New insight into icing and de-icing properties of hydrophobic and hydrophilic structured surfaces based on core–shell particles

Abstract

Icing is an important problem, which often leads to emergency situations in northern countries. The reduction of icing requires a detailed understanding of this process. In this work, we report on a systematic investigation of the effects of geometry and chemical properties of surfaces on the formation of an ice layer, its properties, and thawing. We compare in detail icing and ice thawing on flat and rough hydrophilic and hydrophobic surfaces. We also show advantages and disadvantages of the surfaces of each kind. We demonstrate that water condenses in a liquid form, leading to the formation of a thin continuous water layer on a hydrophilic surface. Meanwhile, separated rounded water droplets are formed on hydrophobic surfaces. As a result of slower heat exchange, the freezing of rounded water droplets on a hydrophobic surface occurs later than the freezing of the continuous water layer on a hydrophilic one. Moreover, growth of ice on hydrophobic surfaces is slower than on the hydrophilic ones, because ice grows due to the condensation of water vapor on already formed ice crystals, and not due to the condensation on the polymer surface. Rough hydrophobic surfaces also demonstrate a very low ice adhesion value, which is because of the reduced contact area with ice. The main disadvantage of hydrophobic and superhydrophobic surfaces is the pinning of water droplets on them after thawing. Flat hydrophilic poly(ethylene glycol)-modified surfaces also exhibit very low ice adhesion, which is due to the very low freezing point of the water-poly(ethylene glycol) mixtures. Water easily leaves from flat hydrophilic poly(ethylene glycol)-modified surfaces, and they quickly become dry. However, the ice growth rate on poly(ethylene glycol)-modified hydrophilic surfaces is the highest. These results indicate that neither purely (super)hydrophobic polymeric surfaces, nor "antifreeze" hydrophilic ones provide an ideal solution to the problem of icing.

Lipid bilayers as potential ice nucleating agents

“…82 This ''structuring'' effect has also been put forward as a key factor regarding the ice nucleating ability of a given surface. 83,84 Here, we focus on the orientational order of the water molecules, as a function of their distance from the centre of the bilayers. In particular, we have investigated the changes in the average value of the angle y defined by the water dipole moment and the z-axis of the simulation box (perpendicular to the bilayers plane).…”

Bio-Inspired Polymeric Structures with Special Wettability and Their Applications: An Overview

“…The literature on the adhesion between frozen oil and micropatterned surfaces is limited; but many efforts have been devoted to exploring possible strategies to remove ice from surfaces, which can all be categorized into either passive strategies or active strategies [184,185,218]. The passive strategy is implemented either by controlling the surface wettability to reduce ice adhesion or by applying mechanical forces to remove the accumulated ice [184,185,218]. This is because superhydrophobic surfaces can be used to delay the ice formation and reduce the contact area, thereby reducing the shear forces between the ice and substrates.…”

“…Among these methods, thermal melting uses sources such as warm air or electrical current and is regarded as one of the most effective ways to remove ice [183,219,220]. One decade-old traditional approach is warm air melting, in which intense warm air is blown onto objects through a special tube [184,185,218]. This raises the temperature of the system quickly, resulting in the melting of ice [183].…”

Polyols-Infused Slippery Surfaces Based on Magnetic Fe3O4-Functionalized Polymer Hybrids for Enhanced Multifunctional Anti-Icing and Deicing Properties

“…24−26 Therefore, the antifreeze liquids were introduced as one component of the slippery liquid lubricants to reduce the freezing point as well as decrease the application cost simultaneously. 27,28 It is well known that the successful construction of a hierarchical micro-/nanosacle rough structure is remarkably crucial for the achievement of SLIPS. 29,30 In our previous work, we have confirmed that the magnetic Fe 3 O 4 nanoparticles are favorable for forming the micro-/nanoscale hierarchical structures.…”