关键词: 蛋白质, 类淀粉样聚集, 表面改性, 纤维, 功能性纺织品

Abstract:

Objective Flexible wearable smart fabric is one of the ideal forms of the next generation of flexible wearable devices, in which the functional fiber construction plays a crucial role. In order to address the issues related to current surface functionalization strategies for polymer fibers such as complex modification processes and poor coating stability, this study developed a fiber surface functionalization strategy based on protein amyloid-like aggregation.

Method This strategy involves immersing polyester fibers in a lysozyme phase transition solution containing functional substances, which can form stable functional coatings on the fiber surface at room temperature. Silver nanoparticle coating-modified fibers and fabrics, quantum dot-modified fibers, and PEG-modified fibers and fabrics were prepared. During the preparation process, the disulfide bonds in the protein molecules are broken and the resulted unfolded molecular chains undergo amyloid-like aggregation to form protein nanocoatings containing functional units on the fiber surface. The electrical conductivity, antibacterial property, luminescence behavior, hydrophilicity and coating stability of the functional fibers and fabrics were characterized.

Results Various functional polyester fibers were fabricated based on the amyloid-like protein aggregation. The proteinaceous coating with specific functions was easily formed on the fibers surface within a short time under ambient conditions, exhibiting exceptional interfacial adhesion to withstand bending stresses and prevent functional coating detachment during the prolonged usage. The silver nanoparticle coating-modified fiber was prepared by means of amyloid-like protein aggregation induced by metal ions. The results suggested that when the lysozyme concentration was 0.02 mg/mL, the silver nanoparticle coating-modified fiber had optimal electrical conductivity with a resistance of only 1.39 Ω when length of fiber was 1 cm. It could withstand 37 tear-off cycles in a 3M tape test and showed no significant change in resistance after 20 000 bending cycles, indicating the high stability of the formed silver nanoparticle coating. Furthermore, the silver nanoparticle coating-modified polyester fabrics exhibited certain antibacterial activity. Therefore, silver nanoparticle coating-modified fibers can be used to prepare the conductive antibacterial textiles. Quantum dot-modified fibers exhibited fluorescence under UV irradiation and the fluorescence properties were closely related to the concentration of lysozyme. With the increase of lysozyme concentration, the fluorescence on the fiber surface first increased and then decreased. When the lysozyme concentration was 5 mg/mL, it had the strongest fluorescence intensity and maintained good stability with no significant decrease in fluorescence intensity after 10 000 bending tests. To improve the hydrophilicity of polyester fibers, the lysozyme-PEG conjugates were firstly synthesis. The lysozyme-PEG coating was formed on the fiber surface significantly improving its hydrophilicity, which was evaluated through the characterizations of water drop immersion and moisture permeability. It is demonstrated that water drop immersion time decreased from 24 s to 2.5 s and moisture permeability increased from 4 500 g/(m²·d) to 5 800 g/(m²·d). Furthermore, the water drops immersion time and moisture permeability of PEG modified fabrics was less affected by the cycle of bending.

Conclusion Inspired by the strong adhesion of protein amyloid structure in nature, functional nanocoatings on the surface of fibers were constructed successfully with high curvature based on the amyloid-like protein aggregation strategy. The strategy is simple, efficient, and environmentally friendly, and the coating function is highly adjustable by controlling the functional substances. Notably, the coating can adhere stably on the surface, effectively solving the coating debonding problem during long-term use. It provides a new method for fiber surface functionalization and has great application prospects in the field of flexible intelligent wearable fabrics.

Key words: protein, amyloid-like aggregation, surface modification, fiber, functional fabric