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Presence of copying pencils in heritage objects poses a significant challenge for conservators due to their proneness to fading, sensitivity to solvents and difficulties in differentiation from regular graphite pencils. In this paper a method of copying pencils identification by means of ATR—FTIR spectroscopy is used. A protocol for spectra processing and dimensionality reduction of spectral data by means of principal component analysis has been developed, allowing for pencil types differentiation and providing an easy to read visual representation of the collected data. The protocol has been developed on mock-up samples and tested on objects from the archives of the State Museum Auschwitz – Birkenau. [ABSTRACT FROM AUTHOR]

Enhancement of latent fingermarks on thermal paper poses a number of problems when using traditional methods used for porous substrates due to blackening of the thermal layer as a result of polar solvents present within the reagents and high temperatures oxidising the acid/dye complex. Thus, methods which prevent such reactions are favoured for the development of latent prints on said substrates. A comparative pseudo-operational trial using UV, Hot Print System (HPS), ninhydrin and ThermaNIN was performed on 1000 thermal paper substrates gathered from various sources. The results indicated that the most effective method was an acetone pre-wash followed by ninhydrin. The sequence of HPS-ninhydrin was similarly effective when compared to ninhydrin as a sole technique. ThermaNIN produced fewer marks than ninhydrin but was superior to HPS. Whilst the HPS developed some fingermarks, there was only a very small number of marks uniquely developed by it. • The Hot Print System (HPS) is inferior to chemical methods on this substrate. • The HPS uniquely developed very few number of fingermarks. • Ninhydrin was the most effective process; however, it compromises text legibility. • The HPS did not adversely affect subsequent chemical development of fingermarks. • ThermaNIN formulation modified to include HFE-71DE to avoid precipitation. [ABSTRACT FROM AUTHOR]

The present study is concerned usage of paper mill sludge (PMS) as an effective adsorbent to remove the two cationic character dyes (Basic Blue 3 [BB3] and Basic Yellow 28 [BY28]) from aqueous solutions. The surface morphology and some characteristics of PMS were determined by Fouirer Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM) and Brunauer Emmett Teller (BET). The parameters affecting the process – temperature (10–55°C), adsorbent dose (0.5–10 g/l), initial pH (2–10 pH), initial concentration (50–250 mg/l) and contact time (0–24 h) – were examined in the batch adsorption experiments. Maximum adsorption capacities (qmax) of two dyes at 1 g/l dose and pH value of 7 were also calculated as 89.35 and 79.81, respectively. Adsorption phenomena of BB3 and BY28 cationic dyes onto PMS is controlled by pseudo-second-order model. Thereafter, equilibrium experimental data were applied to Langmuir, Freundlich and Dubinin–Redushkevich (D-R) isotherms, and Langmuir isotherm is the best represent the equilibrium adsorption process for both dyes. The processes occurred by physical adsorption because of calculated activation values (Ea) of BB3 and BY28 dyes were 19.43 and 9.35 kJ/mol, respectively. In addition, based on thermodynamic calculations such as free energy (ΔG°), enthalpy (ΔH°) and entropy (ΔS°), the results clearly demonstrated that the adsorption process were of exothermic and spontaneous nature for both dyes. At the light of obtained findings, it can be stated that PMS can be used effectively in removal of cationic dyes from textile wastewaters and is an alternative to commercial adsorbents due to its low-cost and abundance in the paper industries. [ABSTRACT FROM AUTHOR]

Surface-enhanced Raman spectroscopy (SERS) is an emerging analytical technique for chemical analysis, which is favourable due to its combination of short measurement time, high sensitivity and molecular specificity. However, the application of SERS is still limited, largely because in real samples the analyte is often present in a complex matrix that contains micro/macro particles that block the probe laser, as well as molecular contaminants that compete for the enhancing surface. Here, we show a simple and scalable spray-deposition technique to fabricate SERS-active paper substrates which combine sample filtration and enhancement in a single material. Unlike previous spray-deposition methods, in which simple colloidal nanoparticles were sprayed onto solid surfaces, here the colloidal nanoparticles are mixed with hydroxyethyl cellulose (HEC) polymer before application. This leads to significantly improved uniformity in the distribution of enhancing particles as the film dries on the substrate surface. Importantly, the polymer matrix also protects the enhancing particles from air-oxidation during storage but releases them to provide SERS enhancement when the film is rehydrated. These SERS-paper substrates are highly active and a model analyte, crystal violet, was detected down to 4 ng in 10 μL of sample with less than 20% point-by-point signal deviation. The filter paper and HEC effectively filter out both interfering micro/macro particles and molecular (protein) contaminants, allowing the SERS-paper substrates to be used for SERS detection of thiram in mud and melamine in the presence of protein down to nanogram levels without sample pre-treatment or purification. [ABSTRACT FROM AUTHOR]

Facile fabrication of flexible substrates containing high concentration of nanoparticles (NPs) is very promising owing to their capability of swab-based surface-enhanced Raman scattering (SERS) trace detection. However, the background signal of the substrate could compromise the trace-detection capabilities. Moreover, the presence of fluorescent molecules may result in intense fluorescence background which could overshadow the Raman peaks. Herein, we demonstrate that the surfactant-free bimetallic (Ag and Au) NPs, synthesized directly on the filter paper, are very effective in reducing the background signal in SERS-based trace detection. Simple soaking of filter paper in a mixture of HAuCl 4 and AgNO 3 solution, and its immediate drying and reduction produces Au-Ag alloy NPs on the filter paper. Interestingly, the substrates are very effective in quenching the background fluorescence of both filter paper and the analyte, thereby effectively detecting the SERS signature of the fluorescent molecules. In particular, Rhodamine6G (R6G) concentrations down to 10−10 M were detected under resonance excitation, both by solution drying and swabbing. The swab detection of ammonium nitrate, which is usually used in homemade explosives, was also demonstrated. Moreover, owing to the fluorescence quenching properties, the Au-Ag alloy substrates (AuAgS) were able to carry out the swab-based multiplex-detection of crystal violet (CV), Brilliant Cresyl Blue (BCB), and R6G upon resonance excitation of R6G. Finally, the substrates have shown good reproducibility, stability, and signal uniformity. This verifies the potential of AuAgS for real-world trace-detection applications. [ABSTRACT FROM AUTHOR]

A disposable surface-enhanced Raman scattering (SERS) substrate was prepared by successively spraying silver nanoparticles (AgNPs) and gold nanoparticles (AuNPs) onto commercial filter paper using an inexpensive consumer sprayer. The strong surface enhancement of AgNPs and chemical stability of AuNPs can be advantageously combined. The substrate exhibited excellent SERS activity for malachite green (MG), methylene blue (MB), and crystal violet (CV) under 785-nm excitation, with limits of detection (LODs) of 4.3 × 10−9, 2.0 × 10−8, and 8.1 × 10−8 M, respectively. The substrate exhibited long-term stability, and it can be stored under ambient conditions for 4 weeks with a relative standard deviation of less than 3% among peak intensities. The substrate also showed good reproducibility with a relative standard deviation of 7.1% among different substrate peak intensities. The substrates enable on-site determination of residual fishery drugs and distinguish MG, MB, and CV mixtures in spiked fish within 5 min, and the average recoveries in fish scales and fish meat were better 90.1% and 76.9%, respectively. The method exhibited rapidity, simplicity, and high sensitivity and is expected to be used for the screening of additives in food. [ABSTRACT FROM AUTHOR]

One of the methods to solve the problem of lead metal in water is adsorption. One of the adsorbents that can be used is cellulose because it has an active group that can bind Pb(II). In this study, cellulose from the HVS wastepaper was used as the adsorbent to adsorb the Pb metal. HVS wastepaper was extracted with 10% w/v NaHCO3 and refluxed with 5% w/v Na2HPO4. Cellulose was characterized using Fourier Transforms Infrared Spectroscopy (FTIR) and Scanning Electron Microscope (SEM). Pb(II) adsorption was carried out by the batch method, and it was evaluated using Atomic Absorption Spectrophotometry (AAS) with varying adsorbent mass, concentration, contact time, and pH. FTIR characterization showed that the presence of O - H, C - H, C = O, and C - O groups played a role in the adsorption process. The surface morphology of cellulose from SEM analysis showed form like a fiber shape with agglomerated fine particles. The optimum conditions for adsorption were 0.100 g of adsorbent mass, Pb(II) concentration of 105 ppm, contact time of 10 minutes, and pH of solution 5. An adsorption isotherm model that is preferable for this adsorption process is the Freundlich isotherm model. From the results of this study, HVS paper waste can be used as an adsorbent to handle Pb(II) metal ions to be an alternative as a lowcost adsorbent. [ABSTRACT FROM AUTHOR]

We present a tilted fiber Bragg grating (TFBG) sensor coated with crystal violet/perfluorinated sulfonic acid (CV/Nafion) composite film for relative humidity (RH) monitoring. The composite film demonstrates the characteristics of an optical "humidity test paper" by exhibiting a color transition from yellow to green within a RH range of 10 % to 80 %. This color variation indicates its potential to effectively monitor RH levels in diverse environments. To achieve a quantitative RH sensing, we coat CV/Nafion composite film on an etched TFBG (ETFBG), where surrounding RH changes can be measured from spectral responses of ETFBG transmission. In experiments, the proposed the CV/Nafion-coated ETFBG sensor exhibits RH sensitivities of 0.068 dB/%RH and 3 pm/%RH for intensity change and wavelength shift measurements, respectively, within a relative humidity (RH) range of 10 % to 80 %. Additionally, based on intensity measurement, short response and recovery times of ∼4.4 and ∼4.6 s are estimated from a continuous RH monitoring. • The proposed sensor's color will change from yellow to green with the increasing of the RH. • The proposed sensor could be used for RH detection of liquids, gases, and solids. • High RH detection sensitivity of 0.068 dB/% RH was obtained. • The response and recovery times are 4.4 s and 4.6 s respectively. [ABSTRACT FROM AUTHOR]

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Surface‐enhanced Raman scattering (SERS) substrate is the key to SERS technology and it is still a basic focus to fabricate desirable SERS substrates offering multiple advantages of strong Raman enhancement and good reproducibility and portability. A flexible paper‐based SERS substrate were fabricated involving the use of Au nanocubes (NCs) monolayer. Au NCs were generated with tunable size in the range of 24 to 63 nm through seed‐mediated growth method. The effect of support on SERS properties of Au NCs–assembled monolayer was systemically explored. As a result, more excellent SERS performance could be obtained by assembling Au NCs on the filter paper. Besides, the influence of Au NCs' size on SERS‐enhanced effect of paper‐based substrate was also investigated. Our results clearly indicated that paper‐based substrate with 39 nm Au NCs possessed the optimal SERS enhancement. This SERS substrate exhibited high sensitivity with enhancement factor (EF) up to 9.75 × 107 and demonstrated good uniformity and time stability. Furthermore, based on this superior paper‐based SERS substrate with advantage of powerful sample extraction performance, the measurement of crystal violet (CV) on shell surface were successfully carried out with detection limit down to 2.17 × 10−7 M. And linear quantification were achieved in the range from 5 × 10−5 to 5 × 10−7 M. To sum up, the as‐prepared SERS substrate is applicable for on‐site detection and analysis of CV on various shell surfaces. [ABSTRACT FROM AUTHOR]

Gamma radiations are known to bring about radiolysis of myriad compounds / dyes which is used to measure of the energy of the incident radiation on the system. The use of various dye solutions for chemical dosimetry is reported in literature. Various thin film dosimeters, semi-conductor dosimeters are also reported and widely used. Similarly ? - dose quantification using paper or polymer impregnated with dyes has also been reported. In the present study, decolouration due to gamma radiation of various dye impregnated papers viz. Gentian Violet (GV), Malachite Blue (MB), Malachite Green (MG), Brilliant Yellow (BY) and Congo Red (CR) has been investigated using device independent colour parameters. The colour analysis was done by standard procedures of Commission Internationale de l'Eclairage CIE. Color has mind dependency so to eliminate the errors in determination colour parameters are evaluated. [ABSTRACT FROM AUTHOR]

Abstract: Triphenylmethanes – Malachite Green (MG), Crystal Violet (CV) and Brilliant Green (BG) are dyes with known genotoxic and carcinogenic properties. Apart from being illegally used in aquaculture for treatment of fish diseases they are also applied in industry such as paper production to colour paper towels widely used in hospitals, factories and other locations for hand drying after washing. The present study provides evidence that the triphenylmethane dye (BG) present in green paper towels can migrate through the skin even when the exposure time is short (30–300s). The transfer of the dye from the towel to food (fish) was also studied and a high amount of colour was found to migrate during overnight exposure. The risk to humans associated with these two dye transfer studies was assessed using a ‘margin of exposure approach’ on the basis of the toxicological data available for the closely related dye MG and its metabolite Leucomalachite Green. The data indicated that the risk associated with the use of triphenylmethane containing paper towels is of a similar proportion to the risk associated with consumption of fish contaminated with these dyes due to the illegal application in aquaculture. [Copyright &y& Elsevier]

[Display omitted] • Inkjet printing Ag nanoparticles on paper coated with chitosan or N,N, N -trimethyl chitosan to obtain SERS substrates. • Biopolymer coatings not only reduce the rugosity and porosity of the paper but also confer hydrophobicity to the paper. • SERS sensitivity and reproducibility was improved when compared with non-coated counterparts. Paper-based sensors for surface-enhanced Raman scattering (SERS) detection of water pollutants have gained much attention in the last decades. However, most of the fabricated paper-based SERS substrates still face some limitations regarding reproducibility and uniformity. In this work, we report the fabrication of hydrophobic paper-based SERS substrates with high reproducibility and uniformity by inkjet printing Ag colloidal nanoparticles (NPs) on office paper pre-treated with chitosan (CH) or N,N, N -trimethyl chitosan (TMC). We demonstrate that the previous coating of paper with such biopolymers substantially improves the SERS performance of the paper substrates. In screening experiments, crystal violet (CV) 100 μM was used as molecular probe, leading to an increase of about 9- and 7-fold in the observed SERS intensity when the papers were coated with CH and TMC, respectively. Also, the reproducibility of the substrates coated with the biopolymers increased more than 2 times compared to non-coated office paper. We suggest that the improved performance of the coated substrates is related to a more uniform deposition of the AgNPs on the paper surface due to the hydrophobic nature, low porosity and roughness of the coated paper. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate the activity, resistance, clonality of MIC distribution, and the correlation between virulence and resistance genes and biofilm formation of omadacycline (OMC) in clinics for Streptococcus agalactiae isolates from China. 162 isolates were collected retrospectively in China. The S. agalactiae were collected from the body's cervical secretions, wound secretions, ear swabs, secretions, semen, venous blood, cerebrospinal fluid, pee, etc. The MIC of OMC against S. agalactiae was determined by broth microdilution. The inhibition zone diameters of OMC and other common antibiotics were measured using filter paper. D-test was performed to determine the phenotype of cross resistance between erythromycin and clindamycin. In Multilocus sequence typing (MLST), some commonly-detected resistance genes and virulence gene of these S. agalactiae isolates were investigated using polymerase chain reaction (PCR). Biofilms were detected by crystal violet staining. Our data demonstrated the correalation of the biofilm formation and OMA antimicrobial susceptibility of S.agalactiae clinical isolates with the carrier of virulence gene scpB. Conclusively, OMC exhibits the robust antimcirobial activity against clinical S. agalactiae isolates from China compared with DOX or MIN, and the carrier of the virulence gene scpB might correlate with the biofilm formation in OMC-resistant S. agalactiae. [ABSTRACT FROM AUTHOR]

