Antigravity Autonomous Superwettable Pumps for Spontaneous Separation of Oil-Water Emulsions.

Oil-water separation based on superwettable materials offers a promising way for the treatment of oil-water mixtures and emulsions. Nevertheless, such separation techniques often require complex devices and external energy input. Therefore, it remains a great challenge to separate oil-water mixtures and emulsions through an energy-efficient, economical, and sustainable way.

Relaxing Wrinkles in Jammed Interfacial Assemblies.

Dynamic covalent bonding has emerged as a mean by which stresses in a network can be relaxed. Here, the strength of the bonding of ligands to nanoparticles at the interface between two immiscible liquids affect the same results in jammed assemblies of nanoparticle surfactants. Beyond a critical degree of overcrowding induced by the compression of jammed interfacial assemblies, the bonding of ligands to nanoparticles (NPs) can be broken, resulting in a desorption of the NPs from the interface.

A Gemini-Type Superwettable Separator for Consecutive Purification of Water and Oil Phases from Oil-Water Mixtures and Emulsions.

Oil pollution results from daily activities and a variety of industries have caused not only severe environmental problems but also wastage of valuable petrochemical resources. Separation based on superwettable materials holds promise; however, practical applications of a single type of superwettable materials were often limited due to their ability in treatment of complicated oil-water systems. Herein, a Gemini-type separator was created through the cooperation of two kinds of superwettable sand particles with opposite wettability, i.

Aquabots.

Soft robots, made from elastomers, easily bend and flex, but deformability constraints severely limit navigation through and within narrow, confined spaces. Using aqueous two-phase systems we print water-in-water constructs that, by aqueous phase-separation-induced self-assembly, produce ultrasoft liquid robots, termed aquabots, comprised of hierarchical structures that span in length scale from the nanoscopic to microsciopic, that are beyond the resolution limits of printing and overcome the deformability barrier. The exterior of the compartmentalized membranes is easily functionalized, for example, by binding enzymes, catalytic nanoparticles, and magnetic nanoparticles that impart sensitive magnetic responsiveness.

Continuous, autonomous subsurface cargo shuttling by nature-inspired meniscus-climbing systems.

Water-walking insects can harness capillary forces by changing their body posture to climb or descend the meniscus between the surface of water and a solid object. Controlling surface tension in this manner is necessary for predation, escape and survival. Inspired by this behaviour, we demonstrate autonomous, aqueous-based synthetic systems that overcome the meniscus barrier and shuttle cargo subsurface to and from a landing site and a targeted drop-off site.

Visualizing Interfacial Jamming Using an Aggregation-Induced-Emission Molecular Reporter.

With the interfacial jamming of nanoparticles (NPs), a load-bearing network of NPs forms as the areal density of NPs increases, converting the assembly from a liquid-like into a solid-like assembly. Unlike vitrification, the lineal packing of the NPs in the network is denser, while the remaining NPs can remain in a liquid-like state. It is a challenge to determine the point at which the assemblies jam, since both jamming and vitrification lead to a solid-like behavior of the assemblies.

Conductive Thin Films over Large Areas by Supramolecular Self-Assembly.

We report a "one-step" method for preparing conductive thin films with cylindrical microdomains oriented normal to the surface over large areas using the supramolecular assembly of poly(styrene--4-vinylpyridine) (PS--P4VP) and 5,10,15,20-tetrakis(4-hydroxyphenyl)-21,23-porphine (HOTPP). HOTPP interacts with the P4VP block by hydrogen bonding between the hydroxyl group of HOTPP and pyridine ring of PS--P4VP, forming cylindrical P4VP(HOTPP) domains having an average diameter of ∼17 nm in a PS matrix. Dynamic light scattering, contact angle, and grazing incidence small-angle X-ray scattering measurements show a morphological transition from spherical micelles in solution to cylindrical microdomains oriented normal to the substrate surface during the drying process.

Surfactant-Induced Interfacial Aggregation of Porphyrins for Structuring Color-Tunable Liquids.

Locking nonequilibrium shapes of liquids into targeted architectures by interfacial jamming of nanoparticles is an emerging area in material science. 5,10,15,20-tetrakis(4-sulfonatophenyl) porphyrin (H TPPS) shows three different aggregation states that present an absorption imaging platform to monitor the assembly and jamming of supramolecular polymer surfactants (SPSs) at the liquid/liquid interface. The interfacial interconversion of H TPPS, specifically H TPPS dissolved in water, from J- to an H-aggregation was induced by strong electrostatic interactions with amine-terminated polystyrene dissolved in toluene at the water/toluene interface.

Correction: Bioinspired hydrogel-based nanofluidic ionic diodes: nano-confined network tuning and ion transport regulation.

Correction for 'Bioinspired hydrogel-based nanofluidic ionic diodes: nano-confined network tuning and ion transport regulation' by Congcong Zhu et al., Chem. Commun.

Bioinspired hydrogel-based nanofluidic ionic diodes: nano-confined network tuning and ion transport regulation.

Biological ion channel-based mass transport and signal transduction play a crucial role in physiological activities, and biomimetic nanochannels in aqueous solutions for ion transport regulation have been extensively studied. Few studies on non-aqueous systems, gel-based nanochannels, mainly focus on the charged gel network or embedded electrolytes. However, the basic issue of how a nanoscale gel network affects the ion transport in nanochannels has been neglected.

Rapid Multilevel Compartmentalization of Stable All-Aqueous Blastosomes by Interfacial Aqueous-Phase Separation.

