Directed selective transport and enrichment of micropollutants by gradient hydrogels.

Selective autonomous enrichment of micropollutants in the aquatic media has attracted increasing attention because of their low concentration characteristics and diverse coexisting species. Herein, the gradient hydrogels were prepared via free redical polymerization of AA and NH-β-CD under the induction of unilateral UV illumination (P(AA-NH-β-CD)). The gradient hydrogels present autonomous enrichment towards Sb(III) with a higher selectivity both in single and binary solutions.

In Situ Growth of Multiresponsive Structural Color Patterns within Hydrogels for Multiple Information Encryption.

Mimicking natural organisms to directly fabricate multiresponsive structural color patterns from small molecules is of great significance for information encryption but remains challenging. Herein, we present a bionic entanglement-interlocking microphase separation strategy for in situ growth of multiresponsive structural color patterns within hydrogel matrixes. The precursor solutions of common polymerization-induced phase-separated materials are used as small-molecule nutrients.

AgNP Composite Silicone-Based Polymer Self-Healing Antifouling Coatings.

Biofouling poses a significant challenge to the marine industry, and silicone anti-biofouling coatings have garnered extensive attention owing to their environmental friendliness and low surface energy. However, their widespread application is hindered by their low substrate adhesion and weak static antifouling capabilities. In this study, a novel silicone polymer polydimethylsiloxane (PDMS)-based poly(urea-thiourea-imine) (PDMS-PUTI) was synthesized via stepwise reactions of aminopropyl-terminated polydimethylsiloxane (APT-PDMS) with isophorone diisocyanate (IPDI), isophthalaldehyde (IPAL), and carbon disulfide (CS).

A type of multifunctional cellulose nanocrystal composite silicone-based polymer coating for marine antibiofouling.

Nanocomposite polymer coatings are being used as a new generation of marine antibiofouling coatings because of their toxin-free chemical composition and ease of large-scale adoption. Cellulose nanocrystal (CN) exhibits significant potential for composite reinforcement. Herein, CN was surface-modified via α,ω-bis(3-(2-hydroxyl-terminated polydimethylsiloxane (HTPDMS), resulting in dihydroxyl-terminated poly(dimethylsiloxane)-grafted CN (HP-g-CN).

Polyelectrolyte-Mediated Modulation of Spatial Internal Stresses of Hydrogels for Complex 3D Actuators.

Hydrogel actuators with complex 3D initial shapes show numerous important applications, but it remains challenging to fabricate such actuators. This article describes a polyelectrolyte-based strategy for modulating small-scale internal stresses within hydrogels to construct complex actuators with tailored 3D initial shapes. Introducing polyelectrolytes into precursor solutions significantly enhances the volume shrinkage of hydrogel networks during polymerization, allowing us to modulate internal stresses.

Self-Assembly Reinforced Alginate Fibers for Enhanced Strength, Toughness, and Bone Regeneration.

Material reinforcement commonly exists in a contradiction between strength and toughness enhancement. Herein, a reinforced strategy through self-assembly is proposed for alginate fibers. Sodium alginate (SA) microstructures with regulated secondary structures are assembled in acidic and ethanol as reinforcing units for alginate fibers.

Facile Multiple Graded Wrinkle Construction Strategy for Vastly Boosting the Sensing Performance of Ionic Skins.

The construction of surface microstructures (e.g., micropyramids and wrinkles) has been proven as the most effective means to boost the sensitivity of ionic skins (I-skins).

Disassembly of spherical structures into nanohelices by good solvent dilution.

Supramolecular self-assembly of low molecular weight molecules into various organic nanostructures has attracted considerable research interest. However, preparing organic nanostructures through a top-down method, such as the disassembly of one large structure into many smaller nanoscale nanostructures, still remains a big challenge. Here, we make use of anti-solvent method to regulate the hierarchical self-assembly of an achiral C-symmetric molecule in THF/water to prepare various nanostructures, including spherical structures, nanofibers, nanoribbons and nanotwists.

