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With the development of printed electronics technology, the demand for printed conductive inks had also put forward higher standards. The shortcomings of traditional printed circuit boards, such as complex technology, consumables, and pollution, had also been resolved with the development of 3D printing technology. In this paper, low-content silver nanoparticles were blended with graphene alcohol slurry and dissolved in a non-polluting solvent such as absolute ethanol. The synergistic effect of the composite of the hexagonal structure of the graphene sheet and the silver nanoparticles improved the ink’s performance of electrical conductivity, adding water-based polyurethane/acrylic resin system to improve the adhesion between ink and paper. The conductive ink can be used to 3D print circuit circuits on paper. After drying, the resistance was measured. After the battery, diode, and switch were connected, a circuit diagram was made. After pressing the diode emits was lighted. This work is expected to be applied to flexible circuit boards to provide basic research.

In this study, the easy-to-operate silver mirror reaction (SMR) was used for metallizing chromatography paper. The SMR-metallized paper was characterized by water contact angle measurements, a surface profiler, x-ray photoelectron spectroscopy, UV–Vis spectroscopy, x-ray diffraction, and electrical resistance measurement. The characterization results show that Ag was successfully synthesized on cellulose fibers and was electrically conductive after cyclic bending. Moreover, this SMR-metallized paper was used as electrodes for fabricating a supercapacitor. This SMR-metallized paper could be used for realizing cost-effective flexible electronics applied in on-site biochemical sensing in resource-limited settings.

Paper-based microfluidics has been widely used in chemical and medical analysis applications. In the conventional paper-based microfluidic approach, fluid is propagating inside the porous structure, and the flow direction of the fluid propagation is usually controlled with the pre-defined hydrophobic barrier (e.g. wax). However, the fluid propagation velocity inside the paper-based microfluidic devices largely depends on the material properties of paper and fluid, the relative control method is rarely reported. In this study, a fluid propagation velocity control method is proposed for paper-based microfluidics: hydrophobic pillar arrays with different configurations were deposited in the microchannels in paper-based microfluidics for flow speed control, the result indicates the deposited hydrophobic pillar arrays can effectively slow down the fluid propagation at different levels and can be used to passively control the fluid propagation inside microchannels for paper-based microfluidics. For the demonstration of the proposed fluid control methods, a paper-based microfluidic device for nitrite test in water was also fabricated. The proposed fluid control method for paper-based microfluidics may have significant importance for applications that involve sequenced reactions and more actuate fluid manipulation.

The main idea of this research is to design a rechargeable paper battery from local cheap and available materials. The practical part is represented by adding Polyvinyl alcohol (PVA) to conductive polymer (PSS PEDOT) with adding different mineral salts for then study the quantum of electrical conductivity and heat influence on electrical conductivity and acidity factors of the Electrolyte solution.The next step was to produce a rechargeable, flexible battery manufactured from regular cellulose paper, sulfone, and ionic solution.The measurements were made using modern laboratory devices to study the electrical properties, conductivity, resistance (Hall Effect), and voltage quantum of the ionic solution. Through the results we obtained, we noticed an increase in the conductivity of the ionic solution when adding mineral salts. The voltage quantum of one battery ranged between 0.3-0.3 volts, also several batteries were connected in series, and the result was 1.8 volts. Manufactured paper batteries can be recharged with a direct current source and recover their efficiency marked up 98-99%.

Made available in DSpace on 2022-04-29T08:36:18Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-12-01 Paper electronics has emerged as an ecofriendly, light, low-cost, and recyclable material for the fabrication of flexible and printed transistors. In this study, we present fully printed organic electrochemical transistors using an active layer of PEDOT:PSS, carbon electrodes, cellulose-based electrolyte, and three different papers as substrates: bond, vegetal, and Lumi Silk, relating the electrical properties to the different morphologies of the paper surfaces. Each paper presents different regularity, diffusion capabilities, and roughness, with significant influence on the transistor performance. The more organized and smooth the surface, the better the electrical characteristics, the best of these being the Lumi Silk, with higher I on/I off ratio of 46, on-current of 8.3 10-5 A, V on of 1.3 V, and power gain of 43.5 dB associated with ultra-low hysteresis of 0.1 V, high transconductance of -57.3 μS, and suitablity for flexible electronics and sensors applications. S o Paulo State University - UNESP Faculty of Science and Technology (FCT) Physics Department, SP Universidade NOVA de Lisboa and CEMOP-UNINOVA Faculty of Science and Technology (FCT) CENIMAT/I3N Department of Materials Science S o Paulo State University - UNESP Faculty of Science and Technology (FCT) Physics Department, SP

Light-reflecting characteristics play a crucial role in optically rewritable liquid crystal display (electronic paper). By using a special optimizer software, light-reflecting characteristics of the twisted nematic cell were calculated. The achieved values of the normalized reflection coefficients range within ∼ 0.03 - 0.43, which is comparable or better than other commercial technologies. The calculated contrast ratio of the device is 10 : 1. A 2D image, which can be displayed on the electronic paper was obtained. Comparison of the simulated background color and contrast ratio is very similar with the results, which were obtained in experimental cells of other studies. Our calculations indicate that angular dependence of the reflectance coefficient is almost uniform within a wide range of viewing angles.

