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Paper‐based materials are widely used in various fields due to their advantages, such as environmental friendliness and sustainability. However, the highly hydrophilic nature of the cellulose that makes up paper‐based materials limits their use. In this paper, micron/nano‐graphite/polydimethylsiloxane (PDMS) coatings with excellent superhydrophobic and conductive properties were prepared on the surface of filter paper by a simple spraying method. A mixture of micro‐graphite and nano‐graphite was used to form a multistage rough structure on the surface of the filter paper by spraying, and the low surface energy PDMS enhanced the adhesion of the micro‐graphite and nano‐graphite on the surface of the filter paper. The results showed that the samples possessed the best superhydrophobic properties when the ratio of micro‐graphite to nano‐graphite was 1:1, at which time the contact and rolling angles of the samples were 165.4° and 3.2°, respectively. The prepared superhydrophobic samples have good bounce and self‐cleaning properties, while the samples have good mechanical stability and chemical resistance. Additionally, due to the conductivity of micro–nano‐graphite, both particle sizes closely contact the sample surface, creating a conductive network. With a 1:1 ratio of micro‐ and nano‐graphite, the coating exhibits minimal resistance at 1.89 KΩ, and the sample maintains stable conductivity even underwater. The above properties greatly extend the application range of paper‐based superhydrophobic materials. [ABSTRACT FROM AUTHOR]

It is crucial and significant to boost the utilization of renewable resources and exploitation of biodegradable materials alternative to petrochemical plastics. Waste paper, mainly composed of cellulose (82–95 wt%) and derived from the lignocellulose, is a type of abundant, renewable, and biodegradable resource, whose recycling use and conversion to high value‐added products can reduce the pressure on the environment and exert immense economic benefits. Herein, four kinds of common waste paper (e.g., printing paper, newspaper, straw paper and roll paper) were converted into cellulose‐based bioplastic membranes by using ionic liquid 1‐butyl‐3‐methyl‐imidazolium chloride as solvent. The cellulose‐based membranes are smooth and compact, and their mechanical strength is prominently improved about 3–100 times comparison with the original paper. The maximum tensile strength of the film (F4) is over 127 Mpa and its optical transmittance reaches 80% at 450–800 nm wavelength. Besides, this kind of cellulose‐based films have excellent biodegradability. Thus, the results demonstrated that the cellulose‐based bioplastic membranes stemmed from waste paper possess a magnificent application prospect. [ABSTRACT FROM AUTHOR]

Meta‐aramid paper is widely used in transformers because of its perfect heat resistance and dielectric properties. However, the loose structure and the voids of meta‐aramid paper may lead to lower breakdown strength, which will limit the applications of the insulated paper in harsh environment. Accordingly, it is urgent to enhance the dielectric breakdown strength of meta‐aramid paper. This work reports a simple and effective way to increase the breakdown strength of meta‐aramid paper. The paper was coated with salt‐free poly(m‐phenylene isophalamide) (PMIA) slurry and the solid contents of PMIA slurry were 4%, 6%, 8%, and 10%, respectively. To obtain salt‐free PMIA slurry, the meta‐aramid spun fibers were dissolved in dimethylacetamide. After coating 10% PMIA slurry on meta‐aramid paper, the paper demonstrated the best comprehensive performance. The tensile strengths in the cross and machine direction reached 40.67 and 90.76 MPa, which were increased by 29.93% and 20.16% compared with pristine paper. Meanwhile, the dielectric breakdown strength was up to 42.75 kV/mm (the breakdown strength of pristine paper was only 16.41 kV/mm). Because no crosslinking agent and adhesive were used, the coated meta‐aramid paper still maintained excellent properties. [ABSTRACT FROM AUTHOR]

Herein we report the development of bilayer‐coated‐paper with corn starch as the bottom layer and zein protein as the top layer. Two different methods were used for preparation of the coated paper, namely rod‐coating and dip‐coating techniques. The effect of the coating methods was studied by investigating the mechanical and barrier properties of the coated paper. A significant decrease of the water vapor and oxygen transmission rates at various temperatures and relative humidity conditions was observed. Considering the growing need for renewable and biodegradable alternatives to conventional plastics, the coated paper described herein may have strong potential for applications in the food packaging sector. [ABSTRACT FROM AUTHOR]

A transparent, bendable, high oxygen barrier cellulose‐based film was prepared, which has far better oxygen barrier properties than conventional polyethylene, polypropylene and cellophane materials. A series of regenerated cellulose films (RCs) were prepared from filter paper lacking oxygen barrier properties under different cellulose concentrations and gelation times. It was shown that the cellulose concentration and gel time had a greater effect on the oxygen barrier properties of RCs. When the cellulose concentration was 4 wt% and the gel time was 3 h, the RCs obtained the lowest oxygen permeability coefficient (OPC) down to 2.21 × 10−17 cm3 cm cm−2 s−1 Pa−1. The films have a tensile strength of 109.5 MPa, an elongation at break of 27.3% and a light transmission rate of 89%. In further, molecular dynamics simulations showed that when the filter paper was converted to RCs, the increase in hydrogen bonding and the decrease in free volume between cellulose chains caused a decrease in the diffusion coefficient of oxygen. As a novel biobased high oxygen barrier material, the film has broad application prospect in packaging and chemical industry. [ABSTRACT FROM AUTHOR]

