Department of Chemical Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia; Department of Chemistry, Faculty of Science, University of Malaya, 50603 Kuala Lumpur, Malaysia.
Department of Chemical Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia.
Carbohydr Polym. 2017 Oct 1;173:91-99. doi: 10.1016/j.carbpol.2017.05.084. Epub 2017 May 30.
Recently, surface functionality and thermal property of the green nanomaterials have received wide attention in numerous applications. In this study, microcrystalline cellulose (MCC) was used to prepare the nanocrystalline celluloses (NCCs) using acid hydrolysis method. The NCCs was treated with TEMPO [(2,2,6,6-tetramethylpiperidin-1-yl)oxy radical]-oxidation to prepare TEMPO-oxidized NCCs. Cellulose nanofibrils (CNFs) also prepared from MCC using TEMPO-oxidation. The effects of rapid cooling and chemical treatments on the thermo-structural property studies of the prepared nanocelluloses were investigated through FTIR, thermogravimetric analysis-derivative thermogravimetric (TGA-DTG), and XRD. A posteriori knowledge of the FTIR and TGA-DTG analysis revealed that the rapid cooling treatment enhanced the hydrogen bond energy and thermal stability of the TEMPO-oxidized NCC compared to other nanocelluloses. XRD analysis exhibits the effect of rapid cooling on pseudo 2 helical conformation. This was the first investigation performed on the effect of rapid cooling on structural properties of the nanocellulose.
最近，绿色纳米材料的表面功能和热性能在众多应用中受到了广泛关注。在这项研究中，使用酸水解法将微晶纤维素 (MCC) 制备成纳米纤维素 (NCC)。用 TEMPO [(2,2,6,6-四甲基哌啶-1-基)氧基自由基] -氧化处理 NCC 以制备 TEMPO 氧化的 NCC。还使用 TEMPO 氧化从 MCC 制备纤维素纳米纤维 (CNF)。通过傅里叶变换红外光谱 (FTIR)、热重分析-导数热重 (TGA-DTG) 和 X 射线衍射 (XRD) 研究了快速冷却和化学处理对制备的纳米纤维素的热结构性能的影响。FTIR 和 TGA-DTG 分析的事后知识表明，与其他纳米纤维素相比，快速冷却处理增强了 TEMPO 氧化的 NCC 的氢键能和热稳定性。XRD 分析显示了快速冷却对拟 2 螺旋构象的影响。这是首次对快速冷却对纳米纤维素结构性能的影响进行的研究。
