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The use of functional biodegradable wastes to treat environmental problems would create minimal extra burden to our environment. In this paper, we propose a sustainable and practical strategy to turn spent coffee ground (SCG) into a multifunctional palladium-loaded catalyst for water treatment instead of going into landfill as solid waste. Bleached delignified coffee ground (D-SCG) has a porous structure and a good capability to reduce Pd (II) to Pd (0). A large amount of nanocellulose is formed on the surface of SCG after bleaching by H2O2, which anchors and disperses the palladium nanoparticles (Pd NPs). The D-SCG loaded with Pd NPs (Pd-D-SCG) is superhydrophilic, which facilitates water transport and thus promotes efficient removal of organic pollutants dissolved in water. Pd-D-SCG exhibits excellent room temperature catalytic activity for the removal of 4-nitrophenol (4-NP) and methylene blue (MB) in water and shows good chemical stability and recyclability in water, with no obvious decrease even after five repeated cycles.

In this paper, nanochitin was used as an alternative natural nanomaterial to combine with cellulose fibers for fabricating high-strength paper. Two typical chitin nanowhiskers having contrasting sign of surface charge were compared to evaluate the enhancement performance on paper in details. The results show that nanochitin with positive charges on the surface has a significant effect on the strength properties of the prepared paper, especially on wet strength. When the dosage of chitin nanowhiskers was 2%, the wet strength index was increased to 2.48 N·m/g, which is important for paper-based analytical devices with the common use in liquid analysis. Typical colorimetric glucose assays were successfully performed, suggesting the improved analytical performance on these prepared paper.

The cumulative exposure to metals affects cardiac conduction, and the effect of polymetallic exposure on heart rate in children is unknown. To evaluate the relationship between cumulative exposure to metal mixtures and heart rate among Chinese preschoolers, the determination of urinary 24 metals was processed by high-resolution inductively coupled plasma-mass spectrometry. Heart rate was recorded when measuring blood pressure after resting 5 min or longer. As a method to compute the Environmental risk score (ERS) according to heart rate under heavy metal mixtures, adaptive elastic net (AENET) with 299 predictors which were formed by the combination of main effects, squared terms, and pairwise interactions of heavy metals with a total number of 23, 23, 253 respectively. To further assess the associations between ERS and heart rate, regression analyses were performed with complex survey designs. The construction of ERS under heart rate-related metal mixtures was returned by AENET in according to 11 main effects (tin, arsenic, zinc, iron, titanium, vanadium, nickel, manganese, cobalt, copper and chromium) and 2 squared terms (tungsten and rubidium). A high correlation was monitored between the alteration of ERS in the study population and heart rate (β = 1.030, 95% CI: 0.730 - 1.330 in 1239; β = 1.085, 95% CI: 0.777 - 1.393 in 1061). Significant associations of ERS with higher heart rates were also pointed out (Ps 0.05). Our study elucidates the association of the cumulative exposure of heavy metals as mixtures and heart rate among Chinese preschoolers. Further research is obliged to corroborate these findings in longitudinal studies.

Garnet electrolyte is a promising candidate for the development of all-solid-state Li-metal batteries, because of its safety and stability against Li metal. However, its practical application is limited by the difficulty in production of its high-density thin sheet. In this work, we have fabricated garnet thin sheet electrolytes (Li6.4La3Zr1.4Ta0.6O12, LLZTO) by tape-casting technique. By using Li2O as a liquid-phase sintering additive, a high relative density up to 99% was achieved. Electrochemical results show the LLZTO sheets have an ionic conductivity of 5.2 × 10−4 S cm−1 at 30 °C and good cycling stability against Li metal. Based on the sheets, all-solid-state Li/LLZTO/LiFePO4 batteries exhibit excellent reversible cycles at 60 °C and 0.1C with an initial discharge specific capacity of 125.8 mA h g−1 and a retention of 92.3% after 50 cycles. These results indicate that the tape-casting process demonstrated here provides an effective method of producing high-density garnet thin sheet electrolytes for high-performance all-solid-state Li-metal batteries.