In this paper, we have developed a paper-based optical imaging material responding to visible light. This material consists of a thioxanthone (TX) derivative with the additional phenyl carbazole chromophore, namely 1-phenyl-11,12a-dihydrothiochromeno (3,2-b) carbazol-13 (5H)-one (TX-PC), and leuco crystal violet (LCV). TX-PC is newly synthesized and characterized by 1 HNMR, FTIR and high-resolution mass spectrometer. As a visible light absorbing Type II photoinitiator, TX-PC has an excellent absorption property in the visible region in the absence of an added co-initiator. In other words, TX-PC degrades into lively free radicals when irradiating under visible light which resulting in a color reaction on LCV. The degree of reaction is characterized by UV–vis spectrophotometer. In this study, this material is used for imaging within visible light because of the high efficiency color reaction. We coat a paper substrate with this TX-PC/LCV solution and cover with a pattern photomask. Under the irradiation of the visible light, color reaction occurs to irradiated area while the rest remains colorless. Thus the two areas are distinguished to obtain a clear image as same as the original version. [ABSTRACT FROM AUTHOR]

• Fabrication of an inkjet-printed paper-based SERS platform. • An effective AuSph Ink was developed with high stability over 1 year of storage. • Improvement of SERS capabilities by a hydrophobic modification of the paper. • Ultrasensitive quantification of thiram at 10−11 M with low sample volume (2 μL). • Reliable, robust and ultralow-cost SERS substrates (less than $ 0.01 per spot). We report the fabrication of a low-cost paper-based SERS platform with enhanced sensing capabilities. The sensor consists of a highly concentrated glycerol/ethanol dispersion of ca. 77 nm Au nanospheres (AuSph) inkjet-printed on hydrophobic chromatographic paper forming circular sensing spots of 1 mm in diameter. The AuSph ink exhibits high stability for 1 year. Interestingly, we demonstrate that the modification of the paper surface with hydrophobic ligands improve the sensing capabilities by confining the analyte solution in the AuSph sensing platform. It contributes to both concentrate the analyte, as well as, to decrease the sample volume to just a few μl. We also analyze the effect of the amount of the nanoparticles, tunable by the number of printing cycles, in the SERS performance of the plasmonic spots. The results show that 5 printing cycles give rise to sensing platforms with great SERS response in terms of intensity and uniformity. The spot-to-spot reproducibility is also analyzed observing good results even for AuSph spots from different printed papers. The paper-based SERS platform was tested towards the detection of crystal violet (CV) and the fungicide thiram. Additionally, applying a digital protocol for SERS analysis, a good linear correlation between the digital counts (or positive events) and the analyte concentration was obtained at the single-molecule SERS regime. In both cases, the quantification region threshold was 10−11 M. The great sensitivity performance of the inkjet-printed SERS substrate is reflected by the low sample volume needed (only 2 μL). The inkjet-printed SERS substrate and the fabrication method demonstrated to be efficient, reliable, reproducible and robust, with a cost less than $ 0.01 per spot. [ABSTRACT FROM AUTHOR]

In this work, we demonstrate a seeded approach for in-situ growth of Ag nanostructures directly on filter paper. Multiple growth steps were used to increase the size of Ag NPs grown from Au seeds. Essentially, this procedure generated a high density of NPs on filter paper which in turn provided high enhancement of Raman signals. We have seen a marked increase in the SERS enhancement factor with each growth step. Moreover, the relative standard deviation (RSD) values decreased with each growth step, indicating the relatively uniform distribution of NPs on the substrate. With four growth steps, we were able to achieve an EF of 9.28 × 104 with RSD values of 14%. In particular, the detection limit of 10 nM for CV has been achieved by both solution drying and swabbing. Moreover, swab detection of explosive material ammonium nitrate down to 100 µM has also been demonstrated. [ABSTRACT FROM AUTHOR]

It is shown that Malachite Green and Crystal Violet immobilized on viscose fabrics can be used as reagents for the rapid determination of selenium(IV) and tellurium(IV). Selenium is determine by the color intensity of ion associates formed by the reagents with the triiodide ion formed upon the reduction of selenium(IV) with potassium iodide and tellurium, by the color intensity of reagent ion associates with telluromolybdic heteropoly acid. The analytical ranges for selenium and tellurium(IV) were 0.005–0.5 and 0.01–0.1 mg/L upon passing 20 and 100 mL of a test solution through the indicator matrix, respectively. The duration of analysis does not exceed 15–20 min. The relative standard deviation is 50%. Test strips were proposed for determining 0.1–100 mg/L selenium(IV) and 1–1000 mg/L tellurium(IV) by the length of the colored zone. The determination of selenium(IV) is based on the oxidation of 4-nitrophenylgydrazine to its diazonium salt and salt interaction with naphthylamine chemically immobilized on paper with the formation of a red azo compound. The determination of tellurium(IV) is based on its reaction with Bismuthol II immobilized on a paper. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

The article presents a case in which the patient, an office clerk got an irritant vesicular rash on the palms which spread to the back and sides of her fingers. Her work entailed day-long handling of significant quantities of Carbonless copy paper and carbon paper and operating a visual display unit. Initial patch tests to a standard battery and to carbonless copy paper gave positive allergic reactions to nickel sulphate 5%, cobalt chloride 1% and fragrance mix 8%, but no reaction to the paper handled. Further tests indicated an allergic reaction to crystal violet lactone present in the carbonless copy paper.

