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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.

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.

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.

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.

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

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 large quantities of waste sludge produced by the pulp and paper industry present significant environmental challenges. In order to minimize the amounts of waste, the pulp sludge should be utilized for productive applications. In order to find feasible solutions, the sludge need to be characterized. In this study, the potential of using acid pretreatment and ashing method to determine the chemical compositions of the sludge is investigated. This study shows that acid pretreatment could be used to dissolve and determine the composition of CaCO3 in the pulp sludge. CaCO3 removal also facilitates the measurement of fiber and ash (clay) contents by using the ashing method. The optimum acid concentration used to completely dissolve CaCO3 was determined using a titration method. Using this method, the measurement of the chemical composition of the sludge sample revealed that it consisted primarily of CaCO3 (55% w/w), clay (25%, w/w), and fibers (18%, w/w). Based on these chemical compositions, potential utilization for the sludge could be determined.

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.

Low-velocity impact tests of unfilled and foam-filled Kraft paper honeycomb are carried out to investigate the effect of foam, indenter size and location of indentation on maximum or peak force and energy absorption capability. In this study, three indenter sizes (10mm, 12mm, 15mm) and three different locations of indentation (vertical edge, double wall and single wall) were used and compared. The test results show that the foam is given a significant increment of peak force and specific energy absorption to the honeycomb structure subjected to indentation load. The peak force and energy absorption capability also effected by indenter size which due to the contact area of indentation. As for the location of indentation, vertical edge gives highest peak force and energy absorption by the fact that vertical edge is the intersection of three walls of honeycomb cell.

Good combination of pulping variables is required to obtain the quality pulp and paper characteristics. Thus, in this preliminary work, naturally dried durian rind were pulped under Soda-Anthraquinone (Soda-AQ) pulping process with 18% to 22% alkali charge, 0% to 0.1% Anthraquinone (AQ) charge, 90 minutes to 150 minutes of cooking time and 150°C to 170°C to investigate the effect of pulping variables on the characteristics of the pulp and paper. Pulping condition with 0% of AQ charge was also conducted for comparison. Results indicated that the best screen yield percentage, reject yield percentage, freeness, drainage time, tear index, number of folds and optical properties were shown by the pulp produced with combination of the highest active alkali (22%), AQ charge (0.1%), cooking time (150 minutes) and cooking temperature (170°C) except apparent density, tensile index and burst index. This preliminary result shows that the optimum quality of durian rind pulp as a potential papermaking raw material pulp could be produced by selecting the good combination of pulping variables which influences the pulp and paper characteristics.

In this study, three parameters, namely the density of Kraft paper, the thickness of cell wall and the cell size of honeycomb were evaluated. A statistical analysis was performed to investigate the effect of the parameters on the specific compression strength(SCS) and specific energy absorption (SEA) of Kraft paper honeycomb. Based on the design of experiment, 27 configuration of Kraft paper honeycomb with different cell sizes (10mm, 15mm, 20mm), thicknesses of cell wall (1ply, 2ply, 3ply) and paper densities (80gsm, 120gsm, 175gsm) are subjected to quasi static compression loading. An analysis of variance (ANOVA) was used to examine the effect of each parameters and to obtain the optimum configuration of Kraft paper honeycomb. As a result, the thickness of cell wall shows as the most prominent parameter for specific energy absorption and specific compression strength. Meanwhile, the Kraft paper honeycomb with density 175gsm, 3 ply thickness of paper and 10mm cell size of honeycomb shows the optimum configuration with 724.80 J/kg of SEA and 9.35 MPa/kg of SCS.

