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To reduce fire hazards and expand high-value applications of lignocellulosic materials, thin films comprising graphene nanoplatelets (GnPs) and multi-wall carbon nanotubes (CNTs) pre-adsorbed with alkali lignin were deposited by a Meyer rod process. Lightweight and highly flexible papers with increased gas impermeability were obtained by coating a protective layer of carbon nanomaterials in a randomly oriented and overlapped network structure. Assessment of the thermal and flammability properties of papers containing as low as 4 wt % carbon nanomaterials exhibited self-extinguishing behavior and yielded up to 83.5% and 87.7% reduction in weight loss and burning area, respectively, compared to the blank papers. The maximum burning temperature as measured by infrared pyrometry also decreased from 834 °C to 705 °C with the presence of flame retardants. Furthermore, papers coated with composites of GnPs and CNTs pre-adsorbed with lignin showed enhanced thermal stability and superior fire resistance than samples treated with either component alone. These outstanding flame-retardant properties can be attributed to the synergistic effects between GnPs, CNTs and lignin, enhancing physical barrier characteristics, formation of char and thermal management of the material. These results provide great opportunities for the development of efficient, cost-effective and environmentally sustainable flame retardants. [ABSTRACT FROM AUTHOR]

We report the microstructures, electrical conductivity, and electromagnetic interference (EMI) shielding effectiveness of a series of hybrid cellulose papers coated alternatively with silver nanowire (AgNW) and multi-walled carbon nanotube (MWCNT), which are fabricated by controlling the dip-coating sequence and cycle. SEM images and EDS data reveal that AgNWs and/or MWCNTs are sequentially coated on the surfaces of the cellulose papers with increasing the dip-coating cycle and the coating density of the particles decreases gradually in thickness direction of the papers. This result is supported by the anisotropic apparent electrical conductivity of AgNW/MWCNT/cellulose hybrid papers in in-plane and thickness directions. In addition, the apparent electrical conductivity of the hybrid papers in the in-plane direction increases significantly from 0.17–0.22 S/cm to 2.55–2.83 S/cm with increasing the coating cycle from 2 to 10, although it is higher for the hybrid cellulose papers with AgNW top-coating layers than the hybrid papers with MWCNT top-coating layers at the same coating cycle. This result indicates that a highly effective and conductive AgNW/MWCNT network is formed on the cellulose fibers in a layer-by-layer manner. For the hybrid papers with 2.55–2.83 S/cm, high EMI shielding effectiveness of ∼23.8 dB at 1 GHz is achieved. [ABSTRACT FROM AUTHOR]

A general anion-sensing platform is reported based on a portable and cost-effective ion-selective optode and a smartphone detector equipped with a color analysis app. In contrast to traditional anion-selective optodes using a hydrophobic polymer and/or plasticizer to dissolve hydrophobic sensing elements, the new optode relies on hydrophilic cellulose paper. The anion ionophore and a lipophilic pH indicator are inkjet-printed and adsorbed on paper and form a 'dry' hydrophobic sensing layer. Porous cellulose sheets also allow the sensing site to be modified with dried buffer that prevents any sample pH dependence of the observed color change. A highly selective fluoride optode using an AlIII-porphyrin ionophore is examined as an initial example of this new anion sensing platform for measurements of fluoride levels in drinking water samples. Apart from Lewis acid-base recognition, hydrogen bonding recognition is also compatible with this sensing platform. [ABSTRACT FROM AUTHOR]

Flexible broadband photodetectors based on 2D MoS2 have gained significant attention due to their superior light absorption and increased light sensitivity. However, pristine MoS2 has absorption only in visible and near IR spectrum. This paper reports a paper-based broadband photodetector having ZnS-MoS2 hybrids as active sensing material fabricated using a simple, cost effective two-step hydrothermal method wherein trilayer MoS2 is grown on cellulose paper followed by the growth of ZnS on MoS2. Optimization in terms of process parameters is done to yield uniform trilayer MoS2 on cellulose paper. UV sensing property of ZnS and broadband absorption of MoS2 in visible and IR, broadens the range from UV to near IR. ZnS plays the dual role for absorption in UV and in the generation of local electric fields, thereby increasing the sensitivity of the sensor. The fabricated photodetector exhibits a higher responsivity toward the visible light when compared to UV and IR light. Detailed studies in terms of energy band diagram are presented to understand the charge transport mechanism. This represents the first demonstration of a paper-based flexible broadband photodetector with excellent photoresponsivity and high bending capability that can be used for wearable electronics, flexible security, and surveillance systems, etc. [ABSTRACT FROM AUTHOR]

Paper-based electronics have been attracting significant attention because of their inexpensive, renewable, and eco-friendly substrates. In this study, Cu-based composite inks composed of a copper-based metal-organic decomposition (MOD) ink and Cu flakes were prepared as precursors to obtain conductive Cu films on untreated cellulose paper. Copper-based MOD inks have not been explored for the production of conductive Cu films on cellulose paper because the properties of the paper, such as high porosity, high permeability, and surface roughness, are not favorable to obtain continuous conductive Cu films. However, using our method, we have obtained Cu films on paper with resistivities that are ∼10 times lower than those of films on polyimide or glass substrates. Importantly, the Cu films on paper exhibited better mechanical resistance than those on a polyimide substrate, without any pre-treatment of the paper surface. [ABSTRACT FROM AUTHOR]

A flexible composite paper of multi-walled carbon nanotube (MWCNT) and cellulose fiber (CF) were fabricated by traditional paper-making method. Then, the MWCNT/CF papers were carbonized at high temperature in vacuum to remove organic component. The carbonized MWCNT/CF (MWCNT/CCF) papers are consisted of MWCNT and carbon fiber. The papers were characterized by scanning electron microscope (SEM), X-ray diffraction (XRD), and four-point probe resistance meter. The electrochemical performances of the supercapacitors were tested by cyclic voltammetry and galvanostatic charge/discharge >with 1 moL/L LiPF as electrolyte. The MWCNT/CCF electrode yielded a specific capacitance of 156F/g at a current density of 50 mA/g by galvanostatic charge/discharge measurement, which is 1.29 times higher than MWCNT/CF electrode of 68F/g. The MWCNT/CCF electrodes also displayed an excellent specific capacitance retention of 84% after 2000 continuous charge/discharge cycles at a current density of 400 mA/g. The increase of specific capacitance can be attributed to enhanced electrical conductivity of MWCNT/CCF papers and improved contact interface between electrolyte and electrodes. [ABSTRACT FROM AUTHOR]

In this paper, composite materials made of cellulose paper and MOF-5 (Zn(BDC)) Metal organic frameworks (paper@MOF-5) materials, were prepared by an in situ synthesis method using precipitated calcium carbonate (PCC) filled cellulose papers. PCC fillers in the cellulose paper led to decreased inter-fiber bonds, thus facilitating the formation of small-sized MOF-5 crystals. The resultant cellulose paper@MOF-5 composites exhibited zeolite-like frameworks with high specific surface areas. The composite materials were characterized by XRD, ATR-FTIR, SEM and nitrogen adsorption analysis. The results supported the conclusion that the prepared cellulose paper@MOF-5 composite materials have great potential in gas (N, CH, H, CO, etc.) adsorption. [ABSTRACT FROM AUTHOR]

A novel, low-cost and biocompatible three-dimensional (3D) substrate for surface-enhanced Raman spectroscopy (SERS) is fabricated using gold nanoparticles (AuNPs) loaded on cellulose paper for detection of amino acids and melamine. Dysosma pleiantha rhizome (Dp-Rhi) capped AuNPs (Dp-Rhi_AuNPs) were prepared by in situ using aqueous extract of Dp-Rhi and in situ functionalized Dp-Rhi on AuNPs surface was verified by Fourier transform infrared spectroscopy and zeta potentials analysis shows a negative (− 18.4 mV) surface charges, which confirm that presence of Dp -Rhi on AuNPs. The biocompatibility of Dp-Rhi_AuNPs is also examined by cell viability of FaDu cells using MTS assay and compared to control group. In conclusion, the SERS performance of AuNPs@cellulose paper substrates were systematically demonstrated and examined with different excitation wavelengths (i.e. 532, 632.8 and 785 nm lasers) and the as-prepared 3D substrates provided an enhancement factor approaching 7 orders of magnitude compared with conventional Raman intensity using para-nitrothiophenol (p-NTP), para-aminothiophenol (p-ATP) and para-mercaptobenzoic acid (p-MBA) as probe molecules. The strong electromagnetic effect was generated at the interface of AuNPs and pre-treated roughened cellulose paper is also investigated by simulation in which the formation of possible Raman hot-spot zone in fiber-like microstructure of cellulose paper decorated with AuNPs. Notably, with optimized condition of as-prepared 3D AuNPs@cellulose paper is highly sensitive in the SERS detection of aqueous tyrosine (10 − 10 M) and melamine (10 − 9 M). [ABSTRACT FROM AUTHOR]

We have previously reported that crystalline samples of 1-acetylaminopyrene (AAPy), 1-octanoylaminopyrene (OAPy), and 1-stearoylaminopyrene (SAPy) exhibited mechanochromic luminescence. In the present study, we have found that these 1-alkanoylaminopyrenes adsorbed onto cellulose papers also exhibited mechanochromic luminescence; however, their behaviors were essentially different from those observed for their crystalline samples. In addition, these cellulose papers were found to exhibit reversible emission color change upon alternate exposure to ethanol and water vapors. It was suggested that 1-alkanoylaminopyrene molecules were dispersed in the paper without aggregation or crystallization and that intermolecular distance of 1-alkanoylaminopyrenes in the paper was reduced by either mechanical stress or exposure to ethanol vapor, resulting in increasing the sites where excimers could be formed and/or in enhancing the efficiencies of energy migration to reach the excimer sites. [ABSTRACT FROM AUTHOR]

We report on investigation of the mechanical properties of paper electronics (printed and made out of paper). One key objective of such paper electronics is to achieve ultraflexibility. Therefore, it is important to understand electrical functionality and reliability of paper electronics under various physical (mechanical) deformations. Here, we show the general mechanical properties of the cellulose paper used and its electrical behavior under applied strain, tackling the main effects that need to be identified when building paper-based systems, from product performance and stability perspective. An overview of the stress–strain behavior of silver ink on paper is discussed, and then, we tackle a more specific analysis of the performance variations of paper sensors made with recyclable household materials when exposed to various mechanical conditions of tensile and compressive bending. This paper is important for developing stable wearable sensors for incorporation into Internet of Everything applications. [ABSTRACT FROM PUBLISHER]

