Supramolecular Interfaces and Reconfigurable Liquids Derived from Cucurbit[7]uril Surfactants

Abstract

Nanoparticle surfactants (NPSs) offer a powerful means to stabilize the oil‐water interface and construct all‐liquid devices with advanced functions. However, as the nanoparticle size decreases to molecular‐scale, the binding energy of the NPS to the interface reduces significantly, leading to a dynamic adsorption of NPS and “liquid‐like” state of the interfacial assemblies. Here, by using the host‐guest recognition between a water‐soluble small molecule, cucurbit[7]uril (CB[7]) and an oil‐soluble polymer ligand, methyl viologen‐terminated polystyrene, a supramolecular NPS model, termed CB[7] surfactant, is described. CB[7] surfactants form and assemble rapidly at the oil‐water interface, generating an elastic film with excellent mechanical properties. The binding energy of CB[7] surfactant to the interface is sufficiently high to hold it in a jammed state, transforming the interfacial assemblies from a “liquid‐like” to “solid‐like” state, enabling the structuring of liquids. With CB[7] surfactants as the emulsifier, O/W, W/O and O/W/O emulsions can be prepared in one step. Owing to the guest‐competitive responsiveness of CB[7] surfactants, the assembly/disassembly and jamming/unjamming of CB[7] surfactants can be well controlled, leading to the reconfiguration of all‐liquid constructs.

Heteroatom Doped Amorphous/Crystalline Ruthenium Oxide Nanocages as a Remarkable Bifunctional Electrocatalyst for Overall Water Splitting

“…In contrast, the peak of Ru 3p 3/2 shifts 0.44 eV toward higher binding energy after OER test, indicating that active sites attenuate the adsorption of H* intermediate, whereas enhance the adsorption of *O/*OOH intermediate. [30] Moreover, HRTEM images of Co-ZnRuO x nanocages after HER/OER tests exhibit the hollow dodecahedral morphology, demonstrating good stability of catalyst (Figure S17, Supporting Information). Notably, the EDS elemental mapping images further prove that the uniform distribution of Ru, Co, and O as well as the negligible Zn after HER/OER tests.…”

Associative Liquid‐In‐Liquid 3D Printing Techniques for Freeform Fabrication of Soft Matter

“…Another one is the functionalization of nanoparticles and ligands which is a time-consuming and difficult process. [51,52] Despite all these challenges, the prints could become stable indefinitely in this system if a crosslinking mechanism is incorporated into either the printed ink phase or the interfacial assemblies. [12]…”

Structuring liquids through solvent-assisted interfacial association of oppositely charged polyelectrolytes and amphiphiles

“…Structured liquids represent a novel family of liquid/liquid (L/L) systems combining the mobile nature of liquid molecules with the physical characteristics of solids. [1][2][3][4][5][6][7][8][9] In bicontinuous Pickering emulsion gels (bijels) [9][10][11] , for instance, the shape of the two percolating immiscible liquid phases is locked via jamming of the adsorbed particles at their interface. The controlled transport between the liquids offers applications in biphasic catalysis or cross-flow reactors [12] while polymerizing or removing of one of them enables the development of bioimplants [13] , multifunctional fibers [14] , battery electrolytes [15] , or microporous systems [16] .…”

“…The jamming of adsorbed particles could also produce another type of structured liquid via sculpting one of the liquid phases within the other. [1][2][3][4][5][6][7][8] This means that either the shape of individual drops [17] or their coalescence [18][19] is arrested as well as liquids could be printed in various forms into another immiscible liquid. Structuring liquids in this way find applications in all-liquid 3D printing, liquid molding, or in microfluidics.…”