Cellulose Filter Paper Research Articles

Fast supercapacitors based on vertically oriented MoS2 nanosheets on plasma pyrolyzed cellulose filter paper

Fast supercapacitors that can be charged and discharged at tens of hertz high frequency are reported using binder-free electrodes of MoS2 nanosheets grown on plasma pyrolyzed cellulose microfiber (pCMF) paper. Rapid plasma pyrolysis was applied to obtain highly conductive carbon fiber sheet from conventional cellulose filter paper to be used as a scaffold, on which MoS2 nanosheets were grown vertically wrapped around carbon microfibers in a hydrothermal reaction. Such binder-free MoS2-pCMF electrode based supercapacitor demonstrated fast-rate performance in an aqueous electrolyte with a cutoff frequency of 103 Hz. A large specific capacitance density of 125 mF cm−2 was also measured. The organic electrolyte cell of these electrodes exhibited a power density of 12.05 W cm-3 at a rate of 15 V s−1. These MoS2-pCMF electrodes were highly stable. In a cycling test at a current density of 10 mA cm−2, the cell maintained its capacitance with trivial degradation in 50,000 cycles.

Bacterial cellulose for increasing barrier properties of paper products

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

The use of carbon dioxide as the reaction cell gas for the separation of uranium and plutonium in quadrupole inductively coupled plasma mass spectrometry (ICP-MS) for nuclear forensic samples

The use of carbon dioxide (CO2) as a reaction cell gas for separation and trace analysis of uranium and plutonium by inductively coupled plasma mass spectrometry was investigated. For the analysis of the resultant UO2+ product ion, it was shown that quantitative determination of uranium concentration was achievable within ± 7% uncertainty for samples containing plutonium. In addition, uranium isotope ratios were measured within ± 12% for standard reference materials of several enrichments. This was achieved in both nitric acid and digested cellulose filter paper solutions—a common nuclear forensic sample substrate. However, non-linearity and long term signal instability was observed for plutonium at the high flow rate of CO2 and tuning parameters required to minimise uranium interferences. Therefore, plutonium analysis was not achievable.

Synthesis of Highly Monodispersed, Stable, and Spherical NZVI of 20–30 nm on Filter Paper for the Removal of Phosphate from Wastewater: Batch and Column Study

A nanobiodegradable adsorbent was prepared by stabilizing nanoscale zerovalent iron (NZVI) on cellulose filter paper. Characterization of the sample disclosed that the NZVI particles were rounded, ...

New Carrier Made from Glass Nanofibres for the Colorimetric Biosensor of Cholinesterase Inhibitors.

Cholinesterase inhibitors are widely used as pesticides in agriculture, but also form a group of organophosphates known as nerve chemical warfare agents. This calls for close attention regarding their detection, including the use of various biosensors. One such biosensor made in the Czech Republic is the Detehit, which is based on a cholinesterase reaction that is assessed using a colour indicator—the Ellman’s reagent—which is anchored on cellulose filter paper together with the substrate. With the use of this biosensor, detection is simple, quick, and sensitive. However, its disadvantage is that a less pronounced yellow discoloration occurs, especially under difficult light conditions. As a possible solution, a new indicator/substrate carrier has been designed. It is made of glass nanofibres, so the physical characteristics of the carrier positively influence reaction conditions, and as a result improve the colour response of the biosensor. The authors present and discuss some of the results of the study of this carrier under various experimental conditions. These findings have been used for the development of a modified Detehit biosensor.

Selective Detection of K+ by Ion-Selective Optode Nanoparticles on Cellulosic Filter Paper Substrates

This work describes the generation of plasticized poly(vinyl chloride)-based ion-selective optode (ISO) nanoparticles by a piezoelectric inkjet dispensing device. The monodisperse inkjet-generated particles (polydispersity index: 0.177) with an average hydrodynamic diameter of 202 nm are suitable for the highly reproducible deposition onto cellulosic filter paper substrates, resulting in paper-based analytical devices (PADs) for colorimetric cation detection, as demonstrated on the example of potassium-responsive ISOs. In contrast to the deposition of ISO bulk membranes from organic solutions requiring specialized printing equipment, the ISO nanoparticles can be inkjet-deposited from aqueous dispersions by conventional office inkjet printing. The obtained ISO PADs showed highly reproducible (relative standard deviations of the hue mean values in the range of 0.06–0.83% for three independently fabricated batches) and immediate (t95% ≤ 1 min) response to aqueous K+ solutions buffered at pH 7.4, with high se...

