups} of the polyelectrolytes 
The carbodiimide can promote { TAIL ~ the formation } of crosslinks between { HEAD ~ carboxylate and amine groups } of the polyelectrolytes
OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH