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This study utilized pulp and paper mill sludge as a carbon source to produce activated biochar adsorbents. The response surface methodology (RSM) application for predicting and optimizing the activated biochar preparation conditions was investigated. Biochars were prepared based on a Box–Behnken design (BBD) approach with three independent factors (i.e., pyrolysis temperature, holding time, and KOH:biomass ratio), and the responses evaluated were specific surface area (SSA), micropore area (Smicro), and mesopore area (Smeso). According to the RSM and BBD analysis, a pyrolysis temperature of 800 °C for 3 h of holding and an impregnation ratio of 1:1 (biomass:KOH) are the optimum conditions for obtaining the highest SSA (885 m2 g–1). Maximized Smicro was reached at 800 °C, 1 h and the ratio of 1:1, and for maximizing Smeso (569.16 m2 g–1), 800 °C, 2 h and ratio 1:1.5 (445–473 m2 g–1) were employed. The biochars presented different micro- and mesoporosity characteristics depending on pyrolysis conditions. Elemental analysis showed that biochars exhibited high carbon and oxygen content. Raman analysis indicated that all biochars had disordered carbon structures with structural defects, which can boost their properties, e.g., by improving their adsorption performances. The hydrophobicity–hydrophilicity experiments showed very hydrophobic biochar surfaces. The biochars were used as adsorbents for diclofenac and amoxicillin. They presented very high adsorption performances, which could be explained by the pore filling, hydrophobic surface, and π–π electron–donor–acceptor interactions between aromatic rings of both adsorbent and adsorbate. The biochar with the highest surface area (and highest uptake performance) was subjected to regeneration tests, showing that it can be reused multiple times. peerReviewed

A sonication of graphite in polysaccharide (pullulan, chitosan and alginate) is one of the viable methods for the preparation of few-layer graphene. However, the effect of these adsorbed polysaccharides on the electrical performance of the produced graphene so far is not yet clear. In order to investigate the present effect of pullulan, chitosan and alginate on the electrical characteristic of resulted graphene, we have produced few-layer graphene using bath sonication of graphite in pullulan, chitosan and alginate medium for the application as electrical conductive ink in strain-sensitive. Data from the TEM reveals the appearance of folded few-layer graphene flakes after sonication for 150 min while the XPS data shows that the chitosan-based graphene possesses the highest carbon-oxygen ratio of 7.2 as compared to that of the pullulan and alginate-based graphene. By subjecting the produced graphene as the ink for paper-based strain sensor, we have discovered that the chitosan-graphene has the best resistivity value (1.66 × 10-3 Ω⋅cm) and demonstrate the highest sensitivity towards strain (GF: 18.6). This result interestingly implies the potential of the reported chitosan-based conductive ink as a strain-sensitive material for future food packaging.

A bio-inspired cellulose paper–poly(amidoxime) composite hydrogel is explored via UV-polymerization. This hydrogel has a highly efficient uranium capture capacity of up to 6.21 mg g−1 for WU/Wdry gel and 12.9 mg g−1 for WU/Wpoly(amidoxime) in seawater for 6 weeks, due to its enhanced hydrophilicity, good hydraulic/ionic conductivity and broad-spectrum antibacterial performance.

The present study delineates the preparation, characterization, and application of (3-Aminopropyl)triethoxysilane (APTES)/Caprine liver-derived extracellular matrix (CLECM) coated paper matrix for cell delivery. Here, we exploited positively charged surface of the paper matrix (as imparted by APTES derivatization) to improve the biological responses of the cells. Our results demonstrated that the functionalized paper matrixes favored the adhesion, growth, and proliferation of multiple cell types including normal, transformed, cancerous, and stem cells as compared to the pristine paper matrix. Upon implantation into the mice model, the developed paper matrix supported infiltration of the host cells and vasculature without showing any evidence of significant systemic toxicity. Moreover, the cells cultured on the paper matrix, when delivered to the CAM and mouse models, showed an enhanced vascular network around the substrate, thereby confirming its potential to deliver the cells in vivo. Together, the study confirms that the reported paper-based platform is easy to fabricate, cheap, portable and could efficiently be applied to cell delivery applications for either tissue repair or the development of humanized animal model.

Composite adsorbents based on metal-organic frameworks (MOFs) are excellent candidates for solid-phase extraction (SPE) due to their diverse chemical functionality and multilevel porosity. MOF superstructures based on self-assembly at room temperature (RT) could have less energy consumption and easier manipulation due to the larger complex geometry. The π-π stacking of the benzene ring could not only enhance the interaction toward hydrophobic or plane-structured targets but also be expected to promote the formation of the MOF superstructure. In this work, in the established RT self-assembly synthesis system, several factors were investigated to see how to obtain functional MOF superstructures with a regular geometry, among which the number of benzene rings in the ligand was mainly tested for its impact on self-assembly and adsorption capacity. By means of adsorption experiments and computational fluid dynamics (CFD) simulation, the relationship between structure and activity (SARs) was further explored. Interestingly, the MOF unit with the lowest specific surface area performed the best in adsorption. Then, the selected functional MOF superstructure and ionic liquid were used to produce the composite paper membrane facilely applied in the SPE device. After optimization of the preparation conditions and operation parameters, the established SPE-HPLC-UV method could selectively analyze tetracycline-like antibiotics in the range of 16.6-833.3 ng/g (ppb) in a meat sample. This work provided an RT synthesis method to produce a microsize MOF superstructure, with experimental and theoretical insights into the SARs, which could be expanded in the design of other MOF-based SPE composite membranes toward one group of analogues.