A Paper-Based Analytical Device Based on Combination of Thin Film Microextraction and Reflection Scanometry for Sensitive Colorimetric Determination of Ni(II) in Aqueous Matrix.

In this research, the thin film microextraction method was applied for the extraction of Ni(II) ion from aqueous matrixes. Chemically modified cellulosic filter paper with phosphorus was used as a thin film extractor. After extraction, the thin film was treated with a solution of dimethylglyoxime. The colored film was captured by flatbed scanner and the absorbance of the images was extracted by some suitable software. Under the optimum conditions and at the pH 7.0, with the sample volume of 100mL, the stirring rate of 800rpm, and the extraction time of 50min, the calibration curve was obtained in the range of 0.05-5mg/L Ni(II) (R2 = 0.989). Limit and relative standard deviation were achieved to be 18µg/L and less than 6.7%, respectively. Relative recoveries were obtained in the range of 87%-105%. Finally, the proposed method was found to be simple and cost-effective, with adequate analytical performance for the rapid detection of Ni(II) in river and wastewater samples.

Design, fabrication and testing of reduced graphene oxide strain gauge based pressure sensor with increased sensitivity

Pressure sensors with high sensitivity, repeatable output, wide sensing range, suitable for mass production and which can be manufactured cost effectively are highly desirable for pressure sensing applications. Over the years Graphene and rGO (reduced graphene oxide) based strain gauges have typically been prepared on substrates such as silicon, polydimethylsiloxane, polyethylene terephthalate, kapton, and rubber. They have mainly been utilized in the wearable and temperate condition applications. In the proposed work we would like to present a stainless steel based pressure sensor using rigid centre diaphragm and a fixed guided beam along with rGO-filter paper based strain gauges (reduced graphene oxide on a cellulose filter paper). The resulting strain on the fixed guided beam due to the applied pressure is sensed by the rGO-filter paper based strain gauges and the output is measured as change in resistance. The analytical, numerical simulation and experimental studies of this sensor are discussed and the results obtained are in good agreement to each other. The performance of the sensor is evaluated experimentally and is compared against a standard strain gauge for a pressure range of 0 to 20 bar. The developed sensor exhibits a pressure sensitivity of 2.29 Ω/bar, with an enhanced gauge factor of 112 and the effect of temperature is nullified. The high sensitivity and a wide sensing range enable it for a broad variety of applications.

Sensitive determination of hardness and fluoride in ground water by a hybrid nanosensor based on aggregation induced FRET on and off mechanism

Sensitive detection and determination of hardness and fluoride in the ground water is an important issue for the water safety. The present work reports a sensitive, selective, rapid and visual hybrid fluorescent nanosensor by hybridizing carbon dots and hexametaphosphate capped gold nanoparticles through intrinsic interactions of the two components. The hybrid nanosensor can be used for hardness (Ca2+, Mg2+) detection with the fluorescence intensity decreasing at 439 nm and increasing at 608 nm via the aggregation induced fluorescence resonance energy transfer on mechanism. In addition, the hybrid nanosensor mixed with calcium ions can detect fluoride in water with a lower detection limit of 0.339 ppm with the fluorescence color recovery based on the precipitation induced fluorescence resonance energy transfer off process. Experimental results indicate that the as-synthesized hybrid nanosensor has shown efficient feasibility and practicality for hardness and fluoride detection in actual groundwater samples. Furthermore, a paper-based analytical device has been fabricated by immobilizing the hybrid nanosensor on the cellulose filter paper for the visual and on-site detection of fluoride in water. The hybrid nanosensor would provide new sensing materials and mechanisms for the determination and detection of hardness and fluoride in the groundwater.

Isotope-labeling derivatization with 3-nitrophenylhydrazine for LC/multiple-reaction monitoring-mass-spectrometry-based quantitation of carnitines in dried blood spots

