Supercritical CO2-assisted synthesis of porphyrin-based covalent organic framework and construction of photodynamic antibacterial textiles

Photodynamic antibacterial therapy (PDAT) is recognized as a promising antibacterial strategy with high antibacterial efficiency and good biosafety. Porphyrin-based covalent organic frameworks (Por-COFs) with porous conjugated structures and exceptional stability serve as ideal platforms for high-performance in PDAT. Nevertheless, Por-COF synthesis faces crystallinity loss during post-synthetic purification. Here, Por-COFs were synthesized via one-pot reaction with the assistance of supercritical carbon dioxide (scCO 2 ), using 2,5-dihydroxyterephthalaldehyde and 5,10,15,20-tetrakis(4-aminophenyl) porphyrin (TAPP) as monomers, acetic acid (HOAc) as catalyst, and N , N -dimethylformamide (DMF) as co-solvent. The effects of volume ratio of DMF and HOAc ( V (DMF): V (HOAc)), scCO 2 pressure, temperature, and reaction time on the Por-COF morphology and crystallization were investigated. It showed that optimal Por-COFs-HP, with good crystallization, adsorption capacity, photosensitizing reactive oxygen species (ROS) activity and excellent photodynamic antibacterial rates against Staphylococcus aureus ( S. aureus ), Escherichia coli ( E. coli ), Pseudomonas aeruginosa ( P. aeruginosa ), and Staphylococcus epidermidis ( S. epidermidis ) was synthesized under the conditions of V (DMF): V (HOAc)= 8:7, 8 MPa, 70 °C, and 72 h. Por-COFs-HP was incorporated into nylon-66 (PA66) via interfacial polymerization combined with in-situ pulling spinning-coupled twisting to fabricate Por-COFs-HP@PA66 yarns and interwoven fabrics. Photosensitive properties and antibacterial rates of the resultant yarns and fabrics verified the retention of Por-COFs-HP’s excellent antibacterial activity after fabrication into the PA66 matrix. This study establishes a scCO 2 -assisted synthesis route for Por-COFs, and provides key technical references for the development and practical application of COFs-based antibacterial textiles.