Convenient, rapid, and accurate detection of cardiac troponin I (cTnI) is crucial in early diagnosis of acute myocardial infarction (AMI). A paper-based electrochemical immunosensor is a promising choice in this field, because of the flexibility, porosity, and cost-efficacy of the paper. However, paper is poor in electronic conductivity and surface functionality. Herein, we report a paper-based electrochemical immunosensor for the label-free detection of cTnI with the working electrode modified by MXene (Ti3C2) nanosheets. In order to immobilize the bio-receptor (anti-cTnI) on the MXene-modified working electrode, the MXene nanosheets were functionalized by aminosilane, and the functionalized MXene was immobilized onto the surface of the working electrode through Nafion. The large surface area of the MXene nanosheets facilitates the immobilization of antibodies, and the excellent conductivity facilitates the electron transfer between the electrochemical species and the underlying electrode surface. As a result, the paper-based immunosensor could detect cTnI within a wide range of 5–100 ng/mL with a detection limit of 0.58 ng/mL. The immunosensor also shows outstanding selectivity and good repeatability. Our MXene-modified paper-based electrochemical immunosensor enables fast and sensitive detection of cTnI, which may be used in real-time and cost-efficient monitoring of AMI diseases in clinics.

This paper presents the integration process of an ultra-thin PZT/Si chip on paper and that it functions as a simple speaker by applying a voltage in the audible frequency range. The PZT/Si chip used is only 5-μm-thick, so it does not interfere with the flexibility of the substrate, and it can be integrated on paper because it does not use a high-temperature process in the electrode connection process. We have revealed that a paper with an ultra-thin PZT/Si chip of only 1 × 5 mm2 in size generates a fully audible sound pressure level (SPL) of about 40 dB. It was rounded to a radius of curvature of 1 cm without breaking. The overall SPL was about the same even when the paper substrate dimension was reduced to 50 mm square. This technology is expected to be applied to electronic components such as surround speakers or haptics in electronic paper.

Smart materials and devices that possess multiple functions of sensing and actuation have been investigated over decades as being exploited for soft robots in various applications such as artificial muscles, biomimetic actuators, and surgical tools. One of critical requirements involved is the capability of dramatic change in shape and size to be adapted for different circumstances. Recent progress of the emerging materials has showed many remarkable properties to fabricate them in simple way. This paper reports a fused deposition modeling (FDM) method that can be simply implemented by three-dimensional (3D) printing shape memory polymer (SMP) on paper. Through 3D printing of a SMP filament on paper, the bilayer structures and grippers with a starfish shape were fabricated by exploiting the cost-effective and lightweight materials. By virtue of electrothermal actuation (Joule heating) with an electrical power supply, they showed remarkable and reversible change in shape during 100 cycles of movements. As a result, it demonstrated the capability of control over adaptive shape and size in design and fabrication of soft robots. The FDM-based method in the study is therefore beneficial to extend the flexibility in design and fabrication, as compared to the conventional ones particularly applied for rigid grippers. In the near future, a variety of multi-layer structures and materials fabricated by FDM method and 3D printing materials could be applied for applications such as soft actuators and sensors in versatile conditions.

Flexible photodetectors functionalized by transition metal dichalcogenides have attracted great attention due to their excellent photo-harvesting efficiency. However, the field of optoelectronics still requires advancement in the production of large-area, broad band and flexible photodetectors. Here we report a flexible, stable, broad band and fast photodetector based on a MoS2/WSe2 heterostructure on ordinary photocopy paper with pencil-drawn graphite electrodes. Ultrathin MoS2/WSe2 nanohybrids have been synthesized by an ultrahigh yield liquid-phase exfoliation technique. The thin sheets of WSe2, and MoS2 contain two to four layers with a highly c-oriented crystalline structure. Subsequently, the photodetector was exploited under ultra-broad spectral range from 400 to 780 nm. The photodetector exhibits excellent figure of merit such as on/off ratio of the order of 103, photoresponsivity of 124 mA W−1 and external quantum efficiency of 23.1%. Encouragingly, rise/decay time of about 0.1/0.3 s was realized, which is better than in previous reports on paper-based devices.

This experiment initially explored the clean production process of nanocellulose fibrils (NFC) using commercial softwood pulp as raw materials, and selected appropriate biological enzyme pretreatment to prepare NFC1 with a higher concentration. Compared with NFC2 obtained by TEMPO oxidation method, it is found that the diameter of NFC1 obtained by enzymatic pretreatment method (10-30nm) is similar to that of NFC2 (20-30nm). But the length of NFC1 (1-4μm) is much longer than the length of NFC2 (400-600nm). In addition, the influence of two kinds of NFC on the physical strength of paper is also explored. Experimental results show that: NFC1 is better than NFC2 in enhancing the physical strength of paper. And when cationic starch and NFC act synergistically, the enhancement effect is obviously better than using NFC alone or cationic starch alone. When the addition amount of NFC1 is (1.5±0.5)%, the tensile index, burst index, and tear index of the resulting paper increase by (43±3)%, (55±1)%, (37±2), respectively %. When the amount of NFC2 added is (1.5±0.5)%, the paper tensile index is (29±2)%. When the amount of NFC2 added is about (3±1)%, the paper’s bursting index and tearing index growth rate are (29±1)% and (33±1)% respectively.

