Skogberg Anne, Siljander Sanna, Mäki Antti-Juhana, Honkanen Mari, Efimov Alexander, Hannula Markus, Lahtinen Panu, Tuukkanen Sampo, Björkqvist Tomas, Kallio Pasi
BioMediTech Institute and Faculty of Medicine and Health Technology (MET), Tampere University, Korkeakoulunkatu 3, 33720 Tampere, Finland.
Automation Technology and Mechanical Engineering, Faculty of Engineering and Natural Sciences, Tampere University, Korkeakoulunkatu 6, 33720 Tampere, Finland.
Nanoscale. 2022 Jan 6;14(2):448-463. doi: 10.1039/d1nr06937c.
In this study, a nanocellulose-based material showing anisotopic conductivity is introduced. The material has up to 1000 times higher conductivity along the dry-line boundary direction than along the radial direction. In addition to the material itself, the method to produce the material is novel and is based on the alignment of cationic cellulose nanofibers (c-CNFs) along the dry-line boundary of an evaporating droplet composed of c-CNFs in two forms and conductive multi-walled carbon nanotubes (MWCNTs). On the one hand, c-CNFs are used as a dispersant of MWCNTs, and on the other hand they are used as an additional suspension element to create the desired anisotropy. When the suspended c-CNF is left out, and the nanocomposite film is manufactured using the high energy sonicated c-CNF/MWCNT dispersion only, conductive anisotropy is not present but evenly conducting nanocomposite films are obtained. Therefore, we suggest that suspending additional c-CNFs in the c-CNF/MWCNT dispersion results in nanocomposite films with anisotropic conductivity. This is a new way to obtain nanocomposite films with substantial anisotropic conductivity.
在本研究中，引入了一种具有各向异性导电性的纳米纤维素基材料。该材料沿干线边界方向的电导率比沿径向方向的电导率高1000倍。除了材料本身，制备该材料的方法也很新颖，它基于阳离子纤维素纳米纤维（c-CNFs）沿着由两种形式的c-CNFs和导电多壁碳纳米管（MWCNTs）组成的蒸发液滴的干线边界排列。一方面，c-CNFs用作MWCNTs的分散剂，另一方面它们用作额外的悬浮元素以产生所需的各向异性。当不使用悬浮的c-CNFs，仅使用高能超声处理的c-CNF/MWCNT分散体制备纳米复合薄膜时，不存在导电各向异性，而是获得均匀导电的纳米复合薄膜。因此，我们认为在c-CNF/MWCNT分散体中悬浮额外的c-CNFs会导致具有各向异性导电性的纳米复合薄膜。这是获得具有显著各向异性导电性的纳米复合薄膜的一种新方法。