In this paper, a NiAl-LDH with the characteristic structure of a hydrotalc-like compound was applied as a carrier in a two-step hydrothermal process, and a MnCdS/In2S3/NiAl-LDH composite material was successfully prepared by loading MnCdS and In2S3 on the flower spherical-like surface of NiAl-LDH. The combination of NiAl-LDH with In2S3 and MnCdS made the band gap smaller and the light absorption range larger, thus increasing the utilization rate of light. 50% MnCdS/In2S3/NiAl-LDH composites had the best photoinduced charge separation and highest surface enrichment of photogenerated electrons. In the degradation experiment of crystal violet (CV), 50% MnCdS/In2S3/NiAl-LDH composites showed superior photocatalytic degradation efficiency (>98.5%) under full spectrum light. Furthermore, the applicability and universality of photocatalysts were studied by observing the degradation of CV by MnCdS/In2S3/NiAl-LDH composites under different conditions. In addition, the composites showed excellent hydrogen production capacity in the photolysis of water, in which hydrogen production within 8 hours was about 7661.51 μmol g−1. By combining the results of active species capture experiments, density functional theory (DFT) calculations and photoelectrochemical experiments, the possible mechanism of double S-scheme heterojunction photocatalysis among NiAl-LDH, In2S3 and MnCdS was inferred, which is one of the main reasons for the enhancement of photocatalytic activity. [ABSTRACT FROM AUTHOR]

The crystal violet (CV) staining technique represents a prevalent approach for the development of latent fingerprints, especially on adhesive tape surfaces. Nevertheless, the technique necessitates intricate formulations to augment its performance. In this investigation, an optimized CV staining protocol was developed, characterized by the absence of residual dye on the target substrates and the capability of facilitating fingerprint visualization under ambient light conditions. Four donors, comprising two males and two females, deposited natural fingerprints on various substrates, including glass microscope slides, aluminum foil, and 115 g glossy coated paper, without any specific guidelines. Fingerprints developed using cyanoacrylate fuming served as benchmarks and were contrasted with those generated through alternative methods: CV, ardrox, rhodamine 6G, powdering, and the optimized CV staining protocol. The fingerprint development experiment was replicated at seven distinct time intervals, encompassing 1 day, 1 week, 1, 3, 6, 9, and 12 months, resulting in a dataset of 420 fingerprints. The evaluation of fingerprint identifiability employed a scoring system established by the Home Office Centre for Applied Science and Technology. The results indicated that the optimized CV staining technique demonstrated superior performance, boasting a 92.9% rate of identifiable fingerprint development in contrast to other employed methodologies. Consequently, this optimized CV staining approach is recommended as an efficient, rapid, and straightforward critical dyeing method, applicable to a wide array of substrates in forensic investigations. [ABSTRACT FROM AUTHOR]

Chemical enhancement methods for fingermark in blood deposited on the surface of a thermal paper substrate were examined. The blood-sensitive reagents compared were LCV (leuco crystal violet), Amido black and Hungarian red. Fingermark in blood on the surface of thermal paper can be fixed with 2% 5-sulfosalicylic acid solution. LCV was found as an inadequate blood staining reagent because of bubbling, diffusion, and blurring on the surface of thermal paper. Hungarian red was also an inadequate blood staining reagent because excess Hungarian red on the surface of thermal paper was not washed away in the de-staining procedure. Amido black was the best staining reagent among three staining reagents compared. The maximum dilution ratio visible to the naked eye after Amido black staining was 1 in 80 for the thermally sensitive surface and 1 in 20 for the thermally non-sensitive surface. [ABSTRACT FROM AUTHOR]

A new adsorbent was prepared from municipal wastes (a mixture of Corn Stover, Paper Waste, and Yard Waste) by cationization with 3 ̶ Chloro ̶ 2 ̶ Hydroxypropyl Trimethylammonium Chloride. The FTIR spectrum confirmed the quaternary ammonium group's presence on the adsorbent surface (1450 cm−1). The maximum adsorption capacity (148 mg/g) was higher than the earlier reported values. Liu isotherm described well the adsorption process, with a high R2 adj value (0.997). The pseudo-first-order equation fits well for kinetic data, and thermodynamic experiments demonstrated the endothermic nature of the adsorption. The deep neural network (DNN) is applied to simulate the adsorption process, which outperformed the classical machine learning and shallow neural network models. The DNN model predicted accurately the adsorption process with the lowest deviation from the actual values with Mean Absolute Error (MAE = 3.2), Root Mean Squared Error (RMSE = 4.89), and the highest performance accuracy of R2 (0.96) as compared to various classical ML algorithms such as Linear Regressions (MAE = 12.53, RMSE = 18.01, R2 = 0.42), Random Forest (MAE = 5.81, RMSE = 10.05, R2 = 0.82), and Extra Trees (MAE = 4.35, RMSE = 8.22, R2 = 0.88). The utilized DNN model can be used for predicting the removal efficiency of dyes for various combinations of input parameters without going through laboratory experiments. ga1 • Matrix of municipal waste was converted into an absorbent by surface cationization. • The adsorbent had higher adsorption capacity for anionic dye Indigo Carmine. • Liu isotherm described well the adsorption process. • Classical machine learning models didn't predict accurately. • Deep Neural Network was able to model the adsorption process with 96% accuracy. [ABSTRACT FROM AUTHOR]

Abstract: The adsorption of methyl orange and methyl violet from aqueous solutions by Phragmites australis activated carbon (PAAC) was studied in a batch adsorption system. The adsorption studies include both equilibrium adsorption isotherms and kinetics. Several isotherm models were investigated and the adsorption isotherm data were best represented by the Temkin isotherms. The kinetic data were well described by the pseudo-second-order kinetic model. The mechanism of the adsorption process was determined from the intraparticle diffusion model. The results indicate that PAAC could be employed as a low-cost alternative for the removal of the textile dyes from effluents. [Copyright &y& Elsevier]

Insufficient dental restoration finishing and polishing may lead to plaque accumulation, gingival inflammation, staining, caries, and esthetic impairment. Here, the effect of two finishing and polishing systems on surface roughness and bacterial adhesion were evaluated. Two finishing and polishing kits were evaluated: diamond burs (Shine 1-2, Strauss & Co, Raanana, Israel) and paper discs (Sof-Lex 3M ESPE, Seefeld, Germany) (n = 30 each). For each group surface roughness was evaluated using an optical profilometer (Contour GT-K1, Bruker, Billerica, MA, USA) (n = 10). Surface bacteria were evaluated for biofilm biomass using crystal violet (CV) staining (absorbance measured at 538 nm) and viable counts (CFU/mL) (n = 20). The control group included polymerized discs against a Mylar strip (n = 30). Student's t test and one-way ANOVA were used for statistical evaluation. Diamond burs, paper discs, and control average surface RA were 169.4 ± 45.2 µ, 364 ± 77.7 µ, and 121.2 ± 18.1 µ, respectively. There was a significant difference found between all groups (p < 0.00001). Bacterial biomass on diamond burs, paper discs, and control samples were 0.458 ± 0.161, 0.507 ± 0.139, and 0.446 ± 0.142, respectively (p = 0.257). Viable bacterial counts (CFU/mL) on diamond burs, paper discs, and control samples were 2.25 × 104, 2.95 × 104, and 2.75 × 104, respectively (p = 0.856). A comparison between two finishing and polishing kits showed that the shine 1–2 diamond bur kit produced a smoother surface than the polishing disc kit. No differences were found in the biofilm biomass quantification and bacterial viable count between the groups. [ABSTRACT FROM AUTHOR]

The dating of ink in questioned documents remains a significant challenge in forensic investigations in Vietnam and other countries. Many forensic examination methods have been usually applied to ensure the highest accuracy of the assessment results while maintaining high environment awareness. In this study, paper characteristics were physically tested to confirm source similarity, and the relative ink dating was established by high-performance thin-layer chromatography (HPTLC). Absolute ink dating by solvent and dye identification was performed by Raman spectrometry—a green technique, using a time-dependent degradation model for crystal violet and the comparison between 2-phenoxyethanol peak intensities. We found that the relative dating of the questioned document was 14 ± 3 months lesser than that of the reference samples, i.e., the absolute age of the questioned samples was estimated to be 24 ± 3 months. The combination of the conventional HPTLC method with the dynamic crystal violet degradation Raman model provides promising results for relative and absolute ink dating of ballpoint pens, which can be applied for documents written 1–15 years prior to the time of examination. The combination of the abovementioned methods demonstrated an acceptable error margin, affording highly practical applications in modern forensic science. [ABSTRACT FROM AUTHOR]

