Abstract Exploring the potential for secondary utilization of wastewater is a prudent strategy to achieve “take-make-use-reuse” circular economy. Taking advantages of wood’s hierarchical structure and large surface area, in this project, we fabricate surface-encapsulated anion-selective and cation-selective wood membranes (comprising up to 98% eco-friendly materials) through a two-step process: dip-coating with either positively charged 2(dimethylamino)ethyl methacrylate or negatively charged acrylic acid, followed by energy-efficient sunlight-induced polymerization. The output voltage and current of a single modified wood cell (20 × 20 × 3 mm 3 ) in modulated wastewater from flue gas desulfurization are 55 mV and 0.6 µA, respectively, tenfold higher than that of untreated wood cells. When five cells are connected in series, the output voltage reaches 0.27 V, sufficient to power simple electronic devices. This underscores its potential for scaling up and its viability for future applications in industrial power plants.

Electrophoretic displays (EPDs), recognized for their low power consumption and portability, offer a viable alternative to plain paper. However, their adoption in high-frame-rate applications has been limited by slow response times. Here, we report a UV-curable copolymer system through the copolymerization of polyurethane acrylate (PUA) with methyl methacrylate (MMA), with the aim of enhancing the dielectric properties of the microcup layer and thereby improving EPD response performance. After systematic optimization, the PUA-15

Wood delignification and densification enable the production of high strength and/or transparent wood materials with exceptional properties. However, processing needs to be more sustainable and besides the chemical delignification treatments, energy intense hot-pressing calls for alternative approaches. Here, this study shows that additional softening of delignified wood via a mild swelling process using an ionic liquid-water mixture enables the densification of tube-line wood cells into layer-by-layer sheet structures without hot-pressing. The natural capillary force induces self-densification in a simple drying process resulting in a transparent wood film. The as-prepared films with approximate to 150 mu m thickness possess an optical transmittance approximate to 70%, while maintaining optical haze >95%. Due to the densely packed sheet structure with a large interfacial area, the reassembled wood film is fivefold stronger and stiffer than the delignified wood in fiber direction. Owing to a low density, the specific tensile strength and elastic modulus are as high as 282 MPa cm(3) g(-1) and 31 GPa cm(3) g(-1). A facile and highly energy efficient wood nanotechnology approach are demonstrated toward more sustainable materials and processes by directly converting delignified wood into transparent wood omitting polymeric matrix infiltration or mechanical pressing.

The combination of transparency, high dielectric permittivity, biocompatibility and flexibility is highly desired in the embedded capacitors. Herein, we show that assembling biodegradable sodium carboxymethyl cellulose (CMC) microfibers in biocompatible silicon elastomer (PDMS) under direct current (DC) electric field enables the production of high dielectric constant composite film with above desired properties. This process leads to the formation of columns of CMC microfibers spanning across the thickness direction, thus generating microfiber depleted regions in between fibers and polymer matrix. The as-prepared composite film with CMC (15 wt%) aligned exhibits a remarkable and an almost sevenfold higher dielectric permittivity as compared to that of the film with CMC randomly dispersed (72 vs 11.4, at 100 Hz). This high CMC loading does not compromise the flexibility and optical transmittance. Interestingly, the compression modulus along the thickness direction increases by >20 times from 16.4 MPa (CMC unaligned) to 339.9 MPa (CMC aligned). We demonstrate a facile strategy of fabricating high dielectric materials combining transparency, biocompatibility, flexibility and compression resistant, making the dielectric materials more versatile. This work shows that biomass derived CMC is a promising filler for high dielectric constant polymer composites benefiting from electric field driven construction of ordered micromorphology.

Supporting sustainable green energy systems, there is a big demand gap for grid energy storage. Sodium ion storage, especially sodium-ion batteries (SIBs), have advanced significantly and are now emerging as a feasible alternative to the lithium-ion batteries (LIBs) equivalent in large-scale energy storage due to their natural abundance and prospective inexpensive cost. Among various anode materials of SIBs, beneficial properties, such as outstanding stability, great abundance, and environmental friendliness, make sodium titanates (NTO), one of the most promising anode materials for the rechargeable SIBs. Nevertheless, there are still enormous challenges in application of NTO owing to its low intrinsic electronic conductivity and collapse of structure. The research on NTO is still in its infancy, there is few conclusive reviews about the specific function of various modification methods. Herein, we summarize the typical strategies of optimization and analysis the fine structures and fabrication methods of NTO anodes combined with the application of in situ characterization techniques. Our work provides effective guidance for promoting the continuous development equipping NTO in safety-critical systems and lays a foundation for the development of NTO anode materials in SIBs.

