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Bio-based additives received significant attention in pulp and paper properties improvement. For this, the most cited biochemical Cellulose Nano Fibrils (CNFs) and Cationic Starch (CS) were experimentally compared with the most declared synthetic chemical, Cationic Polyacrylamide (CPAM). SEM images showed better paper surface filling by the utilization of the chemicals. The three studied polymers, in solely or combination mechanism, improved mainly bagasse pulp and paper properties compared to the blank sample, except for pulp drainage, which decreased by CNFs to lower volumes presumably due to its intrinsic characteristics. Cationic polymers (CP) compared to CP/CNFs approaches increased pulp retention and drainage but decreased paper density and strengths. The best pulp retention and drainage achieved by CS followed by CPAM, while paper air persistency, density, and strength properties evaluated highest by CP/CNFs followed by CNFs. Generally, CS revealed a more significant improvement in pulp and paper properties than CPAM either with or without CNFs., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Here, we designed paper sheets coated with chitosan, bacterial cellulose (nanofibers), and ZnO with boosted antibacterial and mechanical activity. We investigated the compositions, with ZnO exhibiting two different sizes/shapes: (1) rods and (2) irregular sphere-like particles. The proposed processing of bacterial cellulose resulted in the formation of nanofibers. Antimicrobial behavior was tested using E. coli ATCC ® 25922™ following the ASTM E2149-13a standard. The mechanical properties of the paper sheets were measured by comparing tearing resistance, tensile strength, and bursting strength according to the ISO 5270 standard. The results showed an increased antibacterial response (assigned to the combination of chitosan and ZnO, independent of its shape and size) and boosted mechanical properties. Therefore, the proposed composition is an interesting multifunctional mixture for coatings in food packaging applications.

This study focussed on the development of fully biodegradable composites based on polybutylene succinate (PBS) in combination with raw materials from different processing stages of the pulp and paper industry. Sulfite pulp (SP), kraft pulp (KP) and screened sludge residue (SL) from wastewater treatment plants (WWTP) were investigated as reinforcing fibres contributing to a circular economy. We report a comparative study of the physicochemical properties and mechanical performance of PBS composites reinforced with these cellulosic raw fibres and commercial pure microcrystalline cellulose (MC). The composites were characterised in tensile strength, elongation at break, modulus of elasticity, water absorption and wettability. The incorporation of the fibres into the polymer matrix was also investigated using torque rheometry. Critical concentrations were obtained with maximum incorporation in the range of 15–20 wt% for SP/KP and 25–30 wt% for SL. SP and KP composites showed at least as good physicochemical and mechanical properties as MC at the concentrations studied (0–20 wt%). SP-composites showed the highest tensile strength and modulus of elasticity. It was shown that these fibres from the pulp and paper industry can be used as reinforcement for PBS matrices without additional chemical purification and provide a valuable alternative to commercial microcrystalline cellulose. [ABSTRACT FROM AUTHOR]

We developed a simple method to achieve semiquantitative detection of an amphiphilic biosample through measuring the length of flow on a microfluidic analytical device (μPAD) based on paper. When an amphiphilic sample was dripped into a straight microchannel defined with a printed wax barrier (hydrophobic) on filter paper (hydrophilic), the length of flow was affected by the reciprocal effect between the sample, the filter-paper channel and the wax barrier. The flow length decreased with increasing concentration of an amphiphilic sample because of adsorption of the sample on the hydrophobic barrier. Measurement of the flow length enabled a determination of the concentration of the amphiphilic sample. The several tested samples included surfactants (Tween 20 and Triton X-100), oligonucleotides (DNA), bovine serum albumin (BSA), human albumin, nitrite, glucose and low-density lipoprotein (LDL). The results show that the measurement of the flow length determined directly the concentration of an amphiphilic sample, whereas a non-amphiphilic sample was not amenable to this method. The proposed method features the advantages of small cost, simplicity, convenience, directness, rapidity (<5 min) and requirement of only a small volume (5 μL) of sample, with prospective applications in developing areas and sites near patients for testing at a point of care (POCT).

Recovery of cellulose fibres from paper mill effluent has been studied using common polysaccharides or biopolymers such as Guar gum, Xanthan gum and Locust bean gum as flocculent. Guar gum is commonly used in sizing paper and routinely used in paper making. The results have been compared with the performance of alum, which is a common coagulant and a key ingredient of the paper industry. Guar gum recovered about 3.86mg/L of fibre and was most effective among the biopolymers. Settling velocity distribution curves demonstrated that Guar gum was able to settle the fibres faster than the other biopolymers; however, alum displayed the highest particle removal rate than all the biopolymers at any of the settling velocities. Alum, Guar gum, Xanthan gum and Locust bean gum removed 97.46%, 94.68%, 92.39% and 92.46% turbidity of raw effluent at a settling velocity of 0.5cm/min, respectively. The conditions for obtaining the lowest sludge volume index such as pH, dose and mixing speed were optimised for guar gum which was the most effective among the biopolymers. Response surface methodology was used to design all experiments, and an optimum operational setting was proposed. The test results indicate similar performance of alum and Guar gum in terms of floc settling velocities and sludge volume index. Since Guar gum is a plant derived natural substance, it is environmentally benign and offers a green treatment option to the paper mills for pulp recycling., (Copyright © 2014. Published by Elsevier B.V.)