Microfluidic paper combines pump-free water transport at low cost with a high degree of sustainability, as well as good availability of the paper-forming cellulosic material, thus making it an attractive candidate for point-of-care (POC) analytics and diagnostics. Although a number of interesting demonstrators for such paper devices have been reported to date, a number of challenges still exist, which limit a successful transfer into marketable applications. A strong limitation in this respect is the (unspecific) adsorption of protein analytes to the paper fibers during the lateral flow assay. This interaction may significantly reduce the amount of analyte that reaches the detection zone of the microfluidic paper-based analytical device (µPAD), thereby reducing its overall sensitivity. Here, we introduce a novel approach on reducing the nonspecific adsorption of proteins to lab-made paper sheets for the use in µPADs. To this, cotton linter fibers in lab-formed additive-free paper sheets are modified with a surrounding thin hydrogel layer generated from photo-crosslinked, benzophenone functionalized copolymers based on poly-(oligo-ethylene glycol methacrylate) (POEGMA) and poly-dimethyl acrylamide (PDMAA). This, as we show in tests similar to lateral flow assays, significantly reduces unspecific binding of model proteins. Furthermore, by evaporating the transport fluid during the microfluidic run at the end of the paper strip through local heating, model proteins can almost quantitatively be accumulated in that zone. The possibility of complete, almost quantitative protein transport in a µPAD opens up new opportunities to significantly improve the signal-to-noise (S/N) ratio of paper-based lateral flow assays.

Molecularly imprinted polymers are efficient and selective adsorbents which act as artificial receptors for desired compounds with the ability to recognize the size, shape, and functional groups of the compounds simultaneously. A molecularly imprinted polymer is prepared by the polymerization of functional monomers around a template (analyte) molecule. Afterward, the removal of the template from the polymer matrix leaves a selective cavity behind. The fabrication and development of molecularly imprinted polymers grew rapidly, due to their low cost, simple preparation, selectivity, sensitivity, and stable physicochemical properties. Traditionally, molecularly imprinted polymers can be synthesized using two main methods, namely bulk and surface imprinting. For more efficient use of the latter method, researchers have developed molecularly imprinted polymers grafted on the solid-phase matrix (substrate). This grafting technique would be particularly useful for surface imprinting of macromolecules, such as proteins. Cellulose fibers of papers with unique properties such as being abundant, retaining a porous structure, having good adsorption properties, and possessing hydroxyl groups naturally have gained much attention as substrate. The goal of this review is to introduce molecularly imprinted polymer-grafted or molecularly imprinted polymer-coated paper, as an interesting, simple, and efficient method in the detection and separation of small and large molecules. Therefore, in the present paper, several recent preparation techniques and applications of molecularly imprinted polymer-grafted paper are reviewed and discussed in detail. Green, cost-effective, selective, and sensitive paper-based sensor prepared via grafting molecularly imprinted polymer on paper surface with the potential use for online detection trace of analytes in the point-of-care testing.

Removing benzene from indoor space plays an important role in indoor air purification. A novel filter with vegetal fiber paper (VFP) as matrix hosting silica gel is proposed in this paper for benzene removal. In order to investigate the feasibility and performance of this idea, firstly, three pieces of VFP samples impregnated with different amounts of silica gel are fabricated and their benzene adsorption quantities are tested. The results show that three times is recommended as the optimal number for impregnating. The VFP sample impregnated with silica gel after the third impregnating exhibits commendable coating stability and good benzene adsorption performance. Additionally, at low relative pressure (Pb /Ps ≤ 0.05), the experimental data of benzene adsorption isotherms fit well with the Langmuir model with R2 greater than 0.97. Then, two actual filters made of VFP impregnated with silica gel after the third impregnating were fabricated. It is found that the pressure drop of the actual filter is only 1200 Pa/m when the air velocity is 2 m/s. Besides, the one-pass efficiency of the filter can reach to 19.44%. It is expected that the silica gel coated on the filter can be modified to improve the purification performance of the filter.