Sodium hyaluronate (HA) stabilized curcumin-Ag (Cur-Ag) hybrid nanoparticles were prepared in the water–ethanol mixture under constant mechanical stirring condition. The obtained HA stabilized Cur-Ag hybrid nanoparticles were characterized by fourier transform infrared spectroscopy, UV–visible spectroscopy, and x-ray diffraction to confirm the formation and structural interactions. The obtained Cur-Ag hybrid nanoparticles showed spherical shape with their size range 5–12 nm that was increased with the increasing a amount of silver ions as confirmed by transmission electron microscopic analysis. Further, a fibrous cellulose filter paper was impregnated with these hybrid nanoparticles and chitosan (CS) as biopolymer via polyelectrolyte complexation. The morphological analysis confirmed the uniform distribution of hybrid nanoparticle system onto the cellulose fibers of the fibrous filter paper. As per disc diffusion method, the Cur-Ag hybrid nanoparticles impregnated CS-coated filter paper exhibited excellent antibacterial properties against gram-negative Escherichia coli (E.coli) bacteria compared to HA stabilized Cur only. Moreover, as prepared hybrid nanoparticles impregnated biocomposite system is eco-friendly with efficient antibacterial property and have good potential to be used in medical applications.

The objective of this study is to investigate the crushing strength of Kraft paper honeycomb with different thickness of cell wall and different cell size subjected to compression loading. At first, experimental tests were carried out on Kraft paper honeycomb with 10mm cell size and 0.6mm thickness of paper with different mass density (RO). Then, a finite element model was developed in order to study the effect of cell size and thickness of cell wall on crushing properties of Kraft paper honeycomb. Based on the simulation results, the cell size and thickness of cell wall of Kraft paper honeycomb influence the crushing properties of the honeycomb. Crushing strength increases with decreasing the cell size which for the range of the study, cell size 10mm shows the highest strength. Meanwhile, 0.4mm thickness of cell wall results the higher crushing strength of honeycomb. Also, higher density gives higher crushing strength where in this study is found for 2.236× 106 kg/mm3.

A preliminary test was conducted to investigate the characteristics of linerboard and corrugated medium paper made from durian rind waste. Naturally dried durian rinds were pulped according to Soda-Anthraquinone (Soda-AQ) pulping process with a condition of 20% active alkali, 0.1% AQ, 7:1 liquor to material ratio, 120 minutes cooking time and 170°C cooking temperature. The linerboard and corrugated medium paper with a basis weight of 120 gsm were prepared and evaluated according to Malaysian International Organization for Standardization (MS ISO) and Technical Association of the Pulp and Paper Industry (TAPPI). The results indicate that the characteristics of durian rind linerboard are comparable with other wood or non-wood based paper and current commercial paper. However, low CMT value for corrugated medium and water absorptiveness quality for linerboard could be improved in future. Based on the bulk density (0.672 g/cm3), burst index (3.12 kPa.m2/g) and RCT (2.00 N.m2/g), the durian rind has shown a good potential and suitable as an alternative raw material source for linerboard industry.

A porous carbon prepared from waste palm kernel shells has been applied as a new supercapacitor electrode material. Activated carbon was synthesized through a carbonization process at a temperature of 400 °C which has a particle size of 90 urn and provide a surface area of 301.482 m2g-1. Carbon from waste palm kernel shells was distributed on a sheet of carbon paper surface with a variation of carbon paper and palm kernel shells carbon mass ratio. From the results reported that the capacitance value was increased to 1331.8 uF in rolling method with addition of carbon palm shells mass have higher capacitance values than which was obtained in plate or sandwich method.

We report the preparation, reduction and characterization of GO paper that obtained by assembly of individual GO sheets. The free standing GO paper was prepared from 4 mg/ml GO dispersed in water, and following by evaporation of water and then detach from the petri dish. In order to obtained graphene-like film, the free-standing GO film then thermally reduced by heating the samples at 250°C at varied heating time. Characteristic and properties of the thermally reduced GO paper was measured by means of infrared spectroscopy, X-ray diffraction and EDS.

A cost effective and easy to fabricate stress sensor based on pseudo-Hall effect in Graphite on Paper (GOP) has been presented in this article. The four terminal devices were developed by pencil drawing with hand on to the paper substrate. The stress was applied to the paper containing four terminal devices with the input current applied at two terminals and the offset voltage observed at other two terminals called pseudo-Hall effect. The GOP stress sensor showed significant response to the applied stress which was smooth and linear. These results showed that the pseudo-Hall effect in GOP based four terminal devices can be used for cost effective, flexible and easy to make stress, strain or force sensors.

