Cellulose Paper Research Articles

Construction of efficient ethylene removal and antibacterial cellulose paper-based packaging materials for avocado preservation.

Fruits are susceptible to ethylene ripening and microbial infestation, which can lead to spoilage and further significant economic losses. Thus, using functional preservation materials is an effective controlling technology to improve the post-harvest quality and extend the shelf life of fruits. Hence, a dual-function cellulose-based paper with exceptional antibacterial efficiency, favourable ethylene removal performance, improved mechanical and hydrophobic properties was prepared by covalently grafted antibacterial guanidine salt and surface-modified ethylene scavenger. When the amount of guanidine salt grafted and ethylene scavenger is 1.85 wt% and 1.5 g·m-2, respectively, the prepared cellulose paper exhibited about 99 % ethylene conversion and killing efficiency with no leaching, which extending the post-harvest avocado preservation time to 20 days at room temperature. Packaging with the preservation paper effectively reduced hardness and consumption of soluble solids in avocado during storage, maintaining their appearance and nutritional quality. These findings highlight the excellent preservation capabilities of the dual-function paper, making it a promising material for fruit and vegetable preservation in small and medium planting areas and households.

Multifolding Vertical-Flow Electrochemical Paper-Based Devices with Tunable Dual Preconcentration for Enhanced Multiplexed Assays of Heavy Metals.

This work describes fully integrated multifolding electrochemical paper-based devices (ePADs) for enhanced multiplexed voltammetric determination of heavy metals (Zn(II), Cd(II), and Pb(II)) using tunable passive preconcentration. The paper devices integrate five circular sample preconcentration layers and a 3-electrode electrochemical cell. The hydrophobic barriers of the devices are drawn by pen-plotting with hydrophobic ink, while the electrodes are deposited by screen-printing. The devices exploit the wicking ability of cellulose paper to perform passive preconcentration of the target analytes, resulting in a ∼6-fold signal enhancement. For this purpose, drops of the sample are placed at the five sample pads of the preconcentration layers, the device is folded, and the target metals are eluted in a vertical-flow mode to the electrochemical cell, where they are measured directly by anodic stripping voltammetry (ASV). The working electrode of the ePADs is bulk-modified with bismuth citrate; during the ASV measurements, the bismuth precursor is converted to nanodomains of metallic bismuth at the surface of the working electrode. By combining the triplex signal amplification through passive preconcentration, electrochemical preconcentration, and judicious working electrode modification with in situ generated bismuth nanoparticles, ultrasensitive and multiplexed heavy metal assays can be achieved. Due to their high degree of integration, low cost, easy and fast fabrication, and sensitivity, the multifolding ePADs are particularly suitable for on-site heavy metals' monitoring applications.

Synergistic enhancement of hydrophobicity and mechanical properties of cellulose paper by (3-glycidoxypropyl) trimethoxy and rosin.

Cellulose-based paper is inherently poor in hydrophobicity and mechanical strength, limiting its practical applications in daily life such as packaging materials, water-resistant labels, and disposable tableware. This study aimed to develop an effective and eco-friendly strategy to address these limitations by enhancing the hydrophobicity and mechanical properties of cellulose paper. To achieve this, an internal sizing agent was prepared by combining (3-glycidoxypropyl) trimethoxy (GPS) with natural rosin. This sizing agent was applied to cellulose paper, and its effectiveness was evaluated. Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) confirmed the successful introduction of rosin and GPS into the cellulose fiber network, forming covalent bonds. The variation in the microstructure and surface elemental distribution of the sizing cellulose paper was further analyzed by scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS). Thermogravimetric analysis (TGA) was conducted to evaluate the improved thermostability of the sizing cellulose paper. These structural improvements, including covalent bond formation and gap filling, contributed to the enhanced hydrophobicity and mechanical properties of the paper. This study provides a convenient and cost-effective approach to enhancing the functional properties of cellulose paper, offering new possibilities for its practical applications in eco-friendly packaging materials, disposable paper products, and high-performance paper-based packaging.

