Cellulose Paper Research Articles

An all paper based triboelectric nanogenerators with high output performance in extreme environment manufactured by multi-layer papers forming technology

Triboelectric nanogenerators (TENGs) are regarded as a promising technology to drive the development of flexible/wearable electronics and self-powering sensor. Application of cellulose paper as the triboelectric positive materials makes TENGs more environmentally friendly. However, the limited output performance and stability in harsh environments and oxidation and corrosion of the metal electrodes have limited the practical application of cellulose paper based triboelectric nanogenerators (CPTENGs). Here, we have integrated cellulose paper-based triboelectric material and electrode in one sheet by using multi-layer forming technology in paper industry; the upper triboelectric layer shows excellent triboelectric positive performance, hydrophobicity and acid and alkali resistance, while the bottom electrode exhibits promise conductivity. The all CPTENGs can yield a maximum open-circuit voltage (VOC) of 227.1 V, a short-circuit current (ISC) of 6.9 μA. Furthermore, the VOC values of the all CPTENGs increase from 0.02 V to 225.1 V at the load resistance of 100 Ω∼10 GΩ; and a power density of 520 mW·m−2 is also obtained at a load resistance of 30 MΩ. Moreover, the VOC of CPTENGs not only retains up to 78 % of its initial value at a high relative humidity of 90 %, but also almost maintains unchanged in a wide range of the pH environment (pH = 1∼13). More importantly, the CPTENGs can be readily matched with paper-based zinc supercapacitor (P-ZISC) to act as an all paper based self-charging power system (PSCPS). The PSCPS is capable of driving various miniaturized electronics, such as electronic watch, temperature/humidity indicator, demonstrating its potential application in a sustainable power source for portable and green electronics.

Modifying cellulose fibres with carbon dots: a promising approach for the development of antimicrobial fibres.

This study focuses on the development of antimicrobial fibres for use in medical and healthcare textile industries. Carbon dots (CDs) were designed with boronic acid groups for the attachment to cellulose fibres found in cotton textiles and to enhance their attachment to glycogens on bacterial surfaces. Boronic acid-based and curcumin-based CDs were prepared and characterized using various techniques, showing a nanoscale size and zeta potential values. The CDs inhibited the growth of both Staphylococcus epidermidis and Escherichia coli bacteria, with UV-activated CDs demonstrating improved antibacterial activity. The antimicrobial activity of the CDs was then tested, revealing strong adherence to cellulose paper fibres with no CD diffusion and potent inhibition of bacterial growth. Cytotoxicity assays on human cell lines showed no toxicity towards cells at concentrations of up to 100 µg ml-1 but exhibited increased toxicity at concentrations exceeding 1000 µg ml-1. However, CD-modified cellulose paper fibres showed no toxicity against human cell lines, highlighting the antimicrobial properties of the CD-modified cellulose fibres are safe for human use. These findings show promising potential for applications in both industrial and clinical settings.

Antibacterial biocomposites: efficacy of MWCNT-coated Hanji cellulose paper against E. coli

Antibacterial biocomposites: efficacy of MWCNT-coated Hanji cellulose paper against E. coli

Development of Intelligent Indicators Based on Cellulose and Prunus domestica Extracted Anthocyanins for Monitoring the Freshness of Packaged Chicken.

Meat is a widely consumed food globally; however, variations in storage conditions along its supply chain can pose a potential food safety risk for consumers. Addressing this concern, we have developed freshness indicators designed to monitor the condition of packaged chicken. In this study, anthocyanins were infused with cellulose paper measuring 2 × 2 cm, and subsequent analysis focused on examining color changes concerning deteriorating chicken stored at 30°C for 48 h, with varying sample sizes being considered. The rise in total volatile nitrogen (TVB-N) compounds from an initial value of 3.64 ± 0.39 mg/100 g to 28.17 ± 1.46 mg/100 g acted as the stimulus for the color change in the indicator, simultaneously influencing the pH from the initial 7.03 ± 0.16 to 8.12 ± 0.39. The microbial load (aerobic plate count) of the chicken samples was also significantly increased. This collective shift in various parameters strongly suggests the occurrence of spoilage in chicken meat. The pH indicators exhibited a dark pink to red color for fresh chicken. As the chicken meat turned towards spoilage, the indicators changed to a dark blue and then a pale green color. FTIR spectroscopy results confirmed the presence of cellulose and anthocyanins. The FTIR analysis also validated the immobilization of plum anthocyanins within the cellulose paper and assessed their stability after 8 months of storage. Notably, the indicators demonstrated rapid sensitivity, showing a 20.5% response within one minute of ammonia exposure, which further increased to 29.5% after 3 min of exposure. The total color difference (ΔE) steadily rose in all the examined samples and also under various storage conditions. Overall, the indicators developed in this study exhibited a highly pronounced color transition, capable of distinguishing between fresh and spoiled chicken samples depending on the extent of spoilage and the specific day of observation.