A novel device for targeting proteins with a Molecularly-Imprinted Polymer (MIP) recognition material is presented herein, by employing wax paper with conductive ink as background support. Cellulose paper was modified with paraffin wax to make it waterproof, and afterwards covered by a carbon ink to make it conductive, achieving the goal to make easy and low cost supports, and, in this case, with good detection features. Bovine Serum Albumin (BSA) was used herein as target protein. Albumin has an important role in the human body and BSA is normally used as its model protein because of its good stability and low cost. The development of BSA detection systems is important in various fields, such as biochemistry, medicine and pharmacy. Raman measurements were conducted during all preparation stages of the recognition material and electrochemical assays were used to evaluate the analytical performance of the sensor. The assembly of the device was optimized by employing different polymerization timings and monomers of different chemistries and charges. In general, longer polymerization periods and the use of a positively charged monomer benefited the analytical response. The results obtained within different calibrations indicated a linear response over a wide concentration range, from 0.005 to 100 mg/mL of BSA in buffer solution. In addition, the analytical evaluation of the device under several background solutions, including synthetic and real urine, supported the good performance of the sensor and pointed out that the principle of sensor assembly may be extended to other proteins in urine. In addition, the detection capabilities of the device proposed herein are better than other BSA sensing devices relying on electrochemical transduction. [ABSTRACT FROM AUTHOR]

The ever-growing overlap between electronics and wearable technology is driving the demand for utilizing novel materials that are cost-effective, light-weight, eco-friendly, mechanically deformable and can be conformably and comfortably worn on human body as substrate to support the reliable operation of wearable electronic functionalities. Paper materials comprised of bio-origin ingredients ( e.g., cellulose and carbon derivatives) have recently attracted remarkably increasing research and commercial interests for prototyping next-generation wearable electronics due to their superiorities including natural abundance, flyweight, mature manufacturing process, specific structural properties, favorable mechanical bendability, biocompatibility and nontoxicity over their counterparts. Feasibility of engaging paper materials has been proved by outstanding performances in body-worn healthcare sensing systems, electro-stimulated artificial muscles, on-site memory storage and wearable power supply on paper substrate. In this review, we present a state-of-the-art introduction of diverse paper substrate options and fabrication techniques employed for realizing paper electronics, and discuss both pros and cons of each manufacturing tactic. Additionally, we summarize developing trends of paper-based electronics in the emerging wearable applications. Based upon these, final conclusions, encountering challenges, accompanied with advancing outlooks are illustrated. [ABSTRACT FROM AUTHOR]

A whole paper electro-biosensor detection platform for detecting glucose is reported. Glucose oxidase was immobilized on paper-based screen-printed carbon electrodes. The developed biosensor has an excellent electrochemical characteristic and high heterogeneous electron transfer rate constant (k = 4.23 × 10). This new detection platform exhibited good amperometric responses toward glucose, with a wide linear range up to 10 mM with R is 0.9973 and the sensitivity is 2.07 μA mM. The parallel measurements of glucose by different biosensors had a low relative standard deviation of 4.26 % and demonstrated it had good reproducibility. In the interference studies, there was no significant difference with ascorbic acid or uric acid. For stability, it retained 93.9 % of its initial response after a storage period of 31 days in 4 °C. Besides, the Parkes error grid analysis was indicated that paper-based electrochemical biosensor has a good accuracy on the glucose detection. [ABSTRACT FROM AUTHOR]

In this work, the design and development of a microfluidic paper-based device (μPAD) for the quantification of total phenolic compounds (TPC) in wines is described. The developed μPAD was based upon the vertical flow concept and the colour reaction used was the known Folin-Ciocalteu reaction using gallic acid as reference phenolic compound. After studying operational parameters, namely type of paper, reagents and sample volume, a dynamic range of 5–50 mg L−1 was obtained with a limit of detection of 1.2 mg L−1. The described device proved to have good precision (relative standard deviation < 5%) and no significant interferences were observed from known compounds present in wines. Furthermore, the stability of the colour product and of the device itself were assessed; the μPAD was stable for 30 days (in the dark at room temperature) and it could be scanned up to 8 h after sample introduction. The developed μPAD pose as a simple method for TPC quantification and was successfully applied to several wine samples including sparkling and table wines with two different approaches: i) using gallic acid as reference compound with standard addition; and ii) using taniraisin with external calibration. The accuracy of the proposed μPAD method was assessed by comparison with the reference spectrophotometric method according to the International Organisation of Vine and Wine (OIV) recommendations. [Display omitted] • A μPAD method has been developed for total phenolic compounds quantification. • Vertical-flow design using Folin-Ciocalteu reaction was employed. • After the optimization, μPAD cards were successfully applied to wine samples. • The device was portable, cost-effective and user-friendly. [ABSTRACT FROM AUTHOR]

This study investigates the ability of cellulose filter paper coated with silver nanoparticles to removeEscherichia colifrom drinking water. The cellulose filter paper was coated with silver nanoparticles by a chemical reduction method using two different ratios of sodium borohydride and silver nitrate. In consideration of drinking-water quality standards and non-carcinogenic health risks, the optimum sodium borohydride:silver nitrate ratio for coating the cellulose filter paper was determined by comparing the silver in the effluent afterE. coliremoval. For both ratios, 100%E. coliremoval was realised. In terms of the silver in the effluent, only the first two lowest concentrations for both ratios of sodium borohydride and silver nitrate were compliant with the drinking-water quality standards, demonstrating hazard quotients (HQs) between 0.084 and 0.484. On the basis of the highest level ofE. coliremoval with the lowest HQ value, the optimum sodium borohydride:silver nitrate ratio for coating the cellulose filter paper as an antibacterial water filter was 2:1 molar ratio (0.002 M:0.001 M). Silver nanoparticle-coated cellulose filter paper was found to be an inexpensive and easy-to-use emergency antibacterial water filter to generate clean drinking water. [ABSTRACT FROM PUBLISHER]

