Development of durable and superhydrophobic nanodiamond coating on aluminum surfaces for improved hygiene of food contact surfaces

• Published in: Journal of food engineering 2021-06, Vol.298, p.110487, Article 110487
• Main Authors: Liu, Shuhao, Ulugun, Beril, DeFlorio, William, Arcot, Yashwanth, Yegin, Yagmur, Salazar, Karla Solis, Castillo, Alejandro, Taylor, T. Matthew, Cisneros-Zevallos, Luis, Akbulut, Mustafa
• Format: Article
• Language: English
• Subjects: Aluminum; Anti-adhesion; Food safety; Food-contact surfaces; Nanodiamond; Pathogens
• ISSN: 0260-8774; 1873-5770
• DOI: 10.1016/j.jfoodeng.2021.110487

Foodborne illness outbreaks caused by bacterial pathogens may take place on a large scale and result in millions of hospitalizations and thousands of deaths every year throughout the world. One key strategy for dealing with this global issue is the design of smart surfaces and coatings which inhibit and reduce bacterial attachment. This can mitigate contamination and cross-contamination during farm-to-table food processing, promoting food safety, and hygiene. Herein, we reported a durable superhydrophobic coating on aluminum surfaces fabricated by sequential deposition of ultrahard nanodiamond, self-assembly of l-3,4-dihydroxyphenylalanine (l-dopamine), and chemical modification with an organoflurosilane. This coating achieved static, advancing, and receding water contact angles of 159.0 ± 2.5°,154.0 ± 2.4°; and 153.7 ± 1.7°, respectively, representing water super-repellency with a low overall root mean square (rms) roughness of 173.5 ± 69.6 nm. In comparison to the bare, unmodified aluminum, the coated aluminum surfaces prevented the attachment of 99.5% of applied Escherichia coli O157:H7 (E.coli O157:H7) and 99.0% of Staphylococcus aureus (S. aureus) cells. In addition, due to the presence of nanodiamond building blocks, the coated surfaces demonstrated a high mechanical resistance against scratching and endured at least 10,000 shearing/rubbing cycles with a nylon surface. Overall, we anticipate that implementation of this coating could improve safety and hygiene of food-contact surfaces that require harsher mechanical operational conditions. •Development of biocompatible nanodiamond-based superhydrophobic coating on aluminum surfaces.•Attachment of Escherichia coli O157:H7 and Staphylococcus aureus was reduced by >99.0%.•Superhydrophobic aluminum surfaces exhibited excellent mechanical resistance against polymer scratching.•Bacterial antiadhesion properties are based on the minimized contact area and weak intermolecular interactions.•The proposed superhydrophobic coating can be applied on metal food-contact surfaces.