Departamento de Ingeniería en Maderas DIMAD , Universidad del Bío-Bío , Av. Collao 1202, Casilla 5-C , Concepción 4081112 , Chile.
Biobased Colloids and Materials, Department of Bioproducts and Biosystems, School of Chemical Engineering , Aalto University , FI-00076 Espoo , Finland.
Biomacromolecules. 2019 Jan 14;20(1):502-514. doi: 10.1021/acs.biomac.8b01554. Epub 2018 Dec 26.
Cellulose nanofiber films (CNFF) were treated via a welding process using ionic liquids (ILs). Acid-base-conjugated ILs derived from 1,5-diazabicyclo[4.3.0]non-5-ene [DBN] and 1-ethyl-3-methylimidazolium acetate ([emim][OAc]) were utilized. The removal efficiency of ILs from welded CNFF was assessed using liquid-state nuclear magnetic resonance (NMR) spectroscopy and Fourier transform infrared spectroscopy (FTIR). The mechanical and physical properties of CNFF indicated surface plasticization of CNFF, which improved transparency. Upon treatment, the average CNFF toughness increased by 27%, and the films reached a Young's modulus of ∼5.8 GPa. These first attempts for IL "welding" show promise to tune the surfaces of biobased films, expanding the scope of properties for the production of new biobased materials in a green chemistry context. The results of this work are highly relevant to the fabrication of CNFFs using ionic liquids and related solvents.
纤维素纳米纤维薄膜（CNFF）通过使用离子液体（ILs）的焊接工艺进行处理。使用了源自 1,5-二氮杂双环[4.3.0]壬-5-烯[DBN]和 1-乙基-3-甲基咪唑鎓乙酸盐([emim][OAc])的酸碱共轭 ILs。使用液体核磁共振（NMR）光谱和傅里叶变换红外光谱（FTIR）评估了从焊接的 CNFF 中去除 IL 的效率。CNFF 的机械和物理性能表明 CNFF 的表面增塑，提高了透明度。处理后，CNFF 的平均韧性提高了 27%，并且薄膜达到了约 5.8 GPa 的杨氏模量。IL“焊接”的这些首次尝试有望调节生物基薄膜的表面，在绿色化学背景下扩展新型生物基材料生产的性能范围。这项工作的结果与使用离子液体和相关溶剂制造 CNFF 高度相关。
