Hyper-cross-linked polymers based on triphenylsilane for hydrogen storage and water treatment

The present research focuses on the synthesis and applications of a series of hyper-cross-linked polymer networks obtained from the one-step Friedel–Crafts reaction of triphenylsilane and formaldehyde dimethyl acetal. The materials were characterized through FTIR, 13C NMR, PXRD, TGA, N2 adsorption-desorption isotherms, H2 sorption and dye adsorption. These materials exhibited increased surface areas of approximately 441–1101 m2 g−1 with increasing ratio of monomer to cross-linker. The H2 storage capacity of the polymer networks reached 1.19 wt % (5.96 mmol g−1) under 1.03 bar and 77.3 K. In addition, the material showed excellent adsorption capacity of 806 mg g−1 for Congo Red and retained their adsorption capacity after recycling nine times. Taken together, the results demonstrate that the obtained hyper-cross-linked polymers could be applied to H2 storage and water treatment.</p

(Fe_0.5Ni_0.5)_0.96S with Bimetallic Cation Vacancy Defect as an Efficient Catalyst for Regulating the Reaction Kinetics of Li₂S

Recently, defect-engineered modified materials with abundant active sites are considered promising hosts of sulfur cathodes in lithium sulfur batteries (LSBs). Here, a multifunctional (Fe0.5Ni0.5)0.96S-reduced graphene oxide composite (NFS-rGO) has been fabricated by the combination of highly conductive rGO and bimetallic cation vacancy structure and was utilized as a sulfur host. The bimetallic cation vacancies provide plentiful active sites for the adsorption and accelerated conversion of lithium polysulfides (LiPSs). The rGO afforded a highly conductive network and inhibited the aggregation of (Fe0.5Ni0.5)0.96S nanoparticle. After sulfur loading, the NFS-rGO/S exhibited satisfactory electrochemical performances, and it presented a high capacity of 729.3 mAh g–1 at 3 C and a lower capacity attenuation rate of 0.066% per cycle during 700 cycles at 1 C. In addition, the galvanostatic intermittent titration technique and Li2S deposition results indicated that the nucleation barrier of Li2S is effectively reduced, and the polarization is also alleviated. This work provided a simple preparation technique for the fabrication of bimetallic cation vacancy materials and offered a foundation for application of such materials in LSBs

Cancellous Bone-like Polyurethane Foam: A Porous Material with Excellent Properties for Ultra-high Energy Absorption

Compared to osteoporotic bone, normal cancellous bone exhibits greater resistance to impact and energy absorption. The Gibson–Ashby model of cellular structure reveals that the enhancement is attributed to a unique combination of the thick wall and small pores in porous materials. Inspired by this design concept, here, a cancellous bone-like PU foam was developed through the planetary centrifugal mixing (PCM) method. Different from previously reported high energy absorption materials, this porous material possesses a thick-wall (average thickness of 33 μm) and micropore (average size of less than 55 μm) morphology. The enlarged SEM image revealed the presence of nanoscale dispersed conductive carbon blacks embedded within the thick walls in a primary aggregate state. Furthermore, the Raman spectrometer provided additional insights into the interaction between carbon black and the PU matrix. This unique morphology was achieved by the dual actions of centrifugal and tangential forces exerted by PCM, whereby challenges in efficient mixing and dispersion of highly viscous material were successfully overcome. The unique microstructure endows the foam with ultra-high compressive strength (yield strength of 17.0 MPa) and energy absorption capacity (12.19 MJ/m3), which are comparable to polyimide foam (3.31 MJ/m3) and many lattice composite structures (5–14.07 MJ/m3) that are well known for their high energy absorption properties. In addition to the impressive energy absorption capacity, excellent comprehensive properties, such as antistatic property (an electrical conductivity of 0.346 S/m), a low thermal conductivity (0.0274 W/m·K), and fast heating responsiveness (increase by 40 °C within 180 s), are also obtained in this foam. In contrast to the complex and costly approaches in fabricating ultra-high energy absorption materials, this simple and cost-effective method opens up an attractive way in obtaining high energy absorption material with excellent comprehensive properties by a one-step PCM procedure

Cancellous Bone-like Polyurethane Foam: A Porous Material with Excellent Properties for Ultra-high Energy Absorption

