Department of Materials Science, University of Milano - Bicocca, via Cozzi 55, 20131 Milano, Italy.
Department of Materials Science, University of Milano - Bicocca, via Cozzi 55, 20131 Milano, Italy.
Carbohydr Polym. 2024 Jun 1;333:121981. doi: 10.1016/j.carbpol.2024.121981. Epub 2024 Feb 24.
In view of health and environmental concerns, together with the upcoming restrictive regulations on per- and polyfluoroalkyl substances (PFAS), less impactful materials must be explored for the hydrophobization of surfaces. Polysaccharides, and especially chitosan, are being explored for their desirable properties of film formation and ease of modification. We present a PFAS-free chitosan superhydrophobic coating for textiles deposited through a solvent-free method. By contact angle analysis and drop impact, we observe that the coating imparts hydrophobicity to the fabrics, reaching superhydrophobicty (θ = 151°, θ = 136°) with increased amount of coating (from 1.6 g/cm). This effect is obtained by the combination of chemical water repellency of the modified chitosan and the nano- and micro-roughness, assessed by SEM analysis. We perform a comprehensive study on the durability of the coatings, showing good results especially for acidic soaking where the hydrophobicity is maintained until the 8th cycle of washing. We assess the degradation of the coating by a TGA-IR investigation to define the compounds released with thermal degradation, and we confirm the coating's biodegradability by biochemical oxygen consumption. Finally, we demonstrate its biocompatibility on keratinocytes (HaCaT cell line) and fibroblasts (HFF-1 cell line), confirming that the coating is safe for human skin cells.
鉴于健康和环境方面的考虑，再加上即将对全氟和多氟烷基物质 (PFAS) 实施限制规定，必须探索对表面进行疏水处理时影响较小的材料。多糖，尤其是壳聚糖，因其成膜和易于修饰的特性而受到关注。我们通过无溶剂方法制备了一种无 PFAS 的壳聚糖超疏水涂层，用于纺织品。通过接触角分析和液滴冲击，我们观察到该涂层使织物具有疏水性，随着涂层量的增加（从 1.6 g/cm 增加到 1.6 g/cm），达到超疏水性（θ=151°，θ=136°）。这种效果是通过改性壳聚糖的化学拒水性和 SEM 分析评估的纳米和微观粗糙度的结合来实现的。我们对涂层的耐久性进行了全面研究，结果表明，特别是在酸性浸泡条件下，疏水性保持良好，直到第 8 次洗涤循环。我们通过 TGA-IR 研究评估了涂层的降解情况，以确定随热降解释放的化合物，并通过生化需氧量消耗证实了涂层的生物降解性。最后，我们在角蛋白细胞（HaCaT 细胞系）和成纤维细胞（HFF-1 细胞系）上证明了其生物相容性，证实了该涂层对人体皮肤细胞是安全的。
