Abstract

Inexpensive biodegradable and biocompatible materials, which enable a combination of high hydrophobicity with good adhesion of water droplets, as on rose petals, are in demand for modern microfluidic systems. To obtain surfaces with rose petal-effect we used nanocellulose as bio-based non-toxic material with nanoscale structure. Two types of lightweight flexible nanocellulose films were investigated, differing in raw material and manufacturing method, NC_m from Miscanthus x giganteus and NC_p from Phragmites australis. They were coated with semiconductor cuprous iodide (CuI) films using Successive Ionic Layer Adsorption and Reaction method, thereby creating hierarchical structures. The deposition of CuI films increased roughness of the NC_p and NC_m surfaces and ensured high hydrophobicity of the obtained CuI/NC_p and CuI/NC_m film samples due to chemical modification of nanocellulose. These samples have water contact angles 143°, and large wetting hysteresis above 80°. The water droplets sticking on them testify to the Cassie-impregnating state. On the inclined surfaces of the CuI/NC_p and CuI/NC_m film samples water droplets do not roll down even if tilt angles reach 90°. So, in this study, we report a facile process for making green, renewable, and biodegradable material with surface functionalities that are relevant for lab-on-a-chip microfluidic devices.

Graphic abstract

中文翻译：

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基于由纳米结构 CuI 层包覆的纳米纤维素薄膜，具有玫瑰花瓣效应的高度疏水表面

摘要

现代微流体系统需要廉价的可生物降解和生物相容性材料，这些材料能够将高疏水性与良好的水滴粘附性结合起来，如玫瑰花瓣。为了获得具有玫瑰花瓣效果的表面，我们使用纳米纤维素作为具有纳米级结构的生物基无毒材料。研究了两种类型的轻质柔性纳米纤维素薄膜，原材料和制造方法不同，来自芒草 x giganteus 的NC _m和来自芦苇的NC _p. 它们使用连续离子层吸附和反应方法涂上半导体碘化亚铜 (CuI) 薄膜，从而形成分层结构。由于纳米纤维素的化学改性，CuI 薄膜的沉积增加了 NC _p和 NC _m表面的粗糙度，并确保了所获得的 CuI/NC _p和 CuI/NC _m薄膜样品的高疏水性。这些样品的水接触角为 143°，润湿滞后大于 80°。粘在它们上面的水滴证明了卡西浸渍的状态。在 CuI/NC _p和 CuI/NC _m的斜面上即使倾斜角度达到 90°，薄膜样品水滴也不会滚落。因此，在这项研究中，我们报告了一种制造绿色、可再生和可生物降解材料的简便方法，该材料具有与芯片实验室微流体设备相关的表面功能。

图形摘要