Keratin is a potential raw material to meet the growing demand for bio-based materials with special properties. Keratin can be obtained from feathers, a by-product from the poultry industry. One approach for keratin valorization is to use the protein to improve the properties of already existing cellulose and lignin-based materials to meet the requirements for replacing fossil-based plastics. To ensure a successful combination of keratin with lignocellulosic building blocks, keratin must have an affinity to these substrates. Hence, we used quartz crystal microbalance with a dissipation monitoring (QCM-D) technique to get a detailed understanding of the adsorption of keratin peptides onto lignocellulosic substrates and how the morphology of the substrate, pH, ionic strength, and keratin properties affected the adsorption. Keratin was fractionated from feathers with a scalable and environmentally friendly deep eutectic solvent process. The keratin fraction used in the adsorption studies consisted of different sized keratin peptides (about 1–4 kDa), which had adopted a random coil conformation as observed by circular dichroism (CD). Measuring keratin adsorption to different lignocellulosic substrates by QCM-D revealed a significant affinity of keratin peptides for lignin, both as smooth films and in the form of nanoparticles but only a weak interaction between cellulose and keratin. Systematic evaluation of the effect of surface, media, and protein properties enabled us to obtain a deeper understanding of the driving force for adsorption. Both the structure and size of the keratin peptides appeared to play an important role in its adsorption. The keratin–lignin combination is an attractive option for advanced material applications. For improved adsorption on cellulose, modifications of either keratin or cellulose would be required.

中文翻译：

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角蛋白肽对纤维素和木质素的亲和力：先进生物基材料的基础研究

角蛋白是一种潜在的原材料，可以满足对具有特殊性能的生物基材料日益增长的需求。角蛋白可以从羽毛中获得，羽毛是家禽业的副产品。角蛋白增值的一种方法是使用蛋白质来改善现有的纤维素和木质素基材料的性能，以满足替代化石基塑料的要求。为了确保角蛋白与木质纤维素结构单元的成功结合，角蛋白必须对这些底物具有亲和力。因此，我们使用石英晶体微量天平和耗散监测 (QCM-D) 技术来详细了解角蛋白肽在木质纤维素基质上的吸附以及基质的形态、pH、离子强度和角蛋白特性如何影响吸附. 通过可扩展且环保的深共熔溶剂工艺从羽毛中分离出角蛋白。吸附研究中使用的角蛋白部分由不同大小的角蛋白肽（约 1-4 kDa）组成，它们采用圆二色性 (CD) 观察到的无规卷曲构象。通过 QCM-D 测量角蛋白对不同木质纤维素底物的吸附揭示了角蛋白肽对木质素的显着亲和力，无论是光滑的薄膜还是纳米颗粒的形式，但纤维素和角蛋白之间的相互作用很弱。对表面、介质和蛋白质特性影响的系统评估使我们能够更深入地了解吸附的驱动力。角蛋白肽的结构和大小似乎在其吸附中起重要作用。角蛋白-木质素组合是先进材料应用的一个有吸引力的选择。为了改善对纤维素的吸附，需要对角蛋白或纤维素进行修饰。