Anionic pectic substances in whitewater from papermaking are detrimental to machine operation and product quality. Pectinase was immobilized on pulp fiber using cationic polyacrylamide with layer-by-layer method to obtain bound enzyme with tunable activity and good performance for wastewater treatment. It was revealed that high charge density and low molecular weight for cationic polyacrylamide were advantageous for enzymatic activity. During the layer-by-layer adsorption process, the enzymatic activity of the immobilized enzyme increased nearly linearly with the layer number from 983 to 3074 U/g until the fourth layer. The stability of the four-layer immobilized enzyme was improved. The multilayer immobilized enzyme exhibited good reusability and storage stability compared with monolayer enzyme. At dosage of 10 U/mL, the cationic demand of the whitewater samples was reduced by 15% using four-layer immobilized enzyme. The results indicated a potential route to prepare immobilized enzyme with good performance for wastewater treatment in papermaking industry.

The adsorption of hydrocarbons present in gasoline residues on household materials was investigated via inverse gas chromatography (IGC). A series of hydrocarbons (n-heptane, n-octane, n-nonane, toluene, p-xylene, and 1,2,4-trimethylbenzene) and three household materials (carpet fibers, cotton fabric, and cardboard) were selected in this work. IGC measurements using columns packed with these household materials were conducted to obtain molar enthalpies of adsorption of the selected hydrocarbons over the temperature range of 40 to 70 °C. Adsorption isotherms and Henry’s law solubility coefficients (S) were also determined at 40 °C. Results from our IGC measurements revealed that molar enthalpies of adsorption, adsorption isotherms, and solubility coefficients were largely dependent upon the structures and size of hydrocarbons and the choice of solid substrates. Measured molar enthalpies of adsorption became more exothermic with increasing size of hydrocarbons, ranging from −23.4 to −40.9 kJ/mol for carpet fibers, −36.2 to −48.2 kJ/mol for cotton fabric, and −30.1 to −52.5 kJ/mol for cardboard. From the adsorption isotherms and the measured retention times as a function of the injection amount, the adsorption affinity of hydrocarbons to the carpet fibers was found to be weaker than the affinity between hydrocarbon molecules, producing relatively lower solubility coefficients for all hydrocarbons than those measured on cotton fabric and cardboard. However, the adsorption affinities of hydrocarbons to both cotton fabric and cardboard were much stronger with increased solubility coefficients presumably due to the diffusion and dispersion of hydrocarbons through solid substrates. In particular, solubility coefficients of three aromatics on cardboard were significantly larger than those measured on carpet fibers and cotton fabric. This might be responsible for previously reported enhanced persistence of gasoline residues spiked on cardboard.

3-Monochloropropane-1,2-diol (3-MCPD) is a common food processing contaminant and a simple, rapid, sensitive and low cost monitoring technology is needed due to its potential carcinogenic nature. Carbon dots directly intercepted on filter paper provide high fluorescence intensity and can be adapted for use as a sensor. We synthesized a carbon dot-filter paper in combination with a molecularly imprinted polymeric film to extract 3-MCPD from samples. This grafted paper-based sensor exhibited a high adsorption capacity (68.97 mg g−1), an excellent selectivity (imprinting factor = 4.5) and a low detection limit (0.6 ng mL−1). Recoveries ranged from 97.2% to 105.3% with relative standard deviations

In this study, we have attempted to extract cellulose fiber from newspaper waste for circular economy project. Cellulose was successfully extracted from newspaper waste with high purity. It was further developed as a composite with Fe3O4 powder. 10–30 wt% of Fe3O4 was synthesized from conventional synthetic route and it was uniformly distributed into cellulose suspension. The composite was prepared by freeze-dry technique in order to remove water and create the porosity. X-ray diffraction and thermogravimetric analysis were employed to characterize the structural and thermal properties of composite. Scanning electron microscope with energy dispersion analysis can be confirmed that uniformity of cellulose and the existence of Fe3O4 powder. Frequency dependence of dielectric properties was used to imply the polarity enhancement of composite. Preliminary adsorption of composite as adsorbent material for Congo red was investigated.

Porous magnesium oxide (MgO) films on carbon fiber paper (CF) have been successfully fabricated in a hydrothermal route at different calcination temperatures. The CF@MgO samples (CF@MgO-300, -400, and -500) show different morphologies with the increasing surface area from 3 for CF to 27 m2 g−1 for CF@MgO-400. Among the four investigated samples, the CF@MgO-400 exhibits the highest phosphate removal ability (~ 1230 mg g−1) with promising applications for the large-scale utilization at low cost.

Hypotheses (1) The equilibrium size and characteristics of a radially wicked fluid on porous material such as paper is expected to be dependent on the fluid properties and therefore could serve as a diagnostic tool. (2) The change in wicked stain size between biological fluids is dependent on a change in solid-liquid surface interfacial energy due to protein adsorption. Experiments Sessile droplets of increasing volume of blood, its components, and model fluids were deposited onto paper and the equilibrium stain size after coming to a halt was recorded. The contact angle of fluid droplets on model cellulose surfaces was measured to quantify the effect that blood protein adsorption at the solid-liquid interface has on radially wicked equilibrium size. Finally the significance of droplet evaporation for the time scale of interest was analysed. Findings The final stain area of all fluids tested on paper scales remarkably linearly with droplet volume. Different fluids were compared and the gradient of this linear relation was measured. Model fluids varying in surface tension and viscosity all behave similarly and exhibit a constant gradient. Blood and its components produce smaller stains, demonstrated by lower gradients. The gradient is a function of protein concentration, thus the mechanism of this phenomenon was identified as protein adsorption at the cellulose-liquid interface. The slope of the area/volume relationship for droplets is an important quantitative mechanistic variable.

