Abstract

Immediate as well as long-term effects of pulsed lasers operating at three different wavelengths (308, 532 and 1064 nm) and fluences below 2.5 Jcm^-2 on cellulose are reported. The degree of polymerisation was determined viscometrically, while diffuse reflectance FTIR was used to gain insight into the changes in the chemical composition. A strong immediate cellulose degradation effect after excimer laser treatment at 308 nm was observed. Laser irradiation at 1064 nm resulted in an increase of the degree of polymerisation due to the formation of inter- and intra-molecular ether bonds. Nd:YAG processing at 532 nm resulted in no detectable chemical changes after the treatment, although long term resistance appears to be impaired.

PACS: 42.62.-b, 61.80.Ba, 83.80.Lz