In the former section of the present paper, the prospective application of B. mojavensis BI2 derived lipopeptides for dyes biodecolorization was demonstrated. The lipopeptide was mainly composed of linear and cyclic Fengycin and Surfactin isoforms. When using 100 mg/L, we are able to remove about 98% of 100 and 200 mg/L Malachite Green (MG). For the Crystal Violet (CV), the % of biodecolorization does not exceed 85% in the presence of 100 and 400 mg/L BI2 lipopeptide. In the second part of the paper, we proved the efficiency of dyes biosorption by palm waste floor, optimized by a Taguichi design. The bio-treatment efficiency was evaluated by color removal and the enhancement of germination index. Optimum treatments were obtained with 10 g/L and 6 g/L palm waste for 200 mg/L MG and CV respectively during 1 hour. Nevertheless, BI2 lipopeptide addition has no significant effect on color biosorption by date palm waste flour. [ABSTRACT FROM AUTHOR]

Industrial dyes are considered one of the main causes of increased water pollution of water. Many businesses, such as steel and paper, are located along riverbanks because they require large amounts of water in their manufacturing processes, and their wastes, which contain acids, alkalis, dyes, and other chemicals, are dumped and poured into rivers as effluents. For example, chemical enterprises producing aluminum emit a significant quantity of fluoride into the air and effluents into water bodies. Fertilizer facilities produce a lot of ammonia, whereas steel plants produce cyanide. Many nations consider employing wastewater treatment plants using physical, biological, and chemical methods to clean the wastewater to address environmental crises. The treated water can be used for targeting the irrigation systems in its majority, as it is biologically acceptable for that specific use, industrial dyes are considered one of the leading causes of increased water pollution of water. Many businesses, such as steel and paper, are located along riverbanks because they require large amounts of water in their manufacturing processes, and their wastes, which contain acids, alkalis, dyes, and other chemicals, are dumped and poured into rivers as effluents. For example, chemical enterprises producing aluminum emit a significant quantity of fluoride into the air and effluents into water bodies. Fertilizer facilities produce much ammonia, whereas steel plants produce cyanide. Chromium salts are used in. Many nations consider employing wastewater treatment plants using physical, biological, and chemical methods to clean the wastewater to address environmental crises. The treated water can target the majority of irrigation systems, as it is biologically acceptable for that specific use, which economizes the use of freshwater sources for municipal use. This study presents a novel method for fabricating an efficient adsorbent sheet for wastewater treatment. The sheets are fabricated by combining sugarcane bagasse pulp as a scaffold with commercial, naturally activated carbon, and bimetallic‐prepared adsorbents. Sugarcane bagasse is utilized in producing activated carbon because of its high carbon contents, availability, and low cost. The prepared composite sheets are synthesized and investigated for pollutants removal of crystal violet (CV), methyl orange (MO), and Chromium (CI) dyes. Different weight ratios of activated carbon are used to form a bio‐composite mixed sheet. The formed sheets' morphology is performed via a high scanning electron microscope (SEM) and Fourier Transform Infrared Spectroscopy (FTIR). To determine the adsorption mechanism, the intra‐particle diffuse screening experiment is used to test the experimental data. All the prepared sheets can retain the pollutants, with the best removal efficiency of 98% for methyl orange adsorption onto the bio‐composite mixed sheet. The results of the parameter (time, concentration, and dose) sets provided valuable proof that the adsorption of methyl orange onto the bio‐composite sheet mixed with naturally activated carbon is an endothermic phenomenon involving physical adsorption. [ABSTRACT FROM AUTHOR]

This Special Issue includes 12 research papers on the development of various materials for adsorbing different contaminants in water, such as Sb, Cr(VI), Cu(II), Zn(II), fluorine, phenol, dyes (indigo carmine, Congo red, methylene blue, and crystal violet), and drugs (dlevofloxacin, captopril, and diclofenac, and paracetamol). The commercial, natural, and synthetic materials used as adsorbents comprise commercial activated carbon, natural clay and montmorillonite, biosorbent based on sugarcane bagasse or algal, graphene oxide, graphene oxide-based magnetic nanomaterial, mesoporous Zr-G-C3N4 nanomaterial, nitrogen-doped core–shell mesoporous carbonaceous nano-sphere, magnetic Fe-C-N composite, polyaniline-immobilized ZnO nanorod, and hydroxy-iron/acid–base-modified sepiolite composite. Various operational conditions are evaluated under batch adsorption experiments, such as pH, NaCl, solid/liquid ratio, stirring speed, contact time, solution temperature, initial adsorbate concentration. The re-usability of laden materials is evaluated through adsorption–desorption cycles. Adsorption kinetics, isotherm, thermodynamics, and mechanisms are studied and discussed. Machine learning processes and statistical physics models are also applied in the field of adsorption science and technology. [ABSTRACT FROM AUTHOR]

Building an optical filtration function into a microfluidic chip is a promising way of simplifying the optical detection system of a microfluidic device. In this paper, a PDMS microfluidic chip filter that is capable of transmitting chlorophyll fluorescence and blocking interfering light in the visible wavelength range was developed for living algae detection with a smartphone. The chip was fabricated by sealing a layer of crystal violet solution in a PDMS layer on the top of the Sudan II-doped PDMS slab, which has a straight microchannel. Optimum dye concentrations and thicknesses for the crystal violet solution layer and Sudan II-doped PDMS slab were investigated and determined by spectrum measurements. It was found that the cut-on range of this integrated microfluidic chip is extended to about 625 nm and the transmittance in the chlorophyll fluorescence range (650 nm to 710 nm) is as high as 95%, when 25 mg L−1 Sudan II-doped PDMS slab (with a 3 mm thickness) and 2 mg L−1 crystal violet solution (with a 0.3 mm thickness) were used. Living algae detection using this chlorophyll-fluorescence-filtering PDMS microfluidic chip and a smartphone-based imaging platform was achieved, and the results compared favorably with those using a commercial filter. [ABSTRACT FROM AUTHOR]

Environmental monitoring, environmental remediation, microbiotechnology, wastewater treatment, modeling design Meanwhile, other papers also included the studies on modeling design, pollutant degradation and greenhouse gas emissions, which also covered water, soil and constructed wetlands involved with microorganisms. Keywords: environmental monitoring; environmental remediation; microbiotechnology; wastewater treatment; modeling design EN environmental monitoring environmental remediation microbiotechnology wastewater treatment modeling design 1 3 3 05/17/22 20220513 NES 220513 With the continuous improvement of the level of scientific and technological innovation, many emerging materials and chemicals have come into our lives, which has brought great pressure to the environment and caused an increasing number of contamination problems (Atashgahi et al., [2]; Escher Beate et al., [3]; Johnson Andrew et al., [4]). [Extracted from the article]

