Cellulose Paper Research Articles

Modification of cellulose substrate by in situ synthesis of metal-organic framework-5 for thin film microextraction of some non-steroidal anti-inflammatory drugs and their measurement by high-performance liquid chromatography-ultraviolet detector

This work, reports the successful preparation a thin film by a simple and inexpensive process for quantification of a model analytes in the urine sample using HPLC-UV. To this end, cellulose paper was employed as a substrate for the in-situ synthesis of MOF-5, to increase the resistance of the prepared film. The prepared film can be reused 26 times with no reduction in its performance. The thin film prepared by MOF-5 modified cellulose substrate was utilized in thin film microextraction (TFME) method for the extraction and preconcentration of naproxen, aspirin, tolmetin, and celecoxib. Under optimal conditions, the linear dynamic range of the target analytes was 2–500 µg L−1 with correlation coefficients (R2) ranging from 0.9961 to 0.9990. Also, the limits of detection (LODs), the limits of quantification (LOQs) and relative standard deviation (RSD%) of the proposed method for selected analytes ranged between 0.57 and 0.77 µg L−1, 1.7 to 2.3 and 3.5 % to 6.2 %, respectively. Moreover, relative recoveries varied from of 94 % to 108 %, indicating the absence of matrices effect in the proposed method. Eventually, the TFME was successfully used for the extraction of selected analytes from urine samples.

Differentiating Plasmon-Enhanced Chemical Reactions on AgPd Hollow Nanoplates through Surface-Enhanced Raman Spectroscopy.

Plasmonic photocatalysis demonstrates great potential for efficiently harnessing light energy. However, the underlying mechanisms remain enigmatic due to the transient nature of the reaction processes. Typically, plasmonic photocatalysis relies on the excitation of surface plasmon resonance (SPR) in plasmonic materials, such as metal nanoparticles, leading to the generation of high-energy or "hot electrons", albeit accompanied by photothermal heating or Joule effect. The ability of hot electrons to participate in chemical reactions is one of the key mechanisms, underlying the enhanced photocatalytic activity observed in plasmonic photocatalysis. Interestingly, surface-enhanced Raman scattering (SERS) spectroscopy allows the analysis of chemical reactions driven by hot electrons, as both SERS and hot electrons stem from the decay of SPR and occur at the hot spots. Herein, we propose a highly efficient SERS substrate based on cellulose paper loaded with either Ag nanoplates (Ag NPs) or AgPd hollow nanoplates (AgPd HNPs) for the in situ monitoring of C-C homocoupling reactions. The data analysis allowed us to disentangle the impact of hot electrons and the Joule effect on plasmon-enhanced photocatalysis. Computational simulations revealed an increase in the rate of excitation of hot carriers from single/isolated AgPd HNPs to an in-plane with a vertical stacking assembly, suggesting its promise as a photocatalyst under broadband light. In addition, the results suggest that the incorporation of Pd into an alloy with plasmonic properties may enhance its catalytic performance under light irradiation due to the collection of plasmon-excitation-induced hot electrons. This work has demonstrated the performance-oriented synthesis of hybrid nanostructures, providing a unique route to uncover the mechanism of plasmon-enhanced photocatalysis.

Foldable paper-based photoelectrochemical biosensor based on etching reaction of CoOOH nanosheets-coated laser-induced PbS/CdS/graphene for sensitive detection of ampicillin