The purpose of this research is to design a Whatman paper based sensor for quantitative measurement of iodide anion by its quenching effect on the fluorescence intensity of the nitrogen doped carbon quantum dots (N-doped CQDs) using a smart phone as a detection system. In this project, N-doped CQDs were synthesized by a hydrothermal method using citric acid as a source of carbon and hexamethylenediamine as a source of nitrogen. In order to characterize of the synthesized N-doped CQDs, Fourier transform infrared spectrophotometry (FT-IR), Energy-dispersive X-ray spectroscopy (EDX) and dynamic light scattering (DLS) was used. After designing of the paper based sensor, an aliquot of the mixture of the N-doped CQDs:Glue (glue roles as the stabilizing agent) was injected on the hydrophilic zone of the paper and then by injection of different concentrations of iodide anion, the reduction of the fluorescence intensity was measured using the smart phone camera. By optimizing the critical parameters affecting the quenching efficiency of the N-doped CQDs including the size of the hydrophilic zone, the volume ratio of the N-doped CQDs:Glue, type of the Whtaman filter paper and the pH of sample solution, the proposed method was used for determination of iodide ion. The results show that two calibration curves in the ranges of 1-10 and 15-200 mmol L-1 iodide were obtained for determination of iodide anion. Also, the detection limit (LOD) of 3 mmol L-1 and the relative standard deviation (RSD) in the range of 2.6-2.9 % were obtained for the iodide anion in the range of 50-150 mmol L-1. The main advantages of the propsed method are rapidity, inexpensively, simplicity, availability and no need of expert for operation.

Nanostructured dielectric composite has been considered as a promising manner in improving the flashover performance of oil-paper which has been widely used in power systems. In this paper, plasma-enhanced chemical vapor deposition (PECVD) is used to deposit SiO2 on the ceramic fiber-reinforced insulating paper. Scanning electron microscope images show a large number of SiO2 nanoparticles with diameters of 100 nm–250 nm uniformly attached to the fiber surface after the plasma deposition. The surface flashover voltage of the insulating paper was tested in the air and the transformer oil, respectively. Results show that the corresponding DC surface flashover voltages increased by 15.1% in the air and breakdown between liquid and solid interface increased by 24.6% after the PECVD. It is believed that nanoparticles constructed in ceramic fibers change the electron injection barrier which inhibits the injection of negative charges and hinders the accumulation of charges in the dielectric. Nanoparticles can capture electric charges formed in the transformer oil which affects the generation and development of streamers, resulting in an increased dielectric strength. This study provides a new method to comprehensively improve the surface insulating property which has the prospect of promoting other dielectric materials.

Recent Industry looking for paper battery with highly flexibility, easily handling and high voltage. Currently, battery occupies a large quantity of vicinity and contributes to a big part of device weight. In this paper, we use carbon nanotubes with conventional sheet of cellulose based paper as cathode, aluminum foil as anode and a polyethylene (plastic paper) of 50µm as a separator to obtain adaptability, ultra-thin electricity storage without a loss of integrity and performance. In this attempt folded anode and cathode sheets which resulted increase in voltage and achieved approximately 40% more than other paper batteries. Voltage 3.38V is achieved which is better than the preceding existing paper battery voltage.

Empty fruit bunches (EFB) is one of solid waste from crude palm oil (CPO) mill. It’s about 20-22% from fresh fruit bunches (FFB) or equal to the CPO yield. Indonesian CPO production in 2019 was 51.8 million tons; increased by 9% compared to 2018. So, about 51.8 million tons of EFB was available in 2019. EFB is a potential lignocellulosic material for pulp and paper. The utilization of EFB fibers for papermaking has been studied extensively. The use of EFB for printing and writing papers tends to cause pitch problems and poor visual appearance. The most potential use of EFB fibers is for packaging papers. EFB fiber is classified as short up to moderate fibers, so its usage must still be mixed with other fibers to improve the sheet strength. Many experiments have been done regarding the mixture of EFB fibers with other fibers such as OCC (Old Corrugated Containers) and UBC (Used Beverage Cartons) recycled fibers. Other types of paper from EFB are still being developed, including for nursery bags and active packaging papers.

Most papers are made from virgin wood-based pulp of hardwood sources but recently, softwood have received enormous attention as alternative to hard wood because the hardwood takes a significant number of years to mature enough for use in the pulp and paper industry unlike softwood which are majorly annual plants. The annual crop in focus in this work is the yellow open-pollinated variety of corn which generates tons of waste at harvest. A novel attempt is made to ascertain the viability of corn sheaths as raw material for the pulp and paper industry by carrying out a comprehensive analysis on the pulp and paper made from the pulp. The sheaths were dried, shred and cut into pieces suitable for the digester and the pulps obtained were analysed for physico-chemical properties. Hand sheets were also made using the generated pulp and its physico-mechanical properties were analysed. Results obtained were compared with pulp from corn husks from other parts of the country, three Nigerian fibre sources – silk cotton, bagasse and rice straw and other foreign non-wood sources and found to be of competitive properties. Pulp properties of Lignin content, ash content, cellulose, hot and cold water solubility of the fibres were 13.72 ± 1.21%, 1.27 ± 0.23%, 53.26 ± 1.11%, 15.20 ± 2.11 and 6.14 ± 2.43 respectively while the mechanical properties of paper from the pulp were Bursting strength (282.163 KPa m2/g), Tear strength (146.119), Tensile strength (257.6N/m) and Tensile Index (3.9Nm/g). It was found that in all properties, the corn sheath was better than the rice straw fibers but not as good as the silk cotton and bagasse fibers. However, the corn sheath has been identified, as a viable raw material for the pulp and paper industry in Nigeria.