Paper and packaging materials a lignocellulose-based natural biodegradable polymer that spontaneously releases acetic acid, aldehydes, alcohol, and ester-based volatile organic compounds (VOCs) upon ageing and these VOCs start degrading the paper products and decline their mechanical strength properties. The reactivity of the paper of unbleached wheat straw pulp towards acetic acid and hexanal, which has been proven to have more degrading effects on paper than other VOCs, was considered in this work. The papers were exposed to these volatile compounds for 90 days in an air-tight vessel under ambient environmental conditions. The results showed that hexanal was more destructive than acetic acid with regards to cellulose degradation and depletion in the mechanical strength properties. The paper properties like, tensile, tear and burst index, viscosity, pH and carbonyl group content was measured. The growth of the carbonyl group, evidence of the ageing effects in the paper, detected more in the paper exposed to acetic acid. However, the strength of paper properties declined more with hexanal. FE-SEM analysis of the sample showed the development of pores and damage of cellulose fibre upon ageing. Similarly, the damaging effects of VOCs on cellulose, hemicelluloses and lignin were confirmed by significantly reduced peak detection through FT-IR \analysis. The high crystallinity index of the paper products due to exposure to VOCs was detected by XRD analysis, which confirmed the degradation of the low molecular weight cellulose molecule. Thus, the results are strongly recommended that VOCs that generates due to natural or artificial ageing could be the leading cause of paper degradation. [ABSTRACT FROM AUTHOR]

This review focuses on polymeric waste-paper composites, including state-of-the-art analysis with quantitative and qualitative discussions. Waste paper is a valuable cellulose-rich material, produced mainly from office paper, newspaper, and paper sludge, which can be recycled and returned to paper production or used in a new life cycle. A systematic literature review found 75 publications on this material over the last 27 years, with half of those published during the last five years. These data represent an increasing trend in the number of publications and citations that have shown an interest in this field. Most of them investigated the physicomechanical properties of composites using different contents of raw waste paper or the treated, modified, and cellulose-extracted types. The results show that polyethylene and polypropylene are the most used matrices, but polylactic acid, a biodegradable/sourced polymer, has the most citations. The scientific relevance of waste-paper composites as a subject includes the increasing trend of the number of publications and citations over the years, as well as the gaps identified by keyword mapping and the qualitative discussion of the papers. Therefore, biopolymers and biobased polymers could be investigated more, as well as novel applications. The environmental impact in terms of stability and degradation should also receive more attention regarding sustainability and life cycle analyses. [ABSTRACT FROM AUTHOR]

In the pursuit of enhancing food packaging, nanotechnology, particularly green silver nanoparticles (G-AgNPs), have gained prominence for its remarkable antimicrobial properties with high potential for food shelf-life extension. Our study aims to develop corn starch-based coating materials reinforced with G-AgNPs. The mechanical properties were examined using a uniaxial tensile tester, revealing that starch coated with the highest G-AgNPs concentration (12.75 ppm) exhibited UTS of 87.6 MPa compared to 48.48 MPa of control paper, a significant (p < 0.02) 65% increase. The assessment of the WVP showcased a statistical reduction in permeability by up to 8% with the incorporation of the hydrophobic layer. Furthermore, antibacterial properties were assessed following ISO 22196:2011, demonstrating a strong and concentration-dependent activity of G-AgNPs against E. coli. All samples successfully disintegrated in both simulated environments (soil and seawater), including samples presenting G-AgNPs. In the food trial analysis, the presence of starch and G-AgNPs significantly reduced weight loss after 6 days, with cherry tomatoes decreasing by 8.59% and green grapes by 6.77% only. The results of this study contribute to the advancement of environmentally friendly packaging materials, aligning with the UN sustainable development goals of reducing food waste and promoting sustainability. [ABSTRACT FROM AUTHOR]

The present study reports on the development by thermoforming of highly sustainable trays based on a bilayer structure composed of paper substrate and a film made of a blend of partially bio-based poly(butylene succinate) (PBS) and poly(butylene succinate-co-adipate) (PBSA). The incorporation of the renewable succinic acid derived biopolyester blend film slightly improved the thermal resistance and tensile strength of paper, whereas its flexural ductility and puncture resistance were notably enhanced. Furthermore, in terms of barrier properties, the incorporation of this biopolymer blend film reduced the water and aroma vapor permeances of paper by two orders of magnitude, while it endowed the paper structure with intermediate oxygen barrier properties. The resultant thermoformed bilayer trays were, thereafter, originally applied to preserve non-thermally treated Italian artisanal fresh pasta, “fusilli calabresi” type, which was stored under refrigeration conditions for 3 weeks. Shelf-life evaluation showed that the application of the PBS–PBSA film on the paper substrate delayed color changes and mold growth for 1 week, as well as reduced drying of fresh pasta, resulting in acceptable physicochemical quality parameters within 9 days of storage. Lastly, overall migration studies performed with two food simulants demonstrated that the newly developed paper/PBS–PBSA trays are safe since these successfully comply with current legislation on plastic materials and articles intended to come into contact with food.

The present comment concerns some doubtful results included in the above paper., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Within the domain of starch modification, the study delved into cationization of wheat starch through a laboratory-scale twin-screw extruder, exploring various processing conditions. Cationic starch, a crucial component for enhancing paper attributes like dry strength and printability, took center stage. The focus shifted towards integration into papermaking, investigating the transformative potential of reactive extrusion. By contrasting it with conventional dry-process methodology, innovative strides were unveiled. The study extended to pilot-scale extrusion, bridging the gap between laboratory experimentation and potential industrial implementation. Infused with scientific rigor, the investigation navigated the benefits brought about by reactive extrusion. Empirical insights highlighted a significant reduction in the intrinsic viscosity of extruded starch, decreasing from 170 mL·g−1 (native starch) to 100 mL·g−1 at a specific mechanical energy (SME) input of 800 kWh·t−1, demonstrating remarkable stability despite increased mechanical treatment. Moreover, beyond the critical threshold of 220 kWh·t−1, retention efficiency reached a stable plateau at 78%. The study revealed that utilizing a larger extruder slightly improved the mechanical properties of the paper, emphasizing the advantage of scaling up the production process and the consistency of results across different extruder sizes. [ABSTRACT FROM AUTHOR]