A new approach exploiting the dual properties of thiol-grafted cellulose paper for promoting copper-catalyzed [3+2]-cycloadditions of organic azides with alkynes and adsorbing residual copper species in solution was developed. The thiol-grafted cellulose paper, used as a paper strip, effects the reduction of CuII to catalytically active CuI and acts as a powerful adsorbent for copper, thereby facilitating the work-up process and leaving the crude mixture almost free of copper residues after a single filtration. [ABSTRACT FROM AUTHOR]

Thermo-responsive poly( N-isopropylacryl-amide) (PNIPAM), was grafted from cellulose paper via activators regenerated by electron transfer atom transfer radical polymerization (ARGET ATRP). Six solvents with different polarities, including water, methanol, isopropanol, anisole, and methanol/HO, isopropanol/HO mixed solvents, were utilized to perform the grafting polymerization. The results suggested that solvent system with moderate polarity was favored to ensure successful polymerization as well as avoid the destruction of the structure of virgin paper. Modified papers with various grafting ratios were achieved by changing the reaction solvent. Compared to lump-sum addition of excess reducing agent, intermittent addition of reducing agent during the reaction process made the polymerization rate more controllable. ATRFTIR and SEM characterization indicated the successful grafting of PNIPAM from the paper surface. Water contact angle measurements revealed that the polymer-grafted papers were thermo-responsive, presenting reversible switching in wettability with the change of temperature. [ABSTRACT FROM AUTHOR]

Remarkable efforts have been dedicated to paper-based chemosensors and biosensors over the last few years, mainly driven by the promise of reaching the best trade-off between performance, affordability and simplicity. Because of the low-cost and rapid prototyping of these sensors, recent research has been focused on providing affordable diagnostic devices to the developing world. The recent progress in sensitivity, multi-functionality and integration of microfluidic paper-based analytical devices (µPADs), increasingly suggests that this technology is not only attractive in resource-limited environments but it also represents a serious challenger to silicon, glass and polymer-based biosensors. This review discusses the design, chemistry and engineering aspects of these developments, with a focus on the past few years. [ABSTRACT FROM AUTHOR]

An Electrochemical Lateral Flow Immunosensor (ELFI) is developed combining screen-printed gold electrodes (SPGE) enabling quantification together with the convenience of a lateral flow test strip. A cellulose glassy fiber paper conjugate pad retains the marker immunoelectroactive nanobeads which will bind to the target analyte of interest. The specific immunorecognition event continues to occur along the lateral flow bed until reaching the SPGE-capture antibodies at the end of the cellulosic lateral flow strip. The rationale of the immunoassay consists in the analyte antigen NS1 protein being captured selectively and specifically by the dengue NS1 antibody conjugated onto the immunonanobeads thus forming an immunocomplex. With the aid of a running buffer, the immunocomplexes flow and reach the immuno-conjugated electrode surface and form specific sandwich-type detection due to specific, molecular recognition, while unbound beads move along past the electrodes. The successful sandwich immunocomplex formation is then recorded electrochemically. Specific detection of NS1 is translated into an electrochemical signal contributed by a redox label present on the bead-immobilized detection dengue NS1 antibody while a proportional increase of faradic current is observed with increase in analyte NS1 protein concentration. The first generation ELFI prototype is simply assembled in a cassette and successfully demonstrates wide linear range over a concentration range of 1–25 ng/mL with an ultrasensitive detection limit of 0.5 ng/mL for the qualitative and quantitative detection of analyte dengue NS1 protein. [ABSTRACT FROM AUTHOR]

In this contribution the influence of various stresses and their combined impact on the electrostatic charging tendency of oil is studied. Various physicochemical properties were measured according to ASTM Standards to detect changes in oil quality. A free radical reagent, 2.2 diphenyl-1-picrylhydrazyl (DPPH), was added to oil before and after the application of stresses to determine free radical concentration. The results obtained show that the application of stresses contributes to an increase in the electrification current. These results also demonstrate that electrification current is affected by the quantity of the free radicals. [ABSTRACT FROM AUTHOR]

Cellulose nano-fibers were used to fabricate free-standing and flexible paper for its probable application in paper electronic technology. A simple Ag/CdS/Au Schottky diode was realized by successively evaporating Ag, CdS and Au using appropriate masks on cellulose paper. Microstructural properties and Raman spectroscopy measurements were utilized to characterize the individual layers constituting the above Schottky structure. I–V and C–V characteristics were recorded to ascertain the quality of the Ag/CdS/Au diode printed on the cellulose paper used as substrate. [Display omitted] [ABSTRACT FROM AUTHOR]