High-performance electronics demand extremely sensitive piezo-resistive sensors with important features such as low-fabrication cost, easy implementation, low power consumption and high-pressure sensitivity over broad pressure range. Herein, we report a flexible piezo-resistive paper-based device functionalised by WSe2 nanosheets. An efficient and low-cost fabrication strategy using Whatman filter paper and tissue paper is adopted for versatile sensing applications. The WSe2 nanosheets were synthesized by high-yield and size-controlled liquid phase exfoliation technique. The flexible WSe2 nanosheets-paper sensor shows excellent response in broad pressure range of 1 Pa-100 kPa with exceptionally high sensitivity of 29.24 kPa-1, current responsivity of 70 and response time of 100 ms. The pressure sensor is also employed to recognize the pressure generated due to finger tapping. Encouragingly, the piezo-resistive sensors can also sense extremely small pressure differences of about 1.4 Pa generated by water drops.

Zinc oxide nanoparticles (ZnO–NPs) were synthesized and decorated simultaneously onto the glass fiber pre-filter paper (GF paper) by the sonochemical method without using any additional reagents (a ‘Green’ synthesis approach). ZnO–NPs decorated GF paper was characterized by electron, confocal laser scanning and atomic force microscopy, fourier transform infrared and atomic emission spectroscopy, X-ray diffraction, and thermogravimetric analysis etc. Due to the massive void volume space, exceptional dimensional stability, large thickness (790 μm) of the GF paper (unlike other paper materials) and ultrasonic irradiation effects, ZnO–NPs were decorated in the enormous amount (96 mg per paper) without causing any adverse effects on the GF paper. Such a huge amount decoration onto GF paper makes it multifunctional, fluorescencet (orange-pink color, 535–624 nm) under ultra-violet light (360 nm) and antibacterial. The antibacterial activity of the ZnO–NPs decorated GF paper was examined against Gram-positive bacteria Bacillus subtilis 168 and Staphylococcus aureus (MCC 2043, pathogenic). The outcomes from the antibacterial experiments revealed ∼99% (2 log) reduction in the survival of the filtered bacteria (B. subtilis) on the ZnO–NPs decorated GF paper due to the toxicity of ZnO–NPs on bacterial cells like cell shrinkage, cytoplasmic leakage, cell burst, etc. Multifunctional, ZnO–NPs decorated GF paper could be used for fluorescencet and antibacterial paper-based applications.

A novel solid state reaction method has been followed to prepare LiCoO2 (LCO) using micro porous filter paper as scaffolds. FT-IR spectroscopy confirms the vibration spectrum for the identification of CoO6 as well as LCO. XRD diffraction analyses confirmed the formation rhombohedral crystal system of the prepared LCO materials with R-3m space group. The sharp XRD diffractogram of filter paper scaffold LCO demonstrate its crystallinity and purity. The presence of high intensity (003) plane, formation of Co–O–Co linkage with (104) plane and splitting of (006)/(012); (108)/(110) planes confirm layered structure of the prepared LCO. FESEM demonstrate that the presence of micropores in the cellulose backbone of filter played significant role for the solid state reaction and can be used as a scaffold to change the morphology of LCO in the microstructural aspect. UV-visible spectroscopy study reveals that the band gap energy of filter papers assisted LCO are less than the LCO prepared directly from raw materials.

Using conductive interlayers to act as the "upper current collector" is a common strategy to suppress the shuttle effect in lithium-sulfur batteries. However, the current widely used interlayers generally have the disadvantages of poor conductivity and complicated fabrication. Herein, we report a novel carbon paper prepared by simple wet laid method. The as-prepared carbon paper exhibits excellent conductivity of 11.9 S/cm and 3D conductive structure. Finally, the carbon paper as an interlayer for lithium-sulfur batteries displays an initial capacity of 1091 mAh g-1 at C/5 rate, and remains 631 mAh g-1 after 200 cycles with a decay rate of 0.21% per cycle.

We have proposed and fabricated resistive-type flexible pressure sensors composed of multi-walled carbon nanotube thin films, liquid metal droplets, sponge rubber, and paper. The pressure sensor detects external pressure in the range of tens of kilopascals. The resistance change was found to be approximately 70% when a pressure of 100 kPa was applied. The sensor operation showed good reproducibility under cyclic applied pressure. The simple sensor structure and environment-friendly materials allow the sensor to be easily disassembled into its components, which are reusable and combustible.

Utilization of agro-based fibre for paper making has been the subject of interest in order to expand the usage of renewable resources as well as reduced the dependence on wood pulp. As one of the major countries in palm oil production, some of the waste from the oil palm plantation like the oil palm fronds, empty fruit bunches, and its leaf is a potential source of non-wood industry which can be used as raw material in the paper industry manufacture. This study was done to examine the potential of palm leaves to be used as a raw material of non-wood resources in the papermaking industry. In this study, sodium hydroxide (NaOH) pulping and process was employed to investigate the effectiveness of lignin removal for good fibre production. The concentration of the pulping agent was fixed at 7% at treatment of 1-7 hours to investigate the best condition for defibrillation of the cellulose fibre. Based on this study, it was found that the soda pulping produces fibre that can be molded into paper sheet without any binding agent. The morphology of the fibre observed under Scanning Electron Microscopy (SEM) shows that, soda pulping fiber consist of individual micro fibrils that are well separated. Both tensile strength and tear index gives highest value at 1.93 kg/cm2 and 37 Nm2/kg respectively at 7 hours treatment time. his reflects that lignin removal effectively occurred in soda pulping. Tensile strength found to increases with treatment time and both tensile strength and tear index of the paper falls within the value comparable to commerical non-wood paper. The paper produced has rough surface and has the potential to be develop for craft paper.