Simultaneous detection of testosterone, nandrolone, and boldenone esters in dried blood spots for doping control in sports by liquid chromatography-tandem mass spectrometry.

Testosterone, nandrolone, and boldenone, which are listed as doping substances on the World Anti-Doping Agency Prohibited List, are mostly available commercially in esterified forms. Isotope ratio mass spectrometry (IRMS) represents a key tool for identifying these substances, as they are hydrolyzed and discharged in the urine as pseudo-endogenous substances. However, IRMS, which comprises a complicated process, cannot achieve the direct detection of steroid esters in blood samples. These substances can be detected using dried blood spots (DBSs), reducing the impact of esterase hydrolysis. Here, a simultaneous liquid chromatography-tandem mass spectrometry method for detecting 28 steroid (13 testosterone, nine nandrolone, and six boldenone) esters was developed using three DBS types of samples, including a cellulose paper and polymer. The substances were first derivatized with methyloxime to increase their sensitivities (the limits of detection were <0.1-0.4, <0.1-0.9, and <0.1-0.9ng/mL for the testosterone, nandrolone, and boldenone esters, respectively). Further, the DBS absorbents were verified since the effect of interferences depended on it. Next, a study involving seven participants was conducted to detect intramuscularly administered testosterone enanthate (100 mg). Polymer and cellulose papers were used to collect blood from their upper arms and fingertips, respectively, and testosterone enanthate was identified and detectable at both blood-collection sites for up to 144 and 216 h, respectively. Furthermore, testosterone enanthate was detectable in the DBS samples stored under refrigeration after 6 months, indicating the stable nature of DBS.

Enhancing carbon fiber reinforced aluminum laminates with cellulose paper interlayers: experimental characterization of tensile, flexural, and interlaminar fracture toughness

ABSTRACT The mechanical properties of fiber metal laminates (FML) are influenced by several various factors. Interface adhesion plays a particularly crucial role in interlaminar strength. Enhancing the interlaminar strength of carbon fiber reinforced aluminum laminate (CARALL) composites present a persistent challenge due to inherent weaknesses between metal and composite elements. Therefore, this study focuses on improving the interlaminar performance of CARALL composites by introducing cellulose paper interlayer at the metal/composite interface. The cellulose paper interlayer offers the advantage of being cost-effective and sustainable. Cellulose paper-interleaved CARALL composites were fabricated by vacuum bagging method and exhibited noteworthy improvements in mechanical properties. Comparative analysis with pristine samples revealed substantial enhancements, including a 15% increase in tensile strength, a remarkable 42% improvement in flexural strength, and a significant enhancement in mode-I fracture toughness by 65%. Furthermore, the cellulose paper interleaving played a crucial role in stabilizing fracture formation at the fiber-matrix interface, with mode II fracture toughness witnessing a 3% increase. Visual examination revealed the underlying toughening processes occurring in the interfacial area. This innovative approach of interleaving laminated composites with cellulose paper emerges as a sustainable and effective strategy, demonstrating the potential to fortify and toughen the interlaminar zones of CARALL composites.

Enhancing Cross-Linking Network for Superior Wet Strength of Paper by Sustainable Hyperbranched Polyimines.