Triboelectric nanogenerators (TENG) have great potential to help enhancing the energy efficiency of buildings, and thus to contribute significantly to the reduction of global greenhouse gas emissions. However, there are major barriers against the adoption of such emerging energy technologies. Meeting the need for sustainable large-scale fabrication of high-performance products remains a critical challenge towards real-world TENGs' building applications. To mitigate this challenge, we enhance the poor polarizability of native wood by a scalable plasma treatment, a facile approach which to the greatest degree preserves wood's warm colors, mechanical robustness while efficiently enhancing the triboelectric output. We demonstrate the enhancement of electric output by assembling wood triboelectric nanogenerators (W-TENGs) in both contact-separation and single -electrode operation modes. We show that when two radial-cut wood samples (L x R x T: 100 x 80 x 1 mm(3)), one treated with an O-2 plasma and the other with a C4F8 + O-2 plasma, are subjected to periodic contact and separation with an applied pressure as low as 0.0225 MPa, a maximum voltage of 227 V and a current of 4.8 mu A are produced. Eventually, we showcase the real-world applicability of our approach with two prototypes of triboelectric wood floors, opening up new technological pathways towards a 'net-zero emissions' future.

All-cellulose composites (ACCs) were prepared from filter paper via partial dissolution in the ionic liquid 1-ethyl-3-methylimidazolium acetate, and material tensile properties were investigated using various approaches. One is based on data directly taken from a tensile testing machine, and the other uses two-cameras stereovision with digital image correlation (DIC) technique. In the latter case, virtual extensometer with different locations on the sample and averaging over sample surface were tested. Nominal and true stress–strain dependences were built and Young's modulus, tensile strength, elongation at maximal stress and toughness were evaluated as a function of ACC density. A minor difference was observed for the stress–strain dependences derived from different approaches which use the DIC technique, most probably because of low ACC deformation. However, the results reveal that the nominal stress–strain curve from DIC is significantly different from that which is directly derived from the data provided by machine sensors thus strongly impacting Young’s modulus and elongation at break values. This study provides an insight into the evaluation of the mechanical properties of ACCs.

All-cellulose composites (ACCs) is a new generation of biocomposites with both the matrix and reinforcing fibers being based on cellulose. This thesis explores various designs of ACCs using either macro- or nano-scale cellulose fibers as raw materials and ionic liquids (ILs) as cellulose solvents. Prior to ACCs fabrication, the swelling and dissolution kinetics of different cellulose fibers (natural fiber flax, viscose-type Cordenka and two Ioncell fibers with one containing lignin and hemicelluloses) in solvent power tuned ILs (1-ethyl-3-methylimidazolium acetate, [EMIM][OAc] and N-methyl-1,5-diazabicyclo[4.3.0]non-5-enium dimethyl phosphate, [mDBN][DMP]) was studied. High performance unidirectional flax-based ACCs, isotropic filter paper-based ACCs and nanopaper were then produced involving controlled dissolution and/or swelling of cellulose fibers. The fundamental investigation on fibers swelling and dissolution kinetics revealed that the rate of fiber dissolution in [EMIM][OAc] depended on fiber accessibility and solvent viscosity. The fastest dissolution (in [EMIM][OAc] and [EMIM][OAc]-5% water) or swelling (in [EMIM][OAc]-15% water) was recorded for Ioncell fibers and the slowest for Cordenka. An anomalous two-step dissolution-swelling behavior of flax was observed in [mDBN][DMP] and [mDBN][DMP]-water. ACCs from either unidirectional flax or isotropic filter paper were produced via selective dissolution strategy. For flax-based ACCs, it was shown that the mechanical properties were controlled by the sufficient amount of matrix and the non-dissolution of the inner, mechanically strong cell walls in the fiber. The interface between the matrix and the fibers was further artfully re-modelled by utilizing two-step dissolution-swelling phenomenon in [mDBN][DMP], resulting in increased tensile strength in both transverse direction and fiber direction. For isotropic paper-based ACCs, a digital image correlation technique was explored for accuracy enhanced analysis of mechanical properties. A 30-60 min impregnation allowed increasing tensile strength, Young's modulus and toughness of a filter paper in almost 10 times, 5 times and 25 times, respectively.Isotropic ACC constructed from highly disordered and entangled cellulose nanofibrils (CNFs) through their self-binding exhibited an exceptional ductility (up to 35%) while combining high strength (up to 260 MPa) and toughness (up to 51 MJ/m3). This was realized by swelling of hemicelluloses in-between the nanofibrils in [EMIM][OAc]–water below the dissolution limit of cellulose and hemicellulose, thus allowing delamination of thick CNF bundles into thinner ones without influencing the length. The results obtained demonstrate that a fundamental understanding of cellulose swelling and dissolution promotes various possibilities to design ACCs with engineered performance. The findings bring new perspectives to the design of macroscale and nanoscale cellulosic materials.