The goal of the research is to improve the surface states of kraft paper and to make coated kraft paper with wear resistance suitable for packaging material. Based on wear and coating mechanism, the research analyzed and compared the characteristics and microstructure of uncoated paper and coated paper.The result shows that coating can reduce the surface resistance and friction of paper.Kraft paper was coated with the VaporCoatTM2200.s coating in the research. The research studied the influence of coating process on wear resistance of coated kraft paper.Two hundred groups of experimental datum of each sample show that the optimal coating weight is 18g/m2. As expected, coated kraft paper has better wear resistance and other performance than the uncoated kraft paper. The results show that the coating technology is an inexpensive and environmentally friendly process. The research provides the theoretical basis and data supporting for packaging enterprises to produce the coated paper-based packaging materials with wear resistance.

As a powerful analytical tool of molecular detection, surface-enhanced Raman spectroscopy (SERS) has attracted great attention in varied fields. However, it has seriously impeded the development of SERS that the preparation process is generally complicated and traditional substrates lack eco-friendliness, economy and flexibility. Herein, we fabricated the inkjet-printed paper-based semiconducting SERS substrates for the first time via an inexpensive office inkjet printer with representative two-dimensional MoO3-x nanosheets ink. Compared with conventional substrates, these paper-based semiconducting substrates not only could meet the requirements of simple and large-scale preparation, but also realize efficient sample collection by merely swabbing the surface. We obtained the detection limit concentration of rhodamine 6G as low as 10-7 M. Furthermore, these flexible paper-based substrates were successfully applied to detect crystal violet and malachite green on the fish surface by swabbing. With immense potentiality in practical applications, the inkjet-printed paper-based semiconducting SERS substrates are expected to open a new prospect for SERS.

Thermal paper is a special type of paper that is coated with chemicals on the paper layer to change color when exposed to heat. When discovering fingerprints by using chemical reagents such as ninhydrin solution with thermal paper, it shows black staining background on the heat-sensitive front side. Thus, the latent fingerprints cannot be discovered. In this study, we have reported the first utilization of ninhydrin with water glue in different ratios for the development of latent fingerprints on the thermal papers. The results showed that at 0.020-0.060 g/mL of water glue in ninhydrin solution reduced the black strain after tested with thermal paper and made the appearance of the fingerprint more clearly. So, the detectable minutiae can be used for visualization and identification of latent prints. Using an Automated Fingerprint Identification System (AFIS), it is showed between 59-87 points of minutiae. As the results, this method could be used as an alternative method to developing latent fingerprints with non-hazardous materials, reduce costs and easy to find.

Computational simulation for the fluid flow in a paper based microfluidic system was performed and was experimentally validated in this work. Comsol Multiphysics based simulation was performed and the module used was species transport in porous medium. Two separate simulation for the reagent distribution and the interaction of sample with the immobilized reagent in paper based microfluidics devices were carried out. This was performed by varying the parameters such as adsorption constant, diffusivity and average velocity of fluid in the porous medium for finding the concentration profile. Finer mesh were used for the simulation which gives more accurate results with less computational time. The reagent distribution was experimentally validated by dropping methylorange indicator over Whatman filter paper.

This paper is devoted to study a structure of SiC-based materials using ultrasonic tomography method. The SiC-based materials were fabricated from preceramic paper using spark plasma sintering (SPS) method. Also as part of the study the Young's modulus and density of sintered materials were determined and the effect of sintering pressure changing to this parameters value was investigated. The preceramic paper is a composite material including a matrix of organic cellulose fibers and inorganic powder filler (SiC). The sintering temperature and pressure were 2373 K and 20-40 MPa, respectively. The holding time for the sintering process was 10 min. The density of sintered materials was investigated by the hydrostatic weighing method. Ultrasonic tomography was implemented using of single-channel sensor at 10 MHz frequency. © Published under licence by IOP Publishing Ltd. Russian Science Foundation, RSF: 19-19-00192 The research was supported by the Russian Science Foundation (grant No. 19-19-00192) as well as by

This work describes comparation two designs of a microfluidic paper-based analytical devices (µPADs) using a wax printing for fabrication of hydrophobic zones on the chromatographic paper and their application to the detection of lead in waste samples. Two different designs used in this research were distance-based method and analysis image method. Sodium rhodizonate in tartrate buffer solution (pH 2.8) solution are used as the colorimetric reagents for the direct naked eyed detection of lead(II) on µPADs. The detection of lead(II) concentration is conducted by measuring the distanceof a colored reaction product which propagate in the detection zone (design 1) and the change in color intensity on the µPADs is also used for the lead detection using ImageJ software to determine the RGB value (design 2). Related to both methods can be used to determine the concentration of lead(II) with a comparable coefficient of determination, but based on the analysis method, design one is a design that is very simple, easy, fast, inexpensive and only uses the naked eye for detection.

The electrophysical characteristics of experimental types of electrical insulating paper modified by bacterial cellulose made of nano-gel film Komagataeibacter xylinus, disintegrated in various ways, were studied. The advantage of composites over traditional electrical insulating paper made of pine cellulose is shown in terms of electrical and mechanical strength, sorption activity and heat resistance. The efficiency of using an industrial blender to grind bacterial cellulose has been confirmed, which significantly reduces the time of its high-quality grinding.