The present paper focused on synthesizing a polyacrylamide-titanium dioxide (PAA@TiO2) nanocomposite using a cross-linking method with N, N′-methylenebisacrylamide and then using this composite to eliminate crystal violet (CV) dye from water and to characterize the adsorbent by XRD, FT-IR, and SEM-EDX techniques. The characterization revealed that TiO2 nanoparticles dispersed homogeneously within the polymer matrix. The maximum amount of adsorption was about 38.9 mg g−1 under the adsorbent dose of 5 g L−1, 500 mg L−1 CV dye concentration, and pH 6.9. The interaction between the CV molecule and the PAA@TiO2 nanocomposite surface was studied using Monte Carlo (MC) and molecular dynamics (MD) simulations. The negative value of the Eads (− 586.56 kcal mol−1) of the CV molecules onto the PAA@TiO2 nanocomposite surface gives credibility to the experimental results. All obtained results showed that PAA@TiO2 hybrid polymer nanocomposite could be an alternative adsorbent for crystal violet dye removal from wastewater. [ABSTRACT FROM AUTHOR]

This paper's purpose was to evaluate the interaction between three imidazole derivatives, (2-methyl-1H-imidazol-1-yl)methanol (SAM3), 1,1′-methanediylbis(1H-benzimidazole (AM5) and (1H-benzo[d]imidazol-1-yl)methanol 1-hydroxymethylbenzimidazole (SAM5) on the one hand, and sodium dodecyl sulphate (SDS) on the other, as antifungal combinations against Candida spp. Inhibitory activity was assessed using the agar diffusion method and Minimal Inhibitory Concentration (MIC) and showed moderate inhibitory activity of single imidazole derivatives against Candida spp. The mean value of MIC ranged from 200 µg/mL (SAM3) to 312.5 µg/mL (SAM3), while for SDS the MIC was around 1000 µg/mL. When used in combination with SDS, the imidazole derivatives demonstrated an improvement in their antifungal activity. Their MIC decreased over five times for AM5 and over seven times for SAM3 and SAM5, respectively, and ranged from 26.56 µg/mL (SAM3) to 53.90 µg/mL (AM5). Most combinations displayed an additive effect while a clear synergistic effect was recorded in only a few cases. Thus, the FIC Index (FICI) with values between 0.311 and 0.375 showed a synergistic effect against Candida spp. when SDS was associated with SAM3 (three strains), SAM5 (two strains) and AM5 (one strain). The association of imidazole derivatives with SDS led to the increased release of cellular material as well as the intracellular influx of crystal violet (CV), which indicated an alteration of the membrane permeability of Candida spp. cells. This favored the synergistic effect via increasing the intracellular influx of imidazoles. [ABSTRACT FROM AUTHOR]

Escherichia coli is an important bacterium for preventing food poisoning and biofilm infections. The emergence of antibiotic-resistant microorganisms necessitates the development of new antibiotics. The formation of bacterial biofilm is a drug-resistance mechanism utilized by diverse microorganisms. Therefore, it is important to identify compounds that can inhibit biofilm formation and cell survival, without triggering drug resistance. Herein, the antibacterial and antibiofilm activities of 2 types of Thai propolis (collected from Chiang Mai and Chanthaburi) against E. coli were investigated. The antibacterial activity was evaluated using the paper-disc method, while the minimum inhibitory concentration assay was performed using 2-fold serial dilution. Both types of Thai propolis and their isolated compounds showed antibacterial activity against E. coli (minimum inhibitory concentration: 32 µg/mL). The biofilm growth and development were assessed using a crystal violet solution. In particular, the extracts of the Chiang Mai propolis exhibited a significant antibiofilm formation activity against E. coli. Four prenylflavonoids, present in high proportions in the Chiang Mai propolis extracts, inhibited biofilm formation at low concentrations, contributing to the overall antibiofilm activity. These findings indicate that Thai propolis, a natural product, exhibits antibacterial and antibiofilm activities against E. coli. [ABSTRACT FROM AUTHOR]

In this paper, 4‐aminosalicylic acid functionalized multiwalled carbon nanotubes (CNT‐ASA) filled in a mini‐column and attached to a Flow‐injection system for the adsorptive removal of Crystal violet (CV) dye was employed. The remaining CV concentration was detected by a UV‐Visible Spectrophotometric method, which is proposed in this paper. The factors influencing the adsorption and desorption of CV, such as pH, eluent, sample and eluent flow rates were optimized. The optimum pH was 5.5, the eluent selected for desorption was 1 N acetic acid: ethanol (8 : 2), and the sample and eluent flow rate were both 5 mL min−1. Under the optimum conditions, the results obtained showed that CNT‐ASA possessed excellent dye removal efficiency of ∼99 % and adsorption capacity of 440 mg g−1 for CV. The advantage of using the flow‐injection system is the faster adsorption process (in just 1 minute), less amount and high reuse of the nano‐adsorbent, which is better in comparison to the traditional column method. The proposed method was applied on industrial and river water samples and good recovery (99–105 %) was obtained. Hence, it can be concluded that the proposed method is fast, effective, and can be applied on large‐scale wastewater treatment. [ABSTRACT FROM AUTHOR]

In this paper, Fe3O4 magnetic nanoparticles (Fe3O4 NPs) were successfully synthesised and dispersed on alfalfa to prepare Fe3O4/alfalfa nanocomposite for cationic dye removal from aqueous solutions. Characterisation of Fe3O4/alfalfa nanocomposite using FT-IR, FESEM, and EDX analyses showed that the Fe3O4 NPs were excellently dispersed on alfalfa. The results display that the Fe3O4/alfalfa as a green adsorbent have high removal ability for toxic cationic dyes, such as malachite green (MG) and crystal violet (CV). For Fe3O4-alfalfa, the average particle size of nanoparticles on alfalfa (around 20–30 nm) has decreased compared with alone Fe3O4. The experiments showed that the adsorption of dyes onto Fe3O4-alfalfa better described with pseudo-second-order kinetic and Freundlich isotherm models, suggesting the surface heterogeneity of the Fe3O4/alfalfa. Furthermore, Fe3O4-alfalfa with adsorption capacity of 62.68 mgg−1 and 55.12 mgg−1 towards MG and CV, respectively, was comparable with those of the reported adsorbents. The results indicated that the adsorption of both dyes onto Fe3O4-alfalfa was thermodynamically spontaneous and more favourable at lower temperatures. The results also confirmed that the removal of MG and CV by Fe3O4-alfalfa were remarkable after reusing five times. Therefore, the Fe3O4-alfalfa as a green and low-cost nanoadsorbent with an easy synthesis route could be used for purification of water and wastewater contaminated by pollutants. [ABSTRACT FROM AUTHOR]

Copyright of Forensic Science & Technology is the property of Institute of Forensic Science, Ministry of Public Security and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The combination of two compounds with known antimicrobial activity may, in some cases, be an effective way to limit the resistance to antibiotics of specific pathogens. Molecules carrying pyrazole moiety are well known for their bioactive properties and have wide applicability in the medical and pharmaceutical field. Surfactants have, among other useful properties, the ability to affect the growth of microorganisms. The paper reports on the effect of the combination of two pyrazole derivatives, (1H-pyrazol-1-yl) methanol 1-hydroxymethylpyrazole (SAM1) and 1,1′methandiylbis (1H–pyrazol) (AM1), with sorbitan monolaurate (polysorbate 21, Tween 21, T21) on the growth of Gram-positive and Gram-negative bacteria. The results demonstrated a different ability of this combination to inhibit Staphylococcus aureus and Escherichia coli. T21 intensified the inhibitory activity of the pyrazoles to a greater extent in the Gram-negative bacteria compared to the Gram-positive ones, a fact confirmed by time-kill experiments. The experimental data showed that the association of T21 with the pyrazoles led to the increased release of intracellular material and a more intense uptake of crystal violet, which indicates that the potentiation of the antibacterial effect was based on the modification of the normal permeability of bacterial cells. T21 acted as a modulating factor and increased the permeability of the membrane, allowing the accelerated penetration of the pyrazoles inside the bacterial cells. This fact is important in controlling the global increase in microbial resistance to antibiotics and antimicrobials and finding viable solutions to overcome the antibiotic crisis. The paper highlights the possibility of using non-toxic surfactant molecules in antimicrobial combinations with practical applications. This could widen the range of adjuvants in applications which would be useful in the control of resistant microorganisms. [ABSTRACT FROM AUTHOR]

