Alkali metal-ion assisted Michael addition reaction in controlled tailoring of topography in a superhydrophobic polymeric monolith

Abstract

An alkali metal ion assisted Michael addition reaction between acrylate and amine groups is strategically exploited in the synthesis of a chemically reactive and tailored hierarchical topography for addressing important fundamental aspects of biomimicked interfaces.

Michael Addition Reaction Assisted Derivation of Functional and Durable Superhydrophobic Interfaces

“…The replacement of alkali metal ion, Cs + , with smaller alkali metal ions (Li + , Na + , K + , and Rb + ) in the same reaction mixture of BPEI/5Acl led to the faster growth of CRPNCs (Figure 3D). 58 Such accelerated growth of CRPNC could also be achieved by replacing methanol with its higher analogues as shown in Figure 3E, where no alkali metal ions were associated. 59 Such customization of mild reaction conditions (i.e., solvent media and alkali metal salt) controlled various relevant properties (e.g., porosity, shrinkage, morphology, compressive modulus, etc.)…”

“…To overcome this challenge, the Michael addition reaction between BPEI and 5Acl was employed strategically to achieve rapid and controlled growth of chemically "reactive" nanocomplexes (CRPNCs) in solution phase, instead of on a solid surface. The research group of Manna et al introduced and extended these solution phase CRPNCs for developing porous, three-dimensional superhydrophobic monoliths and flexible polymeric superhydrophobic coatings for applications in oil/water separation, 58,59,[62][63][64]73,[75][76][77]79,80 drug delivery, 57,65,78 patterned interfaces, 67,71,74,83 etc. The controlled growth of CRPNCs through Michael addition reaction and its strategic postcovalent modifications allowed different durable bioinspired wettabilities to be adoptedincluding controllable adhesive/nonadhesive superhydrophobicity, hydrophilic/superhydrophobic patterns, chemically "reactive" superhydrophobicity, and stimuli-responsive superhydrophobicityfollowing simple and scalable fabrications processes.…”

“…The controlled gelation of the selected reactants via formation of CRPNC resulted in three-dimensional (bulk), free-standing, chemically "reactive" polymeric monoliths to associate tailorable water wettability and other physical properties. 56,58,59 Rather et al, in a chemically "reactive" sol−gel approach, developed CRPNC through mixing ethanolic solutions of BPEI However, the growth of the nanocomplexes was highly influenced by the presence of various alkali metal salts 58 and the selection of alcoholic solvents 59 in the reaction solution as shown in Figure 3D,E. The replacement of alkali metal ion, Cs + , with smaller alkali metal ions (Li + , Na + , K + , and Rb + ) in the same reaction mixture of BPEI/5Acl led to the faster growth of CRPNCs (Figure 3D).…”

“…This same chemical reaction was repeated in the presence of other alkali metal ions to examine the rate of gelation. 58 LiCl doped polymeric nanocomplexes in ethanol were the first to transform into a gel, whereas NaCl, KCl, RbCl, and CsCl doping required longer times, respectively. As the size of the metal ion decreases, the barrier height for the reaction between amine and acrylate decreases, facilitating the charge transfer from acrylate to metal ions and, thus, increasing the charge deficiency on βcarbon of the vinyl group.…”

Dynamics of the mixtures of fullerene‐60 and aromatic solvents: A molecular dynamics approach

“…[34] Molecular dynamics is a tool to investigate the dynamics of the molecules at small scales. [35][36][37] In the present work, we study dynamical properties of fullerene C60 in four aromatic solvents, namely, 1-chloronaphthalene, 1-methylnaphthalene, 1,2,4-trimethylbenzene, and chlorobenzene. The snapshots of the systems are given in Figure 1.…”