For proper treatment, recycling, or disposal of the pulp and paper mill secondary sludge qualitative and quantitative determination of its characteristics are necessary. Chemical extraction, quantitative characterization, and spectroscopic experiments have been performed to determine the molecular composition and chemical functionality of a pulp and paper mill secondary sludge. In order to extract the low-molecular-weight substances, soxhlet extraction with polar and non-polar solvents was performed where most of the target substances (17±1.3%.) were extracted after 2 hours. Over time, this extraction followed a first-order kinetics. Fiber analyses have shown 12±3% lignin, 28±3% cellulose, and 12±4% hemicelluloses content. The ash content was about 17±0.5%. In this work, 7 and 16% intra- and extracellular polymeric substances, respectively, were extracted from the secondary sludge. EPS and mixture of intra- and extracellular biopolymers have shown similar chemical functionalities. These analyses confirmed that the paper secondary sludge consisted mainly of wood fiber, i.e. lignocellulosic substances, along with proteins and polysaccharides originated from microorganisms.

The dominance of plastics in the packaging market is due to their low weight and thickness, which save transportation costs. However, their non-biodegradability poses a significant threat to the environment. Paper, on the other hand, is considered as a safer alternative due to its natural composition and biodegradability. The porous structure of paper limits its application in packaging, and its poor water resistance further restricts its use in humid environments. Therefore, lamination is a method useful tool to improve the barrier properties of paper. Additionally, the researchers are focusing on developing biodegradable and water-based coatings with anti-fat properties as a green alternative to plastic packaging. The impact of a new grease-resistant coating composed of starch, gelatin and sodium alginate on the mechanical properties of paper was investigated through tensile, tearing, and bursting strength tests. The results showed significant improvements in the mechanical properties of the coated paper sheets. Furthermore, the biodegradability test indicated that the paper samples coated with the new composition showed a 50% weight loss after one week of incubation in the soil, and after three weeks, they exhibited 100% weight loss, demonstrating their outstanding biodegradability. [ABSTRACT FROM AUTHOR]

Bamboo leaves are a resource of cellulose fibers that can be further developed into value-added products. In this research, cellulose nanofibers were obtained from Tinwa bamboo leaves, and then chemically modified with (i) hexadecyltrimethoxysilane (HDTMS) and (ii) perfluorooctyltriethoxysilane (POTS). The modified nanofibers were then used as a hydrophobic biopolymer coating on paper, as an alternative to commonly used fossil-based coatings. Hydrophobicity in terms of surface and bulk properties of the coated paperboards was investigated. The results showed that the hydrophobic coatings obtained provided a high contact angle up to 141° and a decrease of water penetration speed during immersion up to 94% when using ultrasonic technique. The coated paperboards exhibited color difference values compared with an uncoated paperboard in the range of 0.4 to

Much recent research has focused on electrochemical biosensors to meet the growing demands for rapid and accurate diagnostic tests for diseases, detecting toxic molecules present in the environment, and biomolecules used as in pharmaceuticals. Carbon nanotubes (CNTs) have been shown to be effective for electrochemical biosensors because of their favorable chemical, physical and electrical properties. Here we report the use of a two-dimensional entangled mat of CNTs, known as buckypaper, as electrodes for electrochemical biosensors. The buckypaper electrodes exhibit superior sensitivity towards tryptophan, L-carnitine, tyrosine and myoglobin. When engineered with metals or other specific molecules, the buckypaper shows an up to 1000-fold increase in the signal compared with electrodes based on glassy carbon. This enhanced electrochemical performance of the modified buckypaper demonstrates potential for a new platform for electrochemical biosensor technologies.

• Achieving high waterproofing in modified cellulose sheets using silylated starch. • Accelerating to biodegradation rate of starch-modified cellulose material by water. • Increasing service life and decay acceleration by fungi for modified paper. Modifying natural polymers with silicones gives new possibilities for packaging products and waste management. In this study, the innovative papers produced were altered following the reaction of polysaccharides and organosilicon compounds. The susceptibility of the studied material to biodegradation caused by a brown-rot fungus was assessed. Strength properties by tensile strength and dynamic mechanical analysis and hydrophobic properties by water uptake test and water contact angle analysis were evaluated. Moreover, elemental analysis by ICP method was controlled. The durability against fungi and the hydrophobic properties were increased by the modification. The fungal decay resistance of the silanized paper was reduced by water storage, which allows for managing paper waste. Cellulose-based paper treated with starch-modified methyltrimethoxysilane showed potential as a packaging material due to its reduced water uptake. Possible application areas could be corrugated boxes, cellulose thermoformed products for electronics, and food packaging. However, the water-repellent effect is limited to short-term exposure in humid conditions. [ABSTRACT FROM AUTHOR]

Paper is one of the most promising materials for food packaging and wrapping due to its low environmental impact, but surface treatments are often needed to improve its performance, e.g., the resistance to fats and oils. In this context, this research is focused on the formulation of a new paper bio-coating. Paper was coated with liquids containing poly(hexano-6-lactone) (PCL), glycerol and variable percentages of starch (5–10% w/w PCL dry weight), agar-agar (0–1.5% w/w PCL dry weight), and polyethylene glycol (PEG) (5% or 15% w/w PCL dry weight) to improve coating uniformity and diffusion. A design of experiments approach was implemented to find statistically reliable results in terms of the best coating formulation. Coated paper was characterized through mechanical and physical properties. Results showed that agar content (1.5% w/w PCL dry weight) has a beneficial effect on increasing the resistance to oil. Furthermore, the best coating composition has been calculated, and it is 10% w/w PCL dry weight of starch, 1.5% w/w PCL dry weight of agar, and 15% w/w PCL dry weight of PEG.

