The natural world abounds in lignocellulosic biomass, which is an environmentally friendly renewable resource. Cellulose nanofibrils (CNFs) made from biomass have the advantages of high optical ...transparency, light weight, good mechanical properties, high specific surface area and biodegradability. Increasing applications of CNFs have been identified in emerging high-tech fields, such as flexible electronics and clean energy. A variety of thermal management materials have been discussed in flexible electronic products. This paper reviews the merits of CNFs compared to other polymers in flexible electronic products and emphasizes the application status of CNF-based thermal management materials in flexible electronic products. The thermal conductivities of the CNF-based composites are analyzed with respect to the heat transfer mechanism, the thermal conductivity of the polymer, the loading of the filler, the size and morphology of the filler, the type of filler, and the surface treatment of the filler. Current challenges and future research opportunities are also discussed, offering a reasonable and scientific route for the structural design of future flexible thermal management materials that will promote the development of the flexible electronics industry.
Abstract
The effective acquisition of clean water from atmospheric water offers a potential sustainable solution for increasing global water and energy shortages. In this study, an asymmetric ...amphiphilic surface incorporating self-driven triboelectric adsorption was developed to obtain clean water from the atmosphere. Inspired by cactus spines and beetle elytra, the asymmetric amphiphilic surface was constructed by synthesizing amphiphilic cellulose ester coatings followed by coating on laser-engraved spines of fluorinated ethylene propylene. Notably, the spontaneous interfacial triboelectric charge between the droplet and the collector was exploited for electrostatic adsorption. Additionally, the droplet triboelectric nanogenerator converts the mechanical energy generated by droplets falling into electrical energy through the volume effect, achieving an excellent output performance, and further enhancing the electrostatic adsorption by means of external charges, which achieved a water harvesting efficiency of 93.18 kg/m
2
h. This strategy provides insights for the design of water harvesting system.
It is urgently needed to develop high-performance materials that can synchronously remove heavy metals and organic pollutants. Herein, the visible-light responsive Zn3In2S6/AgBr composites were ...prepared for concurrent removals of metronidazole (MNZ) and Cr (VI). In the Cr (VI)-MNZ coexisting system, the removals of MNZ and Cr (VI) using the optimized Zn3In2S6/AgBr-15 photocatalyst reached 98.2% and 94.8% within 2 h, respectively; higher than those using counterparts. The radical species trapping and electron spin resonance (ESR) results demonstrated that ·OH was the most dominated species for MNZ oxidation, and photo-generated electrons were responsible for Cr (VI) reduction. Besides, slight competition for ·O2ˉ during the simultaneous MNZ degradation and Cr (VI) reduction occurred. Energy band structure analysis, ESR and the outstanding photocatalytic performance for MNZ and Cr (VI) removals demonstrated that the Zn3In2S6/AgBr-15 was a Z-scheme photocatalyst, which promoted photo-induced carrier′s separation. Possible MNZ degradation pathways and mechanism over the Z-scheme Zn3In2S6/AgBr were also proposed based on the identified intermediates. This study could inspire new ideas for design of efficient Z-scheme photocatalysts for wastewater treatment.
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•Novel Z-scheme Zn3In2S6/AgBr photocatalysts were synthesized and characterized.•Efficient metronidazole oxidation and Cr (VI) reduction were concurrently achieved.•Efficient charge transfer and separation in Z-scheme Zn3In2S6/AgBr was verified.•Metronidazole degradation pathway and pollutants removal mechanism were proposed.
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•Enzyme and cold alkali assisted mechanical production of CNF was studied.•Thermal stability of CNF will be affected by cellulose crystalline structure.•Presence of hemicellulose in ...CNF improves their thermal stability.•Presents new avenues for research on CNF-based electronic devices.