Paper-based microfluidics is an emerging field focused on creating inexpensive devices, with simple fabrication methods for applications in various fields including healthcare, environmental monitoring and veterinary medicine. Understanding the flow of liquid is important in achieving consistent operation of the devices. This paper proposes capillary models to predict flow in paper-based microfluidic channels, which include a flow accelerating hydrophobic top cover. The models, which consider both non-absorbing and absorbing substrates, are in good agreement with the experimental results.

Femtosecond laser ablation of freestanding reduced graphene oxide (rGO) paper and its mechanisms were investigated. An abnormal phenomenon was discovered: the ablated area remained unchanged for the rGO paper with an increasing number of pulses, which was found to be a general feature for a large range of laser fluences. We also studied femtosecond laser ablation of graphene oxide paper and highly oriented pyrolytic graphite film for comparison. Experimental results indicated that the abnormal phenomenon was unique to the rGO paper. As revealed by a combination of SEM, TEM, XRD and Raman techniques, femtosecond laser nonthermal ablation through rolling up of rGO nanoflakes, induced by the distinctive multi-level layer-by-layer structures and the ultrafast energy relaxation of the rGO paper, were considered to be responsible for the non-incubation effect.

Empty fruit bunches of oil palm is a by-product of the palm oil industry that contains a high element of carbon. This by-product can be processed into a conductive carbon paper that could be applied as fuel cell electrodes. Carbon paper for this application must be conductive, porous, and hydrophobic. Utilization of oil palm empty fruit bunches begins with the carbonization process at a temperature of 500°C that produced charcoal. It is followed by heating at temperature of 900°C and 1300°C. To obtain the carbon paper, powdered charcoal with polymer binder (PEG and EVA) were mixed in solvent and molded using tape casting method. This process successfully produced carbon paper with dimensions of ±(20x20) cm2 and a thickness of 0.1-0.3 mm. Properties of carbon paper were characterized and analyzed in terms of electrical conductivity, porosity, hydrophobic property, and microstructure. Polytetrafluoroethylene (PTFE), a hydrophobic agent, was treated on carbon paper to enhance the hydrophobicity of the carbon paper. PTFE coating on the surface of the carbon paper could change their physical properties. Carbon paper shows excellent properties in terms of porosity and hydrophobicity. Whereas, its electrical property needs to be improved further by increasing the pyrolysis temperature. But overall, this might show a potential GDL material for PEMFC.

In this study, a paper-gate transistor was developed to detect glucose using an extended-gate field-effect transistor (FET). A filter paper was used as an extended gate electrode, in which Au nanoparticles (AuNPs) modified with phenylboronic acids (PBAs) were included. PBA–AuNPs play an important role as a support to not only be entrapped in cellulose fibrils but also bind to the targeted glucose in a paper. The surface properties of PBA–AuNPs were investigated to elucidate the electrical properties of the paper-gate electrode using an absorption spectrum and a zeta potential analysis. Moreover, the paper-gate electrode enabled us to detect glucose at the micromolar level on the basis of the principle of FET devices. A platform based on the paper-gate transistor is suitable for a highly sensitive system to detect glucose in trace samples such as tears, sweat, and saliva in the future.

Two carbon fibers were first fabricated by one-step pyrolysis of papers (filter paper and facial tissue), and then employed as catalytic materials for counter electrodes in dye-sensitized solar cells (DSCs) to investigate their potential application. The results show that the microstructure transformation and main weight loss of both the papers are mainly happened in the temperature range of 300–400 °C. After pyrolysis at 800°C, the weight remaining of the filter paper and facial tissue is 1.92% and 4.95%, respectively. The obtained carbon fibers belong to an amorphous carbon consisting of the randomly oriented stacks of graphene sheets. The diameters of both the carbon fibers are about 10 μm, on which there are a certain amount of fine carbon nanofibers. The amorphous microstructure and unique fine nanofibers of the carbon fibers induce more excellent catalytic activity for triiodide ion reduction compared with the biochar (derived from poplar leaf) and the graphite. As a result, the carbon fiber based DSCs display obviously higher efficiency than the biochar or graphite based ones. The conversion efficiency of the DSCs employing the filter paper derived carbon fiber, facial tissue derived carbon fiber, biochar and graphite is 4.72%, 4.70%, 1.33% and 0.77%, respectively.