Issues related to the performance and processing remain a challenge when managing materials from renewable and natural resources. This study aims to show the potential of biopolymer film composite from cassava starch and carboxymethylcellulose to replace the synthetic coating and the area of studies are its barrier, mechanical and chemical properties. Fourier Transform Infrared analysis identified that only film containing CMC could act as antimicrobial agent carrier. The biopolymer film coated on the kraft paper with the presence of 30% v/v glycerol and 10% w/w CMC had the highest tensile strength, at 15 MPa. The film-coated paper also exhibited a hydrophobic surface with reduction of the contact angle from 104.95° to 96.33° for 120 seconds. Meanwhile, addition of turmeric oil into developed BF 3 showed insignificant changes in tensile strength but reduced the contact angle to less than 90°. Thus, the formulated coating materials can be used as an alternative green technology for paper coating used in food industry and can be classified as a form of active packaging.

High-permeability paper has a wide range of applications in air filtration media, packaging materials, sound insulation or insulation materials. However, there are still some limitations in the current method for preparing high-thickness and high-permeability paper. In this paper, NaOH/thiourea is used to gently treat wood pulp fibers to improve the bulk of paper. The effects of low temperature treatment time on the surface morphology and physical properties of the paper were investigated. The results showed that, with the increase of mild pretreatment time, the length of fiber decreased slowly, the content of fine fiber was less, and the fiber became swollen and bent and kinky. The effect of thiourea dosage on fiber was further investigated when the treatment time was 20 min. The results showed that when the treatment condition was NaOH of 8 wt% and thiourea of 8 wt%, the length was shorten by 14.51%, the fine fiber content was reduced by 60.62%, and the surface etching phenomenon was aggravated compared with the untreated fiber. The SEM and AFM analysis showed that the fiber surface was obviously folded and the roughness increased by 158%. At the same time, the bulk of paper increased by 39.53% and the average pore diameter of the paper increased from 28.79 μm to 49.62 μm, the air permeability increased by 105.38%. FT-IR indicated no new changes in the chemical structure after treatment. XRD indicated that the fiber crystallinity after treatment decreased by 2.17%.

As a new kind of paper-based textile materials and thanks to its healthiness and environmental protection, the paper yarn and its production will have a good future. This study mainly explores the papermaking process as follows: the beating degree of hemp pulp is 75°SR, the addition amount of PVA fiber, polyamide polyamine epichlorohydrin (PAE) and alkenone dimer (AKD) is 2.0%, 2.5% and, 0.2%, respectively. In addition, the pressure light pressure is 15 N/mm. The high hydrophobic paper yarn base paper has the wear resistance, water resistance, acid and alkali resistance. The analysis shows that the paper yarn base paper can be used as raw material in textile and weaving industries, thus reducing the use of viscose, polyester, plastic, etc.

H1 NMR relaxometry is a method that is extremely sensitive to the presence of magnetic nanoparticles, which significantly affect the transverse relaxation time of the water proton. Accordingly, the use of magnetic nanoparticles as labels allows detection of even extremely small amounts of the test substance. This paper analyzes the prospects for applying the method of solid-phase NMR-relaxometric determination of biologically active molecules. The nitrocellulose membranes are chosen as a solid phase and nanoparticles based on iron core with a carbon shell are used as magnetic labels. The possibility of detecting small concentrations of magnetic particles in porous medium is demonstrated. Finally, the ability to detect extremely low concentrations of an analyte, in this case, streptavidin protein (0.5 ng/ml to 100 ng/ml), which is actively used in various fields of biology and medicine, is demonstrated. © Published under licence by IOP Publishing Ltd. Russian Science Foundation, RSF: 17-15-01116 The work was carried out within the Russian Science Foundation project 17-15-01116. equipment of the Ural Center for Shared Use Modern nanotechnology UrFU was used.

In chemical pulping process, lignin is targeted to be dissolved and eliminated as much as possible in order to obtain better fiber separation. A primary study was carried out to investigate the effect of sodium hydroxide pretreatment prior to bamboo chemical pulping. The selected bamboo species was Gigantochloa scortechinii which is a well-known bamboo in Malaysia. The bamboo chips were soaked in 2 % sodium hydroxide solution for 6 hours at 60 °C. These treated chips were cooked at 14 % and 18 % of alkali active via kraft pulping process. The unbleached pulp was obtained and made into paper. The pulp and paper were tested according to pulp yield, pulp freeness, paper optical, paper physical and paper mechanical properties. The results exhibited that by using treated bamboo chips, the value of pulp yield, freeness and paper brightness increasing. Slight decrement was observed for mechanical paper properties such as tensile, tear and burst strength. Chemical pretreatment prior to pulping process was investigated to offer significant effects to the pulp and paper properties of bamboo Gigantochloa scortechinii. Hence, mild kraft pulping can be carried out to produce bamboo unbleached pulps. In addition, dependency on bleaching sequences can also be declined.