Copper-Modified Cellulose Paper: A Comparative Study of How Antimicrobial Activity Is Affected by Particle Size and Testing Standards

This study aims to provide evidence that when testing cellulose paper modified with copper particles (CuPs), the particle size and the analysis method influence the antimicrobial activity observed by this material. Commercial CuPs of nanometric size (2.7 nm, CuNPs) and micrometric size (2.5 µm, CuMPs) were used to modify cellulose paper sheets. CuPs were incorporated during the pulp disintegration phase (stage 1) of the sheet formation process, according to the ISO 5269-1:2005 standard. Modified paper sheets retained 16% and 14% of CuNPs and CuMPs, respectively. Additionally, CuPs were distributed randomly on the fiber surfaces, often forming aggregates. Finally, the antimicrobial activity of the modified paper sheets was evaluated using ISO 20645:2004 and ISO 20743:2013. The results showed that the antimicrobial activity assessed using each standard method is conditioned by the mechanism of action of the CuPs and, therefore, by their size. It was concluded that ISO 20645:2004 is suitable for evaluating the antibacterial effect of paper/CuNPs, as nanoparticles diffuse from the paper and are released into the culture medium. In contrast, ISO 20743:2013 can be used for both CuNP- and CuMP-based paper, as it evaluates the antibacterial effect based on the direct interaction between the copper particle and the bacteria.

Double-layer microencapsulation of ammonium polyphosphate and its enhancement on the hydrophobicity and flame retardancy of cellulose paper.

Cellulose paper is a flammable and hygroscopic material, which limits its application. In this paper, melamine-formaldehyde resin (MF) and silane coupling agents were used to microencapsulate ammonium polyphosphate (Si@MFAPP) in turn and added to the fibers suspension to prepare hydrophobic and flame-retardant cellulose paper. It was found that the surface of the ammonium polyphosphate (APP) was smooth with the water solubility of 0.24 g/100 mL. After microencapsulation with MF, the surface of MFAPP became rough, and the solubility was reduced to 0.1 g/100 mL. When further encapsulation with polysiloxanes, the surface showed significantly higher roughness, and a lotus leaf-like microspherical structure was formed. Specifically, its solubility decreased to 0.04 g/100 mL. In addition, the residual char weight of Si@MFAPP at 800 °C was increased from 25.27 % to 38.56 %. The water contact angle (WCA) of MFAPP/Pulp increased from 84.23° to 90.78°, and the limiting oxygen index (LOI) increased from 31.8 % to 34.1 %, meaning that the flame retardancy was obviously raised. The WCA of Si@MFAPP/Pulp enhanced to 96.45°, and the LOI was 34.5 %, meaning that the hydrophobicity was further raised. Therefore, Si@MFAPP significantly improved the flame-retardancy and hydrophobicity of the cellulose paper.

Optimised properties of conductive polyaniline-polyvinyl alcohol ink painted on paper for ductile pressure sensor with reduced electrical drift

Polyaniline (PANI) powder in its emeraldine salt form was blended with various concentrations of polyvinyl alcohol (PVA) to create semiconducting inks with desired fluid properties. These inks were coated on cellulose paper, and their resistive responses were tested under different vacuum pressures. Enhanced conductivity and reduced creep behavior were achieved by incorporating an O–H bond between the H of PANI and O of PVA, which stabilizes the polymer structure. This bonding minimizes electrical drift, improving the reliability of the synthesized inks for applications such as designing flexible circuits and fabricating thermoelectric generators. The strain field developed under vacuum is accountable for the observed variation in electrical properties. Due to the increase in strain field, the polaron hopping barrier increases, and as a result, the effective conductivity decreases with a decrease in pressure. These ‘use-and-throw’ sensors are economical, adaptable, and environmentally friendly, ideal for various disposable electronics and sensing applications.

Flexible trilayer cellulosic paper separators engineered with the BaTiO3 ferroelectric fillers for high energy density sodium-ion batteries

Development of sustainable and flexible trilayer cellulose-based composite separator membranes for full cell systems in sodium-ion batteries.

Eco-friendly cellulose paper composites: A sustainable solution for EMI shielding and green engineering applications.