Compared to osteoporotic bone, normal cancellous bone exhibits greater resistance to impact and energy absorption. The Gibson–Ashby model of cellular structure reveals that the enhancement is attributed to a unique combination of the thick wall and small pores in porous materials. Inspired by this design concept, here, a cancellous bone-like PU foam was developed through the planetary centrifugal mixing (PCM) method. Different from previously reported high energy absorption materials, this porous material possesses a thick-wall (average thickness of 33 μm) and micropore (average size of less than 55 μm) morphology. The enlarged SEM image revealed the presence of nanoscale dispersed conductive carbon blacks embedded within the thick walls in a primary aggregate state. Furthermore, the Raman spectrometer provided additional insights into the interaction between carbon black and the PU matrix. This unique morphology was achieved by the dual actions of centrifugal and tangential forces exerted by PCM, whereby challenges in efficient mixing and dispersion of highly viscous material were successfully overcome. The unique microstructure endows the foam with ultra-high compressive strength (yield strength of 17.0 MPa) and energy absorption capacity (12.19 MJ/m3), which are comparable to polyimide foam (3.31 MJ/m3) and many lattice composite structures (5–14.07 MJ/m3) that are well known for their high energy absorption properties. In addition to the impressive energy absorption capacity, excellent comprehensive properties, such as antistatic property (an electrical conductivity of 0.346 S/m), a low thermal conductivity (0.0274 W/m·K), and fast heating responsiveness (increase by 40 °C within 180 s), are also obtained in this foam. In contrast to the complex and costly approaches in fabricating ultra-high energy absorption materials, this simple and cost-effective method opens up an attractive way in obtaining high energy absorption material with excellent comprehensive properties by a one-step PCM procedure

CRISPR-Cas-Driven Single Micromotor (Cas-DSM) Enables Direct Detection of Nucleic Acid Biomarkers at the Single-Molecule Level

The target-dependent endonuclease activity (also known as the trans-cleavage activity) of CRISPR-Cas systems has stimulated great interest in the development of nascent sensing strategies for nucleic acid diagnostics. Despite many attempts, the majority of the sensitive CRISPR-Cas diagnostics strategies mainly rely on nucleic acid preamplification, which generally needs complex probes/primers designs, multiple experimental steps, and a longer testing time, as well as introducing the risk of false-positive results. In this work, we propose the CRISPR-Cas-Driven Single Micromotor (Cas-DSM), which can directly detect the nucleic acid targets at a single-molecule level with high specificity. We have demonstrated that the Cas-DSM is a reliable and practical method for the quantitative detection of DNA/RNA in various complex clinical samples as well as in individual cells without any preamplification processes. Due to the excellent features of the CRISPR/Cas system, including constant temperature, simple design, high specificity, and flexible programmability, the Cas-DSM could serve as a simple and universal platform for nucleic acid detection. More importantly, this work will provide a breakthrough for the development of next-generation amplification-free CRISPR/Cas sensing toolboxes

Construction of Alkaline Gel Polymer Electrolytes with a Double Cross-Linked Network for Flexible Zinc–Air Batteries

Flexible zinc–air batteries have broad potential as the next generation of energy storage component in wearable electronic devices. However, the mechanical performance and ionic conductivity of electrolytes are urgent issues that hinder the commercial application of flexible batteries. Herein, the alkaline gel polymer electrolyte (AGPE) with a double-network structure is developed, which consists of a covalently cross-linked polyacrylamide (PAM) by in situ polymerization and a physically cross-linked poly(vinyl alcohol) (PVA) by the freeze–thaw method. The freestanding PVA/N-PAM/KOH gel electrolyte demonstrates high ionic conductivity (309.9 mS cm–1) and excellent mechanical toughness (0.69 MJ m–3), benefiting from the synergistic effect of the double cross-linked system and hydrogen bonds. Meanwhile, the assembled ″sandwich″-type zinc–air battery presents excellent power density (40.43 mW cm–2), long-term cycle life (113 cycles), super-high-energy efficiency (70.2%), and stable discharge plateau. Impressively, the PVA/N-PAM/KOH-based batteries attached to the human body surface are reliably capable of powering light-emitting diodes