Paper waste is a raw material for a lot of products with different added value. The engineering, economic and environmental aspects of paper waste recycling are analysed for production of composite material, cellulose nanofibers and nanocrystals, bricks with paper components, porous carbon, film of biopolymer, enzymatic sugar and bioenergy: bioethanol, hydrogen and biofuel. Through multicriteria analysis, it was possible to determine the most feasible paper waste recycling product in case of four product groups: egg packaging boxes, cardboard, reused paper, cellulose nanomaterials (nanofibers and nanocrystals). The production of cellulose nanofibres and cellulose nanocrystals has an advantage over egg packaging and cardboard production as well as reusable paper. [ABSTRACT FROM AUTHOR]

The present study reports on the development by thermoforming of highly sustainable trays based on a bilayer structure composed of paper substrate and a film made of a blend of partially bio-based poly(butylene succinate) (PBS) and poly(butylene succinate-co-adipate) (PBSA). The incorporation of the renewable succinic acid derived biopolyester blend film slightly improved the thermal resistance and tensile strength of paper, whereas its flexural ductility and puncture resistance were notably enhanced. Furthermore, in terms of barrier properties, the incorporation of this biopolymer blend film reduced the water and aroma vapor permeances of paper by two orders of magnitude, while it endowed the paper structure with intermediate oxygen barrier properties. The resultant thermoformed bilayer trays were, thereafter, originally applied to preserve non-thermally treated Italian artisanal fresh pasta, "fusilli calabresi" type, which was stored under refrigeration conditions for 3 weeks. Shelf-life evaluation showed that the application of the PBS–PBSA film on the paper substrate delayed color changes and mold growth for 1 week, as well as reduced drying of fresh pasta, resulting in acceptable physicochemical quality parameters within 9 days of storage. Lastly, overall migration studies performed with two food simulants demonstrated that the newly developed paper/PBS–PBSA trays are safe since these successfully comply with current legislation on plastic materials and articles intended to come into contact with food. [ABSTRACT FROM AUTHOR]

Paper is one of the most promising materials for food packaging and wrapping due to its low environmental impact, but surface treatments are often needed to improve its performance, e.g., the resistance to fats and oils. In this context, this research is focused on the formulation of a new paper bio-coating. Paper was coated with liquids containing poly(hexano-6-lactone) (PCL), glycerol and variable percentages of starch (5–10% w/w PCL dry weight), agar-agar (0–1.5% w/w PCL dry weight), and polyethylene glycol (PEG) (5% or 15% w/w PCL dry weight) to improve coating uniformity and diffusion. A design of experiments approach was implemented to find statistically reliable results in terms of the best coating formulation. Coated paper was characterized through mechanical and physical properties. Results showed that agar content (1.5% w/w PCL dry weight) has a beneficial effect on increasing the resistance to oil. Furthermore, the best coating composition has been calculated, and it is 10% w/w PCL dry weight of starch, 1.5% w/w PCL dry weight of agar, and 15% w/w PCL dry weight of PEG. [ABSTRACT FROM AUTHOR]

The vast amount of synthetic polymers used in packaging is putting a strain on the environment and is depleting finite, non-renewable raw materials. Abundantly available biopolymers such as alginate, chitosan and microfibrillated cellulose (MFC) have frequently been suggested in the literature to replace synthetic polymers and their barrier properties have been investigated in detail. Many studies aim to improve the properties of standalone biopolymer films. Some studies apply these biopolymers as barrier coatings on paper, but the solids content in most of these studies is quite low, which in turn would result in a high energy demand in industrial drying processes. The aim of this study is to suggest a laboratory procedure to investigate the suitability of these biopolymers at higher and such more industrially relevant solids content as potential coating materials for paper and board in order to improve their barrier properties. First, biopolymer solutions are prepared at a high solids content at which the viscosity at industrially relevant higher shear rates of 50,000 s−1 (1000 s−1 for MFC) is in the same range as a synthetic reference material (in this case ethylene vinyl alcohol EVOH) at 10 wt%. These solutions are analyzed regarding properties such as rheology and surface tension that are relevant for their coatability in industrial coating processes. Then, free-standing films are cast, and the films are characterized regarding important properties for packaging applications such as different surface, mechanical and barrier properties. Based on these results suitable biopolymers for future coating trials can be easily identified. [ABSTRACT FROM AUTHOR]

This paper describes the fabrication of paper-based microfluidic devices using a novel, inexpensive ink composed of bovine serum albumin (BSA), utilizing BSA's thermal denaturation and aggregation to create a hydrophobic barrier on Whatman® Grade 4 filter paper. A 20% aqueous solution of BSA was inked onto the paper using a pen plotter at moderate speed (5 cm/s) with desired shape and size followed by heating at 80 °C to denature the BSA leading to hydrophobic barriers formation, whereas below 80 °C the barrier layer is prone to collapse. The minimum line gap and line width of ~1 mm and ~1.3 mm were achieved. Finally, a proof-of-concept glucose sensing was shown while addressing the issue of the coffee ring effect using the biopolymer NanoCheck-ATH® from ChitoLytic Inc. The glucose concentration limit of detection (LOD) as low as 0.2 mg/mL was estimated. The developed technique offers ease of fabrication, high reproducibility, cost-effectiveness, and is environmentally friendly. [ABSTRACT FROM AUTHOR]

Here, we designed paper sheets coated with chitosan, bacterial cellulose (nanofibers), and ZnO with boosted antibacterial and mechanical activity. We investigated the compositions, with ZnO exhibiting two different sizes/shapes: (1) rods and (2) irregular sphere-like particles. The proposed processing of bacterial cellulose resulted in the formation of nanofibers. Antimicrobial behavior was tested using E. coli ATCC® 25922™ following the ASTM E2149-13a standard. The mechanical properties of the paper sheets were measured by comparing tearing resistance, tensile strength, and bursting strength according to the ISO 5270 standard. The results showed an increased antibacterial response (assigned to the combination of chitosan and ZnO, independent of its shape and size) and boosted mechanical properties. Therefore, the proposed composition is an interesting multifunctional mixture for coatings in food packaging applications.