Cellulose paper-based composites represent a promising and sustainable alternative for electromagnetic interference (EMI) shielding applications. Derived from renewable and biodegradable cellulose fibers, these composites are enhanced with conductive fillers namely carbon nanotubes, graphene, or metallic nanoparticles, achieving efficient EMI shielding while maintaining environmental friendliness. Their lightweight, flexible nature, and mechanical robustness make them ideal for diverse applications, including wearable electronics, flexible circuits, and green electronics. This paper explores the fabrication techniques, composite properties, with particular emphasis on ways to enhance the shielding properties, and performance metrics of cellulose-based composites, highlighting their potential to replace traditional metallic materials in various EMI shielding scenarios, thus contributing to the development of eco-friendly and high-performance electronic devices. Despite advancements, challenges such as achieving uniform filler dispersion and scalability of eco-friendly production methods persist, limiting industrial application.

Application of santalin dye extracted from Pterocarpus santalinus (red sandalwood) as a natural colorimetric indicator for real-time monitoring of spoilage in ready-to-cook idly batter

The growing demand for natural and eco-friendly solutions in food quality monitoring has sparked significant interest in using natural dyes as sustainable alternatives to chemical dyes for detecting food freshness. In this study, a colorimetric indicator based on natural santalin dye was developed for real-time monitoring of spoilage in ready-to-cook (RTC) idly batter. Santalin, extracted from Pterocarpus santalinus (red sandalwood), is a stable red pigment renowned for its antioxidant, antimicrobial, and antiinflammatory properties. The santalin dye was immobilised in a polyvinyl alcohol-methylcellulose matrix and applied to cellulose paper, creating a low-cost pH-sensitive colorimetric indicator label. The developed indicator label displayed a visible colour change from dark brown to lighter brown hues in response to increased carbon dioxide concentrations, corresponding with a decrease in pH from 5.3 to 4.0 and a rise in titratable acidity (TA) from 0.5% to 0.9 % during the spoilage of RTC idly batter. The colour changes were captured and converted into grayscale images for pixel intensity analysis using MATLAB. The results revealed a consistent decline in mean pixel intensity as fermentation and spoilage progressed, demonstrating the effectiveness of the santalin-based indicator. This novel, natural santalin dye-based indicator offers a promising alternative to synthetic indicators, addressing safety concerns such as chemical migration into food. It can thus serve as an "on-package sticker" for real-time monitoring of spoilage in RTC idly batter.

Point-of-Care Diagnosis of Tuberculosis Using a Portable Nucleic Acid Test with Distance-Based Readout.

Rapid and accurate diagnosis of tuberculosis (TB) infection in resource-limited settings is critically needed to stop the spread of the disease but remains difficult to achieve. Herein, we report a fast, inexpensive nucleic acid test with distance-based readout (FINDR) for TB. Based on the unique chromatographic behavior of DNA intercalating dye on unmodified cellulose paper, our FINDR platform converted the amplicons of loop-mediated isothermal amplification (LAMP) into the migration distance on a paper-based analytical device. A suite of innovations were further introduced to enhance the accessibility of FINDR, including (1) screening optimal LAMP primers for distance-based readout; (2) developing a chip-on-cover design capable of streamlining LAMP amplification and distance-based detection in a fully sealed FINDR chip with a simple hand-based swirling for liquid transfer; and (3) integrating FINDR with an upstream portable pipetting-free DNA extractor and a downstream smartphone app to simplify sample processing and data interpretation. With these innovations, FINDR demonstrated a high clinical sensitivity (96.6%) and specificity (100%) upon validation against clinical sputum samples. Successful clinical validation was also achieved when FINDR was deployed as a point-of-care test for detecting TB under resource-limited conditions.

High-Barrier, Photothermal Conversion, and Antibacterial Composite Enabled by Kraft Lignin-Coated Cellulose Paper for Plastic Replacement

High-Barrier, Photothermal Conversion, and Antibacterial Composite Enabled by Kraft Lignin-Coated Cellulose Paper for Plastic Replacement

Data Mining for the Characterization of a Paper Prototype Obtained with Bacterial Cellulose Derived from Banana and Pineapple By-Products