Inkjet printing is a rapidly expanding technology for non-contact digital printing. The focus for the technology has changed from office printing of text and image documents increasingly toward wider applications, including large-scale printing of on demand books and packaging or ultra-small-scale functional printing of microscopic volumes of precious/rare materials formulated for use in precisely printed digitally defined patterning arrays, such as printed diagnostics, flexible electronics, anti-counterfeiting, etc. For efficiency, as well as resource management and conservation, predicting the stable runnability of an inkjet ink remains largely a key unknown. Today the only way to know often means simply trialling it, which at best takes time, and at worst incurs costs rectifying possible equipment damage. We propose a mechanically driven displacement device providing constant high-shear flow rate through an extended capillary. This differs from a standard capillary viscometer, which is commonly pressure driven only and lacks the ability to mimic consistent volume flow inkjetting. The novel method is used to study the aqueous colloidal stability of polymer solution, latex polymer suspensions and complete pigment-containing inks, including a reference pigment only comprising suspension. The results reveal the tendency to build agglomerates, determined by dynamic light scattering particle size distribution, optical and electron microscopy. Liquid phase parameters, including surface tension, and suspension intrinsic viscosity are also studied. Repeated application of high shear is seen to act as a milling process for pigment and agglomerate building tendency for latex binder. Consequences for ink jettability are discussed.

While current trends in Green Analytical Chemistry aim at reducing or simplifying sample treatment, food usually comprises complex matrices where direct analysis is not possible in most cases. In this context, sample treatment plays a pivotal role. Biogenic amines are naturally formed in many foodstuffs due to the action of microorganisms, while their presence has been associated with adverse health effects. In this work, the extraction of seven biogenic amines (cadaverine, histamine, phenylethylamine, putrescine, spermidine, spermine, and tyramine) from beer samples has been simplified using laboratory filter paper as sorbent without any further modification. The analysis of the eluates by direct infusion mass spectrometry reduces the time of analysis, increasing the sample throughput. This simple but effective method enabled the determination of the analytes with limits of detection as low as 0.06 mg•L−1 and relative standard deviations better than 11.9 %. The suitability of the method has been assessed by analyzing eight different types of beers by the standard addition method.

A molecularly imprinted paper-based analytical device (MIP-μPAD) was developed for the sensing of bisphenol A (BPA). The platform was screen-printed onto a filter paper support, where the electrodes and the fluorescence μPADs were designed. Owing to its dual electrochemical and fluorescence responses, molecularly imprinted curcumin nanoparticles were used to sense BPA. The μPAD design was characterized by transmission electron microscopy, scanning electron microscopy, fluorescence spectroscopy, and electrochemical techniques. The sensor design comprised a wide linear range from 1 to 200 μg L−1 with limits of detection of 0.47 ± 0.2 and 0.62 ± 0.3 μg L−1 (LOD, S/N = 3) for electrochemical and fluorescence sensing, respectively. Furthermore, the system showed good analytical performance such as selectivity, stability, and reproducibility. The feasibility of the MIP-μPAD was demonstrated for the sensing of BPA in seawater, foods, and polycarbonate plastic packaged water with recovery values of 97.2 and 101.8%.

Clinical application of direct sampling electrospray ionization mass spectrometry (ESI-MS) remains limited due to problems associated with very “dirty” sample matrices. Herein we report on a microfluidic platform that allows direct mass spectrometric analysis of serum samples of microliter sizes. The platform integrates in-line paper adsorption-based sample clean-up and voltage assisted liquid desorption ESI-MS/MS (VAL DESI-MS/MS) to detect multiple targeted compounds of clinical interest. Adenosine monophosphate (AMP), adenosine diphosphate (ADP), and adenosine triphosphate (ATP) were selected as model analytes. Simultaneous quantification of these compounds in human serum samples was demonstrated. For all the three compounds, linear calibration curves were obtained in a concentration range from 0.20 to 20.0 μmol/L with r2 values ≥ 0.996. Limits of detection were 0.019, 0.015, and 0.011 μmol/L for AMP, ADP, and ATP, respectively. Recovery was found in the range from 96.5% to 103.5% at spiking concentrations of 0.25 and 2.50 μmol/L. The results indicate that the proposed microfluidic mass spectrometric platform is robust and effective. It may have a potential in clinical analysis.