Carnitines are diagnostic biomarkers of fatty acid oxidation defects and organic acidemias. Quantitative measurements of various carnitines in dried blood spot (DBS) have potential use in remote health applications for disease diagnosis and epidemiological surveillance. To provide an improved LC/multiple-reaction monitoring (MRM)-MS method for quantitation of carnitines in DBS, 3-nitrophenylhydrazine (3NPH) was tested as a high-efficiency chemical isotope-labeling reagent for pre-analytical derivatization of 24 routinely-analyzed species. Reaction conditions were optimized and carnitine structural isomers were separated by reversed-phase LC with positive-ion MRM/MS detection, giving on-column lower LOQs of sub- to low-femtomole levels. 13C6-3NPH was used to produce 13C6- or 13C12-labeled derivatives of the mono- and di-carboxylic carnitines in a “one-pot” reaction. These labeled analogues were used as stable isotope-labeled internal standards to compensate for possible ESI matrix effects. Combined with an optimized, two-step procedure for the extraction of carnitines from DBS, this isotope-labeling derivatizaiton - LC/MRM-MS method provided good linearity, high precision (intra-day CVs of ≤7.8% and inter-day CVs of ≤8.8%) and high accuracy (three levels of standard substances spiked in, with recoveries of 86.9%–109.7%) quantitation of carnitines in three sets of DBSs on cellulose or cotton filter paper. This method was then applied to determine the concentration changes of the analytes in the DBSs under two stability-testing regimes: 1) a one-time 4-h sunlight exposure and 2) a set of cycled temperature transitions (−20 °C for 2 days, 40 °C for 2 days, and back to −20 °C for 2 additional days). All of the carnitines showed good stabilities under the first testing condition. Under the second testing condition, free carnitine showed concentration increases of 9.3%–16.1%; acetyl carnitine, 3-OH butyryl carnitine, and malonyl carnitine showed concentration decreases of 12.2%–17.3%, 12.9%–17.1% and 10.7%–15.3%, respectively, and other 20 acyl carnitines showed concentration changes of <10% in three sets of DBSs on cellulose or cotton filter paper. These preliminary stability-testing results indicate a need to more systematically investigate the effects of various environmental conditions on the chemical stabilities of carnitines in DBS specimens if this sampling method is to be used in remote health applications.

Smart functional polymer coatings for paper with anti-fouling properties.

Cellulose, as the main component of paper, is becoming more and more important for several high tech applications because of its beneficial properties, such as abundance, low cost, renewability, mechanical robustness and biocompatibility. To make cellulose accessable for new applications it is necessary to introduce new properties, which can be done by surface modification e.g. grafting of polymers onto surfaces. In this work, two comb copolymers, poly[(2-methyl-2-oxazoline methacrylate)-co-glycidyl methacrylate] and poly[(2-methacryloyloxyethyl phosphorylcholine)-co-glycidyl methacrylate], were synthesized by free radical polymerization of glycidyl methacrylate and oligo(2-methyl-2-oxazoline) as well as 2-methacryloyloxyethyl phosphorylcholine. After extensive characterization the polymers were covalently attached to thin cellulose model layers and filter paper using a one-step grafting-to approach. For the comprehensive analysis of these layers, thin cellulose films were fabricated on silicon wafers by spin coating of trimethylsilyl cellulose followed by acid hydrolysis which resulted in homogeneous layers as substrates for the grafting process of the functional polymers. The layers were characterized by X-ray photoelectron spectroscopy (XPS), attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), atomic force microscopy (AFM) and energy-dispersive X-ray spectroscopy (EDX). To demonstrate the high potential of such polymer-modified cellulose materials, protein repellance of the cellulose films, containing peptidomimetic 2-methyl-2-oxazoline and zwitterionic phosphorylcholine groups after successful functionalization, is shown. Cell adhesion experiments using Bacillus subtilis, Escherichia coli and Saccharomyces cerevisiae indicate the considerable anti-fouling capacity against both Gram-positive and Gram-negatve bacteria as well as the yeast fungus.

Constituting fully integrated colorimetric analysis system for Fe(III) on multifunctional nitrogen-doped MoO3/cellulose paper

Using ammonium molybdate and thiourea as precursors, nitrogen-doped MoO3 was produced by a one-step carbonization and then fixed into the cellulose filter paper (NMCP) with acrylic resin as a fixative. NMCP was designed as a multifunctional nanocomposite, i.e., solid phase adsorbent for Fe(III) preconcentration, photocatalyst for iron species transformation and color interference removal, and colorimetric sensor for Fe(III) determination. After photocatalysis, the complex of Fe-humic substances could be transformed into Fe(III) ions, the interference of colored organic matter (e.g., aqueous humic substance) was removed, Fe(III) was enriched selectively onto NMCP with the coexistence of interference metal ions (e.g. Co(II) and Cd(II)) and then transformed into Fe(II) by hydroxylamine and photoreduction and for colorimetric analysis. The obstacle of o-phenanthroline colorimetric method was overcome. The photodegradation activity of MoO3 was improved 2.02 times by nitrogen doping with the optimal mass ratio, which was also 5.11 times of P25-TiO2. The concentration of Fe(III) on NMCP was quantified by the gray-scale using smart phones and image processing software, without complicated equipment. Based on multifunctional NMCP, a fully integrated visual analysis system was proposed and suitable for the field detection of Fe(III) in natural water. The log-linear calibration curve for Fe(III) was in the range of 0.05–5mg/L with a determination coefficient (R2) of 0.976 and detection limit of 15μg/L.

