Sterilization of escherichia coli in cotton fabric by supercritical carbon dioxide fluid

Abstract Sterilizing clothing is essential due to the health risks posed by bacteria, which thrive in fabrics. Traditional sterilization methods have limitations, making supercritical carbon dioxide (scCO 2 ) an innovative alternative. This technology effectively inactivates microorganisms at lower temperatures and moderate pressures without generating waste. Using first-order inactivation kinetics, results show that increased temperature and pressure lead to higher E. coli mortality rates. The stages of the deactivation process can be divided into two stages: a rapid phase lasting 1 to 15 minutes, followed by a slower phase after 15 minutes. Performance tests reveal that scCO 2 -treated cotton fibers exhibit greater surface roughness, fracture strength, and elongation, though their structure becomes denser and permeability decreases. Under optimal conditions of 50°C, 12 MPa pressure, and 25 minutes, the inactivation logarithm reaches 6.7 orders of magnitude, suggesting a promising new method for fabric sterilization.