GAS SORPTION
Nitrogen adsorption studies on hair samples after bleaching and UV damage were
conducted using a Quantachrome Autosorb-lC instrument. Samples were cut in very
fine pieces and then added to a sample cell where they were placed under vacuum at
145øC for 0.5 hr. Complete water removal is necessary toobtain accurate measurements,
which is why 145øC was used. This value is based on the data collected from differential
scanning calorimetry (DSC), in which a dehydration peak appears at about 125øC. A
5-pt BET (Brunauer-Emmett-Teller) surface area analysis was used for all samples. The
total pore volume was collected at a P/Po of-0.995. The pore size distribution curves
are from the adsorption portion of the isotherm.