Slippery Liquid-Infused Porous Surfaces (SLIPS) Using Layer-by-Layer Polyelectrolyte Assembly in Organic Solvent

Abstract

Slippery liquid-infused porous surfaces (SLIPS) have potential impact on a wide range of industries, including healthcare, food packaging, and automobile. A tremendouseffort has been focused on developing novel fabrication methods for making SLIPS. However, current fabrication methods usually involve harsh conditions and complicated postfabrication modifications or are limited to specific substrates. Presented here is a novel method for the fast and facile fabrication of SLIPS. Layer-by-layer (LBL) assembly of branched polyethylenimine and Nafion, a perfluorinated polyelectrolyte, is performed with methanol as the solvent. Hierarchically rough and superhydrophobic surface is obtained directly without further modification on various substrates. The surface properties are shown to highly depend on the LBL assembly parameters, including deposition cycles, dipping time, rinsing time, and drying time between baths. The polyelectrolyte multilayers obtained with this method are infused with Krytox 100 to form SLIPS surfaces, which show excellent omniphobic, antifouling, self-cleaning, flexible, and optical properties. The result of this study not only simplifies the fabrication of SLIPS surfaces, but also provides great insight for making LBL films with specific morphologies.

Porous Layer-by-Layer Films Assembled Using Polyelectrolyte Blend to Control Wetting Properties

“…This is assumed to be because of the film structure with higher interdiffusion and chain entanglement. The degree of ionization in solution is below 10% and 20% for PAA and BPEI at the assembly, pH 3.5 for the PAA and pH 7.5 for the BPEI [ 42 , 46 ]. At this low degree of ionization, the LbL films typically consist of loop-rich intermingled structures because of the more coiled polymer chain conformation [ 32 , 52 ].…”

“…Shiratori et al utilized the porous LbL films of chitin nanofiber/silica nanoparticles in the implementation of SLIPS [ 44 ]. Additionally, the porous LbL films prepared by using azlactone polymers [ 45 ] and hierarchically rough PEI/Nafion LbL films assembled in organic solvents [ 46 ] have been used as porous matrices for SLIPS. Furthermore, the microstructure with a worm-like surface morphology obtained from the pH-amplified exponential growth of the PEI/PAA film, was used for the patterned SLIPS, which can guide the sliding movement of liquid droplets [ 47 ].…”

Weak Polyelectrolytes as Nanoarchitectonic Design Tools for Functional Materials: A Review of Recent Achievements

“…The swelling process was accompanied by structural changes in multilayer films, such as the emergence of holes in PLL/HA films when the NaCl concentration was changed from 0.15 M to 0.48 M [ 105 ] and the growth of pores in (PEI/PAH)/PAA films after the post-assembly pH was decreased to pH 2 [ 106 ]. The potential of such porous coatings was tested for designing slippery liquid-infused porous surfaces [ 106 , 107 ]. Concurrently, the modulation of the mass transport properties of weak polyelectrolyte multilayer films by post-assembly treatment has attracted much attention [ 108 ], leading to systems with tailored functions ( Table 4 ), including ionic current rectification [ 109 ], enhanced Li + conductivity [ 110 ], and filtration [ 111 ].…”

Sustainable, self-cleaning, transparent, and moisture/oxygen-barrier coating films for food packaging

“…[28][29][30][31][32] The second reference is for a self-cleaning food packaging material, which involves the slippery liquid-infused porous surfaces (SLIPS) technology, firstly reported by J. Aizenberg et al 33 In brief, a nanotextured porous surface is impregnated with an oily liquid, which is contained in the space stably without leaking. [34][35][36][37][38] As a result, it is superhydrophobic and repels the liquid and solid fouling on the surface. However, to ensure this condition, the surface and the repelling liquid of SLIPS are typically composed of inorganic nanomaterials and petrochemical oils, respectively.…”