Fabrication and characterisation of Slippery Icephobic Coatings for application to High Voltage Insulators

Slippery liquid-infused porous surface (SLIPS) based on Nepenthes pitcher plant has attracted increasing interest in many applications, particularly for mitigating icing hazard. Aside from exhibiting a water repellency, such surfaces have low contact angle hysteresis of <2.5° and low tilt angle of <5°. Nonetheless, SLIPS still suffer from challenges related to the oil depletion that reduces their service life. Herein, two different approaches, namely, microtexturing and the use of oil absorbent, are presented to effectively produce the slippery surfaces for the enhanced durability of engineered lubricant-infused materials. In the first approach, the replication method was employed to produce liquid-infused textured surfaces (LITS) through the chemical etching technique. Analysis such as lubricant depletion/recovery, confirmed that the presence of microtextures and lubricant viscosity can have significant roles in controlling the oil migration rate. Furthermore, merging microtexturing and slipperiness in LITS can enhance the icephobic performance. Such surface demonstrated an ice adhesion strength of less than 20 kPa, which is four orders of magnitude lower than the pristine surface. Furthermore, LITS can offer more long-lasting icephobic properties compared with pristine surface lacking microtextures. For the second strategy, the lubricant-loaded carriers were used to prohibit the rapid oil consumption, thus prolonging the life service of the prepared coatings. Accordingly, the negative pressure was applied to promote the incorporation of the lubricant within carrier pores and increase the carrier loading capacity. For this purpose, the thermogravimetric analysis (TGA), and the BET (Brunauer, Emmett and Teller) method have been used to evaluate the lubricant infusion quantitively. High oil content (around 50 wt. %) has been commonly used to enhance icephobic performance, but the presence of excessive amount of lubricant within the matrix can result in decreased mech