The New Silk Road: Silk Fibroin Blends and Composites for Next Generation Functional and Multifunctional Materials Design

Silk Fibroin (SF), a protein typically extracted from Bombyx mori cocoons, is considered to play an essential role in advancing the development of a more sustainable generation of multifunctional materials. The unique properties of SF have led to its widespread application in various fields, including energy harvesting, electronics, and biomedicine. However, to further expand SF's potential and tailor it for specific applications, modifying its main properties and adding novel functional characteristics becomes often necessary. This review offers a comprehensive overview of the most significant modifications of SF and their respective applications. We explore blends and mixtures of SF with emerging bio-based materials, which serve as an excellent platform to enhance SF's processability and functionality. Additionally, we analyze the most relevant fillers, which play a pivotal role in the development of SF composites, enabling the achievement of active and specific behaviors. By examining these aspects, we aim to shed light on the potential of SF as a versatile and customizable material, contributing to the implementation of sustainable and functional materials in various application domains.