The primary objective of this research is to evaluate the feasibility of two of the most prevalent agricultural residues in Ecuador, banana peels and pineapple peels, as a carbon source in the culture medium of Komagataeibacter hansenii for the production of bacterial cellulose (BC) and BC-based paper. This analysis includes an assessment of the productivity parameters of the obtained BC and the quality parameters of the BC-based paper, employing multivariate statistical methodologies. The experimental design consisted of fifteen treatments: T1 served as the control using the standard HS medium, while treatments T2–T8 used banana peel extracts (BPE), and treatments T9–T15 used pineapple peel extracts (PPE) at concentrations from 10% to 40% (v/v). Extracts were prepared with tailored pretreatments for each type of peel to optimize bioactive compound recovery. Standardized fermentation and purification conditions were applied, and once the cellulose was obtained, additives and coating agents were incorporated to produce paper samples from each treatment. The results indicated that higher BPE concentrations (T5, T6, T7, and T8) correlated significantly with increased Weight and Yield of BC, as well as improved grammage and water content in the BC-based paper. This highlights that efficient paper production is influenced by the quality of the bacterial cellulose used, with BPE-based media yielding optimal results due to their nutrient composition, which promotes bacterial growth and metabolic activity. This approach suggests a pathway for advancing sustainable and economical paper production.

High-Performance Sustainable Cellulosic Paper Based on Flame Retardancy Coating with Photothermal Sterilization

High-Performance Sustainable Cellulosic Paper Based on Flame Retardancy Coating with Photothermal Sterilization

Fabrication of hydrophobic cellulosic paper via physical vapor deposition of alkenyl succinic anhydride.

While plant fibers are abundant and biodegradable natural polymers, their high hydrophilicity often limits their applicability. To broaden the applicability of plant fiber materials across diverse fields, the present study employed cellulosic paper as a substrate and alkenyl succinic anhydride (ASA) as a low surface free energy material to fabricate a series of hydrophobic cellulosic papers (ASAP, ASA-P@Si, ASA-P@Ca, and ASA-P@Ti) through surface coating and physical vapor deposition of ASA. The results demonstrated that, in comparison to uncoated cellulosic paper, the coated variants exhibited significantly improved hydrophobicity. Notably, ASA-P@Si demonstrated superior hydrophobic performance with a contact angle of 140.90° and a sizing degree of 7.2s, thereby meeting the requirements for specific fine paper grades. In contrast to the traditional ASA internal sizing process, the method in this study necessitates only approximately one-tenth of the conventional ASA internal sizing agent to achieve or even exceed the hydrophobic properties of paper attainable with ASA inter sizing process. Furthermore, the mechanism through which hydrophobic properties are conferred to paper can be elucidated by its surface roughness and low surface free energy, distinguishing it from the traditional ASA internal sizing approach.

Impact of accumulation of organic acids on the degradation of cellulose in historic paper

Impact of accumulation of organic acids on the degradation of cellulose in historic paper

Recent advances in paper (cellulose)-based energy storage devices: a review

Recent advances in paper (cellulose)-based energy storage devices: a review

Bioplastics based on waste paper cellulose, glycerol, and chitosan: the evaluation of mechanical properties

Abstract Bioplastics are an alternative to conventional plastics to overcome environmental problems due to the accumulation of plastic waste. Cellulose is one of the materials that can be used as reinforcement for natural polymer-based bioplastics. One material that has a very high cellulose content is waste paper. This study was conducted to make bioplastics based on waste paper cellulose, glycerol, and chitosan. The mass of waste paper cellulose was the variable that varied in this study. The parameters of mechanical properties evaluated in this study include tensile strength, elongation, degradation rate, and water absorption. The results showed that increasing the mass of added cellulose increased the tensile strength value of bioplastics but decreased the elongation value. The results also show that increasing cellulose mass can reduce the water absorption of bioplastics produced. The sample with the highest tensile strength value is the addition of 3 grams of waste paper cellulose, with a tensile strength value of 1.99 MPa and an elongation of 4.4%.

