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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]

Renewable superhydrophobic materials have attracted great attention due to their extensive applications in the fields such as cost‐effective and biodegradable oil/water separation field. Herein, we reported an eco‐friendly and facile methodology to develop the superhydrophobic cellulosic paper by immersion method using the ethanol solution of stearic acid. Furthermore, the treated cellulosic papers showed super‐hydrophobicity with water contact angle (WCA) above 153°. Interestingly, this method can realize superhydrophobic‐hydrophilic conversion by simply adjusting the temperature and is amenable for different substrates and with the WCA of 114‐162°. More importantly, the utilization of fluorinated reagents has been avoided, thereby minimizing the production cost and improving safety and environmental aspects. Meanwhile, the modified natural cellulosic paper is applied for oil–water separation, and its separation efficiency was as high as 95% after 10 cycles, indicating the good reusability of stearic acid modified filter papers. Consequently, this simple strategy based on the stearic acid immersion method thus provided an easy conversion of superhydrophobic‐hydrophilic interface and provided facile strategies for conversion of commercial quantitative filter paper to functional materials for oil/water separation. [ABSTRACT FROM AUTHOR]

Flexible gas sensors made of polyaniline (PANI)‐reduced graphene oxide (rGO) nanocomposite were prepared using three different substrates, namely filter paper, cotton fabric, and weighing paper, through in‐situ reduction of GO and in‐situ polymerization of aniline. Preliminary analysis showed that the PANI/rGO coated on filter paper possesses a superior electrical conductance than PANI/rGO coated on cotton fabric and weighing paper. Such observation was attributed to the good attachment of the PANI/rGO nanocomposites onto the high‐density mesh‐like structure of the filter paper with rough surfaces. In contrast, PANI/rGO coated onto weighing paper and cotton fabric of different surface structures presented lower‐to‐almost negligible conductance. Accordingly, PANI/rGO filter paper was selected for the subsequent evaluation of gas sensing properties. The gas‐sensing performances of the PANI/rGO filter paper sensors indicated that the 5 wt% PANI/rGO (i.e., 5 wt% rGO) sample exhibited the best response of 306% for 500 ppm carbon dioxide (CO2) gas at room temperature with a recovery rate of 41.5%. On the other hand, the optimum recovery rate of 59.5% was identified at 0.5 wt% PANI/rGO sample which exhibited a response of 155%. Owing to the synergy effect, the PANI/rGO sensor outperformed the sensor made of pure PANI or pure rGO. [ABSTRACT FROM AUTHOR]

Cross‐linked cationic polyvinyl alcohol (CPVA) is obtained by solution polymerization using vinyl acetate (VAc) and N‐(isobutoxymethyl)acrylamide (IBMA) as main raw materials and free radical co‐polymerization using glycidyl methacrylate (GMA) and dimethylaminoethyl methacrylate (DM) as modified monomers. The structure is characterized by HNMR. The effects of DM monomer on the properties of CPVA are investigated. It turns out that CPVA dispersion is a Bingham fluid with good stability. The particle size of CPVA reaches minimum and the value is 147.2 nm, which is in favor of infiltration into the paper. It is more suitable for the DM dosage ranging from 2% to 2.5% in light of the mechanical properties of CPVA film. The obtained CPVA is amorphous and the degree of crystallinity is decreased. When used as surface sizing agent for paper, the water absorption of the sizing paper reaches minimum and the folding resistance reaches maximum when DM is 2.5%. The maximum dry and wet tensile indexes of the paper are increased by 190.71% and 331.09%, respectively. SEM results shows that the larger pores between the paper fibers are filled and cross‐linked after CPVA sizing, which is beneficial to the improvement of paper strength. [ABSTRACT FROM AUTHOR]

ABSTRACT: Conventional cellulosic paper, rendered electro‐conductive, may hold considerable promise for diversified applications in such areas as electro‐magnetic interference shielding and energy storage. Here, an electro‐conductive cellulosic paper was prepared by surface application of multi‐walled carbon nanotubes (MWCNTs)/polyaniline (PANI) nanocomposites onto a conventional base paper. MWCNTs/PANI nanocomposites were prepared by in situ polymerization of aniline with different contents of MWCNTs and used as electro‐conductive filler for the fabrication of electro‐conductive surface‐coated paper. The achieved MWCNTs/PANI nanocomposites exhibited a core‐shell structure, as evidenced by TEM. Effects of feeding ratios of MWCNTs on the rheological behavior of nanocomposite coatings, as well as the mechanical properties and electrical conductivity of surface‐coated paper were studied. Results revealed that the rheological behavior of the nanocomposite coatings showed strong dependence on the MWCNTs content. Moreover, both the electro‐conductivity and mechanical properties of surface‐coated paper were improved as a function of surface application of MWCNTs/PANI nanocomposites, particularly, in presence of an optimum content of MWCNTs. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46329. [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]

