Mikolei Joanna Judith, Helbrecht Christiane, Pleitner Janine Christin, Stanzel Mathias, Pardehkhorram Raheleh, Biesalski Markus, Schabel Samuel, Andrieu-Brunsen Annette
Ernst-Berl Institut für Technische und Makromolekulare Chemie, Macromolecular Chemistry - Smart Membranes, Technische Universität Darmstadt Peter-Grünberg-Straße 8 D-64287 Darmstadt Germany
Paper Technology and Mechanical Process Engineering, Technische Universität Darmstadt Alexanderstraße 8 64283 Darmstadt Germany.
RSC Adv. 2024 Apr 29;14(20):14161-14169. doi: 10.1039/d4ra01957a. eCollection 2024 Apr 25.
Paper-based materials with precisely designed wettabilities show great potential for fluid transport control, separation, and sensing. To tune the wettability of paper, paper sheets are usually modified after the paper manufacturing process. This limits the complexity of the local wettability design. We combined the wettability design of the individual fibres with subsequent paper sheet fabrication through either fibre deposition or fibre printing. Using silica-based cellulose fibre functionalization, the wettability of the paper sheets, containing only one specific fibre type, could be gradually tuned from highly hydrophilic to highly hydrophobic, resulting in water exclusion. The development of a silica-functionalized fibre library containing mesoporous or dense silica coatings, as well as silica with varying precursor compositions, further enabled the variation of the paper wettability and fluid flow. By combining this fibre library with the paper fabrication process by (i) fibre deposition or (ii) fibre printing, the paper wettability architecture and thus the local fibre composition were adjusted without any further processing steps. This enabled the fabrication of papers with wettability integration, such as a wettability pattern or a Janus paper design, containing wettability gradients along the paper sheet cross section. This asymmetric wettability along all three spatial dimensions enabled side-selective oil-water separation.
具有精确设计润湿性的纸质材料在流体传输控制、分离和传感方面显示出巨大潜力。为了调节纸张的润湿性，通常在造纸过程之后对纸张进行改性。这限制了局部润湿性设计的复杂性。我们将单根纤维的润湿性设计与随后通过纤维沉积或纤维印刷制造纸张相结合。通过基于二氧化硅的纤维素纤维功能化，仅包含一种特定纤维类型的纸张的润湿性可以从高亲水性逐渐调节到高疏水性，从而实现防水。包含介孔或致密二氧化硅涂层以及具有不同前驱体组成的二氧化硅的二氧化硅功能化纤维库的开发，进一步实现了纸张润湿性和流体流动的变化。通过将这个纤维库与通过（i）纤维沉积或（ii）纤维印刷的纸张制造过程相结合，无需任何进一步的加工步骤即可调整纸张的润湿性结构以及局部纤维组成。这使得能够制造具有润湿性整合的纸张，例如具有润湿性图案或双面纸设计的纸张，其沿纸张横截面包含润湿性梯度。这种在所有三个空间维度上的不对称润湿性实现了侧向选择性油水分离。
