UV-to-IR highly transparent ultrathin diamond nanofilms with intriguing performances : Anti-fogging, self-cleaning and self-lubricating

Fouling and abrasive wear severely affect the transparency of optical sensors and windows employed in marine, biomedical and aerospace applications. Herein, we report a strategy to create a robust and superhydrophilic surface based on ultrathin transparent diamond nanofilms synthesized by an enhanced self-assembly seeding and chemical vapor deposition approach. A quartz glass coated with an ultrathin (~50 nm) and smooth diamond nanofilm exhibits a high optical transparency of 90% in air and 98% underwater in UV–Vis range. Especially, an IR transmittance of 85% is recorded, which is even 10% higher than that of uncoated quartz. The transparent diamond nanofilms are superhydrophilic and underwater superoleophobic after oxygen plasma treatment, leading to the anti-fogging capability in air and underwater self-cleaning of oil. Importantly, the quartz coated with the diamond nanofilms shows excellent mechanical robustness with unchanged morphology and transparency under severe sandblasting condition. Moreover, this ultrathin diamond nanofilm can make the deposited substrates self-lubricating, which significantly decreased the friction coefficient of the quartz from 0.18 to 0.05. High transparence from ultraviolet to infrared and intriguing performances of the ultrathin diamond nanofilms make them promising for several important applications, such as aircraft fairing and window, optical lens, and marine exploration, etc.