Physicochemical Characterization of Acid-Treated Nanocrystal Cellulose and Amorphous Cellulose from Bamboo Sawdust

ABSTRACT

The major by-product of bambooworking (i.e. making items from bamboo) is bamboo sawdust, which is a waste product from bambooworking operations and can cause human health hazards. Specifically, this experimental research investigates the effects of acid treatment methods on the physicochemical characteristics of nanocellulose fibers from bamboo sawdust. The experimental acid treatment methods are sulfuric acid hydrolysis for bamboo fiber nanocrystal cellulose (BBF-NCC) and sulfuric acid dissolution for bamboo fiber amorphous cellulose (BBF-AC). The physicochemical properties of nanocellulose from bamboo sawdust include the crystalline structure, morphology, and colloidal stability. The experimental results indicate that BBF-NCC possesses a higher crystallinity index (89.5%), in comparison with 35.4% for BBF-AC. The BBF-NCC is of rod shape with 10 nm in diameter and 50–100 nm in length, while BBF-AC coalesces into clusters of varying sizes. In addition, BBF-NCC possesses higher colloidal stability than BBF-AC, as indicated by a zeta potential of −30.93 mV for BBF-NCC, compared with −19.73 mV for BBF-AC. Essentially, this research is the first to experimentally convert bamboo sawdust into cellulose nanofibers as an eco-friendly and economically viable solution to the waste problem from the bamboomaking industry. Moreover, BBF-NCC and BBF-AC could potentially be adopted as a reinforcing agent in biocomposites or as a carrying agent in multiple applications.

摘要

竹木加工（即用竹子制作物品）的主要副产品是竹木屑，这是竹木加工过程中的废物，会对人类健康造成危害. 具体而言，本实验研究了酸处理方法对竹木屑纳米纤维素纤维物理化学特性的影响. 实验酸处理方法为硫酸水解竹纤维纳米纤维素（BBF-NCC）和硫酸溶解竹纤维无定形纤维素（BBF-AC）. 竹木屑纳米纤维素的物理化学性质包括晶体结构、形态和胶体稳定性. 实验结果表明，BBF-NCC的结晶度指数（89.5%）高于BBF-AC的35.4%. BBF-NCC是直径为10 nm、长度为50-100 nm的棒状，而BBF-AC聚结成不同尺寸的团簇. 此外，BBF-NCC比BBF-AC具有更高的胶体稳定性，如BBF-NCC的ζ电位为-30.93 mV所示，而BBF-AC的ζ电势为-19.73 mV. 从本质上讲，这项研究是第一次通过实验将竹木屑转化为纤维素纳米纤维，作为一种环保且经济可行的解决方案，来解决竹子制造业的废物问题. 此外，BBF-NCC和BBF-AC可能被用作生物复合材料中的增强剂或多种应用中的载体.

KEYWORDS:

• Bamboo
• sawdust
• cellulose nanocrystal
• amorphous cellulose
• chemical treatment

关键词:

• 竹子
• 锯末
• 纤维素纳米晶体
• 无定形纤维素
• 化学处理

Highlight of this paper

1. This paper compares the effects of different acid treatment methods on the physicochemical characteristics of bamboo fiber (BBF) nanocellulose from bamboo sawdust.

2. In this paper, we are the first to report an experimentally convert bamboo sawdust into cellulose nanofibers (crystalline nanocellulose, BBF-CNC and amorphous cellulose, BBF-AC) as an eco-friendly and economically viable solution to the waste problem from the bamboo-making industry.

3. The bamboo waste from industry is sawdust often found in many bamboo-making factories or communities which is regarded as waste, and most of this waste is burned or landfilled. If we can turn it into a value-added of BBF-CNC and BBF-AC we can help the reduction of waste problem.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Author contributions

Conceptualization, P.P., W.A., and S.E.; Methodology, P.P., W.A., and S.E.; Validation W.A.; Writing-review and editing, P.P., W.A.and S.E. All authors have read and agreed to the published version of the manuscript.

Additional information

Funding

This research was supported by The Science, Research and Innovation Promotion Funding (TSRI) (Grant no. FRB650070/0168). This research block grants was managed under Rajamangala University of Technology Thanyaburi (FRB65E0708).