Generally, the mechanical strength and stiffness of old corrugated cardboard (OCC) waste paper are decreased after multiple recycling procedures. Surface sizing starch, which is extensively used in the surface sizing of paper making, accumulates after dissolving from the fibers and is transformed into pollutant during the OCC re-pulping process. To overcome the pollution and reutilization problem of the waste starch during the recycling process of OCC paper, waste starch was ionized using hydrogen peroxide (H2O2) to improve the mechanical properties of OCC paper during the reutilization. The results showed that the carboxyl group of waste starch increased with an increasing degree of ionization, resulting in enhanced copper ion adsorption capacity. Furthermore, the retention rate of the modified starch in the wet-end increased from 18.0% to 48.2%. The OCC paper presented the highest burst index and tensile strength of 8.94 kPa m2/g and 112.5 N m/g, respectively, when MS-2 was added. This work has great significance for implementation of the cleaning production of OCC waste papers and the reutilization of the waste starch.

This study presents 5-hydroxymethylfurfural removal from waste hand paper hydrolysate using activated carbon adsorption. In this context, the effects of adsorbent dosage, initial 5-hydroxymethylfurfural concentration, temperature, and agitation speed on 5-hydroxymethylfurfural adsorption were investigated. Moreover, isotherm and kinetic evaluations were performed using Langmuir, Freundlich, and Temkin models. The experimental data were correlated with zero, first, pseudo-first, and Weber–Morris intraparticle diffusion models. The toxicity of 5-hydroxymethylfurfural was determined using the resazurin reduction assay, and the EC50 of 5-hydroxymethylfurfural in the hydrolysate was found as 192 mg/L. Most convenient 5-hydroxymethylfurfural adsorption was obtained at 5 g/L AC dosage, 40 °C and 150 rpm agitation speed. The highest 5-hydroxymethylfurfural removal efficiency was 92% at 7 g/L AC dosage. The adsorption data fitted best with the Langmuir isotherm model with a maximum uptake capacity of 70.92 mg/g (R2: 0.96). The zero-order reaction kinetic model was the most suitable one among the others inspected. It was determined that intraparticle diffusion was not the rate-limiting step. This study showed that waste hand paper hydrolysate can effectively be detoxified by activated carbon adsorption. © 2019, Islamic Azad University (IAU).

RATIONALE Accurate measurement of trace compounds in blood samples is important in clinical diagnosis and life science. Ambient ionization mass spectrometry, however, suffers from the matrix effect when dealing with complex samples such as blood. Therefore, it is important to reduce the matrix effects in blood samples. METHODS A low-cost and disposable Teflon tube was used as a platform to precipitate the protein in blood. The analytes are extracted into organic solvent, and the precipitated protein can be adsorbed by the chromatography paper inserted. Therefore, the Teflon tube after precipitation can be directly subjected to paper spray ionization mass spectrometry, achieving one-step analysis of blood. RESULTS High sensitivity and satisfactory stability were achieved for pharmaceuticals, acids, and endogenic metabolites in blood. The absolute signal intensities of characteristic product ions of the tested analytes were 8-20 times higher after protein precipitation than those obtained using paper spray. Detection limits and quantitative performance were evaluated for three drugs: carbamazepine, metformin, and tioconazole. In addition, the limits of detection and quantitation were improved 9-14- and 8-12-fold, respectively. CONCLUSIONS Protein precipitation coupled to paper spray with a tube and then to mass spectrometry was successfully achieved and applied in the one-step analysis of trace compounds in blood samples. The experimental results showed that this method was sensitive, stable, convenient, and economic for the direct analysis of blood.

A novel adsorbent, the uniform fiber ball (UFB) loaded with polypyrrole (UFB-PPy), was synthesized for Cr(VI) removal from water in this paper. The structure of the UFB and UFB-PPy were characterized by SEM, EDS, FT-IR, BET, XPS and TG. The adsorption properties of UFB-PPy towards Cr(VI) were investigated by the effects of temperature, initial concentration of Cr(VI), interfering ions and contact time in batch experiments, the isothermal models (Langmuir, Freundlich and Temkin) and the kinetic models (Pseudo first-order kinetic, Pseudo second-order kinetic and Intra-particle diffusion models) were used to describe the adsorption behavior. The effects of the initial concentration and flow rate of the Cr(VI) solution in the column experiments were also studied, and the dynamic models (Yoon-Nelson, Adams-Bohart and Wolborska model) were applied to predict the adsorption performance. The Cr(VI) removal mechanism of UFB-PPy was revealed by studying the effect of pH on adsorption, testing of Cl−, and analyzing the XPS. The results showed that UFB-PPy exhibited excellent adsorption properties for Cr(VI) both in batch and column adsorption. The possible adsorption mechanism involved electrostatic attraction, ion exchange and reduction. Conveniently, the chromium resources can be recovered with the form of high-purity Cr2O3 by simple calcination of Cr(VI)-captured UFB-PPy (UFB-PPy-Cr).

