Polypyrrole-based finishing for textiles with antibacterial, biodegradation-resistant, and hydrophobic properties

Polypyrrole is a conductive and multifunctional polymer obtained from pyrrole, which can be used as a finishing agent on textiles to impart antibacterial, biodegradation-resistant, and hydrophobic properties by creating a durable coating on the fibre surface. These finishes are achieved through in-situ polymerisation (1), spray coating (2), and ultrasound-enhanced deposition (3), which make polypyrrole versatile for applications on various fibres. The positive charges on the polypyrrole backbone confer a biocidal effect, making it difficult for microbes to grow and ultimately killing them (1,3–5) with an efficacy approaching 100%. However, polypyrrole nanoparticles are safe and biocompatible for human cells (2). The antibacterial efficacy is affected by the finishing conditions (1,3), the dopants used in polypyrrole synthesis (6), and the type of fibre in the fabrics (5). In particular, the increase in polypyrrole amount is not necessarily associated with a corresponding increase in antibacterial activity of the fabrics (5). On the other hand, polypyrrole significantly hindered the biodegradation of biodegradable fibres in soil (7), likely due to its inherent antimicrobial properties. In particular, polypyrrole-treated cellulose fabrics exhibited negligible weight loss and morphological changes during biodegradation tests, making the material an attractive option for geotextiles. Finally, the hydrophobic nature of the dopant embedded into the polypyrrole makes the coated fabrics highly hydrophobic (8) with a water contact angle of 111°.