Lignocellulosic biomass is the most abundant renewable resource on the earth. With the development of related fields, the high value utilization of lignocellulosic biomass has gradually become a new avenue for research. In this study, unbleached bagasse pulp was pretreated with xylanase and cold alkali to partially remove hemicellulose and convert to some cellulose I into cellulose II. Cellulose nanofibrils (CNF) were then obtained through ultra-micro grinding and high-pressure homogenization. The prepared CNF were characterized by TEM, Zeta potential, ATR-FTIR and XRD, and a thermogravimetric analyzer was used to analyze the thermal stability of CNF. The results show that xylanase pretreatment can improve the dispersion of fibers during mechanical treatment and can enhance the crystallinity of CNF. With an increase in alkali concentrations, the proportion of cellulose II structures increased, while cellulose crystallinity levels decreased due to the folding of cellulose chains. Under the common influence of crystallinity and crystal structures, the thermal stability of the CNF prepared after cold alkali pretreatment underwent an increasing trend. This shows that the influence of crystal structures on the thermal stability of CNF gradually plays a dominant role as alkali concentrations increase.
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•A ratiometric fluorescent nanofiber sensor was designed for freshness detection.•The sensor exhibited high sensitivity for freshness detection of shrimp and pork.•The nanofiber ...skeleton with nano-scale improved the air permeability of sensor.•The sensor with three-dimensional network structure endowed the high sensitivity.
The low sensitivity of fluorescent sensors limits the on-site and visual detection of seafood freshness. To address these issues, a novel intelligent nanofiber ratiometric fluorescent sensor, known as a BAsCNF, was designed using cellulose nanofibers (CNFs) produced by TEMPO oxidation (TO-CNFs) as the skeleton, and fluorescein isothiocyanate and proporphyrin IX modified nanofibers as the indicator and internal reference, respectively. TO-CNFs with nano-scale characteristics improved the air permeability of BAsCNF films, which endowed the sensor with excellent response performance to biogenic amines (BAs). Thus, the BAsCNF produced obvious colour changes from red to yellow-green in response to an increased concentration of BAs, where the limit of detection for BAs was as low as 1 ppm. Meanwhile, the discoloration trend of the BAsCNF in the freshness detection of shrimp and pork was consistent with the variation of the key indicators during storage, such as the content of total volatile basic nitrogen and the total number of colonies. The results suggest that the BAsCNF sensor possessed high detection accuracy and broad application prospects in the field of food safety.
In this study, we investigated the effects of salinity on elemental sulfur-driven autotrophic denitrification (SAD) efficiency, and microbial communities. The results revealed that when the salinity ...was ≤6 g/L, the nitrate removal efficiency in SAD increased with the increasing salinity reaching 95.53% at 6 g/L salinity. Above this salt concentration, the performance of SAD gradually decreased, and the nitrate removal efficiency decreased to 33.63% at 25 g/L salinity. Approximately 5 mg/L of the hazardous nitrite was detectable at 15 g/L salinity, but decreased at 25 g/L salinity, accompanied by the generation of ammonium. When the salinity was ≥15 g/L, the abundance of the salt-tolerant microorganisms,
and
, increased, while that of other microbial species decreased. This study provides support for the practical application of elemental sulfur-driven autotrophic denitrification in saline nitrate wastewater.
Highlights
This review systematically discusses the interfacial properties of cellulosic material preparation processes, top-down, bottom-up, and composite processes.
The rational design strategies ...of cellulosic triboelectric materials are summarized in detail, and the effects of different design strategies on the surface charge characteristics and charge density of cellulosic triboelectric materials are discussed.
A comprehensive review of the research progress of cellulosic triboelectric nanogenerators in the field of self-powered wearable electronics.