Producing artificial multicellular structures to process multistep cascade reactions and mimic the fundamental aspects of living systems is an outstanding challenge. Highly biocompatible, artificial systems consisting of all-aqueous, compartmentalized multicellular systems have yet to be realized. Here, a rapid multilevel compartmentalization of an all-aqueous system where a 3D sheet of subcolloidosomes encloses a mother colloidosome by interfacial phase separation is demonstrated.

Hanging droplets from liquid surfaces.

Natural and man-made robotic systems use the interfacial tension between two fluids to support dense objects on liquid surfaces. Here, we show that coacervate-encased droplets of an aqueous polymer solution can be hung from the surface of a less dense aqueous polymer solution using surface tension. The forces acting on and the shapes of the hanging droplets can be controlled.

Stabilizing Liquids Using Interfacial Supramolecular Polymerization.

The strong electrostatic interactions at the oil-water interface between a small molecule, 5,10,15,20-tetrakis(4-sulfonatophenyl)porphyrin, H TPPS, dissolved in water, and an amine terminated hydrophobic polymer dissolved in oil are shown to produce a supramolecular polymer surfactant (SPS) of H TPPS at the interface with a binding energy that is sufficiently strong to allow an intermolecular aggregation of the supramolecular polymers. SPSs at the oil-water interface are confirmed by in situ real-space atomic force microcopy imaging. The assemblies of these aggregates can jam at the interface, opening a novel route to kinetically trap the liquids in non-equilibrium shapes.

Building Reconfigurable Devices Using Complex Liquid-Fluid Interfaces.

Liquid-fluid interfaces provide a platform both for structuring liquids into complex shapes and assembling dimensionally confined, functional nanomaterials. Historically, attention in this area has focused on simple emulsions and foams, in which surface-active materials such as surfactants or colloids stabilize structures against coalescence and alter the mechanical properties of the interface. In recent decades, however, a growing body of work has begun to demonstrate the full potential of the assembly of nanomaterials at liquid-fluid interfaces to generate functionally advanced, biomimetic systems.

Light-Driven ATP Transmembrane Transport Controlled by DNA Nanomachines.

In nature, biological machines can perform sophisticated and subtle functions to maintain the metabolism of organisms. Inspired from these gorgeous works of nature, scientists have developed various artificial molecular motors and machines. However, selective transport of biomolecules across membrane has remained a great challenge.

Bacteriorhodopsin-Inspired Light-Driven Artificial Molecule Motors for Transmembrane Mass Transportation.

In nature, biological machines and motors can selectively transport cargoes across the lipid membranes to efficiently perform various physiological functions via ion channels or ion pumps. It is interesting and challengeable to develop artificial motors and machines of nanodimensions to controllably regulate mass transport in compartmentalized systems. In this work, we show a system of artificial molecular motors that uses light energy to perform transmembrane molecule transport through synthetical nanochannels.

A bio-inspired dumbbell-shaped nanochannel with a controllable structure and ionic rectification.

Inspired by the potassium ion channel, here, we firstly report a structure-tailorable dumbbell-shaped nanochannel with controllable ionic rectification. This system creates an ideal experimental and theoretical platform for the precision transportation of ions, which have potential applications in analytical sciences.

Light- and Electric-Field-Controlled Wetting Behavior in Nanochannels for Regulating Nanoconfined Mass Transport.

Water wetting behavior in nanoconfined environments plays an important role in mass transport and signal transmission of organisms. It is valuable and challenging to investigate how water behaves in such a nanometer-scale with external stimuli, in particular with electric field and light. Unfortunately, the mechanism of hydrophobic reaction inside the nanospaces is still obscure and lacks experimental support for the current electric-field- or photoresponsive nanochannels which suffer from fragility or monofunctionality.

Bioinspired Heterogeneous Ion Pump Membranes: Unidirectional Selective Pumping and Controllable Gating Properties Stemming from Asymmetric Ionic Group Distribution.

The creation of an artificial solid-state ion pump that mimics the delicate ion transport behaviors of a biological protein-based ion pump is drawing more and more research attention due to its potential applications in energy conversion, biosensor, and desalination. However, the reported bioinspired double-gated ion pump systems are generally very primary and can only realize nonselective ion pumping functions with no directionality and uncontrollable ion gating functions, which are far from their biological counterparts. To make the bioinspired device "smart" in a real sense, the implementation of high-level selectivity and directionality in the ion pumping process, while achieving great controllability in the ion gating process, is a necessity.

Ultrathin and Ion-Selective Janus Membranes for High-Performance Osmotic Energy Conversion.

The osmotic energy existing in fluids is recognized as a promising "blue" energy source that can help solve the global issues of energy shortage and environmental pollution. Recently, nanofluidic channels have shown great potential for capturing this worldwide energy because of their novel transport properties contributed by nanoconfinement. However, with respect to membrane-scale porous systems, high resistance and undesirable ion selectivity remain bottlenecks, impeding their applications.

A Tunable Ionic Diode Based on a Biomimetic Structure-Tailorable Nanochannel.

A tunable ionic diode is presented that is based on biomimetic structure-tailorable nanochannels, with precise ion-transport characteristics from ohmic behavior to bidirectional rectification as well as gating properties. The forward/reverse directions of the ionic diode and the degree of rectification can be well-regulated by combining the patterned surface charge and the sophisticated structure. This system creates an ideal platform for precise transportation of ions and molecules, and potential applications in analytical sciences are anticipated.