Patterned micro/nanomaterials display efficient light management capabilities owing to their control of light propagation within multiscale periodic structures. Here a hierarchical photonic structure composed of polystyrene microspheres and cholesteric assembly of cellulose nanocrystals is described, acting as a polarization-sensitive retroreflective coating and microlens array. Micropatterned photonic films are prepared by casting an aqueous cellulose nanocrystal suspension onto a monolayer of polystyrene microspheres substrate through evaporation-assisted transfer imprinting lithography, integrating a bulk cholesteric matrix and patterned surface. By directing light at the as-assembled polystyrene surface, an enhanced structural color develops from the circularly polarized light retroreflection. Whereas when light travelling across the photonic film, the transparent layer of polystyrene microspheres forms into plano-convex microlens to converge the transmitted light into the focus plane and reduce centimeter-scale illuminated image into a high-fidelity miniaturized replica. This simple method, combining self-assembly with imprinting lithography, is expected to pave the way for designing custom-tailored optics with novel functions.

Swelling behavior of cotton, dissolving wood pulp (DWP), viscose staple fibre (VsF), and Tencel staple fibre (TsF) in varying sodium hydroxide (NaOH) were investigated by means of optical microscopy and were characterized by molecular mass distribution, X-ray diffractometer, and dynamic vapor sorption. Effect of temperature (20-45 °C) and duration (0-120 min) was studied. The results reveal that the swelling ratio of fibre in alkali solution depends on fibre accessibility and NaOH concentration. Among all the materials, VsF exhibited the highest swelling ratio and lowest swelling ratio has been observed for cotton fibre. The results suggest that the swelling is limited by the presence of plant cell wall structures in cotton and DWP, rather from fringed-fibrillar, semi-crystalline sub-structures, which result from the inherent tendency of cellulose molecules to form such structures during the biosynthesis of plant cell walls as well as during the formation of regenerated cellulosic textile fibre in wet-spinning.

Cellulose nanopaper is a strong lightweight material made from renewable resources with a wide range of potential applications, from membranes to electronic displays. Most studies on nanopaper target high mechanical strength, which compromises ductility and toughness. Herein, we demonstrate the fabrication of highly ductile and tough cellulose nanopaper via mechanical fibrillation of hemicellulose-rich wood fibers and dispersion of the obtained cellulose nanofibrils (CNFs) in an ionic liquid (IL)-water mixture. This treatment allows hemicellulose swelling, which leads to dissociation of CNF bundles into highly disordered long flexible fibrils and the formation of a nanonetwork as supported by cryogenic transmission electron microscopy (cryo-TEM) imaging. Rheology of the suspensions shows a 300-fold increase in storage and loss moduli of CNF-IL-water suspensions, compared to their CNF -water counterparts. The nanopaper prepared by removing the IL-water shows a combination of large elongation (up to 35%), high strength (260 MPa), and toughness as high as 51 MJ/m(3), because of efficient interfibrillar slippage and energy dissipation in the highly disordered isotropic structure. This work provides a nanostructure-engineered strategy of making ductile and tough cellulose nanopaper.

Mechanically strong all-cellulose composites are very attractive in the terms of fully bio-based and bio-degradable materials. Unidirectional flax-based all-cellulose composites are prepared via facile room-temperature impregnation with an ionic liquid, 1-ethyl-3-methyl imidazolium acetate. To determine the optimal processing conditions, the kinetics of flax dissolution in this solvent is first studied using optical microscopy. Composite morphology, crystallinity, density, the volume fraction of cellulose II and tensile properties are investigated, indicating that flax dissolution should be within certain limits. On the one hand, the amount of cellulose II formed through dissolution and coagulation should be high enough to “fuse” flax fibers, resulting in a density increase. On the other hand, only the surface layer of the fibers should be dissolved to maintain the strength provided by the inner secondary layer and avoid a detrimental decrease in crystallinity. The highest Young’s modulus and strength, 10.1 GPa and 151.3 MPa, respectively, are obtained with a crystallinity of 43% and 20 vol% of cellulose II.

The kinetics of the dissolution and swelling of different cellulose fibers in the ionic liquid 1-ethyl-3-methylimidazolium acetate ([EMI-M][OAc]) was studied by varying solvent power and temperature. Natural fiber, flax, and man-made fibers, Cordenka and Lyocell-type (Ioncell) were used with one Ioncell fiber containing lignin and hemicelluloses. Through the addition of water, the solvent power was modified from very good (neat ionic liquid), to moderate (with 5 wt% water) and weak (15 wt% water). The temperature was varied to correlate the fiber dissolution rate with the solvent viscosity. All fibers were characterized by chemical composition, crystallinity, molecular weight distribution and dynamic vapor sorption. It was demonstrated that while the rate of fiber dissolution in neat ionic liquid depends on fiber accessibility and solvent viscosity, the water-induced decreased solvent power dominates the general fiber behavior. Flax appeared to be the most "sensitive" to the solvent power due to its hierarchical structure. The fastest dissolution or swelling was recorded for Ioncell and the slowest for Cordenka.