In this paper, the novel ECL sensor of the 6‐methoxychromone (6‐MC)/S2O82− system was designed by using 2‐naphthalene sulfonic acid (2‐NSA) as a co‐reaction accelerator. Fluorescence, ECL spectrum, and cyclic voltammetry (CV) were used to explore extensively the ECL mechanism of the system. It is worth pointing out that 2‐naphthalene sulfonic acid (2‐NSA) was first proposed as a co‐reaction accelerator, reacting with the coreactant K2S2O8 rather than the luminophore, promoting the generation of additional oxidant SO4− from S2O82−, thus amplifying the ECL signal. Furthermore, under the optimal experimental conditions, the high sensitivity of the 2‐naphthalene sulfonic acid (2‐NSA)+6‐methoxychromone (6‐MC)/S2O82− system was realized for the detection of methyl violet (MV) in the linear range of 10−8~10−2 M, with a detection limit of 5.14×10−10 M. In addition, this find offers some guidance for further developing co‐reaction accelerators with excellent performance in the future. [ABSTRACT FROM AUTHOR]

Developing synthetic strategies for smart materials for the adsorption and separation of toxic chemicals is of great importance. Metal–organic frameworks (MOFs) have been proven to be outstanding adsorbent materials that possess excellent pollutant removal performances in wastewater treatment, including dye recycling. In this work, a neutral Cd(II) based 2D framework with a dual ligand strategy involving –OH functionalized 5-hydroxyisophthalic acid (5-OH-H2IPA) and the amide decorated Schiff base ligand (E)-N′-(pyridin-4-ylmethylene)isonicotinohydrazide (L) has been synthesized by different synthetic routes and characterized by various analytical methods. Thus, crystals of {[Cd(5-OH-IPA)(L)]·CH3OH}n synthesized via diffusion (ADES-7D) and the phase pure bulk product synthesized by conventional reflux (ADES-7C) and the mechanochemical grinding method (ADES-7M) have been established using PXRD data of the respective product showing identical simulated SXRD data to those of ADES-7D. The mechanochemically synthesized ADES-7M possesses a better surface area and CO2 adsorption capability compared to ADES-7C, which is also supported by electron microscopy and particle size measurements. Furthermore, ADES-7 can be used as an efficient adsorbent material for the reversible, selective adsorption (42–99%) and separation of the cationic dyes malachite green (MG), methyl violet (MV), methylene blue (MB), and rhodamine B (RhB) from the mixture of cationic/anionic dyes (methyl orange (MO) and bromocresol green (BCG)) in the aqueous phase. Specifically, ADES-7M possesses better dye capture capability compared to ADES-7C, even in the case of the bigger dye RhB with adsorption differences of 2.38 to 1.01 mg g−1, respectively. The dye adsorption kinetics follows pseudo-second-order kinetics, and the dye adsorption isotherm fits well with the Langmuir/Freundlich adsorption isotherm models. The probable mechanism of adsorption involving the supramolecular interaction between the host MOF and the guest dye has also been proposed. [ABSTRACT FROM AUTHOR]

The thermal decomposition or even explosion of nitrocellulose during long-term storage is prevented by adding stabilizers to nitrocellulose-based propellants. A series of novel arylmalonamide[70]fullerocyclopropane (3a–c) were synthesized through Bingel reaction. The molecular structures of 3a–c were verified through 1H NMR, 13C NMR, Fourier transform infrared spectroscopy (FT-IR), UV–visible spectroscopy, and mass spectrum. The thermal stability of 3a–c to nitrocellulose was studied by methyl violet paper test and iso-thermogravimetry method, and the results showed that the stability of 3a–c to nitrocellulose was significantly better than that of the [60]fullerene-based stabilizers. The thermal stability of 3a–c to nitrocellulose improved as the increase of the carbon chain length on the p-position of the benzene ring. The effects of 3a–c on the thermal decomposition of nitrocellulose were obtained by differential thermal analysis, and the results showed that the critical temperature of the thermal explosion of nitrocellulose can be increased by 0.1–2.8 °C by 3a–c. The thermal stability of 3a–c to nitrocellulose in adiabatic environment was confirmed by accelerating rate calorimetry. In addition, the stabilization mechanism was studied through ESR and FT-IR, and the results showed that 3a–c can react with nitrogen oxide radicals released by nitrocellulose. These arylmalonamide[70]fullerocyclopropane with excellent thermal stability and strong radical scavenging ability can be used as a promising stabilizer for single and double based propellants. [ABSTRACT FROM AUTHOR]

In this research paper, various formulations of zeolite‐loaded carboxymethyl tamarind kernel gum (CMTKG) based hydrogels were synthesized and utilized as a potential adsorbent for the removal of crystal violet (CV) dye. The swelling capacity of all the synthesized hydrogels was investigated and the composition of hydrogel which exhibited maximum swelling was used for the characterization and dye removal experiment. The CV dye was chosen as a model dye for the dye removal experiment. The structure of zeolite and zeolite embedded hydrogel was elucidated by XRD, FTIR, FE‐SEM, EDX and elemental papping techniques. The adsorption experiment was investigated by varying the CV concentration, amount of hydrogel adsorbent, temperature, pH of the dye solution, adsorption time, and ionic strength. The Langmuir and Freundlich isotherm models were used to fit the adsorption data and it was observed that the data fitted well with the Langmuir model. Moreover, hydrogel's maximum dye adsorption efficiency was found at 123.60 mg g−1. The adsorption kinetic studies were followed by pseudo‐ first‐order and intraparticle diffusion kinetic models. In addition, regeneration studies were performed for the best adsorbent hydrogel using ethanol solvent and the result concluded the desorption efficiency of hydrogel (82 %) over four desorption cycles. [ABSTRACT FROM AUTHOR]

An excessive accumulation of crystal violet dye in the human body results in an accelerated heart rate, tetraplegia, eye irritation, and long-term damage to the transparent mucous membrane that protects the eyeballs. Accordingly, in this paper, sodium manganese silicate/sodium manganese silicate hydroxide hydrate was easily fabricated as a novel type of nanostructures for the successful disposal of crystal violet dye from aqueous solutions. The formed sodium manganese silicate/sodium manganese silicate hydroxide hydrate nanostructures after the hydrothermal treatment of the gel produced from the interaction of Mn(II) ions with Si(IV) ions at 180 °C for 6, 12, 18, and 24 h were abbreviated as MS1, MS2, MS3, and MS4, respectively. The XRD showed that the average crystallite size of the MS1, MS2, MS3, and MS4 samples is 8.38, 7.43, 4.25, and 8.76 nm, respectively. The BET surface area of the MS1, MS2, MS3, and MS4 samples is 41.58, 46.15, 58.25, and 39.69 m2/g, respectively. The MS1, MS2, MS3, and MS4 samples consist of spherical and irregular shapes with average grain sizes of 157.22, 88.06, 43.75, and 107.08 nm, respectively. The best adsorption conditions of the crystal violet dye employing the MS1, MS2, MS3, and MS4 products were achieved at pH = 8, contact time = 140 min, and solution temperature = 298 kelvin. The linear pseudo-2nd-order model as well as the linear Langmuir isotherm better describe the disposal of the crystal violet dye using the MS1, MS2, MS3, and MS4 adsorbents. The studied thermodynamic parameters indicated that the disposal of the crystal violet dye employing the MS1, MS2, MS3, and MS4 adsorbents is spontaneous, exothermic, and chemical. The maximum disposal capacities of the MS1, MS2, MS3, and MS4 adsorbents towards crystal violet dye are 342.47, 362.32, 411.52, and 310.56 mg/g, respectively. [ABSTRACT FROM AUTHOR]

