EUROPEAN CONGRESS AND EXHIBITION ON ADVANCED MATERIALS AND PROCESSES - EUROMAT 2021

One approach in the development of the multifunctional coatings is to learn from nature and to mimic it. Inspired from the Nepenthes pitcher plant the slippery liquid infused porous surfaces (SLIPS) attracted a lot of attention during the last years. The SLIPS coatings were stated to offer various properties such as anti-ice, scratch resistance, self-healing, self-cleaning, liquids repellency, anti-fouling, protection against corrosion.
The present approach followed to fabricate the SLIPS porous surfaces is use the electrospinning technique to produce polymeric nanofibers mats. Nanofibers with dimension below 400 nm were successfully produced, as confirmed by SEM investigations. For optimization purposes electrospinning process parameters were tailored: applied voltage between 5 and 12 kV and the distance between collector and needle was increased from 8 to 18 cm. As measured by FIB cross sections, the nanofibers layer thickness was tailored between 1 and 100 µm as a function of electrospinning time and flow rate used. Generated nanofibers mats were infiltrated with oils to generate the SLIPS surfaces.
Surface wettability of various combinations of nanofibers and oils was investigated. The loss of lubricants over time was recoded and changes of the surface wettability due to this were followed by performing contact angle measurement. The investigations demonstrate that the nanofibers mats have self-cleaning properties. Contact angle with temperature down to -20°C were performed to have info related to the nanofibers layers icephobic properties. Furthermore, nanofibers masts were immersed in corrosive solutions with the pH ranging from 1 to 14 for various periods of time (from 1 hour to 24 hours). Nanofibers structure is preserved for corrosive droplets with a pH of 1 and 7, while for a higher pH of 14 their morphology is lost.