In this work, we characterize the impact of large-volume processing upon the analytical sensitivity of flow-through paper-based immunoassays. Larger sample volumes feature greater molar quantities of available analyte, but the assay design principles which would enable the rapid collection of this dilute target are ill-defined. We developed a finite-element model to explore the operating conditions under which processing large sample volumes via pressure-driven convective flow would yield an improved binding signal. Our simulation results underscore the importance of establishing a high local concentration of the analyte-binding species within the porous substrate. This elevated abundance serves to enhance the binding kinetics, matching the time scale of target capture to the period during which the sample is in contact with the test zone (i.e., the effective residence time). These findings were experimentally validated using the rcSso7d-cellulose-binding domain (CBD) fusion construct, a bifunctional binding protein which adsorbs to cellulose in high abundance. As predicted by our modeling efforts, the local concentration achieved using the rcSso7d-CBD species is uniquely enabling for sensitivity enhancement through large-volume processing. The rapid analyte depletion which occurs at this high surface density also permits the processing of large sample volumes within practical time scales and flow regimes. Using these findings, we present guidance for the optimal means of processing large sample volumes for enhanced assay sensitivity.

In the present work, we report the synthesis of chitosan:starch‑silver nanoparticle (Cht:St-AgNPs) coated papers for antimicrobial packaging applications. The starch-assisted synthesized St-AgNPs are spherical in shape with an average particle size of 7 nm. Chitosan was mixed into the synthesized St-AgNPs solution with different ratios of 9:1, 8:2, 7:3, and 5:5 by weight. Further, the influence of different ratios of Cht:St-AgNPs on the various paper properties such as mechanical properties, water and oil resistance, and antimicrobial activities was investigated. It was observed that the properties of the coated papers were strongly dependent on the composition of Cht:St-AgNPs. The Cht:St-AgNPs-coated paper prepared with the ratio of 9:1 showed excellent mechanical properties and good resistance properties against water and oil. The Cht:St-AgNPs coated papers showed a remarkable enhancement in mechanical strength, oil and water resistance, and antibacterial and antifungal activity, which can make them a potential candidate for functional antimicrobial packaging applications.

This paper describes, for the first time, the use of oxidized buckypaper (BP) as a sorbent membrane of a stir-disc solid phase extraction module. The original device, consisting of a BP disc (d = 34 mm) enveloped in a polypropylene mesh pouch, was designed to extract organic micropollutants (OMPs) from environmental water samples in dynamic mode. High-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) was used to analyze the extracts. Several classes of pesticides and pharmaceuticals were chosen as model compounds to evaluate key parameters affecting the recovery rates. To this end, the effects of adsorption time, desorption time, stirring speed, type and volume of solvent, and sample volume were thoroughly examined. After optimization, a novel and in-depth study was conducted to find a correlation between physicochemical properties of the analytes and extraction yields. Recoveries were mainly governed by a combination of logP and pKa values. As indicated, hydrophilic compounds with l...

Two simple routes for the synthesis of a paper-TiO2 composite were tuned up and the efficiency of the resulting paper-TiO2 photocatalyst was investigated in the 2-propanol oxidation in gas phase. The first route involved the in-situ generation over the sheet of paper of a TiO2 layer starting from a solution of Ti (OBu)4 in tert-butanoliacetic acid, followed by hydrothermal treatment at 120 degrees C for 3 h. The sample was labelled as paper-TiO2 (H). The second approach was based on the adsorption on the paper of a ready-made suspension of titania nanoparticles (TiO2 sol), generated in autoclave at 140 degrees C and stable in acid medium at pH

Prompt development of electronic devices and sensors raised the requirement for design/fabrication of advanced energy sources capable of providing considerable amount of energy for consuming platforms through practical nanotechnological approaches. For this aim, we have developed a highly active 2D nanostructure consisted of reinforced conductive polypyrrole (PPy) with decorated reduced graphene oxide (rGO) with hybrid metal oxide complex of Ni/W (PPy-G-Ni-W) toward supercapacitor applications. The hybrid 2D platform showed remarkable specific capacitance of 597 F.g(-1) and 557 F.g(-1) using CV and GCD analyses, respectively, through using three-electrode system. The developed supercapacitor exhibited fantastic stability upon maintaining 98.2% of its total performance after 5000 charge-discharge cycles. Likewise, the applicable two-electrode device using same electrode configurations composed of PPy-G-Ni-W//PPy-G-Ni-W showed specific capacitances of 361 F.g(-1) and 342 F.g(-1) at scan rate and current density of 2 mV.s(-1) and 0.5 A.g(-1) using CV and GCD techniques, respectively. Outcome of optimum supercapacitance configuration consisted of two-electrode system exhibits ideal energy density of 14.4 Wh.kg(-1) at power density of 275 W.kg(-1). More importantly, the device preserved 96.4% of its total specific capacitance after 5000 charge-discharge cycles which highlighting the excellent capacitive capability along with ultra-stability of the developed platform toward real energy applications.