The leather sector is currently under heavy threat to reduce environmental pollution problems associated with the generation of leather waste, especially in terms of public acceptance issues related to environmental welfare requirements. Leather waste must be disposed of in landfills, which has a significant environmental impact. The development of natural polymer/paper mill sludge-based leather replacements for the production of leather goods and footwear products is an alternative solution supported by the recycled leather industry. In this work, a study is carried out to prepare natural polymer leather sheet (NPLS) from leather waste (chrome shavings and buffing dust), paper mill sludge, and natural polymer [natural rubber latex (NRL)] by vacuum-pressure method, for their potential application in leather products industries. The NPLS was characterized by its physicochemical and mechanical properties. Various types of NPLS were produced by comprising different ratios of the NRL. Results portrayed that 300 mL w/v NRL significantly improved the physicochemical and mechanical properties of NPLS. Hence, the research has revealed a revolutionary idea of NPLS developed which is cost-effective, eco-friendly, and energy efficient. [ABSTRACT FROM AUTHOR]

In heritage conservation, paper deterioration can be slowed down by controlling the environmental conditions surrounding heritage objects and stabilizing the materials these objects are made of. As conservation materials can also cause optical, chemical, and physical changes in the object, their application should be safe, minimalistic, and purposeful. This paper aimed to observe the functional applications of three biopolymers used in paper conservation. For that purpose, a model paper was coated with methylcellulose (MC), cellulose nanocrystals (CNCs), and wheat starch (WSP) using different wet film deposits. The prepared samples were characterized by determining their physical, optical, and surface properties. The results show that changes in the wet film deposit thickness influenced paper properties. With CNCs, the increase has caused a drastic change of colour properties, with MC hydrophobicity increased and with WSP grammage and thickness increased. All coatings (except CNC24) have contributed to the preservation of the colour properties of the paper from the damage caused by thermal ageing. [ABSTRACT FROM AUTHOR]

[Display omitted] • A chitosan-based coating for paper packaging to store specialty coffee is presented. • Chitosan-based film enhanced the mechanical and permeability properties of paper. • Coffee beverage differs in flavor regarding the two samples of chitosan used as coating in packaging. Cellulose-based packaging has received great attention due to its characteristics of biodegradability, sustainability, and recyclability. Natural polymer coatings are usually applied to the paper surface to enhance the barriers to water vapour and improve the mechanical properties. A chitosan-based coating for paper packaging was developed in this work to store specialty roasted coffee beans, evaluating two samples of chitosan (Sigma® and molasses chitosan), and following the physico-chemical and microbiological characteristics of coffee beans along a period of 60 days. Sensory tests (Ranking Descriptive Analysis and Preference Test) were applied to the beverage prepared with the roasted and ground coffee beans stored in each packaging. Thin chitosan films provided good coverage and adhesion on the paper. Improved mechanical properties and lower water permeability were observed in the chitosan-coated papers. The physicochemical and microbiological characteristics of the coffee beans were not influenced by the packaging along 60 days of storage. The molasses chitosan coating resulted in slightly darker roasted beans. In sensory evaluation, there is a clear difference between the chitosan samples, so that molasses chitosan-coated packaging had higher scores compared to Sigma® chitosan treatment for flavor and global impression in the preference analysis of the beverage. The molasses chitosan-coated packaging had three to four more consumers attributing the highest scores for the beverage prepared with the roasted beans stored in this type of packaging. [ABSTRACT FROM AUTHOR]

A functional biopolymer-coated paper was prepared by coating a ternary blend of the alginate, carboxymethyl cellulose, and carrageenan with grapefruit seed extract (GSE) for the substitute use of synthetic polymer-coated paper. The microstructure of the surface and cross-section of the coated paper analyzed by field emission scanning electron microscope (FE-SEM) indicated that the biopolymer was compatible with the base paper and filled the pores of the porous fiber to make a smooth-surfaced coating paper. The properties of the biopolymer-coated paper, such as water and oil resistance, water vapor barrier, surface hydrophobicity, and mechanical properties, increased significantly compared with not only the base paper but also commercially used PE-coated paper. The blended biopolymer coating material exhibited strong antibacterial activity against food-borne pathogenic bacteria, Listeria monocytogenes and Escherichia coli , which were destroyed completely within 3 and 9 h, respectively. The packaging test for a minced fish cake packed with the biopolymer-coated paper showed the complete destruction of surface inoculated bacteria in 6–9 days. The biopolymer-coated paper showed a high potential for disposable food packaging applications to increase the shelf-life of packaged food. [ABSTRACT FROM AUTHOR]

The proliferation of microplastics in the ocean and other water bodies is becoming an alarming issue. The development of plastic‐free water‐ and oil‐resistant paper can contribute toward mitigating this problem. Herein we report a plastic‐free paper coating derived from chitosan and sunflower oil. Chitosan grafted sunflower oil paper coatings were prepared via the ring opening of the partially epoxidized sunflower oil with chitosan. The product of these reactions was characterized by nuclear magnetic resonance and infrared spectroscopy techniques. The sunflower oil grafted chitosan solution was coated onto a Kraft paper. The Cobb 60 and kit rating values were determined to be 8.00 g/m2 and 7.66, respectively, for the optimal formulations. Meanwhile, the water contact angle was found to be 94.0 ± 1.6° after 30 s. Scanning electron microscopy analysis was employed to gain insight regarding the changes that occurred on the paper surface at the microscopic level. [ABSTRACT FROM AUTHOR]