Cellulolytic Activities of the Dung Beetle, Euoniticellus Intermedius, Larva Gut Micro-Flora

Background:The life style and biology of dung beetles offer a significant opportunity for innovation in biofuel production. The larvae of the African dung beetle,Euoniticellus intermedius, feed solely on cow dung, eating and digesting the fibre while adults live on juices found in fresh dung. The larval gut system consists of a small, almost unrecognizable foregut and two distinct chambers; the midgut and hindgut. It is clear that these two chambers are the centres in which the dung material whose composition includes cellulose is processed. The goal of this study was to assess the cellulolytic activities of cultured gut micro-flora derived fromE. intermedius, (Coleoptera: Scarabaeida).Method:Late second to third instar stageE. intermediuslarvae were dissected and the isolated gut micro-flora consortia aerobically cultured in media containing cellulose (filter paper) as the sole carbon source. Genomic DNA isolation was done on the gut consortia cultures after 10 days of culturing, using the ZR Fungal/Bacterial DNA MiniPrep kit (Zymo Research, USA). A complete and unbiased primary cosmid library was then constructed from the isolated genomic DNA using a cloning ready, pWEB-TNC™ Cosmid Cloning kit (EPICENTRE Biotechnologies, USA). The primary cosmid library clones were screened for endo-glucanase and cellobiohydrolase activities using Carboxymethyl Cellulose (CMC) and 4-Methylumbelliferyl-β-D-Cellobioside (MUC) plate assays respectively.Results:Results indicate that a total of 7 colonies out of 160 screened colonies showed positive CMC and MUC activities.Conclusion:This proves thatE. intermediusis a potential source of cellulolytic micro-organisms and enzymes that can be used for cellulose derived biofuel production.

Consolidated bioprocessing for sodium gluconate production from cellulose using Penicillium oxalicum

The feasibility of consolidated bioprocessing for sodium gluconate production from cellulose was studied. A recombinant strain named z19 was constructed from Penicillium oxalicum wild-type strain 114-2 for simultaneous expression of glucose oxidase and catalase from Aspergillus niger. While keeping a cellulolytic ability similar with that of 114-2, z19 secreted certain amounts of glucose oxidase and catalase. Fed-batch and two-stage temperature control strategy (0–120 h, 30 °C; 120–192 h, 45 °C) was utilized for sodium gluconate production from cellulose (filter paper power), with 13.54 g/L of sodium gluconate obtained at the end of the fermentation. The results provide an alternative route for producing sodium gluconate from cellulose in a one-pot reaction.

Development and validation of a stochastic molecular model of cellulose hydrolysis by action of multiple cellulase enzymes

BackgroundCellulose is hydrolyzed to sugar monomers by the synergistic action of multiple cellulase enzymes: endo-β-1,4-glucanase, exo-β-1,4 cellobiohydrolase, and β-glucosidase. Realistic modeling of this process for various substrates, enzyme combinations, and operating conditions poses severe challenges. A mechanistic hydrolysis model was developed using stochastic molecular modeling approach. Cellulose structure was modeled as a cluster of microfibrils, where each microfibril consisted of several elementary fibrils, and each elementary fibril was represented as three-dimensional matrices of glucose molecules. Using this in-silico model of cellulose substrate, multiple enzyme actions represented by discrete hydrolysis events were modeled using Monte Carlo simulation technique. In this work, the previous model was modified, mainly to incorporate simultaneous action enzymes from multiple classes at any instant of time to account for the enzyme crowding effect, a critical phenomenon during hydrolysis process. Some other modifications were made to capture more realistic expected interactions during hydrolysis. The results were validated with experimental data of pure cellulose (Avicel, filter paper, and cotton) hydrolysis using purified enzymes from Trichoderma reesei for various hydrolysis conditions.ResultsHydrolysis results predicted by model simulations showed a good fit with the experimental data under all hydrolysis conditions. Current model resulted in more accurate predictions of sugar concentrations compared to previous version of the model. Model results also successfully simulated experimentally observed trends, such as product inhibition, low cellobiohydrolase activity on high DP substrates, low endoglucanases activity on a crystalline substrate, and inverse relationship between the degree of synergism and substrate degree of polymerization emerged naturally from the model.ConclusionsModel simulations were in qualitative and quantitative agreement with experimental data from hydrolysis of various pure cellulose substrates by action of individual as well as multiple cellulases.

