Graduate School of Agricultural and Life Science, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan.
Biomacromolecules. 2012 Feb 13;13(2):553-8. doi: 10.1021/bm201659b. Epub 2012 Feb 1.
An environmentally benign surface modification process for plastic films was demonstrated by fabricating composite coatings through layer-by-layer assembly with green solid materials: aqueous dispersions of two kinds of crystalline polysaccharide nanofibrils. Anionic cellulose nanofibrils were obtained by the TEMPO (2,2,6,6-tetramethylpiperidine-1-oxyl radical)-mediated oxidation of native cellulose, while cationic β-chitin nanofibrils were prepared by the protonation of squid pen chitin. Uniform layer depositions, driven by electrostatic attraction and enhanced by hydrogen bonding, were observed on silicon wafers and then reproduced onto poly(ethylene terephthalate) films. Contact angle measurements and dyeing tests on the resulting films revealed their hydrophilic nature and the sorption of both charged and uncharged substances. Antireflection properties were also confirmed via the light transmittance measurements. As might be presumed from all these properties, this composite coating exhibited its unique behavior largely due to its structure, which was distinct from both those of nanofibril cast films and polymer films.
两种结晶多糖纳米纤维的水性分散体，制备了复合涂层，从而展示了一种环保的塑料薄膜表面改性方法。阴离子纤维素纳米纤维是通过 TEMPO（2,2,6,6-四甲基哌啶-1-氧自由基）介导的天然纤维素氧化获得的，而阳离子β-壳聚糖纳米纤维是通过鱿鱼笔壳聚糖的质子化制备的。在硅片上观察到均匀的层沉积，这是由静电吸引驱动的，并通过氢键增强，然后将其复制到聚对苯二甲酸乙二醇酯薄膜上。对所得薄膜进行接触角测量和染色试验表明其具有亲水性以及带电荷和不带电荷物质的吸附性。还通过透光率测量证实了其具有抗反射性能。从所有这些特性可以推测，这种复合涂层的独特行为主要归因于其结构，这与纳米纤维铸膜和聚合物膜的结构明显不同。