Starch is an inexpensive, easily accessible, and widespread natural polymer. Due to its properties and availability, this polysaccharide is an attractive precursor for sustainable products. Considering its exploitation in adhesives and coatings, the major drawback of starch is its high affinity towards water. This study aims to explain the influence of the silane-starch coating on the hydrophobic properties of paper. The analysis of the organosilicon modified starch properties showed an enhanced hydrophobic behavior, suggesting higher durability for the coatings. Molecules of silanes with short aliphatic carbon chains were easily embedded in the starch structure. Longer side chains of silanes were primarily localized on the surface of the starch structure. The best hydrophobic properties were obtained for the paper coated with the composition based on starch and methyltrimethoxysilane. This coating also improved the bursting resistance and compressive strength of the tested paper. A static contact angle higher than 115° was achieved. PDA analysis confirmed the examined material exhibited high barrier properties towards water. The results extend the knowledge of the interaction of silane compositions in the presence of starch. [ABSTRACT FROM AUTHOR]

Microbial degradation of lignin, a natural complex biopolymer, a renewable raw material with a wide range of applications, has been mainly directed at fungal systems, nevertheless, recent studies have proposed the bacterial role in lignin degradation and modification since bacteria possess remarkable environmental adaptability, and various production of enzymes and biochemistry. An occurrence of a high proportion of lignin-degrading genes has been confirmed in actinobacteria and proteobacteria classes by bioinformatics analysis, which points to the probability of undiscovered pathways and enzymes. Because of that, bacterial lignin decomposition might be substantially different from fungal lignin decomposition. Bacteria capable of lignin modification and degradation belong to actinomycetes, some Firmicutes, α-proteobacteria, and γ-proteobacteria. The enzymes responsible for lignin degradation are lignin peroxidase, manganese-dependent peroxidase, versatile peroxidase, dye-decolourizing peroxidase, and laccases. One of the main lignin producers is the pulp and paper manufacturing industry. Lignolytic microorganisms have been identified from diverse habitats, such as in plants, soil, wood, and the gut. Bacterial strains Bacillus, Rhodococcus, Sterptomyces, and Pseudomonas have been reported to have lignin decomposition ability. This review aims to describe the role of bacteria in lignin degradation, bacterial species, and bacterial enzymes included in lignin degradation. Several reports about bacterial species involved in lignin degradation are also highlighted, and the current state of the knowledge on the degradation of lignin from the pulp and paper manufacturing industry are reported. [ABSTRACT FROM AUTHOR]

Purpose: This study aims to restore the lost mechanical properties of the prints with carrageenan, methyl hydroxyethyl cellulose (Tylose) and hydroxypropyl methylcellulose (Methocel). Design/methodology/approach: The effect of these materials on the properties of the printed paper (modern and historical samples) has been evaluated under the influence of accelerated aging using pH measurement, the mechanical properties (tensile and elongation), FTIR and color changes. Findings: The three consolidates reduced the acidity of treated samples significantly, but after ageing, it was observed that the pH of aged treated samples decreased slightly as compared to the untreated samples. The results of the mechanical properties showed the superiority of hydroxypropyl methylcellulose (Methocel) in improving the tensile and elongation forces of the samples compared to carrageenan and methyl hydroxyethyl cellulose even during the accelerated aging. Consolidation materials succeeded in reducing ΔE of the paper samples under accelerated aging, especially carrageenan. The IR spectra confirmed that no dramatic difference was observed in topically function vibrations of samples after treatment beside that the O-H stretching band intensity increased observably after treatment with the three consolidates, after ageing the treatment, and it protected the treated paper from oxidation processes as the infrared spectrum analysis showed a decrease in intensities of carbonyl and carboxyl groups as compared to aged untreated samples. Originality/value: The research provides new biopolymers in strengthening the historical printed paper, where printed papers lack studies related to their conservation. This makes the current study a promising step for treating historical printed paper. [ABSTRACT FROM AUTHOR]

Waste paper as a resource for polyhydroxyalkanoate (PHA) production through anaerobic digestion is a low-cost strategy to produce bioplastic. In this study, volatile fatty acids (VFAs) produced from waste paper, one of the significant constituents of municipal solid waste, was utilized as a feedstock for polyhydroxyalkanoate (PHA) production. PHA production from synthetic VFAs by Cupriavidus necator was initially optimized under different VFAs concentrations, VFAs ratios, and nitrogen sources. VFAs concentration of 10 g/L, 5:1:4 ratio of acetic, propionic, and butyric acids (HAc:HPr:HBu) and NaNO3 as nitrogen source were considered the optimum conditions with 56.98% PHA and 0.31 g/g yield. Anaerobic digestion of shredded office paper (OP/S) produced the maximum VFAs (521.50 mg/L) after 15 days of incubation and were utilized for PHA synthesis. Almost 2.24-fold increase in the yield of PHA was achieved with limited nutrient medium compared to nutrient contained medium with a PHA content of 53.50 and 23.88%, respectively. PHA production using anaerobic effluent of waste paper is a promising approach where a series of pretreatment processes, the expensive enzymatic hydrolysis, and detoxification were no longer required, suggesting an environmentally friendly way of biopolymer production. [ABSTRACT FROM AUTHOR]

Recently, fiber-based and functional paper food packaging has garnered significant attention for its versatility, excellent performance, and potential to provide sustainable solutions to the food packaging industry. Fiber-based food packaging is characterized by its large surface area, adjustable porosity and customizability, while functional paper-based food packaging typically exhibits good mechanical strength and barrier properties. This review summarizes the latest research progress on food packaging based on fibers and functional paper. Firstly, the raw materials used for preparing fiber and functional paper, along with their physical and chemical properties and roles in food packaging, were discussed. Subsequently, the latest advancements in the application of fiber and paper materials in food packaging were introduced. This paper also discusses future research directions and potential areas for improvement in fiber and functional paper food packaging to further enhance their effectiveness in ensuring food safety, quality, and sustainability. • Properties of materials for fiber and functional paper were introduced. • The roles of materials in food packaging were discussed. • The application of fiber and paper materials in food packaging were introduced. • Limitations and future development directions were discussed. [ABSTRACT FROM AUTHOR]