Modification of cellulose foam paper for use as a high-quality biocide disinfectant filter for drinking water

Development of a foam-formed cellulose filter paper with high wet strength was carried out for application as a drinking water filter. The wet strength and antimicrobial activity of cellulose foam paper against several bacteria species (Bacillus subtilis MTCC 441 (Gram +ve), B. cereus NCDC 240 (Gram +ve), Pseudomonas aeruginosa NCDC 105 (Gram −ve), Klebsiella pneumonia NCDC 138 (Gram −ve), and Escherichia coli MTCC 40 (Gram −ve)) were investigated. The morphology and structure of the cellulose foam paper were characterized using scanning electron microscopy (SEM). The results of our study confirmed that glutaraldehyde solution or 1,2,3,4-butanetetracarboxylic acid (BTCA) added to cellulose foam paper pretreated with cationic polyacrylamide (C-PAM) provided very high and stable wet strength performance together with excellent antimicrobial properties.

Sustainable and Biodegradable Superhydrophobic Coating from Epoxidized Soybean Oil and ZnO Nanoparticles on Cellulosic Substrates for Efficient Oil/Water Separation

Conventional superhydrophobic materials for oil/water separation were usually prepared from nondegradable and nonrenewable resources, which would not only increase resource crisis but also cause environmental pollution after discarding. In this study, we report a renewable and biodegradable superhydrophobic material, which was fabricated via a two-step curing dip-coating method and was composed of cellulosic filter paper or fabric, cured epoxidized soybean oil (CESO), ZnO, and stearic acid (STA) as the substrate, adhesive, rough structure, and low energy modifier, respectively. The CESO combined ZnO nanoparticles with cellulosic substrate tightly to show excellent stability when suffering from immersing in water and oil for 7 days without losing superhydrophobicity. When the superhydrophobic coating was constructed onto the surface of cellulosic fabric, the material showed high separation efficiency with the values higher than 97% during separation of various oil/water mixtures. The sustainable and biodeg...

Development of antibacterial paper coated with sodium hyaluronate stabilized curcumin-Ag nanohybrid and chitosan via polyelectrolyte complexation for medical applications

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.

Superhydrophobic Substrates from Off-the-Shelf Laboratory Filter Paper: Simplified Preparation, Patterning, and Assay Application.

Off-the-shelf laboratory filter paper of different pore sizes and thicknesses can be modified with fluorine-free organosilanes to be superhydrophobic, patternable, and ready for quantitative assay applications. In particular, we have demonstrated that the cellulose filter paper treated with a binary hexane solution of short (methyltrichlorosilane) and long (octadecyltrichlorosilane) organosilanes exhibits remarkably high water contact angles (>150°) and low wetting hysteresis (∼10°). Beyond the optimized ratio between the two organosilanes, we have discovered that the thickness rather than the pore size dictates the resulting superhydrophobicity. Scanning electron microscopy images showed that silanization does not damage the cellulose microfibers; instead, they are coated with uniform, particulate nanostructures, which should contribute to the observed surface properties. The modified filter paper is chemically stable and mechanically durable; it can be readily patterned with UV/ozone treatment to create hydrophilic regions to prepare chemical assays for colorimetric pH and nitrite detections.

Simple immobilization of mercury ion chemosensors to solid substrate

To develop selective and disposable mercury chemosensors, four different mercury chelators were synthesized and grafted onto cellulose filter paper. Three colorimetric sensors were azobenzene derivatives bearing a dithiaazadioxo crown ether moiety as a core chelator for Hg2+ ions. The fourth chelator was a rhodamine-based turn-on mercury binder that responded to both methylmercury and Hg2+ ions. This sensor develops the typical pink color of rhodamine (colorimetric) and exhibits strong fluorescence (fluorometric). For paper immobilization, the cellulose filter paper was first primed with 3-(aminopropyl)trimethoxysilane (APTMS) so that all the four ligands were covalently immobilized, simply by soaking them in each solution.