Timely and rapid detection of antibiotic residues in the environment is conducive to safeguarding human health and promoting an ecological virtuous cycle. A foldable paper-based photoelectrochemical (PEC) sensor was successfully developed for the detection of ampicillin (AMP) based on glutathione/zirconium dioxide hollow nanorods/aptamer (GSH@ZrO2 HS@apt) modified cellulose paper as a reactive zone with laser direct-writing lead sulfide/cadmium sulfide/graphene (PbS/CdS/LIG) as photoelectrode and cobalt hydroxide (CoOOH) as a photoresist material. Initially, AMP was introduced into the paper-based reaction zone as a biogate aptamer, which specifically recognized the target and then left the ZrO2 HS surface, releasing glutathione (GSH) encapsulated inside. Subsequently, the introduction of GSH into the reaction region and etching of CoOOH nanosheets to expose the PbS/CdS/LIG photosensitive material increased photocurrent. Under optimal conditions, the paper-based PEC biosensor showed a linear response to AMP in the range of 5.0 - 2 × 104 pM with a detection limit of 1.36 pM (S/N = 3). In addition, the constructed PEC sensing platform has excellent selectivity, high stability and favorable reproducibility, and can be used to assess AMP residue levels in various real water samples (milk, tap water, river water), indicating its promising application in environmental antibiotic detection.

Highly water-resistant paper via infiltration with polymeric microspheres from nanocellulose-stabilized plant oil-derived monomer

Sustainable strategies to improve the water resistance of cellulose paper are actively sought. In this work, polymeric microspheres (PMs), prepared through emulsion polymerization of cellulose nanofibers stabilized rubber seed oil-derived monomer, were investigated as coatings on corrugated medium paper (CMP). After infiltrating porous paper with PMs, the water-resistant corrugated papers (WRCPn) with enhanced mechanical properties were obtained. When 30 wt% PMs were introduced, WRCP30 turned out to be highly compacted with an increased water contact angle of 106.3° and a low water vapor transmission rate of 81 g/(m2 d) at 23 °C. Meanwhile, the tensile strength of WRCP30 increased to 22.2 MPa, a 4-fold increase from CMP. When tested in a well-hydrated state, 71% of its mechanical strength in the dry state was maintained. Even with a low content of 10 wt% PMs, WRCP10 also exhibited stable tensile strength and water wettability during the cyclic soaking-drying process. Thus, the plant oil based sustainable emulsion polymers provide a convenient route for enhancing the overall performance of cellulose paper.

Dimethyl Amine Detection using Polydiacetylene Functionalized Cellulose Paper

AbstractThis work demonstrates our effort to develop stimuli responsive cellulose films for the detection of dimethyl amines, a biogenic amine, released during food decomposition. Herein, we demonstrate that thin layer deposition of polydiacetylene‐zinc oxide nanosheets (PDA‐ZnO) on cellulose (CE) paper yields a stimuli responsive strip exhibiting strong thermochromism and solvatochromism against dimethyl amine. The incorporation of Zn nanoclusters within the composite plays an essential role in achieving reversible thermochromism while strong intermolecular interactions promote adsorption of PDA‐ZnO on cellulose paper. X‐ray diffraction and infrared spectroscopy reveal that the Zn2+ ions intercalate with PDA bilayer and strongly interact with the carboxylate headgroup of PDA. Furthermore, the reversible thermochromism persist when the nanosheets are deposited on cellulose (CE) paper when assembling PDA‐ZnO−CE paper. In addition, PDA‐ZnO−CE displayed selective solvatochromism allowing the utilization of the paper in the detection of dimethyl amine as it displayed a distinct and remarkable purple to orange colour transition. In particular, the response of the PDA‐ZnO−CE paper in several other organic solvents was poor as no transitions were observed hence its selectivity towards dimethylamine. In conclusion, the incorporation of PDA‐ZnO on cellulose paper is a step forward towards designing of a stimuli responsive packaging material that can detect biogenic amines released during food decomposition thereby preventing food poisoning.