There is current interest in using agro-based biopolymers in industrial applications. Because cottonseed protein is abundantly available, it would be useful to explore its feasibility as a polymeric additive and possible substitute for petroleum-based materials. In this work, we studied cottonseed protein isolate as a paper additive and observed its effects on the paper’s dry and wet strength. The tensile strength of paper was found to vary with the amount of the protein applied. By application of an 11% protein solution to the paper, the dry and wet strength increased by 33 and 16% compared with the paper by itself, respectively. The combined use of cottonseed protein and an acid (acetic, adipic, aspartic, and citric acids) to promote adhesion resulted in even greater dry paper strength but not in greater wet paper strength. Thermogravimetric analysis, infrared spectroscopy, and scanning electron microscopic studies suggested that the protein interacted with acid and that both components interacted with paper fibers to produce increased strength. [ABSTRACT FROM AUTHOR]

A state-of-the-art, ultrasensitive, paper-based SERS sensor has been developed using silver nanostars (AgNSs) in combination with synthetic and natural antibodies. A key component of this innovative sensor is the plastic antibody, which was synthesized using molecularly imprinted polymer (MIP) technology. This ground-breaking combination of paper substrates/MIPs with AgNSs, which is similar to a sandwich immunoassay, is used for the first time with the aim of SERS detection and specifically targets nucleolin (NCL), a cancer biomarker. The sensor device was carefully fabricated by synthesizing a polyacrylamide-based MIP on cellulose paper (Whatman Grade 1 filter) by photopolymerization. The binding of NCL to the MIP was then confirmed by natural antibody binding using a sandwich assay for quantitative SERS analysis. To facilitate the detection of NCL, antibodies were pre-bound to AgNSs with a Raman tag so that the SERS signal could indicate the presence of NCL. The composition of the sensory layers/materials was meticulously optimized. The intensity of the Raman signal at ∼1078 cm−1 showed a linear trend that correlated with increasing concentrations of NCL, ranging from 0.1 to 1000 nmol L−1, with a limit of detection down to 0.068 nmol L−1 in human serum. The selectivity of the sensor was confirmed by testing its analytical response in the presence of cystatin C and lysozyme. The paper-based SERS detection system for NCL is characterized by its simplicity, sustainability, high sensitivity and stability and thus embodies essential properties for point-of-care applications. This approach is promising for expansion to other biomarkers in various fields, depending on the availability of synthetic and natural antibodies. [Display omitted] • Use of sandwich methods for the detection of nucleolin by surface-enhanced Raman scattering (SERS), including plastic and natural antibodies. • Use of plastic antibodies (molecularly imprinted polymers, MIPs) to capture nucleolin. • Assembly of plastic antibodies directly on cellulose paper substrates. • Capture of nucleolin by MIPs followed by binding to antibodies on silver nanostars. • SERS detection by a Raman probe connected to the silver nanostars. [ABSTRACT FROM AUTHOR]

Coatings contribute to about 10% of the overall cost of paper production of which, the binder is the highest cost component in the formulation. In addition to costs, the binders that are currently being used are synthesized from fossil fuel feedstock raising concerns towards the sustainability of paper coatings. Furthermore, papers coated with waxes, polyolefins and other synthetic materials are difficult to recycle or compost. These challenges inherent with synthetic binders can be addressed by using renewable, plant based binders. This research focused on an abundant and underutilized source of hemicellulose based binders (DG gum) that can be extracted from distiller's dried grains. The extracted binder was compared with polyvinyl alcohol (PVA) in a coating formulation consisting of 10:1 CaCO 3 to binder formulation coated on light weight paper. Cobb test, dry and wet tensile tests, optical properties (brightness, color, opacity), water vapor transmission rate (WVTR) analysis were performed to compare the hemicellulose based binder with PVA. The results indicate water absorptivity reduction by 25% for both DG gum and PVA coatings from the base paper value. Dry tensile index was lower with higher coating weights for both coatings with similar performance. The performance on WVTR analysis for both coatings was also comparable. No significant differences in optical properties after coating were observed from that of the base paper. These results suggest that hemicellulose based binder extracted from distiller's grains has the potential to replace synthetic binders in paper coating formulations. [ABSTRACT FROM AUTHOR]

Abstract: Bacterial cellulose was combined with wood cellulose papers in order to obtain biomaterials with increased barrier properties. For this purpose, different parameters were assessed: two producing bacterial strains (Komagataeibacter xylinus and Gluconacetobacter sucrofermentans), two paper supports to hold bacterial cellulose (filter paper and eucalyptus paper), two kinds of combined biomaterials (composite and bilayer) and two drying temperatures (90 °C and room temperature). Papers with increased barrier properties (100° of water contact angle, 1220 s of water drop test and air permeability < 1 µm (Pa s)−1) were obtained by the addition of bacterial cellulose to each paper support. However, due to the lower initial barrier properties of filter paper, higher improvements were produced with this paper. In addition, bacterial cellulose provided smoother surfaces with higher gloss without a detrimental effect on physical properties. Higher resistance to water absorption was obtained with K. xylinus possibly explained by its longer size fibers than G. sucrofermentans, as analysed by SEM. Smoothness and gloss were specially increased in the bilayer biomaterial although resistance to air and water were further improved in the composite. In this biomaterial drying at high temperature had a detrimental effect. SEM analysis of the products obtained showed the intimate contact among fibers of bacterial cellulose and wood paper. Results obtained show the contribution of bacterial cellulose to improve the properties of paper and its potential for the design of new added value paper products from biomass.Graphical abstract: [ABSTRACT FROM AUTHOR]

Nonwoven membranes based on electrospun fibers are of great interest in applications such as biomedical, filtering, and protective clothing. The poor mechanical performance is a limitation, as is some of the electrospinning solvents. To address these problems, porous nonwoven membranes based on nanofibrillated cellulose (NFC) modified by a hydroxyethyl cellulose (HEC) polymer coating are prepared. NFC/HEC aqueous suspensions are subjected to simple vacuum filtration in a paper-making fashion, followed by supercritical CO(2) drying. These nonwoven nanocomposite membranes are truly nanostructured and exhibit a nanoporous network structure with high specific surface area, as analyzed by nitrogen adsorption and FE-SEM. Mechanical properties evaluated by tensile tests show high strength combined with remarkably high strain to failure of up to 55%. XRD analysis revealed significant fibril realignment during tensile stretching. After postdrawing of the random mats, the modulus and strength are strongly increased. The present preparation route uses components from renewable resources, is environmentally friendly, and results in permeable membranes of exceptional mechanical performance.

