Szekeres G P, Nemeth Z, Schrantz K, Hernadi K, Graule T
Empa, Swiss Federal Laboratories for Materials Science and Technology, Laboratory for High Performance Ceramics, Überlandstrasse 129, Dübendorf, CH-8600, Switzerland.
Department of Applied and Environmental Chemistry, University of Szeged, Rerrich tér 1, Szeged H-6720, Hungary.
J Nanosci Nanotechnol. 2018 Apr 1;18(4):3000-3005. doi: 10.1166/jnn.2018.14536.
An easy way of controlling pore sizes during the preparation of cellulose nanopapers using nanofibrillated cellulose and different solvents, such as water, ethanol and acetone, was applied in this study. A possible mathematical model is also presented, that describes the occuring processes, which model is based on simple probability theory computations taking the number of possible hydrogen bonds into consideration. This model allows the better understanding of the solvent dependence of pore formation on a molecular level. For the comparison of the effects of solvents two different series of cellulose nanopapers were prepared. In the cases of both series, an aqueous nanofibrillated cellulose suspension was used for the fabrication of nanopapers, and different solvents were used for their modification. Based on scanning electron microscopy images and mercury intrusion porosimetry data it has been concluded, that using different solvents was a crucial point in controlling pore sizes. A theory about the swelling effects, as well as the formation and decomposition of nanofibrillated cellulose aggregates based on the hydrogen bonding abilities of the solvents, was proposed and proven in this paper. As-prepared nanocellulose papers can be excellent candidates for further applications as support materials (e.g., virus filtration).
本研究采用了一种简便方法来控制使用纳米纤化纤维素和不同溶剂（如水、乙醇和丙酮）制备纤维素纳米纸期间的孔径。还提出了一个可能的数学模型，该模型描述了所发生的过程，其基于考虑了可能氢键数量的简单概率论计算。此模型有助于在分子水平上更好地理解孔形成对溶剂的依赖性。为了比较溶剂的影响，制备了两个不同系列的纤维素纳米纸。在这两个系列中，均使用水性纳米纤化纤维素悬浮液来制造纳米纸，并使用不同溶剂对其进行改性。基于扫描电子显微镜图像和压汞孔隙率测定数据得出结论，使用不同溶剂是控制孔径的关键因素。本文提出并证明了一种基于溶剂氢键能力的关于溶胀效应以及纳米纤化纤维素聚集体形成与分解的理论。所制备的纳米纤维素纸作为支撑材料（如病毒过滤）的进一步应用可能是极佳的候选材料。