The paper industry has long been a crucial part of our lives, providing printing materials, tissue paper, and packaging products. However, the low wet strength of commercially available paper limits its application in packaging, particularly when it comes into contact with liquids. To address this issue, researchers have explored various strategies, including the use of wet strength agents. The most widely used agent, polyamide-epichlorohydrin resin (PAE), has limitations, such as poor dimensional stability and limited recyclability. Additionally, PAE can release harmful chlorinated organics. To overcome these challenges, we report a novel approach using a hyperbranched wet strength agent (referred to as "OA-PI") based on the cross-linking of oxidized amylopectin from waxy corn and polyamines through the Schiff base reaction. The hyperbranched structure of OA-PI provides multiple binding sites, enhancing the cross-linking strength of cellulosic paper under wet conditions. The paper treated with OA-PI exhibited exceptional wet strength, significantly higher than that of PAE-treated paper and paper with traditional starch-based additives. Moreover, the biomass-based OA-PI showed improved recyclability and reduced harm from chlorinated organic compounds. This study not only enhances the wet strength of paper but also opens sustainable avenues for the design of functional adhesives.

A multifunctional cellulose paper with excellent flame retardancy, hydrophobicity and oil/water-separation performance via reaction with ammonium phytate and poly(methylhydrosiloxane)

Paper-based materials have become increasingly prevalent in the packaging and daily life. However, paper is flammable and hydrophilic, hindering its widespread application. Here, a novel reactive flame retardant of m-xylylenediamine phytate ammonium (MPAP) was prepared. Cellulose paper with superior flame-retardant and hydrophobic properties was successfully prepared by surface spraying technology and impregnation process, through the reaction of flame retardant and poly(methylhydrosiloxane) (PMHS) with cellulose fibers. The water contact angle (WCA) of the modified paper was 122.6°, while the limit oxygen index (LOI) value reached 41 %, which had significant self-extinguishing performance. The total heat release rate of the modified paper was reduced from 12.8 kJ/g to 0.6 kJ/g. The modified paper also exhibited excellent performance for oil/water separation. Furthermore, this effective and simple strategy can also be applied to other cellulose-contained substrates for the application in construction, textiles, furniture and other fields.

Development of acidochromic colloidal polymer nanoparticles containing azobenzene derivatives as eco-friendly time-dependent anticounterfeiting inks

N,N-dihydroxyethyl azobenzene compounds with different functional groups of hydrogen, electron-donating hydroxyl (OH), and electron-withdrawing nitro (NO2) were synthesized by a two-step diazotization and coupling method. Colloidal poly(methyl methacrylate) (PMMA) nanoparticles, prepared by emulsifier-free emulsion polymerization, were doped with 3 wt% of the three azobenzenes to prepare acidochromic colloids. Acidochromic properties of all the azobenzenes and the polymer colloids were investigated in acidic buffers. Azobenzene compounds doped on polymer particles showed different colors in buffers with different pH values due to the presence of different functional groups, which makes them highly applicable as acid detectors. The electron-withdrawing NO2 functional group caused a small bathochromic shift in the azobenzene spectrum, and the azobenzene containing OH functional group showed higher bathochromic shift than the unsubstituted azobenzene. The colloidal PMMA nanoparticles doped with the three azobenzene compounds were used as eco-friendly inks for stamping and hand-signing on cellulosic papers. Exposure to acidic HCl vapor resulted in different coloration of the printed marks due to the protonation of the azobenzenes. These colors of the protonated forms were decayed with time and also after exposure to triethylamine vapor. The stamped patterns showed a high fatigue and no change in color intensity up to 20 cycles. This shows that these polymeric inks can be used as anticounterfeiting inks for security-marking of confidential documents and banknotes. The developed inks showed time-dependent characteristics and responsivity to acid and base vapors, which make them highly applicable in security marking of confidential documents and also detection of acid and base.

FLEXIBLE COMPOSITE AgNPs-PPy/CELLULOSIC PAPER ELECTRODE FOR ELECTROCHEMICAL DETECTION OF NITRATE

In this work, we describe a simple strategy for the preparation of a low-cost electrode material based on polypyrrole (PPy) film grown on an insulating cellulosic paper (CP) substrate via in-situ oxidative polymerization technique and functionalized by silver nanoparticles (AgNPs) uniformly dispersed on its surface. The properties of the obtained AgNPs-PPy composites were characterized using X-ray diffraction, scanning electron microscopy and energy dispersive X-ray analysis. The electrocatalytic activity of the prepared electrode was investigated for the electroreduction of nitrate using cyclic voltammetry in 0.1 M KOH solution. Results demonstrated that the incorporation of AgNPs into the PPy matrix significantly improves the catalytic behaviour of this film. The effect of the amount of incorporated AgNPs on the electrode response was also investigated.