• The auto-fluorescence of cellulose is explored as a response fluorescence. • The lignosulfonate is primarily speculated as the main source of auto-fluorescence. • The lignin on the paper exhibits the spatial solid phase dispersion behavior. • Molecular simulation proved that heavy metal ions replaced Na+ of lignosulfonate. Auto-fluorescence of cellulose paper is often considered as an interfering fluorescence, which directly impedes the cellulose paper as a substrate material. This paper creatively explored the composition and properties of auto-fluorescence, and lignosulfonate was primarily speculated as the main source of auto-fluorescence. Surprisingly, its spatial solid phrase dispersion-induced fluorescence enhancement behavior was found. Then, cellulose paper was modified with Mn-doped ZnS quantum dots, and the prepared ratiometric fluorescent paper chip has good performances on morphology, stability, and fluorescence properties. Besides, the paper chip exhibited different fluorescence responses to three heavy metal ions in water sample. The limit of detection for Cd2+, Hg2+ and Pb2+ reached 1.61 nM, 0.01 nM, and 0.02 nM, respectively. In short, the molecular simulation results theoretically proved that heavy metal ions owned substitution affinity with lignosulfonate. Ultimately, this study was the first attempt to utilize paper-based auto-fluorescence, which could better accelerate the development of paper-based chips. [ABSTRACT FROM AUTHOR]

For more than a century, conventional mineral oil/cellulose insulation is being used as main insulation for power transformers. The life span of these major assets is determined amongst others by the insulation system?s mechanical resistance to withstand short circuit current forces. Since cellulose paper aging is accelerated by temperature, moisture and oxygen, poly-aramid-based synthetic insulation paper, with better thermal stability emerged for application in transformers. However the relatively limited number of studies on hybrid insulation and the cost of aramid paper still limit their use in distribution transformers. This contribution attempts to demonstrate that despite the high cost of aramid paper, hybrid insulation could be used in large power transformers which represent a significant financial investment. To do this, the quality of mineral oil aged with hybrid solid insulation and the thermal aging of the cellulose paper of this insulation are investigated. Comparison was made with traditional mineral oil impregnated cellulose paper to provide a benchmark for comparison. The samples underwent thermal accelerated aging procedure according to ASTM-D1934 standard and, furthermore, were submitted to local overheating. The condition of oil samples collected from each aging vessel was assessed using several diagnostic techniques, namely the relative amount of the Dissolved Decay Products (DDP), Turbidity, and Interfacial Tension (IFT). The Degree of Polymerisation (DPv) and Dissolved gas Analysis (DGA) were used to monitor the thermal aging of the cellulose paper samples. The results indicate that oil aged with hybrid solid insulation yield fewer decay products at some aging stages, especially after the application of a local overheating. The results also indicate that the cellulose paper within solid hybrid insulation is slightly less degraded compared to that of conventional insulation. [ABSTRACT FROM AUTHOR]

A combination of thin-film microextaction based on an aptamer immobilized on modified Whatman cellulose paper followed by electrospray ionization ion mobility spectrometry has been developed for the analysis of codeine in urine samples. The immobilization is based on the covalent linking of an amino-modified anticodeine aptamer to aldehyde groups of the oxidized cellulose paper. The covalent bonds were examined by infrared spectroscopy and elemental analysis. The effect of the extraction parameters, including the elution conditions (solvent type and volume), extraction time, and extraction temperature, on the extraction efficiency were investigated. Under the optimized conditions, the linear dynamic range was found to be 10-300 ng/mL with a detection limit of 3.4 ng/mL for codeine in urine. The relative standard deviation was 6.8 % for three replicate measurements of codeine at 100 ng/mL in urine. Furthermore, the samples were analyzed with a standard method for the analysis of codeine using high-performance liquid chromatography with ultraviolet detection. The comparison of the results validates the accuracy of the proposed method as an alternative method for the analysis of codeine in urine samples. [ABSTRACT FROM AUTHOR]

Cellulose paper (CP)-based asymmetrical thin film supercapacitors (ATFSCs) have been considered to be a novel platform for inexpensive and portable devices as the CP is low-cost, lightweight, and can be rolled or folded into 3D configurations. However, the low energy density and poor cycle stability are serious bottlenecks for the development of CP-based ATFSCs. Here, sandwich-structured graphite/Ni/Co2NiO4-CP is developed as positive electrode and the graphite/Ni/AC-CP as negative electrode for flexible and high-performance ATFSCs. The fabricated graphite/Ni/Co2NiO4-CP positive electrode shows a superior areal capacitance (734 mF/cm2 at 5 mV/s) and excellent cycling performance with ≈97.6% Csp retention after 15 000 cycles. The fabricated graphite/Ni/AC-CP negative electrode also exhibits large areal capacitance (180 mF/cm2 at 5 mV/s) and excellent cycling performance with ≈98% Csp retention after 15 000 cycles. The assembled ATFSCs based on the sandwich-structured graphite/Ni/Co2NiO4-CP as positive electrode and graphite/Ni/AC-CP as negative electrode exhibit large volumetric Csp (7.6 F/cm3 at 5 mV/s), high volumetric energy density (2.48 mWh/cm3, 80 Wh/kg), high volumetric power density (0.79 W/cm3, 25.6 kW/kg) and excellent cycle stability (less 4% Csp loss after 20 000 cycles). This study shows an important breakthrough in the design and fabrication of high-performance and flexible CP-based electrodes and ATFSCs. [ABSTRACT FROM AUTHOR]

Cellulose-based materials have recently drawn much interest due to their sustainability, biodegradability, biocompatibility, and low cost. In this present work, cellulose fiber paper (CFP) was fabricated from sugarcane leaves and used as a friction material for a triboelectric nanogenerator (TENG). Fe 3 O 4 was incorporated to CFP triboelectric material to increase the dielectric constant of CFP for boosting power generation of TENG. The Fe 3 O 4 filled CFP was synthesized using a facile one-pot co-precipitation technique. The effect of Fe 3 O 4 content in CFP on dielectric property and TENG performance was investigated and optimized. The CFP filled with Fe 3 O 4 nanoparticles exhibited the improved dielectric constant and possessed a superior TENG performance than pristine CF. The highest power density of 1.9 W/m 2 was achieved, which was able to charge commercial capacitors serving as a power source for small electronic devices.

