Reactive Multilayer Coating As Versatile Nanoarchitectonics for Customizing Various Bioinspired Liquid Wettabilities

Abstract

In last few decades, multilayer coatings have achieved enormous attention owing to their unique ability to tune thickness, topography, and chemical composition for developing various functional materials. Such multilayer coatings were mostly and conventionally derived by following a simple layer-by-layer (LbL) deposition process through the strategic use of electrostatic interactions, hydrogen bonding, host–guest interactions, covalent bonding, etc. In the conventional design of multilayer coatings, the chemical composition and morphology of coatings are modulated during the process of multilayer constructions. In such an approach, the postmodulations of the porous multilayers with different and desired chemistries are challenging to achieve due to the lack of availability of readily and selectively reactive moieties. Recently, the design of readily and selectively reactive multilayer coatings (RMLCs) provided a facile basis for postmodulating the prepared coating with various desired chemistries. In fact, by taking advantage of the inherent ability of co-optimizing the topography and various chemistries in porous RMLCs, different durable bioinspired liquid wettabilities (i.e., superhydrophobicity, underwater superoleophobicity, underwater superoleophilicity, slippery property, etc.) were successfully derived. Such interfaces have enormous potential in various prospective applications. In this review, we intend to give an overview of the evolution of LbL multilayer coatings and their synthetic strategies and discuss the key advantages of porous RMLCs in terms of achieving and controlling wettability properties. Recent attempts toward various applications of such multilayer coatings that are strategically embedded with different desired liquid wettabilities will be emphasized.

Responsive and reactive layer-by-layer coatings for deriving functional interfaces

“…50 Moreover, the thickness and architecture of the prepared coating can be controlled strategically even with molecular precision. 50,68,[71][72][73] The construction of electrostatic interaction-driven multilayer assembly is found to be entropy-driven as the counter ions are released in this process. 74 Various advantages, such as (i) an easy and uncomplicated fabrication process, (ii) controlled modulation of multilayer thickness down to the nanometer scale and (iii) a surface-independent nature, make this fabrication method distinct and special from other approaches.…”

“…The design of reactive polymers and their reactive multilayer coatings provide a platform to modify multilayer coatings with selected chemicals to achieve desired properties. 72,89 Various reactive polymers like chitosan, branched poly(ethyleneimine) (BPEI), poly(2-vinyl-4,4-dimethylazlactone) (PVDMA), etc. are mostly involved in forming covalent crosslinking between two adjacent layers during the LbL deposition process.…”

“…69 While a remarkable breakthrough in the development of such multilayer coatings has been made in the field of biomedical engineering, 70 surface engineering, 71 etc., the impacts of the durability of such interfaces limit their application in practical scenarios. Recently, studies of chemically reactive multilayer coatings (CRMLCs) 72 have guided one to achieve a durable design with tunable reactivity for tailoring interfaces with desired and adequate functionality and promoting their application in diverse prospective areas. 73 In this review, we intend to give an overview of the recent attempts towards the progress of LbL multilayer coatings in surface engineering to develop multi-functional interfaces and discuss both stimuli-responsive and CRMLCs to achieve and control various functions via adopting a facile LbL deposition process.…”

“…, the impacts of the durability of such interfaces limit their application in practical scenarios. Recently, studies of chemically reactive multilayer coatings (CRMLCs) 72 have guided one to achieve a durable design with tunable reactivity for tailoring interfaces with desired and adequate functionality and promoting their application in diverse prospective areas. 73…”

Editorial for Forum on Applied Supramolecular Materials

“…The physical properties of the supramolecular assemblies, such as wettability and elasticity can be modulated by intricate engineering of the building units. In this context, Manna et al reported a concise overview of the development of layer-by-layer (LbL) coatings with the design strategies and advantages of porous reactive multilayer coatings (RMLCs) toward achieving and controlling wettability properties . To improve the elasticity of such assemblies, Sun and co-workers demonstrated the preparation of a hydrogel membrane by complexing sulfonate-containing polyurethane (SPU) and poly­(acrylic acid) (PAA) with Zn 2+ ions (SPU-PAA/Zn).…”