Dip-coated graphene nanoplatelets and multiwall carbon nanotubes composite ink electrode for metal-free paper-based flexible heating device

A paper-based flexible heating device (PFHD - paper-based flexible heating device) composed of a cellulose paper substrate and a carbonaceous functional electrode is reported. The functional composite electrodes containing graphene nanoplatelets (GNP - graphene nanoplatelets) and multi-walled carbon nanotubes (MWCNT) in various compositional ratios were prepared by dip-coating the oxygen plasma-treated paper substrate into the composite ink, and subsequently dried at 110 ℃ for 30 min to prepare PFHDs. The electrochemical characteristics and heat generation properties of PFHDs indicated that the GNP component in the functional electrode enhanced the electrical conductivity of the electrode, and the physical stability was enhanced mainly by the MWCNT component. Accordingly, PFHD0.33 which contains 33 % GNP and 67 % MWCNT in the functional electrode shows excellent heating performance with high stability and areal rated power of 0.68 W cm−2 (specific rated power = 45 W g−1). The measured sensitivity of PFHD0.33 is 31.50 ℃ V−1 at the applied DC voltage of 0.1–2.0 V.

Application of back propagation neural network in complex diagnostics and forecasting loss of life of cellulose paper insulation in oil-immersed transformers

Oil-immersed transformers are expensive equipment in the electrical system, and their failure would lead to widespread blackouts and catastrophic economic losses. In this work, an elaborate diagnostic approach is proposed to evaluate twenty-six different transformers in-service to determine their operative status as per the IEC 60599:2022 standard and CIGRE brochure. The approach integrates dissolved gas analysis (DGA), transformer oil integrity analysis, visual inspections, and two Back Propagation Neural Network (BPNN) algorithms to predict the loss of life (LOL) of the transformers through condition monitoring of the cellulose paper. The first BPNN algorithm proposed is based on forecasting the degree of polymerization (DP) using 2-Furaldehyde (2FAL) concentration measured from oil samples using DGA, and the second BPNN algorithm proposed is based on forecasting transformer LOL using the 2FAL and DP data obtained from the first BPNN algorithm. The first algorithm produced a correlation coefficient of 0.970 when the DP was predicted using the 2FAL measured in oil and the second algorithm produced a correlation coefficient of 0.999 when the LOL was predicted using the 2FAL and DP output data obtained from the first algorithm. The results show that the BPNN can be utilized to forecast the DP and LOL of transformers in-service. Lastly, the results are used for hazard analysis and lifespan prediction based on the health index (HI) for each transformer to predict the expected years of service.

A cellulose derived nanofibrous nitrogen-doped carbon/TiO2/SnO2/carbon composite anodic material for lithium storage

SnO2 with high theoretical specific capacity is regarded as a desirable anodic material for lithium storage. However, the serious volume variation during discharge/charge cycling and poor conductivity significantly constrain the electrochemical performance. Herein, nanofibrous nitrogen-doped carbon (NC)/TiO2/SnO2/carbon composite was fabricated through layer-by-layer assembly of SnO2 and TiO2-gel layers alternately using cellulosic filter paper as the structural scaffold, followed by deposition of polypyrrole on the surface by chemical polymerization method, and subsequent calcination of the as-obtained matter in inert atmosphere. The achieved composite possesses a typical three-dimensional fibrous porous network structure inherited from the cellulosic substrate, and complete NC nanolayer coating on each nanofiber by adjusting the amount of pyrrole, which can alleviate the volume change and increase the conductivity of SnO2. Furthermore, the interlaced TiO2 multilayer can enhance the cycling stability during cycling, as well as facilitate the lithium-ion transfer through abundant interface. The optimal NC/TiO2/SnO2/carbon composite delivers an initial discharge capacity of 1492.6 mAh g−1 at a current density of 100 mA g−1, and retains a reversible capacity of 680.8 mAh g−1 after 200 discharge/charge cycles. This work provides an efficient strategy for design and construction of metal-oxides/carbon composite anodic materials with hierarchical microstructure that hold great potential in lithium storage.