Garnets are promising solid electrolytes for developing solid state Li batteries, owing to their features of relatively high conductivity and stability against lithium metal. However, they show shortcoming of Li penetration through garnets during Li plating and stripping, which limits their practice application. Herein, we present a strategy to solve such problem by coating SnO2 films on the surfaces of the Li6·4La3Zr1·4Ta0·6O12 pellets. Through conversion reaction of SnO2 with Li at 200 °C, the nanocomposite layers consisting of crosslinked LixSn and Li2O are formed between the Li and the Li6·4La3Zr1·4Ta0·6O12 electrolytes. This leads to transition from lithiophobicity to lithiophilicity, thus greatly reducing interfacial resistance from 1100 Ω cm2 to 25 Ω cm2. Furthermore, taking advantage of suppressing volume change of LixSn alloy which is about 260%, the intermediate layers maintain integrity under the current densities of 0.2 mA cm−2 for 650 h cycles. In addition, the critical current density of Li/SnO2-Li6.4La3Zr1·4Ta0·6O12-SnO2/Li can be as high as 1.15 mA cm−2. As a proof-of-concept, this effective interface modification based on conversion reaction method contributes to a useful way of solving the Li/garnet interface problem and promoting the solid state Li batteries development.

Recently, flutter-driven triboelectric nanogenerator (TENG) has shown huge potential in wind energy harvesting from ambient environments. However, almost all the reported devices are based on parallel structure which suffers from a critical problem of insufficient contact between triboelectric surfaces. In this work, we propose an angle-shaped TENG (AS-TENG) with the above issue resolved. The device is based on two Al layers stacked to form an angle shape and a FEP film positioned in between by sharing a common side. Thanks to this design, the FEP film can contact fully and intimately with the Al layers to facilitate the effect of contact electrification and electrostatic induction. Compared with the existing parallel-structured TENG, the AS-TENG shows an overwhelming output performance because of the enhanced contact area. Furthermore, the AS-TENG is introduced a wedge-shaped wind guide channel which can provide a driving force for the flutter and hence lower the start-up wind speed largely. To further enhance the electric output, the AS-TENGs can be facilely integrated into a 360° radial array, showing an enlarged windward area and a high level of integration. The AS-TENG array can be applied to harvest outdoor weak wind and act as a direct power source to charge a capacitor or drive electronic devices. This work provides a design strategy for natural weak wind scavenging which may push forward the practical applications of TENG for wind power.

Recently, ambient energy harvesting has attracted a great deal of attention to develop clean and renewable energy technologies. In this work, a flexible photo-thermoelectric nanogenerator (PTENG) based on MoS2/PU photothermal film and Te/PEDOT thermoelectric layer has been demonstrated for harvesting environmental infrared (IR) light. The MoS2/PU photothermal film is carefully designed to exhibit excellent flexibility, transferability, and photothermal property. By integrating the photothermal layer with a Te/PEDOT thermoelectric device, the PTENG can produce electrical output without a spatial temperature gradient which is necessary for conventional thermoelectric device. Under IR light illumination, a high temperature difference can be generated across the device, and hence a potential difference established between two electrodes based on a coupling of photothermal effect and Seebeck effect. This type of PTENG exhibits numerous advantages, such as flexible, shape-adaptive, light-weight, and simple-fabrication, which may have a great potential of application in photo-thermoelectric energy harvesting for wearable electronics and implantable electronics.

The electrochemical conversion of the greenhouse gas, carbon dioxide (CO2), to energy fuels and value-added chemicals presents one of the most valuable approaches to harvest pollutants and produce renewable energy. However, the stable molecular structure of CO2 and the sluggish reaction kinetics make CO2 reduction reaction (CO2RR) formidably challenging to achieve reaction rate and selectivity practical in industry. Graphene and its derivatives have been considered a group of intriguing materials to develop advanced CO2RR electrocatalysts due to their large specific surface area, remarkable electron transfer ability, superior stability, and easy tunability of the structure and surface properties. Herein, we comprehensively discuss the state-of-the-art electrocatalysts constructed with graphene and derivatives for active and selective CO2RR within the recent five years, mainly including the electrocatalysts with both metal-based (e.g., noble, non-noble, or combined thereof) and non-metal (e.g., doped, modified, defected, or composited) catalytic sites. To present the versatile, high-performance metal-based CO2RR electrocatalysts constructed with graphene, we further subdivide them according to the sizes, oxidation states, metal species synergies, dimensionalities, and versatility. Finally, we provide the challenges and perspectives in this emerging area of utilising CO2 to produce various carbon-based fuels and chemicals via graphene chemistry.