Papers are one of the most used materials in food packaging industries. Additives need to be added in order to improve and prolong sensory properties of food. This is to maintain the food quality level before reaching to the end users. A preliminary study has been conducted to produce antimicrobial paper by blending the pulps of Citronella (Cymbopogon nardus) with oil palm empty fruit bunch (EFB). The papermaking was done according to TAPPI Standard Method. Morphological observation using Scanning Electron Microscope was carried out for all samples while physical, optical and mechanical paper properties were also determined. A simple antimicrobial test was also done by using 3 types of fungus namely as Aspergillus brasiliensis ATCC 16404, Gram positive Escherichia coli ATCC 25922 and Salmonella choleraesuis (subtype enterica). The morphological observation showed the difference between EFB paper and paper made of blended pulps. Citronella was found to affect the physical, optical and mechanical paper properties as expected. To be specific, the paper opacity was improved while the mechanical properties especially tensile and tear indices were dropped tremendously. However, the presence of Citronella in the paper sheet seems to have good potential as an antimicrobial agent as shown by the antimicrobial test

The paper-based photodetector has recently captivated a great deal of attention in various opto-electronics applications because of facile, cost effective and green synthesis. Two-dimensional transition metal dichalcogenides materials are promising for photodetection under the broad spectral range. In this work, we have fabricated paper-based device by rubbing the tungsten di-selenide (WSe2) crystals on paper substrate. Low-cost, facile and green synthesis technique was employed to make a high-performance paper-based WSe2photodetector. Paper-based photodetector was fabricated via non-toxic simply rubbing process of WSe2nanosheets on low-cost bio-degradable paper. The photodetector shows good responsivity of 72.5 μA W-1and detectivity at around 2.4 × 107Jones at very low bias (1.0 V) at wavelength of 780 nm, respectively. Due to good photo-absorption strength, photodetector exhibits excellent photo-response over wide wavelength range from visible to near infrared. This device also shows very good flexibility with a stable photo-response. This device shows a general and reliable study for the design of photodetectors that is eco-friendly and cost-effective. Overall studied results of the fabricated device indicate that they have the ability to be used in large-scale preparation of the device.

Palm Oil Fly Ash (POFA) has been considered as a potential source of silica for paper filler. The objective of this work is to prepare a filler from the Palm Oil Fly Ash (POFA) to reduce disposal and waste problem. The extraction of silica from POFA can be carried out using solution of 5 M NaOH with ratio 1:5 (w/w, with respect to POFA), stirring speed of 600 rpm for 4 hours, resulting the 0.8770 M silica in Na2SiO3. The product is then reacted with Ca(OH)2 to produce paper filler (CaSiO3). The filler was characterized with Fourier Transform Infrared (FTIR), Scanning Electron Microscope-Energy Disperse X-Ray (SEM-EDX), X-ray Diffractometer (XRD) and Particle Size Analyzer (PSA). FTIR spectrum showed the formation of OH, C = O, Si-O-Ca and Si-O-Si functional groups, whereas the SEM-EDX analysis revealed the porous surface with the aggregation of needle-like morphology and contained five elements such as O (45,14%), Mg (0,85%), Si (15,65%), Ca (36,77%) and Al (1,59%). Meanwhile, XRD spectroscopy showed the presence of calcium silicate, calcite, vaterite, calcium hydroxide and quartz. Data from PSA analysis indicated that the filler has narrow particle size distribution compared with commercial fillers (GCC & PCC) and has small average particle size compared with PCC. The filler and the commercial counterparts were then applied as a paper simulation (hand sheet). Analysis of hand sheet showed that the presence of the synthetic filler in the hand sheet can improve brightness, opacity and bulk values, but slightly reduced in tensile and tearing index compared to that of PCC & GCC.

The insulation state of the converter transformer is closely related to the properties of the oil-paper insulation material. The study of the partial discharge characteristics of the wrinkled of the insulation paper has practical engineering significance for the fault diagnosis of the converter transformer. According to the actual operating environment inside the converter transformer, a set of oil-paper-insulated partial discharge measurement platform under the action of AC and DC composite voltage was built. The test results show that insulation paper wrinkles under the action of AC/DC composite voltage will cause insulation damage due to higher surface electric field and partial discharge; the discharge pulse repetition rate and discharge volume increase in the initial stage, development stage and final dangerous stage of discharge. The partial discharge caused by paper wrinkled significantly increases the CH4 content in the dissolved gas in the oil. This conclusion provides a certain basis for the realization of converter transformer fault diagnosis and condition monitoring.

Two-step activation of paper batteries has been successfully demonstrated to provide quick activation and to supply high power to credit card-sized biosystems on a plastic chip. A stack of a magnesium layer (an anode), a fluid guide (absorbent paper), a highly doped filter paper with copper chloride (a cathode) and a copper layer as a current collector is laminated between two transparent plastic films into a high power biofluid- and water-activated battery. The battery is activated by two-step activation: (1) after placing a drop of biofluid/water-based solution on the fluid inlet, the surface tension first drives the fluid to soak the fluid guide; (2) the fluid in the fluid guide then penetrates into the heavily doped filter paper with copper chloride to start the battery reaction. The fabricated half credit card-sized battery was activated by saliva, urine and tap water and delivered a maximum voltage of 1.56 V within 10 s after activation and a maximum power of 15.6 mW. When 10 k? and 1 K? loads are used, the service time with water, urine and saliva is measured as more than 2 h. An in-series battery of 3 V has been successfully tested to power two LEDs (light emitting diodes) and an electric driving circuit. As such, this high power paper battery could be integrated with on-demand credit card-sized biosystems such as healthcare test kits, biochips, lab-on-a-chip, DNA chips, protein chips or even test chips for water quality checking or chemical checking.

