EM - Escola de Minas

Notícias

A Escola de Minas de Ouro Preto foi fundada pelo cientista Claude Henri Gorceix e inaugurada em 12 de outubro de 1876.

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Chemical modification of lignocellulosic materials by irradiation with Nd-YAG pulsed laser.
(Applied Surface Science, 2001) Botaro, Vagner Roberto; Santos, Cláudio Gouvêa dos; Arantes Júnior, Gilberto; Costa, Adilson Rodrigues da
Most reports about modification of lignocellulosics are mainly based on chemical modifications such as specific reactions on hydroxyl groups of cellulose. In this work, we describe the irradiation of Whatman 5 filter paper, microcrystalline cellulose and organosolv lignin with Nd-YAG laser pulses at 1064 nm. The chemical and structural properties of the degraded products were investigated by using FTIR and UV spectroscopies, conductimetrical and SEC analyses. While irradiation affects molar mass and polydispersity of lignin, no detrimental effects caused by Nd-YAG laser treatments were observed for cellulose samples. These results demonstrate that Nd-YAG laser can be used as a practical and selective degradation tool, opening a new field for obtaining surface modified natural fibers.