The polyelectrolytes can become {HEAD ~ cross} linked and unable to undergo further transitions in {TAIL ~ porosity} 
The polyelectrolytes can become { HEAD ~ cross } linked and unable to undergo further transitions in { TAIL ~ porosity }
OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL