Chemical and wood anatomical properties of tumorous wood in a Turkish white oak (Quercus robur subsp robur)

Chemical and anatomical properties of tumorous and normal wood of Quercus robur L. subsp. robur were compared. Tumorous growth appeared as a result of topping stress. Orientation of cells was severely disrupted in the affected wood. In cross section, aspects of cells changed abruptly from transverse to longitudinal, and in tangential section all wood elements appeared to turn around each other like a fingerprint. Vessel elements and fibres of affected wood were shorter than those of healthy wood. The vessels of affected wood were smaller in diameter especially in the earlywood. On the other hand, multiseriate ray height was shorter than that of normal wood. In addition, perforated ray cells occurred. The ray and axial parenchyma cells of tumorous wood contained dark coloured phenolic compounds. Normal wood had calcium oxalate crystals, while tumorous wood did not. Chemical analyses showed that hemicellulose content and solubility rates in 1\% NaOH, cold water, hot water, and alcohol-benzene were higher than those of normal wood. Cellulose and ash contents of tumorous wood were slightly lower than in normal wood. In addition, air-dry specific gravity of tumorous wood was higher than that of normal wood

Biodegradation of Abies bornmulleriana (Mattf.) and Fagus orientalis (L.) by the white rot fungus Phanerochaete chrysosporium

The effects of Phaneroehaete chrysosporium, a white rot fungus, on the chemical composition of Abies bornmulleriana and Fagus orientalis wood chips were investigated. After the chips were inoculated with the fungus, 20-, 40- and 60-day samples were analysed in order to determine the influence of fungal treatment on the chemical components of the cell walls, and the fibre properties of both species were measured. As a result of P. chrysosporium growth, both types of wood had slight relative increases in percentage cellulose. Percentage holocellulose showed statistically significant decreases and solubility values increased considerably. The lignin ratio for F orientalis decreased significantly in relation to zero-time control samples. (C) 2004 Elsevier Ltd. All rights reserved

Biofilms from micro/nanocellulose of NaBH4-modified kraft pulp

WOS: 000407842800009Industrial applications of microfibrillated cellulose (MFC) and nanofibrillated cellulose (NFC) have been in use for some time; however, there is a need to improve the production steps and at the same time to obtain better quality products. NFC and MFC were generated from -modified kraft pulp, produced from a red gum tree plant (Eucalyptus camaldulensis). The generated NFC and MFC were characterized by high-performance liquid chromatography, Fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA) and -nuclear magnetic resonance (NMR). Morphological and viscoelastic properties were investigated by scanning electron microscopy and rheometry, respectively. The storage moduli of biofilms produced from NFC and MFC were investigated by dynamic mechanical thermal analysis (DMTA). Both exhibited mostly identical FTIR spectra. When the spectra were compared with those of -modified kraft pulp, minor shifts were observed due to crystallinity. In NMR spectra, disordered cellulose structures were observed for both NFC and MFC, and these findings were also confirmed by differential scanning calorimetry. Rheology studies revealed that the lowest viscosity was observed with MFC. TGA results showed that NFC degraded earlier compared with -modified kraft pulp. DMTA exhibited that NFC films had about six times higher storage modulus compared with MFC.TUBITAKTurkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [COST 114O022]; Istanbul University Research FundIstanbul University [4806, 19515]We thank TUBITAK (Project Number: COST 114O022) for supporting this research. We also acknowledge Istanbul University Research Fund for financially supporting this study (Project Numbers 4806 and 19515)