Search results for " cellulose"
showing 2 items of 72 documents
Regeneration of cellulose by water addition to phosphoric acid/cellulose mixture
2013
In the last years, phosphoric acid has been increasingly considered as a simple and economic solvent for cellulose pretreatment before its degradation to glucose. Cellulose swells in 71–80% phosphoric acid solutions, whereas at higher H3PO4 concentrations dissolution appears to occur. In addition, it is reported that regenerated cellulose is more easily fermentable to bioethanol. The aim of the present study was to elucidate the mechanism for cellulose regeneration following treatment with phosphoric acid at room temperature. CPMAS 13C NMR spectra revealed a downfield shift of the 13C NMR signals from the regenerated cellulose as compared to the crystalline one. CPMAS 31P NMR spectroscopy s…
Application of Broadband Dielectric Spectroscopy to Cultural Heritage: characterization and preservation of ancient paper artwork
2016
Within the cultural heritage the characterization and conservation of artworks based on paper represents a significant issue for both restorers and scientists. The paper deterioration is affected by the degree of hydrolytic and oxidative reactions which occur upon aging. Moreover, the durability of cellulose fibers depends on the intrinsic composition/structure of the paper as well as on the conservation conditions, such as temperature and humidity. The structural and dynamical characterization of the cellulose matrix and of the water confined within its pores is therefore of central interest. Our working hypothesis is that WATER DYNAMICS is one of the main determinants of paper degradation…