Facile optimization of hierarchical topography and chemistry on magnetically active graphene oxide nanosheets

Abstract

<p>‘Confined-optimization’ of desired topography and appropriate chemistry on a magnetically-active and two-dimensional (2D) graphene oxide (GO) nanosheets is unprecedentedly achieved following a rapid and facile 1,4-conjugate addition reaction.</p>

Evaluating the Impact of Tailored Water Wettability on Performance of CO2 Capture

“…In our current design, an amine-amplified chemically reactive coating has been introduced for (a) tailoring of water wettability and (b) investigating its impact on CO 2 separation performance. In the recent past, our research group has extended the 1,4-conjugate addition reaction (Scheme A) between BPEI (Scheme B) and dipentaerythritol penta-acrylate (5Acl) to synthesize chemically reactive polymeric nanocomplex (CRPNC, Scheme C) loaded with residual acrylate group. , In the past, the spray deposition and layer-by-layer deposition of this CRPNC provided chemically reactive coatings for customizing different water and oil wettability through appropriate post-covalent modification with the selected small molecules. − Further, this CRPNC was successfully deposited on fibrous cotton to develop a chemically reactive coating (CRC, Scheme D,E), where the post-covalent modification of the coating with octadecylamine (ODA) provided durable superhydrophobicity, which was extended for remediation of oil spillages following an environment-friendly selective absorption and filtration approach . In contrast to these earlier designs, a facile and covalent amine amplification process has been integrated to this CRPNC-derived chemically reactive coating through post-covalent modification with BPEI polymer (Scheme E,F).…”

Michael Addition Reaction Assisted Derivation of Functional and Durable Superhydrophobic Interfaces

“…In 2020, Das et al reported a magnetically active and 2D-confined superhydrophobic submicrometer interface. 75 AGO nanosheets were deposited with iron oxide nanoparticles (Figure 7B) to obtain magnetically active, hydrophilic, and oleophilic graphene oxide nanosheets (MAGO, Figure 7C,D). The prepared MAGO were covalently integrated with CRPNCs (Figure 7A) to obtain chemically "reactive" and magnetically active graphene oxide nanosheets (MACRGO, Figure 7E).…”

“…Such characteristics are of utmost importance for realistic and diverse applications of the bioinspired coating. In this regard, the environment-friendly Michael addition reaction between amine and acrylate requiring mild operational conditions would provide a prospective platform to tailor the bioinspired water wettability and other relevant physical properties (Figure )including transparency, mechanical property, porosity, etc.following simple and scalable fabrication processes. − In the past, the catalyst-free Michael addition reaction was successfully extended to produce amplified “reactive” surfaces. , Ford et al studied the ability of growing different nanostructures on selected substrates following the catalyst-free aza-Michael addition reaction between branched polyethylenimine (BPEI) and dipentaerythritol penta-acrylate (5-Acl) that resulted in hyperbranched poly­(ester amines) cross-linked thin films with surface amplified functional groups . In 2012, Bechler et al capitalized on this concept of a nanostructured, “reactive” polymeric film of BPEI/5Acl to construct a relatively thick (∼750 nm) multilayer coating following the layer-by-layer deposition approach .…”

“…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, ,,− ,,− ,, drug delivery, ,, patterned interfaces, ,,, 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 as fabricated chemically “reactive” interfaces with tailorable water wettability exhibited impeccable durability and performance at even chemically harsh and challenging settings.…”

“…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, ,,− ,,− ,, drug delivery, ,, patterned interfaces, ,,, 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 as fabricated chemically “reactive” interfaces with tailorable water wettability exhibited impeccable durability and performance at even chemically harsh and challenging settings. The strategic use of the catalyst-free Michael addition reaction allowed the successful modulation of mechanical property, porosity, shrinkage, optical transparency, etc.…”