Paper based flexible MoS2-CNT hybrid memristors

We report for the first time MoS2/CNT hybrid nanostructures for memristor applications on flexible and bio-degradable cellulose paper. In our approach, we varied two different weight percentages (10% and 20%) of CNT’s in MoS2 to improve the MoS2 conductivity and investigate the memristor device characteristics. The device with 10% CNT shows a low V SET voltage of 2.5 V, which is comparatively small for planar devices geometries. The device exhibits a long data retention time and cyclic current–voltage stability of ∼104 s and 102 cycles, making it a potential candidate in flexible painted electronics. Along with good electrical performance, it also demonstrates a high mechanical stability for 1000 bending cycles. The conduction mechanism in the MoS2-CNT hybrid structure is corroborated by percolation and defect-induced filament formation. Additionally, the device displays synaptic plasticity performance, simulating potentiation and depression processes. Furthermore, such flexible and biodegradable cellulose-based paper electronics may pave the way to address the environmental pollution caused by electronic waste in the near future.

Ultrasensitive detection assay for Cronobacter sakazakii based on nucleic acid-driven aggregation-induced emission of gold nanoclusters and cascaded signal amplification

Cronobacter sakazakii (C. sakazakii), a foodborne pathogen frequently present in contaminated powdered infant formula (PIF), poses a substantial threat to food safety. Herein, a novel fluorescent biosensor based on gold nanoclusters (AuNCs) that exhibit aggregation-induced emission (AIE) when triggered by nucleic acids was developed. This biosensor integrates the exponential amplification reaction (EXPAR) with hybridization chain reaction (HCR) signal amplification (EXHCR), enabling ultrasensitive detection of C. sakazakii. The aggregations of glutathione protected AuNCs assembled by G-rich sequences (HP1, and HP2) was affected by the EXHCR reaction initiated with C. sakazakii, forming G-quadruplex nanowires, leading to the dis-aggregation of AuNCs and a turn-off response of fluorescence, thereby realizing the detection of C. sakazakii. The changes are discernible on cellulose paper with the naked eyes. The biosensor demonstrates exceptional selectivity due to the integration of an aptamer and a dual signal amplification strategy. Under optimized conditions, it achieves a remarkable detection limit of 1.10×100 CFU/mL, and a broad linear range from 1.10×100 to 1.10×107 CFU/mL. Furthermore, the biosensor’s capability to identify C. sakazakii in artificially contaminated milk powder with recoveries ranging from 97.8% to 107%, underscores its reliability and accuracy. Overall, this study offers a promising approach for nucleic acid and AIE-based detection, exhibiting considerable potential for developing highly efficient bacterial detectors.

Sustainable beeswax modified cellulose paper for the determination of tricyclic antidepressants in biofluids

This article describes the synthesis of sorptive phases for bioanalysis based on the modification of cellulose paper with natural beeswax as sorbent, resulting in a substrate completely renewable and sustainable. The preparation of the sorptive phases consisted of the dissolution of beeswax in hexane, followed by its drop-casting on cellulose paper and subsequent evaporation of the solvent. The beeswax modification of paper renders it hydrophobic, enabling the extraction of the target analytes, i.e., imipramine, desipramine, amitriptyline and trimipramine, via hydrophobic interactions. The main variables affecting the extraction performance were investigated (e.g., pH, ionic strength, extraction time, eluent composition, agitation speed). The analytical workflow combines a straightforward sampling, simultaneous extraction of 30 samples in 1 h, and the rapid (<2 min) determination of the analytes via direct infusion mass spectrometry. The method provided limits of detection in the range 2.0 and 3.2 μg L−1, and the precision, expressed as relative standard deviation, was better than 5.4 % and 8.5 % for intra and inter-day analyses, respectively. The accuracy, in terms of relative recovery, ranged from 90 % to 121 % using saliva as model biofluid.

INFLUENCE OF THE REDUCING AGENTS ON MORPHOLOGY AND PROPERTIES OF SIVER STRUCTURES ON PAPER

Abstract. A paper-based SERS substrate with tunable plasmonic properties and excellent flexibility has been applied in various fields. These SERS substrates were prepared using a direct chemical reduction synthesis method for the present work. The isotropic and anisotropic morphology of silver structures on cellulose paper fiber were controlled by the types of reducing agents: (1) sodium borohydride (NaBH4), (2) ascorbic acid (L-AA), (3) glucose, (4) formaldehyde (HCHO). The plasmon characterization of silver structures on paper was systematically investigated. The fabricated paper-based SERS substrates were used to detect melamine in an aqueous solution and determine the influence of type reducing agents on the enhancement factor (EF) and signal uniformity of SERS substrates.

