Magnetic superhydrophobic cellulose nanofibril based aerogel with rope-ladder like structure incorporating both superelasticity and excellent oil absorption.

Achieving an equilibrium between exceptional oil absorption and remarkable elasticity has emerged as a formidable challenge for magnetic porous materials designed for oil absorption. Here, we propose an original, magnetic and superhydrophobic cellulose nanofibril (CNF) based aerogel system with a rope-ladder like skeleton by to greatly improve the issue. Within this system, CNF as the skeleton was combined with multiwalled carbon nanotubes (MWCNT)@Fe3O4 as the magnetic and enhanced component, both methyltrimethoxysilane (MTMS) and acetonitrile-extracted lignin (AEL) as the soft-hard associating constituents. The resultant CNF based aerogel shows a rope-ladder like pore structure to contribute to high elasticity and excellent oil absorption (28.34-61.09 g/g for various oils and organic solvents) under the synergistic effect of Fe3O4@MWCNT, AEL and MTMS, as well as good specific surface area (27.97 m2/g), low density (26.4 mg/cm3). Notably, despite the introduced considerable proportion (0.5 times of mass-CNF) of Fe3O4@MWCNT, the aerogel retained an impressive compression-decompression rate (88%) and the oil absorption efficiency of above 87% for various oils due to the soft-hard associating structure supported by both MTMS and AEL. This study provides a prospective strategy to balance between high elasticity and excellent oil absorption of CNF based aerogel doping inorganic particles.

Electrochemical Hydrophobic Tri-layer Interface Rendered Mechanically Graded Solid Electrolyte Interface for Stable Zinc Metal Anode.

The aqueous zinc-ion battery is promising as grid scale energy storage device, but hindered by the instable electrode/electrolyte interface. Herein, we report the lean-water ionic liquid electrolyte for aqueous zinc metal batteries. The lean-water ionic liquid electrolyte creates the hydrophobic tri-layer interface assembled by first two layers of hydrophobic OTF- and EMIM+ and third layer of loosely attached water, beyond the classical Gouy-Chapman-Stern theory based electrochemical double layer. By taking advantage of the hydrophobic tri-layer interface, the lean-water ionic liquid electrolyte enables a wide electrochemical working window (2.93 V) with relatively high zinc ion conductivity (17.3 mS/cm). Furthermore, the anion crowding interface facilitates the OTF- decomposition chemistry to create the mechanically graded solid electrolyte interface layer to simultaneously suppress the dendrite formation and maintain the mechanical stability. In this way, the lean-water based ionic liquid electrolyte realizes the ultralong cyclability of over 10000 cycles at 20 A/g and at practical condition of N/P ratio of 1.5, the cumulated areal capacity reach 1.8 Ah/cm2 , which outperforms the state-of-the-art zinc metal battery performance. Our work highlights the importance of the stable electrode/electrolyte interface stability, which would be practical for building high energy grid scale zinc-ion battery.

Investigating the effect of exercise on the expression of genes related to cardiac physiological hypertrophy.

Physiological hypertrophy of the heart is associated with an increase in the normal function of the heart, and it directly relates to regular exercise, especially among elite athletes. Researches about special signaling pathways that create physiological hypertrophy have recently received more attention. As a result, the present study was conducted to investigate the effect of aerobic exercise intensity on the expression of genes involved in heart physiological hypertrophy. For this purpose, 30 male Wistar rats were prepared and randomly divided into three groups: control, intense intermittent training, and submaximal continuous training. The intensive intermittent training protocol included 30 minutes of intermittent running, each interval including 4 minutes of running with an intensity of 85-90% VO2max and 2 minutes of active recovery with an intensity of 50-60% VO2max three days a week for 8 weeks. Also, the submaximal continuous exercise group had activity intensity equal to 50-55% of the maximum oxygen consumption. The expression of genes related to cardiac hypertrophy such as MMP-I, TGF-ß1, and TIMP was evaluated through real-time PCR technique. The results showed that the expression of studied genes in the three groups had significant differences (p<0.05). Both training methods led to a significant increase in TGF-ß1 and TIMP gene expression in the heart of rats. But the changes in MMP-I in the intermittent group were not significant compared to the control group. In general, it seems that exercise leads to the improvement of the factors involved in the physiological hypertrophy of the heart. Therefore, the findings of the current research are expressed with caution and more research is needed in the future.

Construction of CNC@SiO2@PL Based Superhydrophobic Wood with Excellent Abrasion Resistance Based on Nanoindentation Analysis and Good UV Resistance.