Biomimetic 3D Color-Changing Hydrogel Actuators Constructed Based on Soft Permeable Photonic Crystals.

The integration of photonic crystals and self-shaping actuators is a promising method for constructing powerful biomimetic color-changing actuators. The major barrier is that common photonic crystals generally block the transfer/orientation of monomers/fillers and hence hinder the formation of heterogeneous structures for programmed 3D deformations as well as degrade the deformation capacity and mechanical properties of actuators. Herein, we present the construction of complex and strong 3D color-changing hydrogel actuators by asymmetric photolithography based on soft, permeable photonic crystals.

Two-Dimensional Sodium Channels with High Selectivity and Conductivity for Osmotic Power Generation from Wastewater.

Conducting target ions rapidly while rejecting rival ions efficiently is challenging yet highly demanded for ion separation related applications. Two-dimensional (2D) channels are widely used for ion separation, but highly selective 2D channels generally suffer from a relatively low ionic conductivity. Here we report that the 2D vermiculite channels have a Na conductivity higher than bulk and at the same time reject heavy metal ions with a selectivity of a few hundreds.

Janus carbon nitride membrane for robust and enhanced nanofluidic power generation from wastewater.

Nanofluidic membranes have shown great promise in harvesting osmotic power. Yet, previous studies extensively focused on osmotic energy released by the mixing of seawater and river water, while there exist many other osmotic energy sources, such as the mixing of wastewater with other water. However, harvesting the osmotic power of wastewater is highly challenging because it requires the membranes to have environmental remediation capabilities to avoid pollution and biofouling, which has not been satisfied by previous nanofluidic materials.

Self-Powered Gradient Hydrogel Sensor with the Temperature-Triggered Reversible Adhension.

The skin, as the largest organ of human body, can use ions as information carriers to convert multiple external stimuli into biological potential signals. So far, artificial skin that can imitate the functionality of human skin has been extensively investigated. However, the demand for additional power, non-reusability and serious damage to the skin greatly limits applications.

Hierarchical nano-helix as a new reinforcing unit for simultaneously ultra-strong and super-tough alginate fibers.

Fabricating alginate fibers of high strength and toughness remains a great challenge because of the difficulty in improving both strength and toughness simultaneously. Herein, this work reported the hierarchical assembly of sodium alginate nano-helix and its potential application as a new reinforcing unit for alginate fibers. Contributed from the hierarchical structures of α-helix, β-sheet and tertiary helical alignment of nanofibrils, nano-helix improved the tensile strength of fibers with enhanced modulus, and prolonged elongation through unravelling the tertiary structures.

The Thermosensitive Injectable Celecoxib-Loaded Chitosan Hydrogel for Repairing Postoperative Intervertebral Disc Defect.

Percutaneous endoscopic lumbar discectomy has been widely used in clinical practice for lumbar spine diseases. But the postoperative disc re-herniation and inflammation are the main reason for pain recurrence after surgery. The postoperative local defect of the intervertebral disc will lead to the instability of the spine, further aggravating the process of intervertebral disc degeneration.

Electric field modulated water permeation through laminar TiCT MXene membrane.

Controlling water transport is central to a wide range of water-related energy and environment issues. In particular, enhancing the water permeation is highly demanded for practical membrane applications such as water treatment. In this work, we demonstrate that the water permeation through the laminar and electrically conductive MXene membrane can be facilely modulated with electric field.

Strong and tough self-wrinkling polyelectrolyte hydrogels constructed a diffusion-complexation strategy.

Self-wrinkling hydrogels enable various engineering and biomedical applications. The major challenge is to couple the self-wrinkling technologies and enhancement strategies, so as to get rid of the poor mechanical properties of existing self-wrinkling gels. Herein we present a facile diffusion-complexation strategy for constructing strong and ultratough self-wrinkling polyelectrolyte hydrogels with programmable wrinkled structures and customizable 3D configurations.

Reliable and Low Temperature Actuation of Water and Oil Slugs in Janus Photothermal Slippery Tube.