A statistical analysis was performed to evaluate the effect of factor and to obtain the optimum configuration of Kraft paper honeycomb. The factors considered in this study include density of paper, thickness of paper and cell size of honeycomb. Based on three level factorial design, two-factor interaction model (2FI) was developed to correlate the factors with specific energy absorption and specific compression strength. From the analysis of variance (ANOVA), the most influential factor on responses and the optimum configuration was identified. After that, Kraft paper honeycomb with optimum configuration is used to fabricate foam-filled paper honeycomb with five different densities of polyurethane foam as filler (31.8, 32.7, 44.5, 45.7, 52 kg/m3). The foam-filled paper honeycomb is subjected to quasi-static compression loading. Failure mechanism of the foam-filled honeycomb was identified, analyzed and compared with the unfilled paper honeycomb. The peak force and energy absorption capability of foam-filled paper honeycomb are increased up to 32% and 30%, respectively, compared to the summation of individual components.

Biomolecules (e.g., proteins and nucleic acids) as target analytes of microfluidic paper-based analytical devices (μPADs) are usually immobilized on a cellulose paper surface (with intrinsically anionic surface) through physical adsorptions by van der Waals forces and electrostatic interaction thanks to cationic patches on the biomolecule. However, the physical adsorption could lead to weak biomolecule-substrate binding strength and thus low biosensing performance. Benefitting from the abundance of hydroxyl groups on the cellulose paper, chemical modification based on specific surface chemistries is capable of biofunctionalization on the μPADs by providing functional groups for covalent bindings with the target biomolecule. There are many previous reports on chemical modifications of cellulose surface for improvement of biomolecule immobilization. Nevertheless, no study has been performed on experimental evaluation of modification efficiencies of various biofunctionalization methods in the context of biosensing applications. In this paper, we compare five surface chemistries for protein immobilization on μPADs made from pure cellulose paper. For each chemical modification method, surface analyses were first conducted to monitor the surface modification process. Then, paper-based fluorometry experiments and colorimetric enzyme-linked immunosorbent assays (ELISA) were carried out on paper substrates modified by the five surface chemistries to compare their efficiency of covalent protein immobilization. Finally, a stability experiment was carried out on the five types of surface-modified paper after 30-day storage. It was demonstrated that the potassium periodate (KIO4)-modified cellulose paper has the best performance with 53% increase in the signal output and 59% decrease in background noise of the colorimetric ELISA, and only 13% bioactivity loss after the 30-day storage. The comparison results provide valuable experimental guidelines for selecting the suitable surface chemistry for protein immobilization on μPADs.

This paper is devoted to fabrication of Ti3SiC2-based ceramic materials from preceramic paper using spark plasma sintering (SPS) method. The synthesis temperature and pressure were 1373-1473 K and 30 MPa, respectively. The phase composition, microstructure and elemental composition were analysed using X-ray diffraction, scanning electron microscopy and energy-dispersive X-ray spectroscopy, respectively. The effect of temperature on the sintering process as well as on the phase and microstructure of the sintered materials was investigated.

There is an urgent need to develop low cost electrochemical sensors wherein the sensor can be disposed after recording data, thereby eliminating the issue of inaccuracy arising from repeated sensing measurements, which plagues most conventional electrochemical sensors. This work is the first demonstration of a NiSe2 based disposable, one time use electrochemical glucose sensor in bio-mimicking real samples wherein NiSe2 was hydrothermally grown NiSe2 on a biodegradable cellulose paper. Both physicochemical (x-ray diffraction, x-ray photoelectron spectroscopy, field emission scanning electron microscope) and electrochemical (impedance spectroscopy and cyclic voltammetry (CV)) characterization techniques confirmed the growth and presence of NiSe2 on a cellulose paper. Electrochemical techniques like CV and amperometric (i-t) were utilized for the selective and sensitive oxidation of glucose. The results suggests that the proposed NiSe2 sensor is effective in a linear range of 0.1-1 mM with fast response time (3.9 s), low detection limit (24.8 ± 0.1 μM) and high sensitivity (0.25 A M-1 cm-2) at a potential applied (E app = 0.55 V versus Ag∣AgCl). Prior to the real sample analyses i.e. glucose detection in human urine, the fabricated NiSe2 sensor was tested for selectivity towards glucose in co-existing interferences (dopamine, ascorbic acid, uric acid, urea, sodium chloride, fructose, lactose and cysteine). Finally, glucose in artificial blood serum and urine samples was demonstrated with the fabricated NiSe2 sensor and the results are comparable to the conventional laboratory methods. The present methodology presents a novel possibility towards the design of next generation, affordable point-of-care devices for a broad range of clinical diagnostics.

