EFFECTS OF NOX EXPOSURE ON PAPER - THE ROLE OF FREE-RADICALS

In a continuing effort to understand the basic mechanisms of free radi cal reactions in various aspects of paper qualities, we have begun a c oordinated study of the relationship of colour reversion and permanenc e in a radical-containing atmosphere. As there are currently no direct , on-line methods to monitor the aging processes of paper a novel puls ed microwave-induced acoustic (MIA) sensor which indirectly provides r apid monitoring of relative depolymerization of paper via on-line meas urements of water sorption/desorption kinetics. This sensor, in conjun ction with electron spin resonance spectroscopy which directly monitor s the free radicals, affords a potentially powerful technique to exami ne the effects and the relationship between colour reversion and aging processes in paper.