Owing to their very high thermal conductivity as well as large surface-to-volume ratio, graphene-based films/papers have been proposed as promising candidates of lightweight thermal interface materials and lateral heat spreaders. In this work, we study the cross-plane (c-axis) thermal conductivity (k c ) and diffusivity (α c ) of two typical graphene-based papers, which are partially reduced graphene paper (PRGP) and graphene oxide paper (GOP), and compare their thermal properties with highly-reduced graphene paper and graphite. The determined α c of PRGP varies from (1.02 ± 0.09) × 10−7 m2 s−1 at 295 K to (2.31 ± 0.18) × 10−7 m2 s−1 at 12 K. This low α c is mainly attributed to the strong phonon scattering at the grain boundaries and defect centers due to the small grain sizes and high-level defects. For GOP, α c varies from (1.52 ± 0.05) × 10−7 m2 s−1 at 295 K to (2.28 ± 0.08) × 10−7 m2 s−1 at 12.5 K. The cross-plane thermal transport of GOP is attributed to the high density of functional groups between carbon layers which provide weak thermal transport tunnels across the layers in the absence of direct energy coupling among layers. This work sheds light on the understanding and optimizing of nanostructure of graphene-based paper-like materials for desired thermal performance.

The partial discharge in lower porcelain shell of oil paper insulation bushing is one of the important reasons for transformer failures. Based on the analysis of the oil paper insulation bushing structure characteristics, the finite difference time domain simulation model of the partial discharge in lower porcelain shell is established. And the path of UHF signal of partial discharge is obtained that the signal spreads through the insulation between capacitor screens and oil passage to the outer space. Then the lower porcelain shell partial discharge detection method based on the space UHF signal is proposed and verified.

The authors of the title paper (Mater. Res. Express 6 (2019) 116213) claim to have grown a nickel boro phthalate (NBP) crystal by the slow evaporation method. A critical analysis of the paper reveals that the so-called NBP is an improperly characterized material. A reinvestigation of the crystal growth reaction has been performed to unambiguously characterize the product. In this letter to the Editor, it is proved that nickel boro phthalate neither contains nickel nor phthalate but is, in fact, boric acid.

Low concentration of biomarkers (proteins, nucleic acids, metabolites) is a major concern in early disease diagnosis due to the very low concentration of these biomarkers at the early stage of any disease. This challenge can be addressed by preconcentrating the biomarkers to improve the sensitivity of the diagnostic device. This paper describes a novel method to preconcentrate the charged molecules on paper using greenly synthesized iron nanoparticles. The iron nanoparticles were synthesized by utilizing plant extract as stabilizing agent, which both minimizes the cost and protects the environment. Three different samples of the nanoparticles were prepared by changing the charge or attaching a functional group (amine) to the surface. The iron nanoparticles act as a charged nanoporous membrane when deposited on the paper pads inducing electrostatic forces around the membrane leading to the concentration of the charged analytes near the boundary of the membrane. Crystal violet was used as a surrogate for the charged biomolecule. We report ∼24-fold increase in the concentration of crystal violet dye within 120 seconds using the positively charged membrane and the 0.2 mM dye solution. The developed experimental set-up eliminates the need for external pumping device and complex fabrication processes making the proposed method cost-effective, environment-friendly, and simple to use.

In this study, a novel paper biosensor based on Fe3O4@SiO2–NH2 magnetic polymer microspheres and multi walled carbon nanotubes (MWCNTs) for rapid detection of pseudorabies virus (PRV) was first developed. Fe3O4@SiO2–NH2 were functionalized with PRV antibody and doped in cellulose nitrate paper to fabricate the magnetic paper biosensor with good magnetic response and biocompatibility. Using MWCNTs to build conductive network of sensors, PRV antigen binds specifically to the immunomagnetic microspheres on the sensor, and the resulting immune complex changes the magnetic domain structure of the sensor and the structural gap of MWCNTs, causing the magnetic property and impedance change. TEM and EDS characterization proved that the biosensor was successfully doped with Fe3O4@SiO2–NH2 and effectively recognized PRV. Under optimized conditions, the impedance variation was found to be linearly related to the logarithm value of PRV concentrations in the range of 10–1 mg ml−1, with the detection limit of 10 ng ml−1. This paper biosensor demonstrated advantages of portability, high sensitivity and specificity, providing a valuable method for early control of PRV.

In this paper, a simple method for preparing high stability superhydrophobic paper with pH-induced wettability transition was proposed. Firstly, the pH-responsive monomer 2- (dimethylamino) ethyl methacrylate (DMAEMA), the silicon-containing crosslinking monomer 3-trimethoxysilyl propyl methacrylate (TSPM) and the fluorine-containing monomer hexafluorobutyl methacrylate (HFMA) were polymerized to prepare the pH-responsive polymer PHFMA-PTSPM-PDMAEMA. Afterwards, the amino-modified SiO2 was grafted onto the polymer to provide roughness and then coated on the paper to prepare the superhydrophobic paper with pH-responsive properties. Further research found that the modified paper prepared by this method not only has strong stability and transparency, but also can realize the reversible regulation of superhydrophobic & lipophilic and super-oleophobic & hydrophilic properties under different pH-induction, and it has important application value in the field of oil-water separation in industrial applications.

The first urine-activated laminated paper batteries have been demonstrated and reported in this paper. A simple and cheap fabrication process for the paper batteries has been developed which is compatible with the existing plastic laminating technologies or plastic molding technologies. In this battery, a magnesium (Mg) layer and copper chloride (CuCl) in the filter paper are used as the anode and the cathode, respectively. A stack consisting of a Mg layer, CuCl-doped filter paper and a copper (Cu) layer sandwiched between two plastic layers is laminated into the paper batteries by passing through the heating roller at 120 °C. The paper battery is tested and it can deliver a power greater than 1.5 mW. In addition, these urine-activated laminated paper batteries could be integrated with bioMEMS devices such as home-based health test kits providing a power source for the electronic circuit.