Remote control of biofouling by heating PDMS/MnZn ferrite nanocomposites with an alternating magnetic field

BACKGROUND: The accumulation of unwanted microorganisms on wetted surfaces, leading to surface damage and contamination, is a common and significant global issue. RESULTS: Herein, we report a novel technique where the growth of microorganisms can be readily controlled by coating the surfaces with a polydimethylsiloxane (PDMS)/Mn_0.8Zn_0.2Fe₂O₄ (manganese-zinc ferrite) nanocomposite followed by applying alternating magnetic field (AMF). The PDMS/MnZn ferrite nanocomposite is light weight and thermally stable (up to ∼ 330 °C) that can form a flexible coating. PDMS also provides hydrophobicity, which is further enhanced by the addition of Mn and Zn. The improved hydrophobicity makes the coated surface less susceptible to biofilm formation. When external AMF was applied to nanocomposites containing various MnZn ferrite nanoparticle loads of 10%, 20% and 30%, the temperature of the surface of nanocomposites reached to 80, 120 and 160 °C, respectively. Successful biofilm deactivation was achieved by heating the nanocomposites via AMF application, as shown in the biofilm test where up to ∼ 70% of the Pseudomonas aeruginosa PAO1 biofilm cells were killed when the AMF was applied for 20 min to the nanocomposites containing 30% nanoparticles. CONCLUSION: Coating the surface with PDMS/MnZn ferrite nanocomposites followed by applying external AMF can be an effective way to remove biofilm remotely in a wide range of applications.