Photocatalytic/sorption-self-cleaning activity of cellulose decorated with TiO2 and M@TiO2 (M=Au, Ag) polymeric nanocomposites

Titanium oxide nanoparticles (TiO2 NPs) are a semiconductor material widely employed as photocatalysts for environmental remediation owing to its excellent properties. Nevertheless, collecting the nanomaterial once dispersed in the aqueous media is challenging, while the photocatalytic activity is limited mainly to the ultraviolet range of radiation. In this work, we have modified cellulose paper, a sustainable and green support, with a polymer nanocomposite comprising nylon-6 and different nanomaterials, i.e., anatase TiO2 nanoparticles (NPs) as well as TiO2 decorated with Ag and Au in form of NPs by means of a simple procedure. The immobilization of the nanocomposite on paper mediated the subsequent recovery of the substrate upon incubation. The presence of nylon-6 enables both the attachment of the NPs on the support as well as the isolation of the pollutant from the contaminated water due to the interactions with the target analyte, i.e., methyl orange (MO). Additionally, the presence of the mentioned polyamide within the substrate triggers the photocatalytic reaction under visible light radiation. The broadening in the range of the light towards the use of sunlight has been also evaluated via modification of the photocatalyst nanoparticles with noble metals such as silver and gold. The kinetic of degradation of MO upon sunlight exposure with the different polymeric nanocomposites followed a pseudo-first-order model, with k constant values of 0.070, 0.083 and 0.120 min−1 for TiO2, Ag@TiO2 and Au@TiO2 nanocomposites, respectively. The effect of the presence of the polymer on the substrate has been evaluated, observing an increase in the k constant upon addition of the polyamide from 0.036 to 0.069 min−1 for TiO2. The synergistic effect of sorption/degradation enables the regeneration of the substrates modified with the nanomaterials that can be reused several times, the relative standard deviation of k upon three subsequent photocatalytic cycles being in the range 15.7–37.7%.

Cellulose nanowhiskers‐reinforced polymer nanofibers for photoresponsive authentication

AbstractThe objective of the current study is to develop novel photochromic polyurethane (PUR) nanofibrous films supported with cellulose nanowhiskers (CNW) and immobilized with nanoparticles of alkaline‐earth doped aluminate (NAEA) using the highly efficient and low‐cost solution blowing spinning (SBS) technique. CNW revealed a crystal diameter of 4–8 nm, and a crystal length of 55–105 nm. The solution blown spun nanofibers exhibited diameters of 250–450 nm. In order to prepare a transparent film, CNW and NAEA must be dispersed efficiently in the PUR composite. When supported with CNW, the efficiency of PUR nanofibrous films was strengthened. Cellulose paper sheets were coated with the colorless NAEA/CNW@PUR films to emit a green light at 518 nm upon excitation at 365 nm as proved by photoluminescence spectra. The prepared nanofibrous films exhibited efficient optical photochromic characteristics for potential security encoding applications. The nanofibers‐coated papers showed high photochromic reversibility without fatigue. The current approach can be reported as an efficient technology for authentication of commercial products.

Phosphorylated/amine-impregnated cellulosic paper for direct CO2 capture

A scalable papermaking process was employed herein to manufacture cellulosic papers from native and phosphorylated cellulose microfibers (referred to as CMF and PCMF, respectively) impregnated with polyethyleneimine (PEI) for Direct Air Capture (DAC) applications. These papers were analyzed in terms of their physico-chemical properties using several techniques. The impact of PEI content on desorbing the co-adsorbed H2O and CO2 from the air, as well as on the anisotropic microporous network, was explicitly analyzed. The results indicated that phosphorylation promotes the uptake of both CO2 and H2O in the corresponding neat and PEI-loaded papers, reaching a superior CO2 adsorption capacity of ∼0.7–0.9 mmol.g−1 for PCMF papers versus 0.07–0.3 mmol.g−1 for CMF papers. Furthermore, the CMF and PCMF papers exhibited H2O adsorption capacities in the range of 1.5–1.8 mmol.g−1 and 2.2–3.8 mmol.g−1, respectively. This work further highlights the combined role of phosphorylation and favorable PEI impregnation in tuning the cellulose CO2 adsorption properties under humid conditions, facilitating the rapid release of the adsorbed CO2 under mid conditions.

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.