Along with the developing of flexible electronics, there is a strong interest in high performance flexible energy storage materials. As natural carbohydrate polymer, cellulose fibers have potential applications in the area due to their biodegradability and flexibility. However, their conductive and electrochemical properties are impossible to meet the demands of practical applications. In this study, cellulose fibers were combined with polyaniline to develop novel paper-based supercapacitor electrode material. Cellulose fibers were firstly coordinated to Cu(II) and subsequently involved in polymerization of polyaniline. Not only the mass loading of polyaniline was significantly increased, but also an impressive area specific capacitance (2767 mF/cm2 at 1 mA/cm2) was achieved. The developed strategy is efficient, environmentally friendly, and has implications for the development of cellulosic paper-based advanced functional materials. [Display omitted] [ABSTRACT FROM AUTHOR]

Acid‐catalyzed hydrolysis of glycosidic bonds is the most important degradation mechanism affecting cellulose‐based materials. It results in the decrease of DP and in the loss of the original mechanical properties. The neutralization of acidity is therefore one of the most efficient ways to hamper the degradation of cellulosic artworks. However, in the case of acidic and strongly degraded artifacts, in addition to deacidification, a consolidation treatment must be performed. To this aim, a new class of biopolymers, obtained by a synthetic procedure that considers the principles of Sustainable Chemistry, was investigated. Three allyl saccharide/vinyl acetate copolymers, having different molar ratios between starting monomers, were prepared using α,α'‐trehalose, and used to synthesize the corresponding allyl saccharide/vinyl alcohol copolymers. The use of saccharide derivatives as monomers improves the affinity and compatibility of the biopolymer with the artifacts to be treated. After characterization, the efficacy of the copolymers in the strengthening of degraded paper was evaluated with mechanical tests. The most effective system was thus selected for further testing. Its performance was compared to that of Klucel G®, a commercial product belonging to the class of cellulose derivatives, which are largely used in conservation practice. [ABSTRACT FROM AUTHOR]

Herein we are reporting, the in-situ synthesis of polydopamine capped silver nanoparticles (PDA-AgNPs) and its cysteamine (CYS) and tetracycline (TC) drugs sensor applications. The synthesized PDA-AgNPs was characterized by UV–Visible, Fourier Transformed–Infrared, X-Ray Diffraction, Zeta Potential, and High Resolution-Transmission Electron Microscope techniques. We have utilized PDA-AgNPs as probes for the detection of CYS and TC by spectrophotometry method. The addition of CYS has led to a decrease in the absorption of PDA-AgNPs. The yellow color solution becomes colorless and observed the aggregated particles in the TEM image. In contrast, the addition of TC, into the same solution, absorption of PDA-AgNPs was increased. The color of the solution became dark yellow and the particles are obtained de-aggregation. Based on the Surface Plasmon Resonance (SPR) band absorption changes, the detection limit of CYS and TC was calculated to be 180 nM and 17 nM, respectively. Interestingly, 600-fold of common interferences did not interfere with the detection of CYS and TC. PDA-AgNPs was successfully utilized to detect CYS and TC in serum, urine, and drug samples. Finally, we have prepared a paper-based colorimetric kit for on-site monitoring of CYS and TC. [ABSTRACT FROM AUTHOR]

In continuation of previously reported results, the ionic liquid 1,5-diazabicyclo[4.3.0]non-5-ene-1-ium acetate was also found to be a powerful non-derivatizing solvent for cellulosic waste such as paper and cardboard. The ionic liquid could dissolve all the present bio-polymers (cellulose, hemicellulose, and lignin) in high concentrations, resulting in solutions with visco-elastic properties that were suitable for dry-jet wet fiber spinning. The cellulosic raw materials were refined gradually to identify the influence of residual components on the spinnability of the respective solution. Polymer degradation and losses in the spinning process could be avoided nearly entirely. With the exception of virtually unrefined cardboard, all the samples showed excellent spinnability, resulting in fibers with high tensile strength. Prototype textiles were produced to validate the quality of the fibers and demonstrate the possibility of using residual lignin in cardboard as a natural dye. [ABSTRACT FROM AUTHOR]

Paper is one of the packaging materials that presents a biodegradable character, being used in several areas; however, its barrier properties (gases and fat) and mechanics are reduced, which limits its application. Coating papers with synthetic polymers improve these properties, reducing their biodegradability and recyclability. The objective of this work was to develop and characterize coated paperboard, using the tape casting technique, with different ratios of film form agar–agar/chitosan (AA:CHI, 100:0, 50:50, and 0:100) and different numbers of coating layers (operating times for application of 14.25 min and 28.5 min for one and two layers, respectively). A significant reduction in water absorption capacity was found by applying a 0:100 coating (approximately 15%). Considering all coating formulations, the water vapor permeability reduced by 10 to 60% compared to uncoated paperboard, except for two layers coated with 0:100. The tensile index (independent of AA:CHI) was higher in the machine direction (22.59 to 24.99 MPa) than in the cross-section (11.87–13.01 MPa). Paperboard coated only with chitosan showed superior properties compared to the other formulation coatings evaluated. [ABSTRACT FROM AUTHOR]