Muscles and some tough hydrogels can maintain perfect mechanical properties after millions of loading cycles owing to the anisotropic microstructures inside them. However, applications of intrinsic ...anisotropic microstructures in biological tissues and tough hydrogels are limited by the poor mechanical performance in the perpendicular direction relative to the alignment direction. Here, a universal strategy is proposed for developing hydrogels with unprecedented isotropic crack propagation resistance only depending on the interpenetrating entanglements of polymer chains (polyacrylamide (PAAM) or poly‐(1‐acrylanmido‐2‐methylpropanesulfonic acid) (PAMPS)) in deformable polymeric microspheres (PAMPS or PAAM). The deformable interpenetrating network in microspheres can transform the hydrogel from isotropic to anisotropic instantaneously in any load direction, and effectively alleviate the stress concentration at the crack tip, dissipate energy, and eliminate notch sensitivity. The best isotropic hydrogel displays an ultimate strain of 5300%, toughness of 18.9 MJ m–3, fracture energy of 157 kJ m–2, and fatigue threshold of 4.2 kJ m–2. Furthermore, the mechanical strength of hydrogels can be simply tuned by solvent replacement. The strategy presented here can be expanded to prepare other isotropic hydrogels with super tear‐resistant and anti‐fatigue properties, based on a wide variety of deformable microspheres and matrix polymers.
A universal strategy for the preparation of hydrogels with isotropic and unprecedented crack propagation resistance is presented. The hydrogels integrate the seemingly contradictory mechanical properties such as ultra‐stretchability, fatigue resistance, tear resistance, and high toughness by the interpenetrating entanglements of polymer chains in the deformable polymeric microspheres. The prepared hydrogel displays a strain of 5300%, toughness of 18.9 MJ m–3, fracture energy of 157 kJ m–2, and fatigue threshold of 4.2 kJ m–2.
Mechanically strong separators with good electrolyte wettability and low-shrinkage properties are desirable for highly efficient and safe lithium batteries. In this study, multifunctional nanofiber ...membranes are fabricated by electrospinning a homogeneous solution containing amphiphilic poly(ethylene glycol)diacrylate-grafted siloxane and polyacrylonitrile. After the chemical cross-linking of siloxane, the prepared nanofiber membranes are found to exhibit good mechanical properties, high thermostability, and superior electrolyte-philicity with aqueous and nonaqueous electrolytes. Li–metal cells with the fabricated membrane separator exhibit high cycling stability (Coulombic efficiency of 99.8% after 1000 cycles). Moreover, improved cycling stability of Li–sulfur batteries can be achieved using these membrane separators. These membrane separators can be further used in flexible aqueous lithium-ion batteries and exhibit steady electrochemistry performance. This work opens up a potential route for designing multifunctional universal separators for rechargeable batteries.
Herein, we present a strategy for a switchable electrochromic zinc mirror/battery, which acts as a battery and a switchable electrochromic device via the electrodeposition and dissolution of Zn onto ...a transparent electrode. In this device, Zn and viologen constitute the anode and the cathode, respectively. Upon battery charging, Zn is electrodeposited onto the electrode to form a mirror while electric energy is stored as chemical energy. If the Zn mirror dissolves, the stored energy is released as electric energy. Compared with traditional electrochemical metallic mirrors, energy is sufficiently and sustainably utilized in this way. Also, a high reflectance of 84.9% and a specific capacity of 65.0 mAh g–1 are obtained for the Zn mirror, suggesting its excellent mirror performance and intrinsic energy storage properties. It is believed that this successful introduction of the battery concept to electrochemical metallic mirrors opens a wide avenue to drive its development toward a more imaginative and environmentally friendly future.
The development of aqueous metal‐ion batteries has attracted great attention due to their relatively low cost and high safety levels. However, their practical applications are hindered by the ease at ...which their aqueous electrolytes freeze. Inspired by the antifreezing properties of salts and alcohol cryoprotective agents, a “two‐in‐one” cryoprotective agent, hydroxyl‐functionalized poly(ionic liquid) (PIL‐OH)‐based hydrogel electrolyte for aqueous lithium‐ion batteries (ALIBs) is developed. The synergy of both ionic hydration and hydrogen bond interactions between the PIL‐OH and water molecules impairs the hydrogen‐bond networks of water and depresses the freezing point of water below −80 °C. Benefiting from exceptional ultralow temperature tolerance, the prepared PIL‐OH hydrogel exhibits a highly enhanced low temperature adaptability and a high ionic conductivity of 0.08 mS cm−1 at −80 °C. The PIL‐OH hydrogel‐based flexible ALIBs exhibit high flexible durability and good cycling stability with 93% capacity retention over 200 cycles at −80 °C. The PIL‐OH hydrogel report herein opens up new opportunities for practical applications of wearable and flexible aqueous batteries at ultralow temperature environments, such as the North and South Poles.