We report on the formation of water-in-water liquid crystal emulsions with permeable colloidal assemblies. Rodlike cellulose nanocrystals (CNC) spontaneously self-assemble into a helical arrangement with the coexistence of nonionic, hydrophilic polyethylene glycol (PEG) and dextran, whereas the two polymer solutions are thermodynamically incompatible. Stable water-in-water emulsions are easily prepared by mixing the respective CNC/polymer solutions, showing micrometric CNC/PEG dispersed droplets and a continuous CNC/dextran phase. With time, the resulting emulsion demixes into an upper, droplet-lean isotropic phase and a bottom, droplet-rich cholesteric phase. Owing to the osmotic pressure gradient between PEG and dextran phases, target transfer of cellulose nanoparticles occurs across the water/water interface to reassemble into a liquid crystal-in-liquid crystal emulsion with global cholesteric organization. The observed structural, optical, and temporal evolution confirm that the colloidal particles in the two immiscible phases experience short-range interactions and form long-range assemblies across the interface.

Objective To explore noninvasive assessment of liver fat content with iron deposition using magnetic resonance (MR) quantitative technology. Methods A water–fat phantom with iron deposition containing 63 vials with predetermined fat percentages and iron concentrations was constructed. Thirty-three patients underwent fat quantitative MR examinations. The fat fraction (FF) was determined by three Dixon techniques. Pathological evaluation findings and the steatosis area rate (SAR) were used as the gold standards. Results FF IOP and FF LAVA-Flex significantly differed from FF TEST for iron concentrations of 1 to 30 µg/mL and fat components of 10% to 80%. Using the three Dixon techniques, FF IOP was 15.76% ± 6.98%, FF LAVA-Flex was 16.71% ± 6.77%, and FF IDEAL IQ was 13.18% ± 6.42% in patients without liver cirrhosis; these values in patients with liver cirrhosis were 20.35% ± 6.11%, 20.89% ± 8.49%, and 12.86% ± 4.00%, respectively. The SAR in patients without and with liver cirrhosis was 11.31% ± 5.89% and 9.84% ± 4.17%, respectively. There were significant positive correlations between FF IDEAL IQ and SAR with or without liver cirrhosis. Conclusion Iron deposition must be considered when using quantitative MR techniques to evaluate the hepatic fat content. Compared with the IOP and LAVA-Flex techniques, the IDEAL IQ technique has more stability and accuracy in measurement of the hepatic fat content, free from iron deposition.

随着社会的发展、 时代的进步,我国新型城镇化建设的过程中,旧城建筑因年久失修变得老化,旧城改造在不断的进行.旧城改造是城市布局的重要组成部分,它可以提升城市的发展,加快城市经济化的进程,使城市整体形象得到提升.然而,在旧城改造的过程中,还存在很多问题,项目管理方法在旧城改造中具有重要地位.本文以项目管理方法来探讨旧城改造中的问题,并提出相关建议,旨在为项目管理在旧城改造中的运用提供借鉴思路.

The polylactic acid (PLA) grafted cellulose copolymer (OLA-g-C) was synthesized by melt copolycondensation of lactic acid with microcrystalline cellulose (MCC), then PLA/OLA-g-C blends and contrast samples PLA/MCC blends were prepared by solution mixing. The results of scanning electron microscopy (SEM) showed that the existence of PLA side chains improved the dispersion of cellulose in PLA matrix and inhibited the agglomeration. In non-isothermal crystallization process, OLA-g-C and MCC both promoted the crystallization ability of PLA, but the promotion effect of OLA-g-C was better than MCC due to the well dispersion of OLA-g-C in PLA matrix. In isothermal crystallization process, OLA-g-C can accelerate the crystallization rate and improve the crystallinity simultaneously, but had no influence on the growth geometry and nucleation type of the crystal of PLA. The results of polarized optical microscopy (POM) further proved that OLA-g-C as the nucleating agent, reduced crystallization time, and enhanced the crystallization ability of PLA. However, the elongational viscosity decreased with the addition of OLA-g-C, which related to the entanglement between OLA-g-C and PLA matrix.

MCC-g-PLA copolymer can improve the elongational viscosity of PLA at elongation rates of 0.1 s−1.