Ultra-tough transparent conductive elastomers (TCEs) with self-healing performance are of great significance for research in the fields of soft robotics, optical display electronics, wearable electronic equipment and human–computer interaction. However, their limitation, such as the desolventizing process, low polymerization rate or balance between toughness and self-healing performance, cause difficulty in manufacturing by the 3D printing technique. Here, we propose a novel preparation strategy for 3D printed TCEs based on the photopolymerization of maleic acid (MA)/choline chloride (ChCl) and acrylamide (AAm)/choline chloride type polymerizable deep eutectic solvents (PDESs). PDES can polymerize into a tough and rich in hydrogen bonds poly(PDES) in a few seconds without solvent evaporation. The printed TCEs with precision of 10 µm have high transparency (95.6%) and stable electrical signals at 50% compression for 10,000 cycles. In addition, efficient self-healing performance due to the dynamic hydrogen bonds of poly(PDES) provides broad application prospects for 3D printed TCEs in long-term pressure-resistant intelligent applications.

Spent coffee ground (SCG), left over in coffee making, is the most abundant coffee byproduct, of which approximately 70% is made by cellulose and hemicellulose. Herein, we obtained a delignified SCG (D-SCG) by using an aqueous solution of 3 wt% NaOH for 1 h at 90 °C and then an aqueous solution of 3 wt% NaClO2 buffered with acetic acid at pH 4.3 for 2 h at 90 °C, respectively. Next, we used the D-SCG to fabricate holocellulose nanofibers (HCNF) suspension by TEMPO-Mediated oxidation. Finally, HCNF suspension was manufactured into superhydrophobic foams for oil-water separation through freeze-drying and hydrophobic modification. The superhydrophobic foams showed good properties of oil absorption capacity (16 g/g), separation efficiency (98.5%) and continuous separation. This work presents a novel idea for the further application of SCG and provides an eco-friendly and sustainable oil absorbent material to solve oil spill.

In this paper, UV-curable castor oil-based polyfunctional polyurethane acrylate (COME-PUA) was synthesized via photo-click chemistry and isocyanate polyurethane reaction. Facile and highly efficient side-chain functionalization of castor oil (CO) was first achieved via thiol-ene photo-click chemistry with β-mercaptoethanol (ME). 1 H NMR result indicated that almost 100% conversion of double-bond in CO was observed within 10 min, and the average hydroxyl functionality of the obtained polyol COME was about 6. Next, COME was modified by isocyanate polyurethane reaction with hydroxypropyl acrylate (HPA), isophorone diisocyanate (IPDI) and PEG-200 as the chain extender in order to prepare the resin COME-PUA. Results of both 1 H NMR and FTIR revealed that the targeted COME and COME-PUA were successfully synthesized. Furthermore, UV-curing kinetic of COME-PUA was revealed by real-time FTIR, showing a higher UV-curing rate than the common CO-PUA. Finally, some physical properties of curing films were studied.

It is attractive, though it is very challenging, to synthesize conductive elastomers with high transparency and self-healing ability, simultaneously with facile and environmentally friendly preparation process. Here we demonstrate the fabrication of highly transparent, self-healing conductive elastomers based on synergistic hydrogen bonding interactions between poly(polymerizable deep eutectic solvent) (poly(PDES)) and phytic acid (PA) molecules. The hybrid network elastomers showed a fast self-healing property (within 2 s) without any other external stimuli and excellent self-healing efficiency (91.5%) within 48 h. The poly(PDES)-PA elastomers were highly transparent (an average transmittance of 93%), intrinsically conductive (an ionic conductivity of 7.8 × 10−4 S cm−1) and stretchable (strains up to 1300%). Furthermore, the abilities of healable & conductive poly(PDES)-PA elastomers to monitor the human activities retained no matter before or after being damaged. We believe this kind of dynamic bond manipulation is a powerful strategy to design and synthesize various transparent, self-healing, conductive elastomers for versatile applications.

