Electrostatically-Boosted microbial surface Sculpting: Room-Temperature, Low-Energy Paradigm for functionalization of...

Developing green and sustainable biotechnologies for modifying polyethylene terephthalate (PET) fabrics is crucial to overcome their inherent hydrophobicity and expand their application into high-value domains. Conventional modification methods (e.g., alkali treatment, plasma) suffer from fiber damage, high costs, or environmental toxicity. This study demonstrates that a cationic surfactant (polyquaternium-7, PQ-7) can electrostatically switch on the activity of an alkali-tolerant PET-degrading bacterium (strain F6) at room temperature. PQ-7 adsorbs onto the negatively-charged PET surface (ζ potential from -24.6 mV to -7.0 mV), locally enriching OH^- and orientating the ester bonds for nucleophilic attack. This electric-field-like micro-environment lowers the activation barrier for enzymatic hydrolysis without heating. Under the optimized 1.0 g /L PQ-7 condition, bioprocessed fabrics exhibited a moisture transmission rate of 180.6 g/(m²·h) and a friction surface charge density of 4.5 μC/m², both surpassing traditional alkali treatment. Following whole-cell biological treatment, the tensile strength reached 187 N, whereas after alkaline reduction it stood at 122 N. Research has revealed that biological processes generate substantial hydrophilic groups on the fiber surface without penetrating into the fiber interior. This approach enhances performance whilst maintaining structural integrity. Furthermore, the process cuts NaOH use by 77 % and eliminates thermal energy input. This electrostatically-boosted, room-temperature biocatalysis offers a scalable, green route for upgrading PET textiles toward a circular economy.