Summary: Based on the solvothermal method, two new MOFs with 3-(1-Oxo-1H-2,3-dihydroisoindol-2-yl)benzoic acid as the organic ligand, Zn-HBPA and Zn-bpy-HBPA were synthesized. The structure of MOFs was characterized by 1H-NMR, XRD, FT-IR and SEM. A series of modified cellulose paper-based functional materials with different spraying times were prepared by flame spraying method, and the fluorescence property of MOFs modified cellulose paper to EtOH small molecules was investigated by fluorescence spectrometer. The results of FT-IR and SEM showed that the flame spraying method could effectively improve the retention rate of MOFs on cellulose paper materials. The PL characterization results displayed that Zn-HBPA@PFP exhibited a decrease in fluorescence after UV irradiation, while Zn-bpy-HBPA@PFP demenstrated an increase in fluorescence at λ=338 nm. The above results indicated that Zn-bpy-HBPA@PFP had an excellent response ability to EtOH small molecules, and when Cycle=7 times, Zn-bpy-HBPA@PFP had the best fluorescence enhancement effect. [ABSTRACT FROM AUTHOR]

We describe flexible organic light-emitting diodes (OLEDs) with indium tin oxide (ITO) anodes fabricated at low substrate temperatures using facing target sputter (FTS) on a transparent-cellulose substrates. The device structure was cellulose paper substrate/SiO2/ITO/NPB/Alq3:C545T/BCP/LiF/Al. The ITO thin films were deposited at substrate temperatures below 70°C. X-ray diffraction analysis revealed that the ITO thin films were amorphous. As the substrate temperature during deposition increased from 27 to 70°C, the sheet resistivity decreased from 1,400 to 120 Ω/□. The OLEDs with ITO thin film anode with sheet resistivity of 120 Ω/□ exhibited a maximum luminance of 14,543 cd/m2at a driving voltage of 14.75 V. [ABSTRACT FROM AUTHOR]

Abstract: A cellulose paper based p–n junction device was fabricated by synthesizing the ZnO/CuO nanostructures via a hydrothermal process. The CuO nanospindles (NSs) were decorated on the surface of cellulose paper substrate by a simple soaking process. Subsequently, ZnO nanorod arrays were grown on the surface of the CuO NSs decorated cellulose paper (i.e., CuO NSs/paper) by the hydrothermal process. The synthesized ZnO/CuO nanostructures on cellulose paper exhibited good crystal and optical properties and favorably formed the p–n heterojunction with a rectifying behavior. [Copyright &y& Elsevier]

A rapid method, based on a logarithmic degradation model of insulation material, is proposed to reduce the test duration in lifetime assessment of cellulose paper insulating materials. This method proposes the determination of the activation energy from a non-isothermal measurement made by differential scanning calorimetry or another thermal analysis technique and an aging test at a single elevated temperature. The use of the onset temperature of the exothermal peak at ca. 300 °C is proposed for evaluation of the activation energy of degradation. For comparison, the thermal aging of Kraft cellulose paper for power transformer insulation was performed according to the general standard IEC 60216-1/2001 at three different temperatures: 155, 135 and 115 °C, and subsequently, the lifetimes at different service temperatures were estimated. The experimental data proved to have good agreement between the applied methods, the differences being <10 % in terms of the estimated lifetime across the range of service temperatures. The novel proposed method is effective in terms of both energy and manpower costs as compared to the current method: a factor of around 10 in the case of reducing the aging time, a factor of 3 for the time needed for measurements, and a factor of 10 for the reduction of power intake. [ABSTRACT FROM AUTHOR]

Cellulose paper was prepared and utilized as a substrate for flexible top emission organic light-emitting diodes (TE-OLEDs). We successfully fabricated flexible TE-OLEDs with Ni and Au anodes on SiO2/cellulose paper substrate. The SiO2barrier layer coated on the cellulose paper substrate enhanced the surface roughness of the cellulose paper substrate. The surfaces of 100 nm thick Ni and Au films on SiO2/cellulose paper substrate become continuous on the SiO2/cellulose paper substrate, resulting in low sheet resistance of the Ni and Au films. While the maximum luminance of the flexible TE-OLED with Au anode was about 3516 cd/m2at a driving voltage of 12 V, that of the flexible TE-OLEDs with Ni anode was 1280 cd/m2at a driving voltage of 10 V. [ABSTRACT FROM PUBLISHER]