In this work we present an ink-jet printed temperature sensor consisting of PEDOT:PSS printed on paper suitable for packaging, flexible electronics and other printed applications. The substrate showed to have a large influence on both the resistance as well as the temperature sensitivity of the PEDOT:PSS ink. This effect is most likely due to NaCl content in the photo paper coating, which reacts with the PEDOT:PSS. The temperature coefficient of a prepared device of α = −0.030 relative to room temperature (22oC) was measured, which is higher than compared to for example Silicon α = −0.075.

In this study, two different supramolecular recognition architectures for impedimetric detection of DNA hybridization have been formed on disposable paper-supported inkjet-printed gold electrodes. The gold electrodes were fabricated using a gold nanoparticle based ink. The first recognition architecture consists of subsequent layers of biotinylated self-assembly monolayer (SAM), streptavidin and biotinylated DNA probe. The other recognition architecture is constructed by immobilization of thiol-functionalized DNA probe (HS-DNA) and subsequent backfill with 11-mercapto-1-undecanol (MUOH) SAM. The binding capacity and selectivity of the recognition architectures were examined by surface plasmon resonance (SPR) measurements. SPR results showed that the HS-DNA/MUOH system had a higher binding capacity for the complementary DNA target. Electrochemical impedance spectroscopy (EIS) measurements showed that the hybridization can be detected with impedimetric spectroscopy in picomol range for both systems. EIS signal indicated a good selectivity for both recognition architectures, whereas SPR showed very high unspecific binding for the HS-DNA/MUOH system. The factors affecting the impedance signal were interpreted in terms of the complexity of the supramolecular architecture. The more complex architecture acts as a less ideal capacitive sensor and the impedance signal is dominated by the resistive elements.

Paper is a fascinating material for electronic platform devices due to being an inexpensive and environment friendly material. Terahertz wave is able to penetrate paper, thus paper-based terahertz metamaterial will be great terahertz devices. Creating multiple symmetrical Split Ring Resonator (SRR) on upper side paper and depositing metallic plane on back side paper yield terahertz metamaterial absorber. The maximum of absorbance peak for numerical and analytical results are 98% at 0.92 THz and 99% at 0.92 THz, respectively. The superposition of multiple reflections of terahertz wave generated on paper and yielding destructive interference phenomenon. Numerical and analytical works have been carried out in this works and showed good agreement.

This paper presents the use of Escherichia coli as an anode in a paper-based microfluidic urea fuel cell (P-based μUFC). For the construction of this P-based μUFC, a saline solution with E. coli bacteria was deposited on carbon cloth and used as an anode for urea oxidation, furthermore, a piece of Toray® carbon paper was impregnated with Pt/C and used as an cathode to reduce the oxygen present in the air. The P-based μUFC proved with a urea solution of 0.33 M, showed an open-circuit voltage of 0.83 V, a maximum current density of 3.253 mA cm-2 and a maximum power density of 0.608 mW cm2, these values were similar to report when human urine was used as fuel. The microfluidic fuel cell developed was evaluated for 20 consecutive days at room temperature in order to observe the lifetime of the bacteria with respect to the power generated. This work represents an advance in the possible use of physiological fluids such as urine to generate electrical energy in non-implantable medical devices.