Mechanical characteristics and antibacterial activity against Staphylococcus aureus of sustainable cellulosic paper coated with Ag and Cu modified ZnO nanoparticles

In this study, zinc oxide (ZnO) nanoparticles were prepared and modified using a wet chemical method with different concentrations of Ag and Cu nanoparticles. The objective was to improve the mechanical, optical, and antibacterial properties of the coated paper by using the prepared pigments. The long-term antimicrobial effects of the coated paper were evaluated over 25 years. The successful synthesis of a hexagonal structure of ZnO nanoparticles decorated with spherical Ag and Cu nanoparticles ranging from 20 to 50 nm was confirmed using X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and transmission electron microscopy (TEM). By increasing the concentrations of Ag and Cu from 0.01% to 1.0%, the mechanical properties of the coated paper were enhanced. The tensile strength reached a maximum of 6.77 kN/m and 7.03 kN/m, elongation increased to 1.69% and 1.70%, tensile energy absorption improved to approximately 77 and 80 J/m2, and burst strength rose to 218 and 219 kPa, respectively. The use of Ag-modified ZnO maintains the optical properties, while Cu-modified ZnO reduces brightness and whiteness without affecting opacity. The antimicrobial inhibition activity was improved with higher silver (Ag) and copper (Cu) content. The formulations containing 1% Ag/ZnO and 1%Cu/ZnO showed long-lasting antibacterial effects against gram-positive Staphylococcus aureus bacteria. Even after 25 years of aging, they maintained inhibition rates of 92.2% and 62.2%, respectively. The molecular docking and GeneMANIA analysis revealed the potential of ZnO, Ag-modified ZnO, and Cu-modified ZnO nanoparticles to disrupt the S. aureus cell wall biosynthesis pathway by targeting the MurA enzyme and associated cell wall synthesis genes.

Multiple crosslinked alkyl ketene dimer-based superhydrophobic coating for structurally robust waterproof cellulosic paper

The instability of traditional superhydrophobic coating severely restricted the practical application of cellulosic paper in our daily life. Herein, a sort of novel structurally robust waterproof cellulosic paper was elaborately designed via the facile coating alkyl ketene dimer (AKD)/dodecyltrimethoxysilane (DTMS)/silica nanoparticle dispersion (SiO2). Originating from the coupling reaction between DTMS and SiO2 and the adsorption of DTMS on AKD emulsion latex, the growth direction of AKD was regulated and AKD/DTMS/SiO2 coating layer was formed. The outermost SiO2 with relatively dense structure effectively prevent the permeation of moisture into the inside of coating. During 20∼160 °C, the coated paper still remained highly superhydrophobic surface with water contact angle (WCA) >160°. Moreover, the inorganic SiO2 layer endowed the superhydrophobic paper with satisfied chemical and mechanical stability. Various beverages (e.g. milk, yogurt, honey and other edible liquids) could not be adhered onto the surface of superhydrophobic paper, indicating the great potential application as packaging materials. Our findings not only provided a new perspective to design the structurally robust superhydrophobic coating, but also boosted the application of cellulosic fibers in food packaging to replace traditional plastic.

Humidity-induced self-powered photodetection through Bi2Te3/MoS2 nanohybrid material deposited on a flexible substrate

Harvesting energy from humidity is an environmentally friendly technology. In arid regions, instead of negative impact of humidity, it is also feasible to capture water from the air, making our device suitable without the need for any external power supply. Self-powered photodetectors are in high demand due to their zero power consumption and suitability for wearable electronics. Herein, we have incorporated Bi2Te3 nanosheets with MoS2 on a flexible and biodegradable cellulose paper substrate to create the device. According to XPS analysis, Bi 4F7/2 and Bi 4F5/2 levels were identified at binding energies of 157.62 eV and 162.90 eV, respectively indicating double splitting of the Bi atoms. In such a novel Bi2Te3/MoS2 nanohybrid photodetector, rapid electron transfer at Bi2Te3 and MoS2 interface occurs due to humidity, significantly enhancing performance of the photodetectors in the UV spectral range. This performance is better as compared to conventional MoS2-based photodetector, exploiting the unique properties of topological insulator Bi2Te3. The device demonstrated the highest responsivity of 19.1 A/W and detectivity of 7.81 × 1011 Jones, exhibiting significant responsivity of 3.74 mA/W and detectivity of 9.59 × 109 Jones even at 0 V with minimum optical signal of 68.9 μW/cm2. It also offers the highest external quantum efficiency of 6471.29 %.