An optical transparent and hazy film with admirable flexibility, electromagnetic interference (EMI) shielding, and Joule heating performance meeting the requirements of optoelectronic devices is significantly desirable. Herein, a cellulose paper was infiltrated by epoxy resin to fabricate a transparent cellulose paper (TCP) with high transparency, optical haze, and favorable flexibility, owing to effective light scattering and mechanical enhancement of the cellulose network. Moreover, a highly connected silver nanowire (AgNW) network was constructed on the TCP substrate by the spray-coating method and appropriate thermal annealing technique to realize high electrical conductivity and favorable optical transmittance of the composite film at the same time, followed by coating of a polydimethylsiloxane (PDMS) layer for protection of the AgNW network. The obtained PDMS/AgNWs/TCP composite film features considerable optical transmittance (up to 86.8%) and haze (up to 97.7%), while satisfactory EMI shielding effectiveness (SE) (up to 39.1 dB, 8.2-12.4 GHz) as well as strong mechanical strength (higher than 41 MPa) were achieved. The coated PDMS layer prevented the AgNW network from falling off and ensured the long-term stability of the PDMS/AgNWs/TCP composite film under deformations. In addition, the multifunctional PDMS/AgNWs/TCP composite film also exhibited excellent Joule heating performance with low supplied voltages, rapid response, and sufficient stability. This work demonstrates a novel pathway to improve the performance of multifunctional transparent composite films for future advanced optoelectronic devices.

Cellulose paper (CP) is an environmentally-friendly and low-cost material, but its application in petrochemical water disposal is limited by poor wet stability and oil repellency. In this work, based on the crosslinking and low-temperature hydrothermal reaction, we report a novel CP material which is crosslinked by polyethyleneimine (PEI)-glutaraldehyde (GA)-cellulose and modified by Ni-doped brochantite crosslinked CP (NB-PCCP) for the removal of emulsified oils and dyes in wastewater. The crosslinking process enhances the wet strength of CP, and the formation of the multi-slice structure of Ni-doped brochantite on PCCP surface improves the oil repellency. Results show that NB-PCCP possesses outstanding oil-in-water emulsion separation performance with high oil rejection of 99.9%, the Young's modulus of NB-PCCP is quadruple that of untreated CP in wet conditions, indicating improved wet stability in practice application. NB-PCCP also displays excellent removal performance for dyes due to the existence of high-density hydroxyl radicals, as well as excellent acid/alkali resistance. The research on CP provides significant guidance for the design of cellulose-based material with multi-slice structure as well as high wet strength and oil repellency for the purification of wastewater. The Ni-doped brochantite modified polyethyleneimine (PEI)-glutaraldehyde (GA)-cellulose crosslinked cellulose paper was designed for the removal of emulsified oils and dyes. The crosslinking process enhances the wet strength, and the formation of Ni-doped brochantite multi-slice structure on the surface of PCCP improves oil repellency, significantly. [Display omitted] • The durable and antifouling NB-PCCP was prepared by polymer crosslinking and inorganic modification. • The prominent wet strength of NB-PCCP is attributed to the crosslinking of PEI-GA-Cellulose. • The ultrahigh oil repellency of NB-PCCP is due to the multi-slice structure brought by the Ni-doped brochantite modification. • The NB-PCCP shows excellent removal efficiency of emulsified oils and dyes from wastewater. [ABSTRACT FROM AUTHOR]

[Display omitted] • Fire alarm achieves sensitive response of 2 s at lower temperature of 250 °C. • A novel way based on light intensity change for response time is employed. • Designed fire alarm is coupled to a wireless communication interface firstly. Highly sensitive smart sensors for early fire detection with remote warning capabilities are urgently required to improve the fire safety of combustible materials in diverse applications. The highly-sensitive fire alarm can detect fire situation within a short time quickly when a fire disaster is about to occur, which is conducive to achieving fire tuned. Herein, a novel fire alarm is designed by using flame-retardant cellulose paper loaded with graphene oxide (GO) and two-dimensional titanium carbide (Ti 3 C 2 , MXene). Owing to the excellent temperature dependent electrical resistance switching effect of GO, it acts as an electrical insulator at room temperature and becomes electrically conductive at high temperature. During a fire incident, the partial oxygen-containing groups on GO will undergo complete removal, which results in the conductivity transformation. Besides the use of GO feature, this work also introduces conductive MXene to enhance fire detection speed and warning at low temperature, especially below 300 °C. The designed flame-retardant fire alarm is sensitive enough to detect fire incident, showing a response time of 2 s at 250 °C, which is calculated by a novel and quantifiable technique. More importantly, the designed fire alarm sensor is coupled to a wireless communication interface to conveniently transmit fire signal remotely. Therefore, when an abnormal temperature is detected, the signal is wirelessly transmitted to a liquid crystal display (LCD) screen when it displays a message such as "FIRE DANGER". The designed smart fire alarm paper is promising for use as a smart wallpaper for interior house decoration and other applications requiring early fire detection and warning. [ABSTRACT FROM AUTHOR]

