Graduate School of Bioresource and Bioenvironmental Sciences, Kyushu University, 744, Motooka, Nishi-ku, Fukuoka 819-0395, Japan.
Chuetsu Pulp & Paper Co., Ltd., 282, Yonejima, Takaoka, Toyama 933-8533, Japan.
Biomacromolecules. 2021 Feb 8;22(2):620-628. doi: 10.1021/acs.biomac.0c01464. Epub 2021 Jan 8.
Cellulose nanofibrils, which attract extensive attention as a bio-based, sustainable, high-performance nanofibril, are believed to be predominantly hydrophilic. This study aimed to prove the presence of an amphiphilic "Janus-type fiber surface" in water with hydrophobic and hydrophilic faces in a cellulose nanofibril (ACC-CNF) that was prepared by the aqueous counter collision method. We clarified the surface characteristics of the ACC-CNF by confocal laser scanning microscopy with a carbohydrate-binding module and congo red probes for the hydrophobic planes on the cellulose fiber surfaces and calcofluor white as hydrophilic plane probes. The results indicated the presence of both characteristic planes on a single ACC-CNF surface, which verifies an amphiphilic Janus-type structure. Both hydrophobic probes adsorbed onto ACC-CNFs for the quantitative evaluation of the degree of ACC-CNF surface hydrophobicity by Langmuir's adsorption theory based on the optimal maximum adsorption amounts for various starting raw material types.
纤维素纳米纤维作为一种基于生物的、可持续的、高性能的纳米纤维，受到了广泛的关注。本研究旨在证明在通过水相反撞法制备的纤维素纳米纤维（ACC-CNF）中，存在具有疏水和亲水表面的两亲性“双面纤维表面”。我们通过带有碳水化合物结合模块的共焦激光扫描显微镜和用于纤维素纤维表面疏水平面的刚果红探针以及亲水平面探针 Calcofluor White 阐明了 ACC-CNF 的表面特性。结果表明，单个 ACC-CNF 表面上存在两种特征平面，这验证了两亲性 Janus 型结构的存在。两种疏水探针都吸附在 ACC-CNF 上，根据各种起始原料类型的最佳最大吸附量，基于 Langmuir 吸附理论对 ACC-CNF 表面疏水性的程度进行定量评估。