Metal oxide nanoparticles such as zinc oxide are increasingly being recognized for potential use in research and health-related application. It is usually incorporated in the modern healthcare products functioning as antimicrobial properties. These inorganic compounds could be applied for antimicrobial paper. Therefore, the objective of this study is to investigate the growth distribution of zinc oxide nanoparticles prepared via in-situ approaches on unbleached and bleached pulps. In order to produce these pulps, hydrothermal method is used throughout the study. The micrograph obtained from the scanning of Field Emission Scanning Electron Microscope exhibited that zinc oxide nanoparticles appeared in the range of 64.1 nm to 87.5 nm supported by the analysis of Field Emission Scanning Electron Microscopy with Energy Dispersive X-Ray Analysis, as high as 27% zinc and 39% oxygen. As expected, zinc oxide nanoparticles decreased the mechanical properties of paper due to the interference of fiber bonding. Antimicrobial test demonstrated acceptable results which required further test.

Buildings are responsible for 36% of the final energy consumption in Morocco [1-2], and a reduction of this energy consumption of buildings is a priority for the kingdom in order to reach its energy saving goals. One of the most effective actions to reduce energy consumption is the selection and development of innovative and efficient building materials [3]. In this work, we present an experimental study of the effect of adding treated organic waste (paper, cardboard, hash) on mechanical and thermal properties of cement and clay bricks. Thermal conductivity, specific heat and mechanical resistance were investigated in terms of content and size additives. Soaking time and drying temperature were also taken into account. The results reveal that thermal conductivity decreases as well in the case of the paper-cement mixture as that of the paper-clay and seems to stabilize around 40%. In the case of the composite paper-cement, it is found that, for an additives quantity exceeding 15%, the compressive strength exceeds the standard for the hollow non-load bearing masonry. However, the case of paper-clay mixture seems to give more interesting results, related to the compressive strength, for a mass composition of 15% in paper. Given the positive results achieved, it seems possible to use these composites for the construction of walls, ceilings and roofs of housing while minimizing the energy consumption of the building.

In the current research, we performed quantitative characterization of commercially available photo papers with respect to chemical composition and physical properties in order to find the preferred photo paper with the best electrical conductivity through in situ silver nanoparticle sintering. The composition ratio of chloride ions, surface roughness and pore size of the photo papers were quantitatively analyzed. The relationship of the above-mentioned parameters with the conductivity of the silver nanoparticle pattern formed on the printed surface was explored. The experimental results showed that chloride ions on the surface of photo papers activated the decomposition of a capping agent and sintering between the silver nanoparticles. It was also found that the chloride ions above a certain value did not affect the sintering. The surface roughness and pore size of the photo papers were found to be inversely related to the conductivity of electrode pattern. Moreover, it was found that additional heat treatment (for a relatively short time at a low temperature) contributed to the improvement of conductivity. However, this effect varied depending upon the characteristics of the photo papers. This newly developed inexpensive method using a highly accessible substrate will be very helpful for future paper electronics related devices and research.

This paper presents a novel boron diffusion process using boron paper as the boron source to form a p+ layer. It was found that sheet resistance was invariable with changing the distance between boron paper and Si wafers, and diffusion uniformity was the best at a distance of 0.3 cm. Sheet resistance (Rs) decreased with increasing diffusion temperature, showing a value of 6.9 ?/ at 1050 ?C with a high diffusion uniformity of 99.173%. The junction depth increased from 195 nm to 517 nm with diffusion temperature raised from 900 ?C to 1050 ?C. The influence of diffusion time on the performance of B diffusion from boron paper was similar with that of temperature.

Hybrid polymer latex based on combination of organic-inorganic materials, poly(methyl methacrylate-co-butyl acrylate) (PMMBA) and organo-montmorillonite (OMMT) were synthesized via miniemulsion polymerization technique. Modification of montmorillonite (MMT) through the incorporation of myristyltrimethylammonium bromide (MTAB) into the clay's interlayer spaces were investigated by Small-Angle X-ray Scattering (SAXS), Fourier Transform Infrared Spectroscopy (FTIR), Thermogravimetric Analysis (TGA) and Transmission Electron Microscopy (TEM). Barrier property and thermal stability of polymer latex film sample were investigated through its Water Vapor Transmission Rate (WVTR) and Thermogravimetric Analysis (TGA). The results indicated that addition of OMMT as filler in PMMBA increased the barrier property and thermal stability of the latex film. Addition of 8.0% (wt) OMMT increased the barrier property and thermal stability. Miniemusion polymerization process with higher addition (>8.0 wt%) of OMMT resulting in high latex viscosity, particle size, and high amount of coagulum. The utilization of this hybrid polymer could benefits paper and board industries to produce high quality barrier paper for food packaging.