Construction of superhydrophobic woods with high abrasion resistance is still a major challenge, and micro analysis for abrasion resistance is scarce. To improve these issues, cellulose nanocrystals (CNC)@SiO2@phosphorylated lignin (PL) rods were prepared by SiO2 in situ generated on CNC, and then the modified lignin attached to the CNC@SiO2 rods surface. Subsequently, the superhydrophobic coating was constructed using hydrophobic modified CNC@SiO2@PL rods as the main structural substance by simple spraying or rolling them onto wood surfaces, and both polydimethylsiloxane (PDMS) and epoxy resin were used as the adhesives. The resulting coating had excellent superhydrophobic properties with a water contact angle (WCA) of 157.4° and a slide angle (SA) of 6°. The introduced PL could enhance ultraviolet (UV) resistance of the coating due to the presence of these groups that absorbed UV light in lignin. In the abrasion resistance test, compared with the SiO2/PL coating, the abrasion resistance of the one with CNC was much higher, suggesting that CNC could improve the abrasion resistance of the coating due to its high crystallinity and excellent mechanical strength. The coating with PDMS performed better than the one with epoxy resin because the soft surface could offset part of the external impact by deformation in the abrasion process. This was also consistent with the results of the nanoindentation (NI) tests. In view of the simple preparation and good performance, this superhydrophobic wood will have broad application potential.

Exploration of multifunctional wood coating based on an interpenetrating network system of rosin-CO2-based polyurethane and mussel bionic rosin-based benzoxazine.

Polyurethane (PU) prepared by blending rosin base and CO2-polyol already has good mechanical properties and hydrophobic effect and has powerful benefits in acid and alkali resistance and salt resistance. In this study, mussel bionic rosin-based benzoxazine (BZ) was synthesized using dehydroabietylamine, catechol, and paraformaldehyde. Mixing BZ into PU can endow the resulting PU/BZ with special effects such as zero curing shrinkage, excellent mechanical behavior, and flame retardancy through a 3D interpenetrating network system. From the results, the modulus of rupture (MOR) and modulus of elasticity (MOE) of PU wood coatings are 97.04 and 2601.97 MPa, respectively; in contrast, the PU/BZ wood coatings exhibited higher values of MOR and MOE of 110.87 and 2738.11 MPa. PU/BZ wood coatings show higher flexural strength and elastic modulus. They are also stronger than PU coatings in terms of acid/alkali and aging resistance. At the same time, the coating is endowed with flame retardant properties, and the LOI is 30.2 due to the presence of BZ. Thus, PU/BZ can be a versatile and practical wood coating. The interpenetrating network system of PU/BZ has an innovative impact on the preparation of wood coatings.

Investigation into the reaction mechanism underlying the atmospheric low-temperature plasma-induced oxidation of cellulose.

Atmospheric low-temperature plasma has been widely applied in surface modification of lignocellulose for manufacturing lightweight, strong composites. This study is aimed at elaborating the structural changes of cellulose after plasma treatment and further understanding the mechanism underlying plasma-induced oxidation of cellulose. Experiments suggested that atmospheric low-temperature plasma exhibits strong capacity to cleave covalent bonds, leading to oxidation and degradation of cellulose. Theoretical analysis revealed that cleavage of C4O covalent bond is the first-step reaction during plasma-induced oxidation due to its low bond dissociation energy (229.2 kJ mol-1). Subsequent pyranose ring-breaking reaction dominates dynamically and thermodynamically. Obtained outcomes are vital for fundamentally understanding the plasma-lignocellulose interaction. On that basis, plasma treatment for activation and oxidation of lignocellulose can be optimized and designed for improved efficiency. Wettability of lignocellulose can be thus improved in a short time, providing an opportunity to manufacture lignocellulose-based composites with enhanced efficiency and mechanical properties in future.

Atmospheric Low-Temperature Plasma-Induced Changes in the Structure of the Lignin Macromolecule: An Experimental and Theoretical Investigation.