Fluorescence 'turn-off-on' assays for neomycin sulphate and K+ ions with orange-red fluorescent molybdenum nanoclusters.

Fluorescent metal nanoclusters (MNCs) have found extensive application in recognizing molecular species. Here, orange-red fluorescent Arg-A. paniculata-MoNCs were synthesized using Andrographis paniculata leaf extract, arginine as a ligand, and MoCl5 as a metal precursor. The Arg-A. paniculata-MoNCs complex exhibited a quantum yield (QY) of 16.91% and excitation/emission wavelengths of 400/665 nm. The synthesized Arg-A. paniculata-MoNCs successfully acted as a probe for assaying neomycin sulphate (NS) via fluorescence turn-off and K+ ions via fluorescence turn-on mechanisms, respectively. Moreover, the developed probe was effectively used to develop a cellulose paper strip-based sensor for detection of NS and K+ ions. Arg-A. paniculata-MoNCs demonstrated great potential for sensing NS and K+ ions, with concentration ranges of 0.1-80 and 0.25-110 μM for NS and K+ ions, respectively. The as-synthesized Arg-A. paniculata-MoNCs efficiently detected NS and K+ ions in food and biofluid samples, respectively.

Oxidized cellulose as bio‐adhesive for hydrophobic lignocellulosic bioplastic

AbstractThis study presents a novel hydrophobic lignocellulosic bioplastic from corn stover reinforced by oxidized cellulose and in situ regenerated lignin. Cellulose‐lignin mixture as a matrix was obtained by acid‐recyclable deep eutectic solvent (DES) pretreatment of corn stover in mild conditions. Triethoxy(octyl)silane (C14H32O3Si) was employed to improve the water stability of the bioplastic by vapor deposition. The results show that the hydrophobic bioplastic has a high tensile strength, measuring 62.36 MPa. The water contact angle of the bioplastic was increased from 8.50° to 121.9° after hydrophobic modification. We prepared oxidized cellulose‐reinforced cellulose paper by different particle size distributions of oxidized cellulose to investigate the reinforcement of oxidized cellulose. The tensile strength of oxidized cellulose cellulose paper increased from 14.41 to 21.18 MPa with the addition of oxidized cellulose. The zeta potential of oxidized cellulose is −47.99 mV, which shows a more negative charge due to carbonyl groups. The repulsive force of oxidized cellulose contributes to the formation of a brick‐and‐mortar microstructure with cellulose‐lignin mixture. It demonstrates that oxidized cellulose can act as bio‐adhesives and has a good toughening effect on the mechanical properties of bioplastic.Highlights Lignocellulosic bioplastic was prepared by DES pretreatment of corn stover. Oxidized cellulose was used to reinforce the lignocellulosic bioplastic. The tensile strength of the bioplastic was 62.36 MPa after the reinforcement process. Trieth‐oxy(octyl)silane was employed to improve water stability. The water contact angle of the bioplastic was increased from 8.50° to 121.9°.

The role of hornification in the deterioration mechanism of physical properties of unrefined eucalyptus fibers during paper recycling

Physical properties of cellulosic paper deteriorate significantly during paper recycling, which hinders the sustainable development of the paper industry. This work investigates the property deterioration mechanism and the role of hornification in the recycling process of unrefined eucalyptus fibers. The results showed that during the recycling process, the hornification gradually deepened, the fiber width gradually decreased, and the physical properties of the paper also gradually decreased. After five cycles of reuse, the relative bonding area decreased by 17.6%, while the relative bonding force decreased by 1.8%. Further results indicated that the physical property deterioration of the paper was closely related to the decrease of fiber bonding area. The fiber bonding area decreased linearly with the reduction of re-swollen fiber width during paper recycling. Re-swollen fiber width was closely related to the hornification. Hornification mainly reduces the bonding area of unrefined eucalyptus fiber rather than the bonding force. The work elucidates the role of hornification in the recycling process of unrefined eucalyptus fibers and the deterioration mechanism of paper physical properties, which will be helpful to control the property deterioration of paper and achieve a longer life cycle.