The development of solid-state lithium-oxygen batteries is currently limited primarily by the high solid-solid interfacial resistance and the lack of efficient assembly of electrolyte and electrode. In this work, noncovalent interactions between the cations of an ammonium ionic liquid and both solid electrolytes and carbon air cathodes are introduced. The ionic liquid-based electrolytes (ILE) are solidified on Li6·40La3Zr1·40Ta0·60O12 (LLZTO) nanoparticles and gelated by multi-wall carbon nanotubes (MWCNTs), respectively, to construct LLZTO@ILE quasi-solid-state electrolyte (QSSE) and MWCNTs-LLZTO/ILE gel cathode (GC). The QSSE exhibits a high ionic conductivity of 1.71 × 10−3 S cm−1 at 60 °C, high Li-ion transference number of 0.56, broad electrochemical window of ~4.8 V and good thermal stability. The GC shows outstanding compatibility with QSSE. Quasi-solid-state Li–O2 batteries are assembled by integrating QSSE and GC films with a facile roll forming method, showing a low total interfacial resistance (~87 Ω cm2), and excellent reversible cycles (70 cycles) with low charge overpotential ( 70%) at 60 °C and 200 mA g−1. A 0.12 Ah pouch-type Li–O2 battery was achieved by this method. These results suggest that the noncovalent interactions initiated by IL cations could be an effective approach to solve the solid-solid interface issue and achieve high discharge capacity in solid-state energy storage devices.

Nanocomposite hydrogels consisting of a synthetic matrix reinforced by nanosized crystalline polysaccharides offer significant potential in various fields. Different from nanocellulose, the combination of nanochitin with synthetic polymers to obtain nanocomposite hydrogels has not been extensively and systematically studied. Herein, a physically and chemically dual crosslinked nanocomposite hydrogel was successfully synthesized, where chitin nanowhiskers (ChNWs) and Zn2+ were incorporated within polyacrylamide (PAAm) matrix. Nanochitin/metal ion dual reinforcement imparts increased elasticity, enhanced mechanical properties, and improved recovery performance to PAAm network. The PAAm/ChNWs/Zn2+ hydrogel could be stretched to over 13 times its original length with tensile strength of 321.9 ± 8.2 kPa, and restore its original shape rapidly even when compressed at a strain of 95% with a corresponding compressive strength of 6.95 ± 0.20 MPa. The multiple crosslinks and interactions among ChNWs, Zn2+ and synthetic polymeric network were investigated. Moreover, the hydrogel was applied in drug release and soft bioelectronics.

Developing green substrates based on cellulose to substitute synthetic plastics meet the requirement for the sustainable future. However, cellulose-based substrates supporting for building electronic devices are usually opaque and highly hydrophilic, which ultimately limits the performance of optoelectronic devices. Herein, we report a new avenue for fabrication of highly transparent, weakly hydrophilic and biodegradable cellulose film. The acquired cellulose film not only has high transparency (over 90%), but also displays weak hydrophilicity (∼79° of initial water-contact angle) and still remains 3.5 MPa of tensile strength after soaking for two days in deionized water. Additionally, the degradation half-life of cellulose film is 20 days, and the cellulose films also have better thermostability. Moreover, the flexible electroluminescent devices have been successfully constructed by using this cellulose film as a green substrate. This novel strategy will greatly enrich the applications of cellulose films for next generation green electronics.

Nanopaper prepared from cellulose nanofibers (CNFs) is a kind of promising substrate for various high-tech devices. However, several drawbacks including poor water stability and weak corrosion resistance still remain, which limit the practical applications of the nanopaper. Herein, we present a simple and low-cost method for fabricating transparent and superhydrophobic nanopaper by spraying fluorinated silica/multi-walled carbon nanotubes (SiO2/MWCNTs) composite on the nanopaper. A series of functional nanopaper were fabricated, which shows excellent performance of water repellency, chemical stability, conductivity, thermostability and self-cleaning property. Among them, the nanopaper modified with the composite containing 0.5 wt% MWCNTs has a water contact angle of about 163°, transparency of 79.96% and the sheet resistance of 3.15 × 106 Ω sq−1. The combination of the promising features in a material offers attractive prospects, and enables our nanopaper could be tailored for emerging applications such as flexible electronics, display protection and intelligent packages.