We report a general anion sensing platform based on a portable and cost-effective ion-selective optode and a smartphone detector equipped with a color analysis app. In contrast to traditional anion-selective optodes using a hydrophobic polymer and/or plasticizer to dissolve hydrophobic sensing elements, the new optode relies on hydrophilic cellulose paper. The anion ionophore and a lipophilic pH indicator are inkjet-printed and adsorbed on paper and form a “dry” hydrophobic sensing layer. Porous cellulose sheets also allow the sensing site to be modified with dried buffer that prevents any sample pH dependence of the observed color change. A highly selective fluoride optode using an Al(III)-porphyrin ionophore is examined as an initial example of this new anion sensing platform for measurements of fluoride levels in drinking water samples. In addition to Lewis acid-base recognition, hydrogen bonding recognition is also shown to be compatible with this sensing platform.

In this study, we investigated the antibacterial activity of silver-coated gold nanoparticles (Au-Ag NPs) immobilized on cellulose paper. Ag NPs are known to have strong antibacterial properties, while Au NPs are biocompatible and relatively simple to prepare. We made the Au-Ag NPs using a facile process called Ag enhancement, in which Au NPs serve as the nuclei for precipitation of a Ag coating, the thickness of which can be easily controlled by varying the ratio of the reactants. After synthesis, electron microscopy showed that the Au-Ag NPs displayed a core-shell structure, and that they could be successfully immobilized onto a cellulose membrane by heat treatment. We then investigated the antibacterial properties of this NP-coated cellulose paper against E. coli JM109. The inhibition rate, growth curve, and AATCC 100 activity test showed that cellulose paper coated with 15 nm Au-Ag NPs possessed excellent antibacterial activity against E. coli JM109. These results suggest that Au-Ag NPs immobilized on cellulose paper could be a valuable antibacterial technology for applications such as food packaging, clothing, wound dressings, and other personal care products.

In this work, different paper surface modification strategies were compared to obtain an amine functionalized SBA-15 (N-SBA-15) composite for paper-based device development. The synthesized N-SBA-15 was characterized by N 2 adsorption-desorption isotherm, and infrared spectroscopy (FTIR), and it was incorporated to different polymer matrices (κ-carrageenan (CA), polyvinyl alcohol (PVA) and polyethylenimine (PEI)) for the development of the composite modified paper-based device. The retention, interactions, and morphology of the obtained composites were investigated by absorbance measurement, FTIR and scanning electron microscopy (SEM), respectively. To demonstrate the applicability of the modified paper-based device, ascorbic acid (AA) quantification was carried out. Horseradish peroxidase (HRP) was immobilized onto the modified paper surface. HRP in the presence of H 2 O 2 catalyzes the oxidation of 10-acetyl-3,7-dyhidroxyphenoxazine (ADHP) to highly fluorescent resorufin, which was measured by LIF detector. Thus, when AA was added to the solution, it decreases the relative fluorescence signal proportionally to the AA concentration. The linear range from 50 nmol L −1 to 1500 nmol L −1 and a detection limit of 15 nmol L −1 were obtained for AA quantitation. The obtained results allowed us to conclude that N-SBA-15/PEI composite could be considered an excellent choice for the paper-based device modification procedure due to its inherent simplicity, low cost, and sensitivity. Fil: Moreira, Cristian Matias. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; Argentina Fil: Scala Benuzzi, María Luz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; Argentina; Argentina Fil: Takara, Eduardo Andres. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; Argentina; Argentina Fil: Pereira, Sirley Vanesa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; Argentina; Argentina Fil: Regiart, Daniel Matias Gaston. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; Argentina; Argentina Fil: Soler Illia, Galo Juan de Avila Arturo. Universidad Nacional de San Martin. Instituto de Nanosistemas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Raba, Julio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; Argentina; Argentina Fil: Messina, Germán Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; Argentina; Argentina

Six elemental chlorine-free bleaching sequences were studied to see their effect on quality of pulp produced and quantity of pollutants generated during bleaching of wheat straw soda pulp. Impact of parameters like adsorbable organic halogens (AOX), chemical oxygen demand (COD), biochemical oxygen demand (BOD) and sodium adsorption ratio, pH and total dissolved solids generated during bleaching on environment as index of global pollution (IGP) was also studied. The purpose of the study was to investigate six elemental chlorine-free bleaching sequences to compare the pulp quality, effluent properties and their impact on environment. An oxygen delignification stage before D0EOPD bleaching sequence reduced the AOX, COD, colour and BOD by 44%, 42%, 36% and 33%, respectively, whereas an ozonation stage before bleaching reduced the same by 70%, 66%, 73% and 60%, respectively, as compared to those of control. The generation of pollutants as AOX, COD, colour and BOD was reduced further by 88%, 80%, 90% and 77%, respectively, with the use of short bleaching sequences (DD, DP and PD) as compared to those of control. The environmental impact as IGP with D0EOPD bleaching sequence was 2.65 which got reduced to 1.44 with bleaching sequence OZPD. Bleaching sequence OZD0EOPD was found the most effective for improving brightness and whiteness of the pulp, whereas short bleaching sequence OZPD found the most effective for reducing generation of pollutants during bleaching among different bleaching sequences studied.