As reported herein, a bilayer coating approach using poly(vinyl alcohol) (PVOH) and zein is employed to enhance the water vapor and oxygen barrier properties of paper materials. The coating was applied onto three different types of paper substrates to study the general applicability of this approach. The bilayer‐coated paper samples exhibited a reduction of up to 65% in their water vapor transmission rate in comparison to the corresponding uncoated paper substrates at 23°C and 50% relative humidity. In addition, the bilayer‐coated paper samples showed at least a 40‐fold decrease in oxygen transmission rate from that of the uncoated paper samples. In addition, the coated paper showed excellent thermal stability and mechanical properties. Scanning electron microscopy confirmed that the obtained coated paper has a smooth texture without pores. Pulp was recovered from the coated paper by washing with water/ethanol. Thus, this work provides a unique coated paper with excellent barrier properties and therefore has the potential for real‐world application as an alternative to single‐use plastics. [ABSTRACT FROM AUTHOR]

Air pollution caused by particulate matter (PM) poses an imminent threat to the global environment and public health. However, balancing the removal efficiency and pressure drop of most filter materials is difficult. Moreover, filter materials are non‐degradable and non‐recyclable, causing serious harm to the environment. Herein, a strategy to create fully degradable branched poly (lactic acid) (PLA) nanofibers based on electrospinning by adjusting the spinning solution properties was reported and branched PLA nanofibers were applied as nanofiber filter paper for air filtration materials. When the PLA and tetrabutylammonium chloride concentrations were 8 and 5 wt%, respectively, PLA nanofibers with branched structures were obtained. The obtained nanofibers possessed a small pore size (0.70 μm), high porosity (92.3%), appropriate mechanical properties, resulting in high PM0.3 removal efficiency (99.95%), low air resistance (79.67 Pa), and promising long‐term PM2.5 purification. Notably, branched T‐PLA‐5 nanofibers exhibited excellent filtration performance when applied to cellulose wood pulp paper. The filtration efficiency of the nanofiber filter paper remained stable above 85% for PM0.3 (32 L min−1) after 5000 backflushings. Thus, the preparation of such nanomaterials may provide new insights into the design and development of high‐performance degradable filtration materials for various applications. [ABSTRACT FROM AUTHOR]

A simple approach was developed to fabricate high‐performance MXene/cellulose (MC)‐based electromagnetic interference (EMI) shielding papers. The oriented MXene sheets located on one side of cellulose filter paper construct a continuous conductive layer, endowing the MC paper with high electrical conductivity (240.1 S/m) and excellent EMI shielding effectiveness (29.3 dB for 0.192‐mm thickness) at an MXene content of 0.72 vol%. Moreover, the EMI shielding effectiveness of four stacked MC papers reached 40.5 dB. This result means that 99.9911% of the microwave radiation is attenuated, and 0.0089% is transmitted, through the four‐piece MXene/cellulose filter papers. Therefore, MC paper has promising properties for excellent EMI shielding materials in current electronic devices. [ABSTRACT FROM AUTHOR]

Reported herein is an economical, plastic‐ and fluorine‐free coating approach for oil and water repellent paper substrates using blends of poly(vinyl alcohol) and chitosan‐graft‐polydimethylsiloxane copolymer. The obtained coated paper showed good water‐resistance, as evidenced by its low Cobb60 values of ~20 ± 2.1 g/m2 and high water contact angles of 119 ± 6.3 °. The kit rating of the coated paper was 7.6/12, indicating decent grease‐resistant properties as compared to the kit value of 0/12 for the uncoated paper. The coated paper is also repulpable as demonstrated by the complete washing off the coating from the coated paper. Giving the cost‐effective nature of the coating materials and good water and oil‐resistant properties of the coated paper, the approach developed here is commercially viable, and will offer a multitude of environmental benefits such as the elimination of microplastic‐ and PFAS problems associated with existing paper coatings. [ABSTRACT FROM AUTHOR]

The application of traditional cellulosic paper is limited because of its flammability, so it is necessary to explore new materials that can be used in the field of flame‐retardant paper. Based on the synergistic effect between fibers, flame‐retardant lyocell (FRL) and calcium alginate (FRL/Ca‐Alg) composite paper is prepared by a simple but efficient method. The thermal degradation process of the composite paper is analyzed by thermogravimetric (TG) and TG analysis coupled with Fourier transform infrared, the flame retardancy of the composite paper is analyzed by vertical flammability (VF) tests, limiting oxygen index test and cone calorimetry test, and the morphology of the residue after VF tests is observed by scanning electron microscopy. It is found that, the Ca‐Alg releases a large amount of CO2 before ignited, which delayed the ignited time of the composite paper; FRL reduces the effective combustion heat of composite paper during combustion, and the compact char formed by FRL effectively inhibits the smoldering of Ca‐Alg in the end stage of combustion. Based on these, the synergistic flame‐retardant effect of composite paper is proposed. [ABSTRACT FROM AUTHOR]