With the rapid development of the Internet of Things and flexible electronic technologies, there is a growing demand for wireless, sustainable, multifunctional, and independently operating self-powered wearable devices. Nevertheless, structural flexibility, long operating time, and wearing comfort have become key requirements for the widespread adoption of wearable electronics. Triboelectric nanogenerators as a distributed energy harvesting technology have great potential for application development in wearable sensing. Compared with rigid electronics, cellulosic self-powered wearable electronics have significant advantages in terms of flexibility, breathability, and functionality. In this paper, the research progress of advanced cellulosic triboelectric materials for self-powered wearable electronics is reviewed. The interfacial characteristics of cellulose are introduced from the top-down, bottom-up, and interfacial characteristics of the composite material preparation process. Meanwhile, the modulation strategies of triboelectric properties of cellulosic triboelectric materials are presented. Furthermore, the design strategies of triboelectric materials such as surface functionalization, interfacial structure design, and vacuum-assisted self-assembly are systematically discussed. In particular, cellulosic self-powered wearable electronics in the fields of human energy harvesting, tactile sensing, health monitoring, human–machine interaction, and intelligent fire warning are outlined in detail. Finally, the current challenges and future development directions of cellulosic triboelectric materials for self-powered wearable electronics are discussed.
The hot water and green liquor pretreatments were conducted on Eucalyptus wood in the current study. The cellulase adsorption behavior on the isolated lignins and model compounds was clarified by a ...quartz crystal microbalance with dissipation (QCM-D) and atomic force microscopy (AFM). The QCM-D analysis indicated that the hot water pretreated lignin (HPL) adsorbed more cellulase than the green liquor pretreated lignin (GPL) and the protolignin (PL). The AFM analysis revealed that the interaction force between lignin and cellulase was in the order of HPL > GPL > PL which was consistent with the cellulase adsorption. The monomeric lignin model with the ketone group adsorbed more cellulase than the counterpart with the hydroxyl group or aldehyde group. The dimeric lignin models adsorbed more cellulase than the monomeric lignin models. Furthermore, the
β
–
β
dimer model adsorbed more cellulase than the β–5 and 5–5′ dimer models. This study provides fundamental knowledge for developing more efficient pretreatment technologies.
•AOX could be reduced by 21.4–26.6% with xylanase treatment.•Chlorine dioxide demand could be reduced by 12.5–22%.•Lignin and hemicellulose (mainly HexA) were the main source for AOX formation.
...Xylanase-aided chlorine dioxide bleaching of bagasse pulp was investigated. The pulp was pretreated with xylanase and followed a chlorine dioxide bleaching stage. The ATR-FTIR and XPS were employed to determine the surface chemistry of the control pulp, xylanase treated and chlorine dioxide treated pulps. The hexenuronic acid (HexA) could obviously be reduced after xylanase pretreatment, and the adsorbable organic halides (AOX) were reduced after chlorine dioxide bleaching. Compared to the control pulp, AOX could be reduced by 21.4–26.6% with xylanase treatment. Chlorine dioxide demand could be reduced by 12.5–22% to achieve the same brightness. The ATR-FTIR and XPS results showed that lignin and hemicellulose (mainly HexA) were the main source for AOX formation. Xylanase pretreatment could remove HexA and expose more lignin, which decreased the chlorine dioxide demand and thus reduced formation of AOX.
Wood has a natural three-dimensional porous structure. As one main component of wood, lignin is rich in a variety of reducing functional groups which can in situ reduce Au (III) into Au (0). Through ...this efficient, green and convenient method, gold nanoparticles (Au NPs) were generated and anchored in Paulownia
Sieb. et Zucc.
Chip to fabricate an Au NP/Wood membrane reactor. The characterization of Au NP/Wood by SEM, XRD and XPS showed that Au NPs were uniformly dispersed in wood. The catalytic capacity of the reactor for the reduction of methylene blue (MB) and 4-nitrophenol (4-NP) were evaluated. The Au NP/Wood exhibited the substantial catalytic capacity and the reaction rate constants were 0.162 min
−1
and 0.152 min
−1
, respectively. As the filter membrane, the flowing catalytic capacity investigation revealed that the hydrogenation of MB and 4-NP was over 98% as the flux was 0.973 × 10
3
L/m
2
·h. Even after eight cycles, the catalytic capacity of the membrane slightly decreased, while the hydrogenation still remained above 90%. This green synthetic Au NP/Wood has proved to be a viable and potential material for the treatment of dyes and nitroaromatic pollutants, in addition, using wood as a feedstock provides a sustainable feature of this work.
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