ABSTRACT

This paper presents the isolation of kenaf bast fiber to produce cellulose nanofiber (CNF) using chemical-physical treatment (e.g. delignification, bleaching and ultrasonication). Raw bast fiber was bleached and then subjected to high-intensity ultrasonication at four different output powers (100 W, 200 W, 400 W and 700 W). SEM and TEM analysis of treated bast fiber revealed that the morphological structure of CNF with diameter distribution in the range less than 100 nm (100 W) to 10 nm (700 W). Hemicellulose and lignin content were successfully reduced by chemical treatments, as there was increment of the cellulose content in the fiber more than 90% recorded. Higher ultrasonication output power attributes to the decreasing diameter size of CNF. This finding reflected that smaller CNF fibrils provide larger surface area per volume ratio. Larger stretching vibration of – OH group is detected as the higher composition of cellulose in CNF. CNF produced also had higher thermal stability than raw bast fiber after undergoes the chemical-physical treatment. Therefore, chemical-physical treatment did not only to attribute the success of deposition of lignin and hemicellulose, but also to increase the nano-sized fiber distribution in CNF suspension.

摘要

本文介绍了使用化学物理处理（例如脱木质素、漂白和超声波处理）分离红麻韧皮纤维以生产纤维素纳米纤维 (CNF)。将生韧皮纤维漂白，然后在四种不同的输出功率（100 W、200 W、400 W 和 700 W）下进行高强度超声处理。经处理的韧皮纤维的 SEM 和 TEM 分析表明，CNF 的形态结构直径分布在小于 100 nm (100 W) 到 10 nm (700 W) 的范围内。通过化学处理成功降低了半纤维素和木质素的含量，因为记录的纤维中纤维素含量增加了 90% 以上。较高的超声输出功率归因于 CNF 的直径尺寸减小。这一发现反映了较小的 CNF 原纤维提供了较大的单位体积比表面积。-OH 基团的较大伸缩振动被检测为 CNF 中纤维素的较高组成。经化学物理处理后，生产的CNF也比原始韧皮纤维具有更高的热稳定性。因此，化学-物理处理不仅归因于木质素和半纤维素沉积的成功，而且还增加了CNF悬浮液中纳米级纤维的分布。