Ageing Characterization of Transformer Paper Insulation Based on Dispersion Staining Colors of Cellulose Fibers in Oil

In the present study, three pretreatments of sodium hydroxide (NaOH), sulfuric acid (H2SO4), and glycerin were employed with bamboo fibers at two different temperatures of 117 °C and 135 °C, respectively. The chemical composition and structural characterization of the pretreated bamboo fibers were comparatively studied using spectroscopic and wet chemistry methods. Furthermore, the comparative hydrolysis behaviors of pretreated bamboo were studied due to the synergistic interaction between cellulases and xylanase. The NaOH treatment increased the holocellulose contents to 87.4%, and the mean diameter of the cellulose fibers decreased from 50 ± 5 µm (raw fiber bundles) to 5 ± 2 µm. The lignin content and the degree of cellulose polymerization both decreased, while the crystallinity index of cellulose and thermostability increased. The hydrolysis yields of NaOH pretreated bamboo at 135 °C increased from 84.2% to 98.1% after a supplement of 0.5 cellulose to 1 mg protein/g dry xylan. The NaOH pretreatment achieved optimal enzymatic digestibility, particularly at higher temperatures as indicated by the results.

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Preparation and characterization of micro or nano cellulose fibers via electroless Ni-P composite coatings

Proceedings of the Institution of Mechanical Engineers Part N Journal of Nanomaterials Nanoengineering and Nanosystems ◽

10.1177/1740349915590006 ◽

2016 ◽

Vol 230 (4) ◽

pp. 213-221

Author(s):

Yan-Fei Pan ◽

Jin-Tian Huang ◽

Xin Wang

Keyword(s):

Crystalline Structure ◽

Composite Coatings ◽

Fiber Surface ◽

Cellulose Fiber ◽

Cellulose Fibers ◽

Original Structure ◽

Ultrasonic Power ◽

Nano Cellulose ◽

Electroless Ni

Ni-P composite coatings were prepared on cellulose fiber surface via a simple electroless Ni-P approach. The metal-coated extent, dispersion extent of micro or nano cellulose fibers and crystalline structure of Ni-P composite coatings were investigated. The homogeneous hollow composite coatings and metal-coated extent of micro or nano cellulose fibers were improved with the increase in ultrasonic power, and the ideal composite coatings were obtained as ultrasonic up to 960 W. The metallization for cellulose fibers enhanced the dispersion extent of micro or nano cellulose fibers. A uniform coating, consisting of the hollow coating on cellulose fibers surface, could be obtained. At the same time, metallization did not damage the original structure and surface functional groups of cellulose fibers. The concentration of cellulose fibers and ultrasonic power had a direct influence on the metal-coated extent of cellulose fiber surface. The metal-coated extent, dispersion extent of micro or nano cellulose fibers and crystalline structure of Ni-P composite coatings exhibited excellent properties as the concentration of cellulose fibers and ultrasonic power were 2 g/L and 960 W, respectively.

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