Copyright of Food Research & Development is the property of Food Research & Development Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Ink dating is a significant problem in terms of forensic science. Ballpoint pens are generally used as writing tools on the documents. Aging is determination of the changes in dyes and solvents in the composition of ink over time by analytical methods. The evaporation of the solvents from the paper surface is faster than the decomposition process of the dyes. In this study, in 2017, we were asked by the court to determine whether the texts on the suspicious pages of an agenda dated 1996 were written within 2 years or earlier. Phenoxyethanol and dyes were examined in the composition of all suspected ink samples. The results show the determination of both the decomposition process of the dyes and the evaporation process of phenoxyethanol in the aging of the document entries written by ballpoint pen. [ABSTRACT FROM AUTHOR]

Silver chalcogenide quantum dots (QDs) are potential nanosensors for biological and environmental applications. These QDs present low toxicity and their narrow band gap makes them promising as near-infrared (NIR) photoluminescence (PL) probes, exhibiting images with higher penetrability. In addition, hydrophilicity is essential for applications in biological systems as well as detection in aqueous media. Using the same methodology, variations in synthesis conditions can alter the efficiency and performance of their intrinsic properties. Most studies seek the best conditions for each experimental variable in a univariate manner; however, multivariate strategies are a faster and more economical way to achieve this goal. Thus, in this work, we utilized chemometric approaches to enhance the NIR-II PL properties of Ag2Se QDs stabilized with 3-mercaptopropionic acid (MPA). Three experimental designs were used, totaling 58 syntheses, showing that the Ag2Se–MPA QDs, obtained under the conditions of [Ag+] of 2.5 mmol L−1, Ag : Se molar ratio of 8 : 1, MPA : Ag molar ratio of 6 : 1, heating at 70 °C, pH 10, and 180 min, presented the best emission profile with a maximum at 1070 nm and a FWHM of approximately 140 nm. The nanocrystals presented an average diameter of 6 nm and the orthorhombic crystalline phase. Preliminary surface-enhanced infrared absorption (SEIRA) spectroscopy assays were carried out for the detection of methyl violet 2B (MV) dye using these QDs. The enhancement factor obtained was higher than 3.5, which is comparable to those observed for other systems, namely Ag2Se-MSA QDs. These results showed the potential of the Ag2Se–MPA QDs for (bio)sensing applications. [ABSTRACT FROM AUTHOR]

Zinc metal–organic frameworks (Zn-MOFs) of phthalic acid (ZnPA) and nitro-phthalic acid (ZnNPA) microcrystalline particles were fabricated and utilized for the removal of organic cationic dyes (crystal violet (CV), methylene blue (MB) and rhodamine B (RhB)) from water. PXRD studies confirmed the formation of crystalline materials, and BET indicated the mesoporous structure. HR-SEM studies showed the rod and plate morphologies for ZnPA and ZnNPA, respectively. ZnPA revealed low adsorption of dyes (CV, 20%) whereas ZnNPA showed significantly enhanced dye adsorption (CV, 99%). In particular, ZnNPA exhibited higher adsorption of CV (99%) and MB dye (83%) compared to RhB (54%). Nevertheless, ZnNPA could not be reused due to strong adsorption of dyes. Hence, a natural binder was introduced by dipping ZnNPA into tea extract, which also showed high adsorption of CV and MB dyes. Kinetics of adsorption exhibited best fitting with the pseudo-second-order model, indicating strong interactions between the dyes and adsorbent. Adsorption isotherm fitting suggested a good correlation coefficient (R2) with the Freundlich model, suggesting multi-layer adsorption. Interestingly, ZnNPA showed high adsorption of CV and MB dyes across the pH range between 3.0 and 11.0. The binder-introduced ZnNPA adsorbent was easily regenerated and demonstrated three cycles of reusability without significant change in the dye adsorption. Thus, the present work indicated the role of functional groups in the ligand and binder for improving the dye adsorption characteristics of MOFs. [ABSTRACT FROM AUTHOR]

Three-dimensional iodoargentate hybrids [Co(en)3(Ag2I4)]n (1), [Fe(en)3(Ag2I4)]n (2) (en = ethylenediamine) and [Co(dien)2(Ag2I4)]n·nH2O (3) (dien = diethylenetriamine) were prepared in C2H5OH solvent via a one-step reaction under solvothermal conditions. In compounds 1 and 2, AgI4 tetrahedra were interlinked via corner-sharing to form a 3D α-Ag2I4 framework with interpenetrated channels with cross sectional dimensions of 8.071 Å × 9.039 Å and 9.039 Å × 9.039 Å. The AgI4 tetrahedra in compound 3 were connected via both corner- and edge-sharing into a 3D β-Ag2I4 framework with dimensions of 5.929 Å × 8.329 Å, and 8.329 Å × 9.910 Å. Compounds 1–3 showed sensitive photocurrent response under visible light irradiation with steady current densities in the range of 3.46–8.26 μA cm−2. These compounds were catalytically active during the photodegradation of crystal violet (CV), with degradation conversions of 72.2%, 91.5% and 80.1% after 105 min of light irradiation over compounds 1–3, respectively. [ABSTRACT FROM AUTHOR]

Harnessing solar energy using semiconductor-based materials to generate charge pairs to effectively drive photo-redox reactions has been envisioned as a promising approach toward a sustainable future. In this arena, the metal sulfide nanoparticles have demonstrated excellent performance in photomineralizing colored matter. However, their small surface area and relatively slow charge transfer has limited their practical applications. Therefore, for the effective mineralization of colored matter, we devise and construct the Sn2S3–In2S3 S-scheme in collaboration with 2D graphene oxide nanosheets. The material offers a well-defined nanosheet and nanoflake morphology for the effective contact with and catalysis of crystal violet (CV) dye as a model contaminant. Compared to Sn2S3–In2S3/GO, the pristine Sn2S3 and Sn2S3–In2S3 cause negligible degradation of CV using a visible-light source. This enhanced photocatalysis is supported by the peculiar properties of GO, such as its high surface area, electron-shuttling performance, and ability to prevent charge back-recombination. Under simulated conditions, more than 99% of CV was mineralized within 60 min of contact time. The photodegradation follows pseudo-first-order kinetics with a rate constant (Kt) = 0.02317 min−1. Furthermore, the photo mineralization of CV dye was thoroughly investigated using the GC-MS technique. More importantly, Sn2S3–In2S3/GO exhibits promising recyclability over multiple degradation cycles. [ABSTRACT FROM AUTHOR]