Dynamic Imine Chemistry at Complex Double Emulsion Interfaces

Abstract

Interfacial chemistry provides an opportunity to control dynamic materials. By harnessing the dynamic covalent nature of imine bonds, emulsions are generated in situ, predictably manipulated, and ultimately destroyed along liquid-liquid and emulsion-solid interfaces through simply perturbing imine equilibria. We report the rapid production of surfactants and double emulsions through spontaneous in situ imine formation at the liquid-liquid interface of oil/water. Complex double emulsions with imine surfactants are stable to neutral and basic conditions and display dynamic behavior with acid catalyzed hydrolysis and imine exchange. We demonstrate the potential of in situ imine surfactant formation to generate complex surfactants with biomolecules (i.e., antibodies) for biosensing applications. Furthermore, imine formation at the emulsion-solid interface offers a triggered payload release mechanism. Our results illustrate how simple, dynamic interfacial imine formation can translate changes in bonding to macroscopic outputs.

Controlled Movement of Complex Double Emulsions via Interfacially Confined Magnetic Nanoparticles

“…The necessity for the Tween-20 cosurfactant and the lower propensity of aldehyde 2 to assemble at the interface relative to hydrate 1 both likely contribute to the lower MNP-NH 2 coverage. 14 The spatial organization of MNP-NH 2 at the LC/W interface is imaged by fluorescent labeling by reacting the MNP-NH 2 with n -succinimidyl ester rhodamine. Successful functionalization was confirmed by using a confocal microscope equipped with crossed polarizers.…”

“…In this work, we leverage previously demonstrated interfacial imine chemistry to selectively covalently attach amine-functionalized MNPs to one of the interfaces of double emulsions ( Figure 1 a). 14 In our design, water-dispersible amine-functionalized Fe 3 O 4 magnetic nanoparticles (MNP-NH 2 ) react with surface active aldehydes, which can be present in hydrate form, to interfacially confine the MNPs ( Figure 1 b). Hydrate 1 and aldehyde 2 are selectively soluble in fluorocarbon (FC) and hydrocarbon (HC) oils, respectively, leading to specific, directed attachment of MNP-NH 2 at either the FC or HC interface with water (W).…”

Drug‐Sponge Lipid Nanocarrier for in Situ Cargo Loading and Release Using Dynamic Covalent Chemistry

“…On one hand, transient formation of these bonds enables crossing of cell membrane barriers for delivery of cargos inside the cells [16] . On the other hand, these bonds can be used to build nanocarriers [10, 13b, 17] and/or conjugate the nanocarrier with drugs [18] in order to ensure efficient transport and controlled release of the cargo [19] . Hydrazone bonds, sensitive to pH, are particularly attractive in this respect, [11, 20] because targeted tumor tissues are characterized by low pH [19, 21] .…”

Fusion‐Induced Structural and Functional Evolution in Binary Emulsion Communities

“…It has been generally recognized that both the stability and functionality of emulsions are stringently influenced by the surfactants applied in the system. Therefore,bydesigning various stimuli-responsive surfactants in response to temperature, [15] light, [16] and CO 2 , [17] or by developing at ype of dynamically reconfigurable surfactant based on dynamic covalent chemistry [18] or Michael addition chemistry, [19] various smart emulsions with potential applications in emulsion polymerization, improved emulsifier recyclability,and oil/water separation have been demonstrated. [20] However,t hese studies are mainly focused on the design of the external stimuli.…”