Inspired by the antifreezing properties of alcohol cryoprotective agents, a “two‐in‐one” cryoprotective agent, hydroxyl‐functionalized poly(ionic liquid) (PIL‐OH)‐based hydrogel electrolyte, with a low temperature adaptability and high ionic conductivity at −80 °C (0.08 mS cm−1) is prepared. The PIL‐OH hydrogel‐based flexible aqueous lithium‐ion batteries can be operated at an ultralow temperature of −80 °C.
Pollutants in wastewater include oils, dyes, and bacteria, making wastewater cleanup difficult. Multifunctional wastewater treatment media consisting of poly(ionic liquid)‐grafted polypropylene (PP) ...nonwoven fabrics (PP@PIL) are prepared by a simple and scalable surface‐grafting process. The fabricated PP@PIL fabrics exhibit impressive switchable oil/water separation (η>99 %) and dye absorption performance (q=410 mg g−1), as well as high antibacterial properties. The oil/water separation can be easily switched by anion exchanging of the PIL segments. Moreover, the multiple functions (oil/water separation, dye absorption, and antibacterial properties) occurred at the same time, and did not interfere with each other. The multifunctional fibrous filter can be easily regenerated by washing with an acid solution, and the absorption capacity is maintained after many recycling tests. These promising features make PIL‐grafted PP nonwoven fabric a potential one‐step treatment for multicomponent wastewater.
Clothing time: A multifunctional wastewater treatment media was prepared from corona‐charged polypropylene (PP) nonwoven fabrics, based on surface‐grafted poly(ionic liquid)s. The prepared PP nonwoven fabrics exhibited impressive performances in switchable oil/water separation and dye absorption, as well as antibacterial properties.
Heavy metal ion pollution has become a serious environmental problem. Herein, this study reports the synthesis of poly(ionic liquid) (PIL) membranes via in situ photo‐crosslinking of vinyl imidazole ...with both hydrophilic and hydrophobic ionic liquid monomers. The resultant amphiphilic polymer membranes are porous and exhibit high absorption capacity of metal ions (including Hg2+, Pb2+, Cu2+, Cd2+, and Zn2+) in both high (1000 mg L−1) and low (10 mg L−1) concentration metal ion solutions. These metal ionic absorption membranes are easily regenerated in acid solution and can be reused without significant decreases of absorption capacity after many cycles. These PIL membranes may have potential applications as eco‐friendly and safe heavy metal ion removal materials.
Porous poly(ionic liquid) (PIL) membranes are synthesized via in situ photo‐crosslinking of vinyl imidazole with both hydrophilic and hydrophobic ionic liquid monomers. The prepared PIL membranes show high metal ion absorption capacity and can be easily recycled.
•The GMO modified WSiPU is fluorine-free, which makes it friendly to environment and organisms.•The contact angles of water on WSiPU-treated fabric are ˃140°, indicating that the GMO modified WSiPU ...coatings have excellent hydrophobicity.•The WSiPU-treated hydrophobic fabric coating exhibits high abrasion resistance, laundry durability (>50 resistance cycles of abrasion and laundry), resistance to acid, salt, and base solutions, breathability, and biosecurity.•The preparation method of the WSiPU-coated fabric is simple, and it is easy to be prepared on a large scale.
Hydrophobic functionalized coatings have attracted widespread attention in fabric finishing fields, which exhibit breathable properties and can significantly enhance wearer comfort. However, the inadequate hydrophobic durability of inorganic coating and poor biologically safety of fluorine-containing coatings limited the further development of fabric finishing coating, thus it remains a significant challenge to develop fluorine-free and durable fabric finishing coating. In this study, a glyceryl monostearate (GMO)-modified fluorine-free waterborne polyurethane (WPU) emulsion (WSiPU) was synthesized and applied as a hydrophobic coating on different type of fabrics successfully. The optimal additive amount of GMO was determined by investigating the particle size and size distributions of the emulsions, solvent swell rates, wettability of water and oil on the coatings, and hydrophobicity. Cotton fabric treated with optimized WSiPU 8 emulsion exhibited excellent hydrophobicity, durability, reusability, solvent resistance, breathability, and bio-safety. Furthermore, clothing and gloves treated with WSiPU 8 emulsion exhibited excellent water repellency under flowing water and after soaking in sewage. The treated cotton fabric showed excellent hydrophobicity (water contact angle > 140°), durability (>50 resistance cycles of abrasion and laundry), and self-cleaning performance. The findings of this study provided novel insights for various applications such as oil–water separation and hydrophobic coatings.