The carbon composite papers were produced by utilizing carbon materials from coconut coir. In the present work, carbon composite papers (CCP) were prepared by mixing carbon materials in the form of powder and fibre with polymer (ethylene vinyl acetate and polyethylene glycol) in xylene at 100°C. Then, polytetrafluoroethylene (PTFE) with different content was used to treat the surface of CCP. The properties of PTFE-coated CCP were analysed by means of contact angle measurement, tensile testing, porosity, density, and electrical conductivity measurements. As expected, all CCP's surfaces treated with PTFE were found to be hydrophobic with contact angle >120° and relatively constant during 60 minutes measurement. Furthermore, water contact angle, density, and mechanical properties of CCP generally increase with increasing PTFE content. However, the porosity and electrical conductivity of CCP decrease slightly as the PTFE content increased from 0 wt% to 30 wt%. Based on the observation and analysis, the optimum PTFE content on CCP was 20 %, in which the mechanical properties and hydrophobicity behaviour were improved significantly, but it was only caused a very small drop in porosity and electrical conductivity

With the development of novel device applications, e.g. in the field of robust and recyclable paper electronics, came an increased demand for the understanding and control of IGZO Schottky contact properties. In this work, a fabrication and characterization of flexible Ru–Si–O/IGZO Schottky barriers on paper is presented. It is found that an oxygen-rich atomic composition and microstructure of Ru–Si–O containing randomly oriented Ru inclusions with diameter of 3–5 nm embedded in an amorphous SiO2 matrix are effective in preventing interfacial reactions in the contact region, allowing to avoid pre-treatment of the semiconductor surface and fabricate reliable diodes at room temperature characterized by Schottky barrier height and ideality factor equal 0.79 eV and 2.13, respectively.

Present work reports the green synthesis of highly stable, non-toxic, environmental friendly, fluorescent carbon quantum dots (CQD) via simple synthetic route using the waste carbon paper as their precursor. The as-synthesized CQD were post-synthetically modified with (3-Aminopropyl)triethoxysilane (APTES) as a nitrogen source for amine functionalized CQD (NCQD) formation. When excited at wavelength λex = 350 nm, the maximum emission intensity of NCQD was observed at wavelength λem = 450 nm. The QDs show blue colored luminescence with significant photoluminescence quantum yield (~5.1%). Transmission electron microscopy and Energy-dispersive x-ray spectroscopy data show their size about 4.8 nm and the presence of nitrogen in elemental composition respectively. XRD and selected area electron diffraction patterns reveal their amorphous nature. This NCQD based sensing probe selectivity displays the high sensitivity for trinitrotoluene (TNT) in 4.4 nM to the 26.4 μM range. The probe delivers a 7.4ppb detection limit at 1.3% relative standard deviation.

The strength of concrete mix is dependent on many parameters like cement type, coarse aggregate and the interface between aggregate and mortar. However, generally the coarse aggregate is treated as an inert material and only its physical properties like shape, size, water absorption and specific gravity are studied. Whereas, as we increase the quality of mortar mix, the strength of coarse aggregate also comes into picture. In case of high performance concrete, the type of coarse aggregate used has a great influence on the strength and elasticity modulus of concrete. For high strength concrete with compressive strength above 40 MPa, which are generally cast with water-cement ratio less than or equal to 0.4, the strength of mortar and the interfacial bond strength may be comparable to the strength of aggregate. This paper presents a comprehensive review of the past research work done on the effect of using different types of coarse aggregate on various properties of concrete mix like its compressive strength, tensile strength and elasticity modulus.