Benzoylformamide (BFA) derivatives are proposed as new photocaged bases with good solubility in epoxy resin. Initially their structures were confirmed by 1 H NMR, 13 C NMR, and elemental analysis. Next, we detail their thermal stability, solubility behavior, and photolysis products. Furthermore, the model photo-latent anion polymerization (AP) of epoxide system in the presence of BFA-dBA ( N , N -dibenzyl-2-oxo-2-phenylacetamide) as a photocaged base has been investigated, and excellent photopolymerization profile is obtained.

Thioxanthone-based N -phthalimidoamino acid ammonium salt (thioxanthen-DBU) as a photocaged base was synthesized and characterized. The photochemical properties and initiation mechanism were analyzed. It was found that the compound absorbs over the UV and visible region with relatively high absorption coefficients. Furthermore, the covalent binding of N -phthalimidoamino acid and type II chromophores (thioxanthone, TX) remarkably improved the photoreactivity. Specifically, in combination with a benzoyl peroxide initiator, thioxanthen-DBU was able to initiate the amine-mediated redox photopolymerization of trimethylol propane triacrylate (TMPTA), and an excellent photopolymerization profile was obtained.

Nowadays biosource-based materials have received revitalized interest for their ability to substitute for petrochemical-based materials. In this paper, we report a facile synthetic method of soybean oil-based polyfunctional acrylate (PFA) for UV-curable materials. Specifically, rapid and highly efficient side-chain functionalization of soybean oil was achieved via photoclick thiol-ene reaction, soybean oil-based polycarboxylic acid (PCA) was thus obtained. Next, by DCC (N,N′-dicyclohexylcarbodiimide) catalyzed esterification reaction with hydroxypropyl acrylate, polyfunctional acrylate (PFA) was synthesized at room temperature. Real-FTIR result indicated that almost 100% conversion of double-bond within vegetable oil was observed within 16.7 min, yielding the soybean oil-based polycarboxylic acid quantitatively. Furthermore, the structure of PFA was confirmed by 1 H NMR and FTIR. Finally, the excellent UV-curing rate of PFA was revealed by real-FTIR.

The article presents a highly effective strategy for photopolymerization of acrylates via photolatent redox-accelerated reaction based on the synergistic photoinitiating systems containing photolatent superbase and readily available peroxides. Polymerization of acrylates could be instantly initiated with the effective interaction between the photogenerated amine and peroxides. Due to the persistent interaction of produced longeval amine with peroxides, remarkable post conversion after irradiation, which is significant for radiation crosslinking of photo-screened materials, was thus initially achieved in photoinitiated free radical polymerization. To explore the synergistic interactions of the photoinitiating systems, the effect of peroxide structures and QA-DBU:BPO ratios had been examined by RTIR, showing that all peroxides are applicable as the final conversion rate of acrylates is concerned. Further, BPO and CHP significantly accelerated the photopolymerization rate in air atmosphere. The synergistic efficiency of QA-DBU and BPO as a photopolymerization initiatiation system was close to that of the conventional D-1173 photoinitiator.

Type I interferons (IFN) exert multiple effects on both the innate and adaptive immune system in addition to their antiviral and antiproliferative activities. Little is known, however about the direct effects of type I IFNs on germinal center (GC) B cells, the central components of adaptive B cell responses. We used Burkitt's lymphoma (BL) lines, as a model system of normal human GC B cells, to examine the effect of type I IFNs on the expression of BCL-6, the major regulator of the GC reaction. We show that type I IFNs, but not IFNγ, IL-2 and TNFα rapidly down-regulate BCL-6 protein and mRNA expression, in cell lines derived from endemic, but not from sporadic BL. IFNα-induced down-regulation is specific for BCL-6, independent of Epstein-Barr virus and is not accompanied by IRF-4 up-regulation. IFNα-induced BCL-6 mRNA down-regulation does not require de novo protein synthesis and is specifically inhibited by piceatannol. The proteasome inhibitor MG132 non-specifically prevents, while inhibitors of alternate type I IFN signaling pathways do not inhibit IFNα-induced BCL-6 protein downregulation. We validate our results with showing that IFNα rapidly down-regulates BCL-6 mRNA in purified mouse normal GC B cells. Our results identify type I IFNs as the first group of cytokines that can down-regulate BCL-6 expression directly in GC B cells.