Responsive Ionogel Surface with Renewable Antibiofouling Properties

Abstract

The synthesis of ionogels with a responsive, self‐replenishing surface for combating biofouling is described. Ionogels are prepared by infiltrating poly(vinylidene fluoride‐co‐hexafluoropropylene) with binary mixtures of ionic liquids (IL): 1‐octadecyl‐3‐methylimidazolium bis(trifluoromethyl sulfonyl)imide ([C18C1im][NTf2], melting point Tm = 55 °C) and 1‐hexyl‐3‐methylimidazolium bis(trifluoromethyl sulfonyl)imide ([C6C1im][NTf2], Tm = −9 °C). The IL mixtures release spontaneously from the gel matrix and eventually crystallize on the surface. This leads to self‐replenishment of the surface of ionogels even after mechanical damage. The incorporation of [C6C1im][NTf2] provides the antimicrobial efficacy of ionogels while the crystals of [C18C1im][NTf2] serve as a skeleton maintaining [C6C1im][NTf2] on the surface. By heating, the ionogel surface transforms from solid to liquid‐infused state—the removal of biofilms/bacteria developed under a long time of colonization is facilitated. The antimicrobial efficacy is maintained even after several cycles of biofilm formation and detachment. This work provides an opportunity to apply ionogels as functional coatings with renewable antibiofouling properties.

Life and death of liquid-infused surfaces: a review on the choice, analysis and fate of the infused liquid layer

“…235 Ye et al achieve a similar effect using a 3D LIS with an ionic liquid lubricant that can only flow above its melting temperature, which is close to operating temperature. 43…”

“…The silicone oil swells the PDMS matrix through diffusion and forms a lubricious overlayer which is later excreted whenever the overlayer is removed. 38 Other polymer matrices have also been employed such as polyvinylidene fluoride (PVDF) 42,43 and polyethylene 44 . Surfaces of this type draw inspiration from the mucous-excreting glands of toads that cause the animal to be covered in a protective mucous layer that is constantly replenished from said glands.…”

“…171 Edible lubricants enable the application of LIS in areas of food handling and processing, 175 while cheaper oils pave the way for scalability of LIS manufacture in large scale applications. Ionic liquids have also been successfully used as lubricants 37,43,111,[176][177][178][179][180][181][182] . Ionic liquids have negligible vapour pressure, 37 but the molecular composition has to be modified to make them hydrophobic and repellent to water and, as such, all reported ionic liquids include a fluorinated anion.…”

Coatable and Resistance-Proof Ionic Liquid for Pathogen Eradication

“…[Et-hex-en]­[Tf 2 N] repressed bacterial growth in liquid media at submicromolar concentrations (ranging from 150 to 600 nmol L –1 ) (Figure A,B). [Et-hex-en]­[Tf 2 N] displayed increased antimicrobial activity compared to other classes of ILs, − such as imidazolium salts (1-ethyl-3-methylimidazolium chloride, 1-ethyl-3-methylimidazolium ethyl sulfate, and 1-methyl-3- N -octylimidazolium chloride; Figure S1 and Table S1), numerous conventional antibiotics (Table S2) ( e . g ., vancomycin, daptomyci,n and polymyxin B; Table S2), and rationally designed antimicrobial peptides. , Interestingly, [Et-hex-en]­[Tf 2 N] was as active as the most hydrophobic IL tested (1-methyl-3- N -octylimidazolium chloride), thus suggesting a link between hydrophobicity and antimicrobial activity.…”

Recent advances in bio-inspired ionic liquid-based interfacial materials from preparation to application

“…(D) Responsive self-replenishing ionogel with renewable anti-biofouling properties. Reproduced with permission ( Ye et al, 2019 ). Copyright 2019, WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim.…”