Although styrene acrylate emulsions (SAE) have demonstrated promising applications as surface sizing agents for paper, their strengthening effect on pulp fibers in papermaking is not clear. In this study, bagasse fibers, an agricultural waste, were treated with SAE to study the influences on the mechanical properties of the produced papers. SAE copolymers with hard chain (H‐PSA) and soft chain (S‐PSA) were prepared and added to bagasse pulp slurry at concentrations of 1%–4% by weight. The findings indicated that for the soft and hard copolymers, the glass transition temperatures were 19.5 and 26.8°C and their emulsion particle sizes were 166 and 182 nm, respectively. The copolymers strengthened the produced paper by wrapping around and forming a network of chemical and physical bonds with the pulp fibers. Papers treated with 3% H‐PSA exhibited the optimum improvement in tensile strength (38 MPa) and breaking length (67 m) by 13% and 64%, respectively. Treated papers were negatively affected by UV radiation due to phenyl groups spread along the chains. The copolymers demonstrated good wet‐strength properties achieved by self‐ and co‐crosslinked networks. The prepared paper sheets showed a preference for the mechanical properties of treated samples over the untreated ones. [ABSTRACT FROM AUTHOR]

With the implementation of plastic restrictions and the increasingly serious problem of environmental pollution, paper with green and recyclable characteristics is gradually becoming a substitute for packaging materials. However, the rich cellulose structure in the paper, which contains hydroxyl groups leading to its hydrophilicity, allows water molecules to penetrate the paper and disrupt the hydrogen bonds between cellulose, resulting in a decrease in mechanical properties. Therefore, waterproof coatings are crucial for paper‐based materials to be used in many applications. Based on this, the paper surface was chemically modified with castor oil‐based resin (CO‐590) monomer prepared by coupling agent and castor oil (CO). The results indicated that the modified paper with the contact angle (CA) of 114° had excellent waterproof performance and had a reduction by 40.3% in water vapor transmission rate (WVTR), but also its mechanical increased to 26.9 MPa and the decomposition temperature to 410.5°C. In addition, the coating on its surface could be removed in an alkaline solution and had a possibility to recycle blank paper in the future for manufacturing sustainable production. This work not only provides a method for preparing modified packaging paper, but also expands the application fields of materials. [ABSTRACT FROM AUTHOR]

In this study, paper coated with a polyamide film containing a molecularly imprinted polymer (MIP) of benzalkonium chloride (BKC) is prepared. Its BKC adsorption ability and selectivity for BKC adsorption are investigated. The MIP is prepared by agitating an ethylenediamine solution containing an azo initiator, BKC as a template material, and methacrylic acid (MAA) as the functional monomer. First, filter paper soaked in this mixture is impregnated with a cyclohexane solution of terephthaloyl chloride and a BKC–MAA–MIP‐containing polyamide film is prepared on the surface of the paper. Paper containing BKC–MAA–MIP adsorbs BKC. The paper with the highest BKC removal efficiency is prepared under the following conditions: 4 mL MAA functional monomer, 2.5 w/v% ethylenediamine, and 10 min MIP synthesis time. The paper with BKC–MAA–MIP selectively adsorbs BKC from a solution containing BKC, tetracycline hydrochloride, and caffeine. Thus, a polyamide film containing BKC‐MAA‐MIP formed on paper can effectively and selectively remove BKC from aqueous environments. [ABSTRACT FROM AUTHOR]

This study investigates the effect of 1,2,3,4‐butane tetracarboxylic acid (BTCA) crosslinking treatment on the electrical properties of poly‐p‐phenylene terephthalate (PPTA)/cellulose insulation paper to prepare a novel composite insulation paper with low dielectric constant and good electrical performance. Three‐layer PPTA/cellulose composite paper crosslinked by BTCA under various conditions, composite paper without crosslinking, directly mixed composite paper, and conventional Kraft paper are prepared. The morphology and surface chemical composition of the paper samples are characterized. Dielectric, mechanical, and thermal properties are investigated. Results show that the BTCA concentration of 0.2 mol L−1 with a 180°C curing temperature is the relatively superior crosslinking condition to prepare a novel composite with low dielectric constant and good comprehensive performance. The dielectric constant and loss of the novel composite paper decrease to 3.21 and 0.392 at 50 Hz. The tensile strength of the BTCA crosslinked three‐layer PPTA/cellulose composite paper (thickness: 130 μm) has reached 10.01 kN m−1, increased by 41.6% than the directly mixed composite paper. The novel BTCA crosslinked composite paper also shows improved thermal stability. The BTCA crosslinking proves to be a promising method to improve the dielectric properties and electrical performance of the PPTA/cellulose composite paper. [ABSTRACT FROM AUTHOR]

ABSTRACT The production of traditional cellulose paper not only consumes lots of timber, but also brings about some environmental issues. Therefore, it is being increasingly replaced by synthetic paper. In this study, ultrahigh molecular weight polyethylene (UHMWPE)/SiO2 synthetic paper with high application performance was prepared by the thermally induced phase separation method using mineral oil as diluent. The corresponding properties of synthetic paper, including surface morphology, overall porosity, tensile strength, thermal stability, acid and alkali resistance, whiteness, and inkjet print effect were investigated respectively. The results show that the overall porosity of UHMWPE/SiO2 synthetic paper is above 45%, and the tensile strength exceeds 4.3 MPa. UHMWPE/SiO2 synthetic paper also presents light weight, as well as good resistance to heat, acid and alkali. Meanwhile, the average whiteness of the samples is up to 91.8%. The sample K-50, which contains 31.5 wt % SiO2, takes on the best print performance caused by its dense surface and higher SiO2 content. It is indicated that UHMWPE/SiO2 synthetic paper has good market prospects in the color printing. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41529. [ABSTRACT FROM AUTHOR]