Atmospheric low-temperature plasma has emerged as a promising pretreatment for lignocellulose to improve bio-refining. Herein, we investigated plasma-induced changes in the chemical structure of lignin to obtain a fundamental understanding of the plasma-lignocellulose interaction. Based on the results, plasma possesses a strong capacity to cleave C-C covalent bonds in the aliphatic region of lignin, accompanied by oxidation. Plasma treatment leads to the degradation and fragmentation of lignin. Pronounced deconstruction of ß-O-4 aryl ether is observed in plasma. The relative content of ß-O-4 aryl ether was reduced from the initial value of 65.1/100Ar to 58.7/100Ar for lignin from corncob and from the initial value of 72.5/100Ar to 63.8/100Ar for lignin from poplar after plasma treatment, respectively. According to the density functional theory analysis, the oxygen atom of ß-O-4 aryl ether is the most likely potential reaction site and the Cß-O covalent bond exhibits the lowest decomposition free energy (50.5 kcal mol-1), which will easily be cleaved in plasma. The dominant reaction pathway of lignin degradation is the cleavage of the Cß-O covalent bond followed by the cleavage of the Cß-Cα bond. We propose that this investigation is beneficial to optimize and expand the applications of plasma treatment in pretreatment of lignocellulose.

Constructing a Novel Electroluminescent Device with High-Temperature and High-Humidity Resistance based on a Flexible Transparent Wood Film.

Plastic-based electroluminescent devices generally suffer from thermal expansion owing to the high coefficient of thermal expansion (CTE) of the plastic substrate, which reduces the service lifetime of the electroluminescent device. In this study, we employed a delignified veneer synergistically reinforced with epoxy resin as a low-cost substrate for alternating current electroluminescent (ACEL) devices. In brief, the natural interconnected porous structure of wood had a good antideformation capacity to restrict the volume expansion of the epoxy resin under thermal conditions. Furthermore, the impregnation of epoxy resin dramatically improved the optical transmittance of delignified veneer. Considering its low CTE and antideformation capability, the intrinsically high-temperature and high-humidity resistance device based on transparent sliced veneer (TSV) was constructed. Remarkably, the TSV-ACEL device exhibited excellent stability and maintained good luminescence performance even at a high temperature (100 °C, 30 min; as a reference, the poly(ethylene terephthalate)-based ACEL device has stopped operating), completely submerged in water (30 min), or under high-temperature and high-humidity conditions (90 °C, relative humidity: >90%, 30 min). These results pave the way for the realization of flexible and high-temperature resistance ACEL devices.

Orange-Emissive Carbon Quantum Dots: Toward Application in Wound pH Monitoring Based on Colorimetric and Fluorescent Changing.

Monitoring of wound pH is critical for interpreting wound status, because early identification of wound infection or nonhealing wounds is conducive to administion of therapies at the right time. Here, novel orange-emissive carbon quantum dots (O-CDs) are synthesized via microwave-assisted heating of 1,2,4-triaminobenzene and urea aqueous solution. The as-prepared O-CDs exhibit distinctive colorimetric response to pH changing, and also display pH-sensitive fluorescence. Benefiting from the response of O-CDs over a wound-relevant pH range (5-9), medical cotton cloth is selected to immobilize O-CDs through hydrogen bond interactions, the resultant O-CDs-coated cloth with emission at 560 nm shows a high response to pH variation in the range of 5-9 via both fluorescence and visible colorimetric changes. Moreover, the sensitivity of fluorescence to pH is capable of establishing an analytical mode for determining pH value. Further, the O-CDs-based pH indicator possesses not only superior biocompatibility and drug compatibility but also excellent resistance leachability and high reversibility. Importantly, the usage of O-CDs-coated cloth to detect pH is free from the interference of blood contamination and long-term storage, thus providing a valuable strategy for wound pH monitoring through visual response and quantitative determination.

Fast modification on wheat straw outer surface by water vapor plasma and its application on composite material.

The presence of non-poplar extracts, cutin, and wax layer in the wheat straw outer surface (WOS) greatly limit its application in bio-composite preparation. In this study, a dielectric-barrier-discharge plasma using water vapor as feeding gas was used to fast modify the WOS. The morphology, free radical concentrations, surface chemical components, and contact angles of WOS before and after plasma modification were investigated. Wheat straw was further prepared into wheat straw-based composites (WSC) and its bonding strength was evaluated by a paper tension meter. The results showed that water vapor plasma leads to the appearance of surface roughness, the generation of massive free radicals, and the introduction of oxygen-containing groups. In addition, both initial and equilibrium contact angle and the surface total free energy were significantly increased after plasma modification. These results synergistically facilitate the spread and permeation of adhesive onto the WOS and thus improve the bonding strength of all prepared WSCs. A good linear relationship between bonding strength and surface roughness parameters, contact angles, and total free energy were observed. In general, this study provided a time-saving and cost-effective modification method to realize WSC manufacture.