Despite the development of many functional fabrics, they are unable to meet practical needs due to their monolithic functions and low durability. Therefore, a multifunctional waterborne polyurethane ...nanodroplet containing disulfide bonds (WSPU) was synthesized using a simple and environmentally friendly approach. The functional WSPU nanodroplet coating endowed fabrics with a variety of properties, including exceptional hydrophobicity, antibacterial properties, self-healing at room temperature, directional transport, etc. The functionalized fabric demonstrated durable mechanical and chemical stabilities due to the combined effects of disulfide bond reconstruction and hydrophobic chain migration. It exhibited the ability to regain its hydrophobic properties at room temperature after 50 friction cycles were performed without requiring external stimulation. Furthermore, the fabric maintained a water contact angle above 140°, even after being subjected to washing, boiling, and immersion in acid and alkali solutions. In addition, as a result of the fabric’s Janus-like wettability, it performed various functions in accordance with varying weather conditions, in terms of wearing comfort and breathability. In hot weather or during exercise, the Janus fabric with the hydrophilic side facing outward enhances the process of sweat-directed perspiration, resulting in a notable cooling effect. On rainy days, the Janus fabric, when positioned with the hydrophobic side facing outward, exhibited excellent waterproof performance. This study presents an opportunity to explore the development of multifunctional fabrics through the combined effects of several functions.
Solid‐state polymer electrolytes (SPEs) are expected to guarantee safe and durable operations of lithium metal batteries (LMBs). Herein, inspired by the salutary poly(vinyl ethylene carbonate) (PVEC) ...component in the solid electrolyte interphase, cross‐linking vinyl ethylene carbonate and ionic liquid copolymers were synthesized by in‐situ polymerization to serve as polymer electrolyte for LMBs. On one hand, due to rich ester bonds of PVEC, Li+ could transfer by coupling/decoupling with oxygen atoms. On the other hand, the imidazole ring of ionic liquid could facilitate the dissociation of lithium salt to promote the free movement of Li+. The bifunctional component synergistically increased the ionic conductivity of the SPE to 1.97×10−4 S cm−1 at 25 °C. Meanwhile, it also showed a wide electrochemical window, superior mechanical properties, outstanding non‐combustibility, and excellent interfacial compatibility. The bifunctional copolymer‐based LiFePO4 batteries could normally operate at 0 to 60 °C, making them a promising candidate for wide‐temperature‐rang LMBs.
Hot and cold: A novel solid polymer electrolyte is fabricated by in‐situ polymerization method. Cyclic carbonates and ionic liquid bifunctional components synergistically increase the ionic conductivity. The solid polymer electrolyte shows excellent safety properties. Superior cell performances are achieved over a wide temperature range (0–60 °C).
It is extremely difficult for traditional coatings for antifouling constructed around a single antifouling strategy to adapting to the demands of complex marine environment. Herein, a poly-ionic ...liquid-based germicidal polyacrylate-3 coating (AFC-3) was prepared via free radical photo-copolymerization using isooctyl acrylate (2-EHA), butyl acrylate (BA) and ionic liquid monomer (IL-PF6) as monomers. Besides the contact bacteriostasis mechanisms, the introduction of IL-PF6 achieved the switch between self-renewal and hydrophilic surface by the exchange of PF6− and Cl− in artificial seawater. Regarding E. coli and S. aureus, the AFC-3 coating showed anti-bacterial efficiency of 100 % and 99.96 %, respectively. Moreover, with the continuous ionic exchange between PF6− and Cl−, the angle towards the water contact (WAC) of the coating became 11.356 °C, contributing to the enhancement of anti-protein property on the surface of the coating. The AFC-3 coating thus exhibited significantly effective antifouling performances, and is a highly promising coating for a broader range of marine anti-fouling and biomedical materials. Besides, the transmittance of the coating was above 92 % between 400 and 800 cm−1, conferring it great potentials for applications on the surface of optical devices like underwater cameras.
•We developed an enhanced antifouling strategy for switching between self-renewing and hydrophilic surfaces fabricated by the exchange of PF6- and Cl- in artificial seawater and contact bactericidal mechanisms.•With the continuous ionic exchange between PF6- and Cl-, the angle towards the water contact (WAC) of the coating declined from 107° to 10.081° at 80 °C, contributing to the enhancement of anti-protein property on the surface of the coating.•The transmittance of the coating was above 92% between 400 and 800 cm-1, conferring it great potentials for applications on the surface of optical devices like underwater cameras.
