Department of Chemical Engineering and Metallurgy, Clean Technology and Applied Materials Research Group, South Africa.
Biotechnology and Chemistry Department, Vaal University of Technology, South Africa.
J Environ Sci Health A Tox Hazard Subst Environ Eng. 2024;59(2):64-75. doi: 10.1080/10934529.2024.2331942. Epub 2024 Mar 21.
Cellulose was isolated from recycled pulp and paper sludge and used to synthesize cellulose nanocrystals. Response surface methodology and Box-Behnken design model were used to predict, improve, and optimize the cellulose isolation process. The optimal conditions were a reaction temperature of 87.5 °C, 180 min with 4% sodium hydroxide. SEM and TEM results revealed that the isolated cellulose had long rod-like structures of different dimensions than CNCs with short rod-like structures. The crystallinity index from XRD significantly increased from 41.33%, 63.7%, and 75.6% for Kimberly mill pulp sludge (KMRPPS), chemically purified cellulose and cellulose nanocrystals, respectively. The TGA/DTG analysis showed that the isolated cellulosic materials possessed higher thermal stability. FTIR analysis suggested that the chemical structures of cellulose and CNCs were modified by chemical treatment. The cellulose surface was highly hydrophilic compared to the CNCs based on the high water holding capacity of 65.31 ± 0.98% and 83.14 ± 1.22%, respectively. The synthesized cellulosic materials portrayed excellent properties for high-end industrial applications like biomedical engineering, advanced materials, nanotechnology, sustainable packaging, personal care products, environmental remediation, additive manufacturing, etc.
从回收的纸浆和造纸污泥中分离出纤维素，并将其用于合成纤维素纳米晶体。响应面法和 Box-Behnken 设计模型用于预测、改进和优化纤维素分离过程。最佳条件为反应温度 87.5°C，氢氧化钠浓度 4%，反应时间 180 分钟。SEM 和 TEM 结果表明，与具有短棒状结构的 CNC 相比，分离得到的纤维素具有不同尺寸的长棒状结构。XRD 的结晶度指数分别从 Kimberly 磨浆污泥（KMRPPS）、化学纯化纤维素和纤维素纳米晶体的 41.33%、63.7%和 75.6%显著增加。TGA/DTG 分析表明，分离得到的纤维素材料具有更高的热稳定性。FTIR 分析表明，纤维素和 CNCs 的化学结构通过化学处理发生了改变。基于水保持能力分别为 65.31±0.98%和 83.14±1.22%，纤维素的表面比 CNCs 具有更高的亲水性。所合成的纤维素材料具有出色的性能，可用于高端工业应用，如生物医学工程、先进材料、纳米技术、可持续包装、个人护理产品、环境修复、增材制造等。