We report the realization of a resettable resistive switching device based on a nanostructured film fabricated by supersonic cluster beam deposition of gold clusters on plain paper substrates. Through the application of suitable voltage ramps, we obtain, in the same device, either a complex pattern of resistive switchings, or reproducible and stable switchings between low resistance and high resistance states, with an amplitude up to five orders of magnitude. Our device retains a state of internal resistance following the history of the applied voltage similar to that reported for memristors. The two different switching regimes in the same device are both stable, the transition between them is reversible, and it can be controlled by applying voltage ramps or by mechanical deformation of the substrate. The device behavior can be related to the formation, growth and breaking of junctions between the loosely aggregated gold clusters forming the nanostructured films. The fact that our cluster-assembled device is mechanically resettable suggests that it can be considered as the analog of the coherer: a switching device based on metallic powders used for the first radio communication system.

International audience; This paper shows that we can print on paper simple high frequency electronic devices such as resistances, capacitances or inductances, with values that can be changed in a controllable manner by an applied dc voltage. This tunability is achieved with the help of an ink containing functionalized carbon nanotubes and water. After the water is evaporated from the paper, the nanotubes remain steadily imprinted on paper, showing a semiconducting behavior and tunable electrical properties.

Finding a low cost substrate for surface-enhanced Raman spectroscopy (SERS) yielding enhanced, reproducible Raman signal from Raman active samples has been a longstanding goal for researchers for years. Herein, we demonstrate the fabrication of such a SERS substrate from paper. The proposed paper-based SERS substrate was developed by attaching polyvinylpyrrolidone (PVP) capped silver nano-particles (AgNPs) to printing grade paper. The performance of the substrate has been evaluated for paper substrates of various grades (in grams per square meter; GSM). The usability of the developed substrate for detection of two Raman active samples—namely, malachite green (MG) and rhodamine6G (R6G)—is reported. In addition to these samples, the reproducibility of the designed substrate has been evaluated for 1,2-bis(4-pyridyl)ethylene (BPE); a good degree of reproducibility was observed. Finally, applicability of the proposed substrate for reliable detection of Raman signals from two more important samples—namely, glucose and urine—has been successfully demonstrated.

The present study demonstrates an inkjet – printed interdigitated electrode array on paper substrate and its evaluation as humidity sensor. Inkjet droplet formation analysis has been performed in order to achieve repeatable results regarding generated droplets, based on the driving pulses applied on the inkjet piezoelectric element. Droplet formation has been monitored using stroboscopic effect. Three different paper substrates, namely high glossy inkjet photo paper, glossy inkjet photo and matte inkjet photo paper have been evaluated to investigate compatibility with the ink. Relative humidity measurements have been carried out in a controlled environment. Material degradation, long term response and memory effect are some of the aspects which were studied within the frame of the present work. The proposed sensor provides the opportunity for novel biomedical applications given the flexible substrate nature and the low – cost, single – step fabrication approach.

Electronic structure and carrier behavior in semiconductor junctions can be effectively modulated on the application of strain. This work represents the first demonstration of a large-area, flexible, paper-based graphene-molybdenum disulfide (Gr/MoS2) broadband photodetector using a low-cost solution-processed hydrothermal method and enhancement in photodetection through strain modulation by assembling the device on polydimethylsiloxane. Optimization, in terms of process parameters, was carried out to obtain trilayer MoS2 over Gr-cellulose paper. Under strain, potential barrier variation and piezopotential induced in MoS2 leads to 79.41% enhancement in photodetection in the visible region. Piezopotential induced in MoS2 lowers the conduction-band energy thereby increasing the effective electric field favoring easy electron-hole separation. The advantage of vertically stacked Gr/MoS2 for the photodetector is the utilization of the entire area as a junction where effective separation of electron-hole pairs occurs. Detailed studies of the mechanism in terms of potential barrier variation in Gr/MoS2 and an energy-band diagram are presented to help understand the proposed phenomenon. The present work demonstrates the significance of few-layer MoS2 or Gr in relation to strain-modulated photosensing in comparison to their counterparts grown via chemical vapor deposition. The results provide an excellent approach for the fabrication of low-cost heterojunctions for improved optoelectronic performance, which can be further extended to similar 2D-material heterojunctions for analog, digital and optoelectronic applications.