Significant progress has been made in the fabrication of paper-based triboelectric nanogenerators (TENGs) through the increase of the electron-donating ability of cellulose paper. However, challenges still exist in the mass production of cellulose-based tribopositive materials with high output performance. Herein, a facile method was developed to improve the tribopositive performance of cellulose paper by simply loading branched polyethyleneimine (PEI). By changing the loading weight of PEI, PEI-paper composites with different structures and mechanical properties were prepared. The PEI-paper composites show drastically improved triboelectric output performance with an increasing loading weight of PEI because of their sharply increased relative permittivity. By loading 7.5 mg/cm2 PEI to form a network structure and loading 22.5 mg/cm2 PEI to form a hydrogel-like structure, the triboelectric output performances of the formed PEI-paper composite-based TENG are increased by approximately 4 and 6 times, respectively, and their power densities are increased by approximately 7.5 and 16 times, respectively. The PEI-paper composite-based TENG can serve as a self-powered pressure sensor to sense different external stimuli under different working modes and construct self-powered electric skin. Meanwhile, the occurrence of PEI also confers PEI-paper composites with water resistance, antibacterial activity, and flame retardation, yet the disposability of the paper remains. This work provides a simple method for improving the triboelectric performance of cellulose paper. [Display omitted] • PEI-paper composites with network or hydrogel-like structure were fabricated. • PEI-paper composites show multifunctional properties due to loading PEI on paper. • The PEI-paper composites show drastically improved relative permittivity. • PEI-paper composite-based TENGs show high electronic output performances. • PEI-paper composite-based TENG can serve as a self-powered pressure sensor. [ABSTRACT FROM AUTHOR]

Abstract: Cellulose paper based glucose test strips were successfully prepared using 2,4,6-tribromo-3-hydroxy benzoic acid (TBHBA) as the chromogen agent. Cellulose paper is a good substrate for carrying chromogen agents and other chemicals so that the quantitative analysis can be done based on the colorimetric chemistry. The color intensity of the developed compounds, which was measured as the differential diffusive reflectance of the test strip at 510nm, was correlated to the glucose concentration of the sample solutions in the range of 0.18–9.91mg/ml. These colorimetric test strips could be conveniently used, do not have to use an electronic device, and would have potential applications in the home monitoring of blood glucose for people with diabetes. [Copyright &y& Elsevier]

Generally, impregnation of solid insulation is performed to increase the dielectric strength and reduce the dielectric losses of solid insulants. This increase in dielectric strength depends on the oil's diffusion and dielectric properties. This paper investigates the diffusion behavior of mineral oil and ester fluids (synthetic, natural, and mixed) to understand the influence of oil diffusion on paper breakdown voltage. To better understand this phenomenal influence, cellulose insulation paper of different thicknesses has been considered. Wetting characteristics of various oil-paper insulation systems were investigated with and without thermal stressing. Thermal aging was carried out as per modified ASTM D1934 at 110 °C, 140 °C, 160 °C, and 185 °C respectively for 2 weeks. The wetting characteristics and influence of different oils on paper breakdown voltage were explicitly reported. It is inferred that paper wetting characteristics are attributable to the type of oil, the thickness of paper, and the aging factor of oil-paper insulation. Importantly, the increase in paper dielectric strength and diffusion behavior for ester fluids is found to be superior to that of the mineral insulating oils. [ABSTRACT FROM AUTHOR]

The development of a solid substrate for the support and stabilization of zero-valent metal nanoparticles (NPs) is the heart of the catalyst system. In the current embodiment, we have prepared solid support comprise of alginate-coated cellulose filter paper (Alg/FP) for the synthesis and stabilization of Co nanoparticles (NPs) named as Alg/FP@Co NPs. Furthermore, Alginate polymer was blended with 1 and 2 weight percent of CoNi NPs to make Alg-CoNi1/FP and Alg-CoNi2/FP, respectively. All these stabilizing matrixes were used as dip-catalyst for the degradation of azo dyes and reduction of 4-nitrophenol (4NP). The effect of initial dye concentration, amount of NaBH4, and catalyst dosage was assessed for the degradation of Congo red (CR) dye by using Alg-CoNi2/FP@Co NPs. Results indicated that the highest kapp value (3.63 × 10−1 min−1) was exhibited by Alg-CoNi2/FP@Co NPs and lowest by Alg/FP@Co NPs against the discoloration of CR dye. Furthermore, it was concluded that Alg-CoNi2/FP@Co NPs exhibited strong catalyst activity against CR, and methyl orange dye (MO) degradation as well as 4NP reduction. Antibacterial activity of the prepared composites was also investigated and the highest l activity was shown by Alg-CoNi2/FP@Co NPs, which inhibit 2.5 cm zone of bacteria compared to other catalysts. [ABSTRACT FROM AUTHOR]

• A novel EWOD device was made of cellulose paper and paraffin wax as dielectric layer. • The paraffin wax dielectric layer was fabricated via melting and spray-coating method. • The thickness and morphology of paraffin wax dielectric layer can be controlled. • The spray-coating method can reduce the contact angle hysteresis of the EWOD devices. Paper-based microfluidic devices based on electrowetting principle, more specifically electrowetting on dielectric (EWOD), have attracted increasing attention due to their powerful liquid handling capability as compared to continuous-flow paper-based analytical devices (μPAD) that use capillary effects to control liquids. Here, we demonstrate fabrication of paper-based EWOD devices using cellulose paper as substrate and paraffin wax as dielectric hydrophobic layer by a simple pressing treatment for the cellulose paper and melting or spray-coating of paraffin wax. We optimized the key fabrication parameters according to the surface morphology and hydrophobicity of the obtained wax film, including the pressing pressure, thermal annealing temperature and amount of paraffin wax. Moreover, the EWOD devices fabricated by the spray-coating method demonstrate larger contact angle changes but with smaller contact angle hysteresis under DC electric field when compared with the devices fabricated by the melting method. Our study opens up potential fabrication of hybrid paper-based microfluidic device combining advantages of continuous-flow and electrowetting using cellulose paper and paraffin wax. [ABSTRACT FROM AUTHOR]