While actuating liquid with external stimuli on open surfaces has been extensively studied, the actuation in tubes or channels is much more challenging due to the lower accessibility and higher complexity in material/device design, despite its crucial importance for microfluidic applications. Of various potential actuation methods, optical ones are particularly interesting because they can be remotely controlled with high spatial/temporal resolution. Yet, previous optical methods relied on the physical deformation of tubes, raising the concern of material fatigue and compromising reliability.

Self-Powered Multifunction Ionic Skins Based on Gradient Polyelectrolyte Hydrogels.

Human skin is the largest organ, and it can transform multiple external stimuli into the biopotential signals by virtue of ions as information carriers. Ionic skins (i-skins) that can mimic human skin have been extensively explored; however, the limited sensing capacities as well as the need of an extra power supply significantly restrict their broad applications. Herein, we develop self-powered humanlike i-skins based on gradient polyelectrolyte membranes (GPMs) that can directly and accurately perceive multiple stimuli.

Precisely Defining Local Gradients of Stimuli-Responsive Hydrogels for Complex 2D-to-4D Shape Evolutions.

The intellectualization and complication of existing self-shaping materials are limited by the inseparable monotonic relationship between their deformation rate and deformation degree (i.e., a higher deformation rate is accompanied by a high deformation degree).

Preparation of triamcinolone acetonide-loaded chitosan/fucoidan hydrogel and its potential application as an oral mucosa patch.

Oral inflammatory diseases (OIDs) are among the most common lesions in the oral cavity, affecting the quality of human life and even causing oral cancer. However, most of the current oral mucosa patches still have some limitations, particularly instant, poor mechanical strength and conformability, low adhesion to tissue, and foreign body sensation. Herein, triamcinolone acetonide (TA)-loaded chitosan/fucoidan (CF) composite hydrogels were prepared via chemical crosslinking.

Anti-Swelling Gradient Polyelectrolyte Hydrogel Membranes as High-Performance Osmotic Energy Generators.

Emerging asymmetric ionic membranes consisting of two different porous membranes show great superiority in harvesting clean and renewable osmotic energy. The main barriers constraining their applications are incompatible interfaces and a low interfacial ionic transport efficiency, which are detrimental to the long-term stability and improvement of the power density. Here, continuous-gradient all-polysaccharide polyelectrolyte hydrogel membranes prepared by ultrafast reaction/diffusion have been demonstrated to enable high-performance osmotic energy conversion.

Marine polysaccharide-based composite hydrogels containing fucoidan: Preparation, physicochemical characterization, and biocompatible evaluation.

Marine polysaccharide-based hydrogels have drawn much attention for diversified biomedical applications owing to their excellent (bio)physicochemical properties. In the present work, a series of marine polysaccharide-based hydrogels composed of chitosan, alginate, or fucoidan are prepared via a facile chemical cross-linking approach in an alkali/urea aqueous system. The prepared hydrogels possess tunable microporous architecture, swelling, and biodegradable properties by changing the components and proportions of marine polysaccharides.

Bioinspired synthesis of fiber-shaped silk fibroin-ferric oxide nanohybrid for superior elimination of antimonite.

Bioinspired fibrous materials have emerged as a unique class of matrix for fabrication of fiber-shaped nanomaterial assemblies. Here, we report a novel functional fiber-shaped nanohybrid for efficient removal of antimonite via in situ synthesis of ferric oxides anchored to silk nanofibril. The silk nanofibril matrix played important roles in the growth of ferric oxides via metal-ligand interactions.

Electrostatic assembly construction of polysaccharide functionalized hybrid membrane for enhanced antimony removal.

There is a growing demand for heavy metal removal by membrane technology in real applications. However, few studies were reported concerning antimony (Sb) removal by membrane technology. Herein, a novel thin film nanocomposite (TFN) membrane comprising an alginate (SA) selective layer and a polyether sulfone (PSF) support membrane incorporating chitosan functionalized iron nanocomposite has been firstly developed for Sb removal via electrostatic self-assembly.