A new planar sorptive phase based on the simple immobilization of polymeric ionic liquids on paper is proposed. The sorptive phase can develop hydrophobic or mixed-mode (combining hydrophobic and ion exchange) interactions with the target analytes. The polymer is prepared by the Radziszewski reaction, which takes place in aqueous media, and it has been thoroughly characterized by different techniques including infrared spectroscopy, matrix-assisted laser desorption/ionization coupled to high-resolution mass spectrometry and proton nuclear magnetic resonance. Three different strategies aimed to immobilize the polymeric ionic liquid on paper have been evaluated. Among them, simple thermal curing at 120 °C was selected. The as-prepared paper has been evaluated for the extraction of several non-steroidal anti-inflammatory drugs from urine, the analytes being finally determined by liquid chromatography with tandem mass spectrometry. The method detection limits were 3.8, 7.2, 6.8, 9.4, 15.7, and 5.1 μg/L for indomethacin, diclofenac, tolmetin, ketoprofen, naproxen, and ibuprofen, respectively. Calibration models were linear (R2 > 0.9949) up to 1000 μg/L. The intra-day precision, expressed as relative standard deviation and calculated at three different concentrations levels (limit of quantification, 250 μg/L, and 1000 μg/L), varied between 1.1 and 13%. The accuracy, calculated as relative recovery, was in the range from 72 to 95%, thus being considered appropriate. The easiness of polymeric ionic liquid paper synthesis and the multi-sample extraction protocol designed allows the processing of a high number of samples at the same time.

Old corrugated containers with low recyclability were used as raw materials to synthesize a series of aerogels with varying cellulose concentrations in NaOH/urea solution via a freeze-drying process. The resulting aerogels had a rich porous structure with specific surface areas in the range of 132.72-245.19 m

International audience; The fabrication of a fully bio-sourced adsorbent of Cd(II) by covalent immobilization of quinine on cellulose paper is described. The double bond of commercially available quinine was converted to a terminal alkyne function which was reacted with cellulose paper, chemically modified with azide functions, through a 1,3-dipolar cycloaddition, leading to Cell-Quin. The adsorption efficiency of Cell-Quin was investigated to determine the optimal pH, contact time and dose of adsorbent, ultimately leading to high levels of removal. The mechanism of adsorption of Cell-Quin was deeply rationalized through kinetic experiments and isotherm modeling. We also showed that Cell-Quin could adsorb other heavy metals such as Cu(II), Pb(II), Ni(II) and Zn (II).

Enteromorpha prolifera-derived Fe

The wide occurrence of pharmaceuticals in aquatic environments urges the development of cost-effective solutions for their removal from water. In a circular economy context, primary paper mill sludge (PS) was used to produce activated carbon (AC) aiming the adsorptive removal of these contaminants. The use of low-cost precursors for the preparation of ACs capable of competing with commercial ACs continues to be a challenge. A full factorial design of four factors (pyrolysis temperature, residence time, precursor/activating agent ratio, and type of activating agent) at two levels was applied to the production of AC using PS as precursor. The responses analysed were the yield of production, percentage of adsorption for three pharmaceuticals (sulfamethoxazole, carbamazepine, and paroxetine), specific surface area (S ), and total organic carbon (TOC). Statistical analysis was performed to evaluate influencing factors in the responses and to determine the most favourable production conditions. Four ACs presented very good responses, namely on the adsorption of the pharmaceuticals under study (average adsorption percentage around 78%, which is above that of commercial AC), and S between 1389 and 1627 m g . A desirability analysis pointed out 800 °C for 60 min and a precursor/KOH ratio of 1:1 (w/w) as the optimal production conditions., This work was funded by FEDER through COMPETE 2020 and by national funds through FCT by the research project PTDC/AAG-TEC/ 1762/2014. Thanks are also due for the financial support to CESAM (UID/AMB/50017-POCI-01-0145-FEDER-007638), to FCT/MCTES through national funds (PIDDAC), and the co-funding by the FEDER, within the PT2020 Partnership Agreement and Compete 2020. The work was also developed within the scope of the project CICECO - Aveiro Institute of Materials, POCI-01-0145-FEDER-007679 (UID/ CTM/50011/2013), financed by national funds through the FCT/MEC. Vânia Calisto also thanks FCT for her postdoctoral grant (SFRH/BPD/ 78645/2011). Marta Otero and Sérgio Santos thank support by the FCT Investigator Program (IF/00314/2015 and IF/00973/2014, respectively).