Will the Fluorine-Free Textiles Cover us from the Rain and Dirt in the Future?: A Review on Current Water Repellent and Stain Resistant Durable Water Repellents for Textiles

Industries have been utilizing amphiphobicity of durable water repellents (DWRs) to make textiles for decades for both water repellency and stain resistance. However, polymeric per- and polyfluoroalkyl substances (PFASs) were used the most often until today since fluorinated chemicals own super low surface energies and amphiphobic fluorinated moieties. As environmental issues and health concerns have been raised, researchers started investigating environmentally friendly non-fluorinated DWRs. This review paper aims to explore typical works mainly consisting of long-chain PFASs based, short-chain PFASs based, silicones-based, and hydrocarbonsbased DWRs, to exhibit the principles behind their amphiphobicity, and to compare and discuss their water repellency, oil repellency, and durability. In general, neither silicones nor hydrocarbons possess satisfying stain resistance and durability as fluorinated materials, even if the hydrophobicity can reach a similarly high value. In this work, the major purpose is to point out the advantages and corresponding limitations of different types of DWRs for industries and suggest potential improvements that other researchers can make in the future.