contacting {TAIL ~ the polyimide surface} with {HEAD ~ an aqueous solution} of nitric acid having a concentration of about 35 to about 70% by weight or an aqueous solution of hydrochloric acid having a concentration of about 10 to about 38% by weight 
contacting { TAIL ~ the polyimide surface } with { HEAD ~ an aqueous solution } of nitric acid having a concentration of about 35 to about 70 % by weight or an aqueous solution of hydrochloric acid having a concentration of about 10 to about 38 % by weight
OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH