Dye Uptake Research Articles

Influence of zonular tension on molecular transport in the porcine ocular lens

IntroductionAccommodation is the process of changing the ocular lens’ refractive power and focal distance. This process involves application of biomechanical forces on the lens by the surrounding musculature. Previous studies have demonstrated that the lens epithelium demonstrates mechanotransduction and that tension influences its chemical activity. It is not yet known how these forces affect the structure and permeability of the lens. This study aimed to identify the influence of tension on molecular transport of dyes through the lens.MethodsPaired porcine eyes were incubated in each of four dyes for three time periods with no stretch (null), static, or cyclic stretching using a bespoke mechanical lens stretcher. After incubation, the lenses were frozen and cryosectioned sagittally through the optic axis. Photographs of the stretched and unstretched lenses were compared and qualitatively assessed.ResultsNone of the four dyes showed drastic stretch-induced differences in dye penetration depth. However, the dye neutral red showed dramatic stretch-induced changes in the dye uptake color behind lens anterior surfaces, with unstretched lenses appearing far more orange than their stretched counterparts. Three of four dyes showed notable differences between anterior and posterior diffusion patterns. One dye, methylene blue, demonstrated unexpected intensity in the lens nucleus compared to the lower intensity shown in the cortex, suggesting active transport rather than a linearly graded passive diffusion regardless of stretching condition.DiscussionAll this taken together suggests that lens transport is more complex than simple passive diffusion and that active transport of some molecules may be affected by stretching. Future work should assess the mechanisms of transport for the various dyes and attempt to explain the dye permeation patterns observed here, including the effects of stretching.

Effect of PEG‐400 on dyeing properties of cotton fabric in non‐aqueous medium system

AbstractTraditional reactive dyeing has the technical problems of high water consumption and high pollution. In this article, the effect of polyethylene glycol 400 (PEG‐400) on the dyeing properties of cotton fabrics with high concentration reactive dyes in non‐aqueous medium was studied. Initially, the effects of PEG‐400 on colour strength (K/S) and colour fastness of dyed fabric with reactive dye are systematically discussed. In addition, the effect of PEG‐400 on the hydrolysis properties of reactive dyes was analysed by high‐performance liquid chromatography (HPLC). At the same time, the molecular interaction force between the dye and PEG‐400 was analysed by ultraviolet‐visible (UV‐visible) spectroscopy. The results showed that when PEG‐400 concentration was 3.0 g/L, K/S value of dyed fabric (5.0%, on weight of fabric, owf) was increased by 33.5%, and is much higher than dyed fabrics without PEG‐400. HPLC and UV‐visible analysis showed that the addition of PEG‐400 effectively reduced the hydrolysis rate of dye II containing two vinyl sulfone reactive groups, which was converted from C.I. Reactive Black 5 containing contains diethylsulfone sulphate group. Its hydrolysis rate was reduced by 20.9%. PEG‐400 also decreased the aggregation degree of high concentration reactive dye, and increased the solubility of reactive dye. This method has certain universality. Therefore, using PEG‐400 as an additive is an effective way to improve the dye uptake of reactive dyes in non‐aqueous medium dyeing system and realise cleaner production.

Hybrid Chitosan Biosorbents: Tunable Adsorption at Surface and Micropore Domains

Herein, we report a study that provides new insight on the knowledge gaps that relate to the role of biopolymer structure and adsorption properties for chitosan adsorbents that are cross-linked with glutaraldehyde. The systematic modification of chitosan cross-linked with glutaraldehyde (CG) and its quaternized forms (QCG) was studied in relation to the reaction conditions: mole ratios of reactants and pH conditions. Complementary adsorbent characterization employed 13C NMR/FTIR spectroscopy, TGA and DSC, point-zero-charge (PZC), solvent swelling, and sorption studies using selected dye probes. The spectral and thermal techniques provide complementary evidence that affirm the key role of cross-linker content and quaternization on variation of the physicochemical properties of chitosan. The PZC results reveal a neutral surface charge for the modified materials between pH 6.0 to 6.3 ± 0.3, as compared with pH 8.7 ± 0.4 for pristine chitosan. Solvent swelling in water decreased with greater cross-linking, while the QCG materials had greater swelling over CG materials due to enhanced hydration. The adsorption results reveal variable dye uptake properties according to the cross-linker content. Similarly, surface versus micropore adsorption was demonstrated, according to the nature and ionization state of the dye for the modified adsorbents, where the CG and QCG materials had tunable sorption properties that exceeded that of unmodified chitosan. A key step in tuning the structure and surface chemical properties of cross-linked chitosan involves pH control during synthesis. The facile tunability of the physicochemical properties of the modified biopolymers reported herein means that they possess features of biomimetics that are relevant to advanced drug delivery, antimicrobial materials for wound healing, biosensors, and biosorbents for biomedical applications.

Enhanced physicochemical properties of Himalayan Weeping Bamboo-biochar for rapid multicomponent textile dyes uptake under classical and ultrasound irradiation: A comparative study

This study focused on synthesizing a low-cost adsorbent via a unique two-step solvothermal slow pyrolysis of Drepanostachyum falcatum plant biomass. It evaluated its adsorption capabilities for removing various textile dyes, including methylene blue (MB), basic fuchsin (BF), and methyl orange (MO), from aqueous solutions. Under conventional and ultrasound-assisted conditions, the adsorption performance was assessed for single, binary, and ternary dye systems. Comprehensive investigations examined the effects of environmental factors such as temperature, pH, humic acid, and interfering ions on adsorption. The findings revealed that ultrasonication significantly accelerated the adsorption process, making it up to six times faster than classical adsorption methods, and equilibrium was reached in one-tenth the time required without ultrasound. The experimental data best fit the pseudo-second-order kinetics model, indicating that chemisorption was the dominant adsorption mechanism. Additionally, the Freundlich isotherm suggested multilayer sorption on the biochar surface. Maximum adsorption capacities under ultrasound were found to be 139.34 mg/g for MB, 75.09 mg/g for MO, and 98.13 mg/g for BF dyes, with a higher affinity observed for cationic dyes compared to anionic dyes. The study provides insights into an efficient, novel synthesis method for converting waste biomass into a valuable adsorbent for dye removal. It also highlights the role of ultrasound in enhancing physicochemical properties, facilitating improved mass transfer, and promoting better interaction between the dyes and the adsorbent.

Cationic hydrogel with carbon quantum dots: synthesis and methyl orange adsorption capacity

Methyl orange is one of the most commonly used acidic/anionic dyes, and its removal from wastewater is imperative to ensure environmental sustainability. This study developed a novel cationic CQDs/AM/DMC hydrogel using acrylamide (AM) and methylacryloxyethyl trimethyl ammonium chloride (DMC) as main materials, incorporating carbon quantum dots (CQDs). The hydrogel was comprehensively characterized for morphological features, chemical composition and fluorescence characteristics using FTIR, TEM, SEM, PL and XRD analyses. Moreover, as an adsorbent, the hydrogel effectively removed methyl orange (MO) dye from aqueous solutions. Notably, the CQDs/AM/DMC hydrogel exhibited a maximum adsorption capacity of 298.93 mg/g within 30 min, surpassing that of AM/DMC hydrogel (268.29 mg/g within 50 min) in 50 mg/L MO solution. The Langmuir isotherm and pseudo-second-order models had the best agreement with the experimental data, highlighting monolayer and chemical adsorption as the predominant mechanism governing dye uptake. This study contributes valuable insights into the development of an efficient adsorbent for the removal of hazardous materials from wastewater.

In-depth mechanistic insights into Au nanoparticles based polyurethane foams as a selective and efficient dispersive solid phase microextractor for textile dyes from water: performance and reusability study

ABSTRACT Herein, a simple, superhydrophobic, superoleeophilic and low cost microextractor Au nanparticles (Au NPs) based polyurethane (PUFs) solid platform (Au NPs/PUFs) has been developed as a promising sorbent for removal and recovery of Congo red (CR) textile dye from water bodies. The sorbent was characterised using UV-visible and SEM techniques. The procedure relied complete dye retention from the aqueous solution at pH 5.0–5.5 onto an Au NP/PUF extractor. Analytical assessments revealed that the Au NPs/PUFs combination significantly improves mass transfer of dye and enhances creation of active sites for CR retention. CR sorption by the sorbent fitted well with intra-particle diffusion and pseudo first-order kinetic models (R2 = 0.990). The enthalpy change, ΔH (37.8 kJ mol−1) indicates that dye extraction is endothermic whereas the entropy change, ΔS0 (116.6 J mol−1K−1), reveals a significant change in the entropy during dye uptake. The free energy change ΔG (3.12 kJ mol−1 at 298 K) of CR sorption indicated that the dye retention was not spontaneous at all temperatures. A twofold sorption mechanism involving absorption accompanying ‘solvent extraction’ and/or ‘weak ion exchange’, combined with surface adsorption of dye is proposed. Sorbent packed mini column demonstrated effective percent removal and recovery (101.8%) of CR from water samples using acetone or NaOH as an eluting agent. The study expands the utility of Au NPs/PUFs for reusability and spectrophotometric sensing of trace levels of CR in water. The key attention also includes integrating PUFs utility by improving the selectivity and sensing properties towards textile dyes.

Color fastness and antimicrobial activity of Gardenia jasminoides extract against antimicrobial-resistant Staphylococcus aureus

This study investigated the antimicrobial efficacies of fabrics (100% cotton and 100% silk) dyed with an ethanol extract of Gardenia jasminoides (G. jasminoides). More specifically, these fabrics were dyed using a G. jasminoides extract with a dye bath ratio of 1:20 at 40–60 °C for 60 min, followed by post-mordanting. The concentrations of the aluminum sulfate, copper sulfate, and ferrous sulfate mordants were each set to 3% (o.w.f.). The samples were mordanted using a mordant bath ratio of 1:30 at 40 °C for 20 min. The iron mordant slightly increased the dye uptake (K/S) of the cotton fabric but did not increase the dye uptake (K/S) of the silk fabric. The antimicrobial efficacies of the dyed fabrics against methicillin-resistant Staphylococcus aureus (MRSA) ATCC 33591 were determined to be 99.8 and 87.8% for the cotton and silk fabrics, respectively. The inhibitory effects of the cotton and silk fabrics against MRSA were 30.5 × and 167.3 × the inoculum size, respectively, indicating the superior inhibitory effect of the dyed cotton fabric. These results suggest that the fabrics dyed with G. jasminoides extract may possess antibacterial activity against antimicrobial-resistant bacteria.

Comprehensive analysis of dye adsorption and supramolecular interaction between dyes and cotton fibers in non-aqueous media/less water dyeing system

Cotton textile dyeing consumes large amounts of energy and water and discharges large amount of wastewater and pollutants. Zero or less discharge of the wastewater and contaminants from the cotton textile dyeing has been under high demands from textile industry. Recently, a novel reactive dyeing technology of using a non-aqueous medium with little water (NMLW) was developed for cotton fabrics. However, the use of high concentration of reactive dyes in the system triggers aggregation of the dyes in cotton fibers, influencing the quality of dyed cotton textiles. In this investigation, adsorption, diffusion, and aggregation behavior of reactive dyes in cotton fibers were studied. Compared to traditional water-based dyeing system, cotton fabrics demonstrated superior color depth, as long with higher rates of dye uptake and fixation for reactive dyes. At low dye concentrations, the maximum absorption wavelengths of reactive dyes were unchanged, and complied with the Lambot-Beer law. However, when the dye concentration was excessively high, reactive dyes with different molecular structures, as well as multi-layer dye aggregates with π-π stacking and hydrogen bonding interactions, showed different light absorption spectral characteristics and photophysical properties. Moreover, the dye particle size and dye ionization were influenced by the dye concentration, molecular weight, molecular configuration, etc. Analysis of the molecular dynamics of reactive dyes revealed that the maximum dye aggregation size was predominantly dimer at low dye concentration. However, the dimer ratio significantly decreased, while the trimer ratio increased, and higher-order aggregates were observed at a higher dye concentration. The strength of hydrogen bonds between dye molecules and water molecules, as well as the number of water molecules surrounding dye molecules, was influenced by dye concentration and alkali. This study provides a foundation for understanding the micro-aggregation behavior of reactive dyes and offer guidance for optimizing the dyeing process in practical production settings.

Adsorption of synthetic cationic dyes from water (experimental, DFT and Monte Carlo studies) and treatment of real industrial wastewater using dextrose compound-modified layered double hydroxide

Dyes are a major water pollutant, and various methods have been employed to address the dye pollution in aqueous solutions. Currently, adsorption using inexpensive, abundant, and eco-friendly adsorbents like anionic clay is one of the simplest and most effective methods. This study aimed to investigate the fabrication of a novel layered double hydroxide modified with dextrose D@Mg1.5Zn0.5Al-LDH composite via co-precipitation route for removing both synthetic Rhodamine B (RhB) and Basic Fuchsin (BF) dyes from aqueous solutions. Various characterization techniques were employed to comprehensively understand the properties of the as-synthesized material, including XRD, FTIR, SEM-EDX, BET surface area analysis and zeta potential. To enhance the adsorption process of both basic dyes, experiments were conducted in a batch reactor to investigate the effects of key parameters such as reaction duration, initial dye concentration, pH, adsorbent dosage, and solution temperature. Cationic dyes uptake was predominantly observed within the first 10mins, reaching equilibrium in approximately 60mins. The D@Mg1.5Zn0.5Al-LDH composite achieved removal efficiencies of 99% for BF dye and 60% for RhB dye at pH 10, which are considerably higher than that of bare Mg1.5Zn0.5Al-LDH. The experimental adsorption data demonstrated excellent agreement with pseudo-second-order kinetics and the Langmuir isotherm. Density functional theory (DFT) calculations and molecular simulations had been employed to elucidate the adsorption mechanism of BF and RhB dyes onto the D@Mg1.5Zn0.5Al-LDH composite. Quantum parameters were calculated to characterize the electron density of the dyes which provided insights into their reaction behavior. Additionally, Monte Carlo simulations were employed to calculate the fluctuation energy, and to determine probability distributions of adsorption energy, and geometry of the small adsorption energy poses for BF/D@Mg1.5Zn0.5Al-LDH and RhB/ D@Mg1.5Zn0.5Al-LDH. These results offer equilibrium statistical conditions that explain the adsorption mechanism behaviors between the D@Mg1.5Zn0.5Al-LDH composite and BF/RhB dyes optimally. Importantly, the theoretical outcomes are in good agreement well with experimental results. Finally, the adsorption process is used to treat real industrial wastewater that mainly contains a mixture of Rhodamine B and Methylene Blue as the cationic dyes. The D@Mg1.5Zn0.5Al-LDH composite has shown good efficiency in the treatment of real industrial wastewater.

Vital Dye Uptake of YO-PRO-1 and DASPEI Depends Upon Mechanoelectrical Transduction Function in Zebrafish Hair Cells.

Vital dyes allow the visualization of cells in vivo without causing tissue damage, making them a useful tool for studying lateral line and inner ear hair cells in living zebrafish and other vertebrates. FM1-43, YO-PRO-1, and DASPEI are three vital dyes commonly used for hair cell visualization. While it has been established that FM1-43 enters hair cells of zebrafish and other organisms through the mechanoelectrical transduction (MET) channel, the mechanism of entry into hair cells for YO-PRO-1 and DASPEI has not been established despite widespread use. We hypothesize that YO-PRO-1 and DASPEI entry into zebrafish hair cells is MET channel uptake dependent similar to FM1-43. To test this hypothesis, we used both genetic and pharmacologic means to block MET channel function. Genetic based MET channel assays were conducted with two different mechanotransduction defective zebrafish lines, specifically the myo7aa-/- loss of function mutant tc320b (p.Y846X) and cdh23-/- loss of function mutant (c.570-571del). Pharmacologic assays were performed with Gadolinium(III) Chloride (Gad(III)), a compound that can temporarily block mechanotransduction activity. Five-day post fertilization (5dpf) myo7aa-/- and cdh23-/- larvae incubated with FM1-43, YO-PRO-1, and DASPEI all showed nearly absent uptake of each vital dye. Treatment of wildtype zebrafish larvae with Gad(III) significantly reduces uptake of FM1-43, YO-PRO-1, and DASPEI vital dyes. These results indicate that YO-PRO-1 and DASPEI entry into zebrafish hair cells is MET channel dependent similar to FM1-43. This knowledge expands the repertoire of vital dyes that can be used to assess mechanotransduction and MET channel function in zebrafish and other vertebrate models of hair cell function.

Efficacy of white rot fungal biomass of Phanerochaete chrysosporium for adsorption and removal of reactive red and reactive blue dyes from water

Water pollution has become a worldwide issue, particularly in developing countries. This study aimed to cleanse water contaminated with reactive red (RR-198) and reactive blue (RB-19) dyes via adsorption onto nonliving white rot fungal biomass Phanerochaete chrysosporium under different operational conditions. It was found that P. chrysosporium removed more of RB-19 than RB-198. The conditions of pH 3, temperature 50 °C, adsorbent dosage 0.6 g, particle sizes of adsorbent (0.25 mm), and contact time (30 min) were optimum for removal of the dyes. RR-198 and RB-19 were removed with levels of 78.4% and 86.4%, respectively at pH 3; 79.6% and 90.0%, respectively using 0.6 g of adsorbent dosage; 82.0% and 87.0%, respectively at 30 min; and 82.0% and 87.2%, respectively at 50 °C. Thus, dead P. chrysosporium biomass was shown to be a biosorbent for the uptake of RB-19 and RR-198 dyes.

A novel and sustainable approach to efficiently modify cotton material via a physical flash-explosion with sub- or SCF-CO2 as medium

A novel and eco-friendly approach to modify natural cotton fiber by flash-explosion with a sub- or supercritical fluid of carbon dioxide (sub- or SCF-CO2) for improving its structure and properties was constructed for the first time. The achieved results demonstrate that remarkable improvements in the coloration performance of cotton fiber by 71.1 % and the water retention by 1001.2 % against the control could be readily available by employing the flashily-explosion method at a recommended condition with 4-cycle explosion in sub- or SCF-CO2, and system temperature, fluid treatment duration and explosion number exhibited much more pronounced positive influences among all parameters. Additionally, minimal influences from the supercritical explosion on cotton fiber micronaire value, thermal property and tensile breaking strength were also observed. The scanning electron microscopy (SEM) and porosity investigations clearly show that plenty of micropores and/or strip fissures were formed on the fiber surfaces and their inner phases, and notably improved fiber surface area, pore volume and size were also obtained after a subsupercritical flash-explosion. Nuclear magnetic resonance hydrogen spectroscopy (1H NMR) and Fourier transform infrared spectroscopy (FT-IR) analysis disclose that numbers of hydrogen bonds between the fiber macrochains and/or from their intramolecular chains were broken by generating numerous free hydroxyl groups, which reasonably supported the improvements of the dye uptake behaviors and water retention properties, etc. The Energy-dispersive X-ray spectroscopy (EDS) analysis on the fiber cross-sections further confirms that a loosening of the inner aggregation structure of the cotton fiber was achieved after a flash explosion by significantly enhancing its coloration performance, etc. This innovative approach provides a promising idea and possibility as an alternative to chemical methods via mechanically and physically modifying fiber or other materials with sub- or SCF-CO2 fluid in an eco-friendly and sustainable manner.

Eco-Friendly Dyeing Processes of Nylon 6.6 Woven Fabrics with Used Coffee Grounds (UCG)

The increasing demand for sustainable practices in the textile industry has led to the exploration of natural dyes and eco-friendly dyeing processes. This study focuses on the potential of used coffee grounds (UCG) as an eco-friendly natural dye for Nylon 6.6 woven fabrics. Five dyeing processes were evaluated, varying in the use of mordants and acids, to assess their impact on the color saturation, colorfastness to laundering, and crocking resistance of Nylon 6.6. fabric. The processes included a control with no mordant or acid and others that incorporated tannic acid, acetic acid, and ferrous sulfate heptahydrate. The results demonstrated that process 4, which combined tannic acid pre-mordanting with acetic acid in the dye bath, provided the best balance between color saturation and colorfastness. Process 2, utilizing only tannic acid, offered some durability in laundering and crocking tests. Process 5, being the least eco-friendly process, demonstrated high color saturation, but it performed poorly in colorfastness to crocking, which means that it released the UCG-based dye after rubbing the dyed Nylon 6.6. fabric. The findings confirm that UCG can be an effective and sustainable natural dye for Nylon 6.6, with pre-mordanting and acid treatment significantly enhancing dye uptake and retention. However, further research is needed to optimize color intensity and expand the application of UCG in textile dyeing.

Extraction of flavonoid dyes from vine tea (Ampelopsis grossedentata) waste and application in bleached pulp dyeing

AbstractNatural dyes are receiving more attention due to wide and renewable resources and their functionalities. This study delved into the optimal conditions for extracting Ampelopsis grossedentata flavonoid dyes (AGFDs) from vine tea waste, resulting in a dye sample with a total flavonoid extraction percentage of 27.4 %. Ultraviolet (UV), Fourier‐transform infrared (FTIR) and liquid chromatography–mass spectrometry (LC–MS) analysis revealed the presence of 18 flavonoids in AGFD. Additionally, various factors, including pH, light exposure, temperature, metal ions, and redox agents were found to impact the stability of AGFD. Moreover, the dyeing performance of AGFD for the bleached chemical pulp was investigated. Under optimal conditions, the AGFD‐dyed pulp displayed a vibrant yellow hue and excellent colour fastness when using aluminum potassium sulphate dodecahydrate (KAl(SO4)2·12H2O) as a mordant with a dyeing uptake level up to 88 %. FTIR and scanning electron microscopy (SEM) analysis demonstrated that AGFD chemically bound to the pulp fibre. Remarkably, the hand sheet made from the AGFD‐dyed pulp exhibited thermal stability, physical strength properties and antibacterial activity against Escherichia coli and Staphylococcus aureus. Furthermore, the peroxide value of cheese packaged with the AGFD‐dyed pulp hand sheet was only 43 % of that of the undyed one, indicating its good antioxidant properties. This study highlights the promising potential of AGFD in the production of functional coloured paper.

Process optimization of victoria blue dye removal using polypyrrole-encapsulated zirconium oxide: Mechanistic pathway and economic assessment

In this study, an organometallic composite, namely a polypyrrole-encapsulated zirconium oxide (ZrO2/PPy) nanocomposite, was developed and used to eliminate Victoria blue dye (VB) from water system. Specific surface area of the ZrO2/PPy obtained from BET study was observed to be 61.822 m2/g. Solution pH of 7.0, ZrO2/PPy nanocomposite dose of 0.8 g/L, sonication period of 40 min and initial VB dye concentration of 50 mg/L were chosen as optimal test parameters, at which 86.23 (±1.15) % of VB dye elimination was observed. The VB dye uptake process follows pseudo-second-order kinetic model and Langmuir isotherm model, with the later providing the maximum VB dye adsorption capacity of ZrO2/PPy nanocomposite as 238.09 mg/g. Thermodynamics study suggests the spontaneous (ΔGo< 0) and endothermic (ΔHo> 0) nature of the adsorption study. Food processing wastewater causes maximum hindrance (∼20 (±0.90) % −25 (±1.03) %) in the VB dye uptake process while the presence of phosphate (PO43−) ions can create highest interference (∼17 (±0.93) % −19 (±1.08) %) in the VB dye uptake process. At the optimum test parameter values (adsorbent dose: 1.3 g/L, initial VB dye concentration: 20 mg/L, sonication period: 70 min) as suggested by response surface methodology (RSM), maximum VB dye elimination of ∼96 % was observed. Electrostatic attraction, π–π interaction and hydrogen bond formation are amongst the major uptake mechanisms. Regeneration study indicates ∼19 (±1.36) % of decrease in VB dye elimination (%) after fifth cycle of reuse. The lab scale and industrial scale fabrication expense of 1.0 kg of ZrO2/PPy nanocomposite were obtained as 75.74 and 22.20 USD, respectively. The findings of this study suggest the potential of ZrO2/PPy nanocomposite as an effective and economically viable adsorbent to eliminate VB dye from wastewater.

Cationic dye remediation in water treatment with Lizardite–Rice Husk composite: A statistical physics approach

This study presents the development of a novel composite adsorbent, Lizardite-Rice Husk Composite (LRHC), synthesized from lizardite, a mineral derived from chromite ore waste, and rice husk, an agricultural byproduct. The primary objective was to evaluate the efficiency of LRHC in the adsorption of cationic dyes, Malachite Green (MG) and Methylene Blue (MB), from aqueous solutions. Systematic investigations were conducted to assess the influence of adsorbent mass, initial dye concentration, stirring speed, and contact time on adsorption performance. The results revealed that LRHC exhibited optimal adsorption capacities at pH values above 5, with MB and MG adsorption capacities reaching 309.75 mg/g and 51.43 mg/g, respectively. Adsorption equilibrium for MB was achieved within 30 min, indicating rapid dye uptake. Isotherm analysis demonstrated that the Temkin model best described MB adsorption, while the Freundlich model was more suitable for MG, with favorable Langmuir constants. Kinetic studies confirmed that the adsorption followed a second-order model, suggesting chemisorption as the rate-determining step. Intraparticle diffusion and mass transfer were identified as significant contributors to the adsorption process. Thermodynamic studies indicated that MB adsorption was spontaneous (ΔG° = −4.69 kJ/mol for the concentration of 50 mg/L at 298 K) and that MG adsorption was non-spontaneous (ΔG° = 1.52 kJ/mol for the concentration of 50 mg/L at 298 K), with spontaneity increasing at higher initial concentrations. Statistical physics modeling, particularly the monolayer model, provided detailed insights into the adsorption mechanisms and geometry. Furthermore, LRHC demonstrated excellent reusability, maintaining over 80% of its initial adsorption capacity after four regeneration cycles via a heterogeneous Fenton-like reaction. The combination of easy availability, cost-effectiveness, and environmental friendliness makes LRHC a superior adsorbent for the removal of cationic dyes compared to conventional alternatives. This research contributes novel insights into the design and application of composite adsorbents, offering a sustainable solution for water treatment and addressing significant environmental challenges.

Cotton Fabric Coating by Cationic Starches to Aim for Salt‐Free Reactive Dyeing

AbstractCationic starch (CatS) coating of cellulose fabrics enables salt‐free reactive dyeing. However, the relation of the degree of substitution and CatS concentration in the dyeing procedure are open issues. Accordingly, three cationic starches of increasing degree of substitution were used at different concentrations for the coating of cotton fabrics. Fabrics were evaluated for stiffness, dye uptake, dye exhaustion, wash fastness and nitrogen content.With an increasing degree of substitution coating solutions become more viscous, resulting in increased wet pick‐up and less stiff coated fabrics. These fabrics show increasing dye absorption and color generation. Due to the molecular size of the cationic starch, yarn/fiber ring dyeing is supposed present. Specifically, color generation can be adjusted by initial cationic starch coating concentration. Above 5 % CatS concentration ceases to have an increasing coloration effect. Pre‐treating a cellulose fabric with approximately 2.2 % CatS (Ds=0.7) enables similar coloration to a standard reactive dyeing protocol. Light fastness is reduced by 1–1.5 compared to salt‐based reactive dyeing. Rub fastness decreases by 1–2 only for higher substituted cationic starches (Ds=0.7). Nitrogen analysis reveals that a share of the CatS elutes off the fabrics into the dye bath.

Nanocellulose prepared with γ-valerolactone pretreatment and its enhancement in colored paper

New techniques are always demanded to pursuit green and economical ways for nanocellulose preparation. We herein proposed to use γ-valerolactone (GVL) to facilitate the nanocellulose preparation from bleached bamboo pulp fibers as a green and sustainable pretreatment. The GVL pretreatment caused the bamboo fibers to destruct, resulting in an obviously increased fine fiber content, which was systematically studied to disclose the influence of different factors on the fiber changes. The optimum GVL pretreatment conditions were determined as reaction time of 4 h, reaction temperature of 140 °C and the ratio of GVL to water of 4:1. Notably, the GVL pretreatment caused negligible changes in the functional groups on cellulose, as well as its crystalline structure. The resultant nanocellulose (i.e. G-CNF) had a width of ca. 47 nm and it showed good adsorption capacity towards RR195 dye since an impressive dye uptake rate of 46.81 % was attained. The incorporation of G-CNF significantly improved the coloring performance and the ∆E (color difference) value reached up to 33.73. Improvements in the mechanical properties of RR195 dyed paper were also observed with the incorporation of G-CNF. This work sheds light on the nanocellulose preparation with GVL pretreatment and demonstrates a feasible way to apply the resultant nanocellulose in the colored paper manufacture.

Distribution of MRI-derived T2 values as a biomarker for in vivo rapid screening of phenotype severity in mdx mice

Background The pathology in Duchenne muscular dystrophy (DMD) is characterized by degenerating muscle fibers, inflammation, fibro-fatty infiltrate, and edema, and these pathological processes replace normal healthy muscle tissue. The mdx mouse model is one of the most commonly used preclinical models to study DMD. Mounting evidence has emerged illustrating that muscle disease progression varies considerably in mdx mice, with inter-animal differences as well as intra-muscular differences in pathology in individual mdx mice. This variation is important to consider when conducting assessments of drug efficacy and in longitudinal studies. We developed a magnetic resonance imaging (MRI) segmentation and analysis pipeline to rapidly and non-invasively measure the severity of muscle disease in mdx mice. Methods Wildtype and mdx mice were imaged with MRI and T2 maps were obtained axially across the hindlimbs. A neural network was trained to rapidly and semi-automatically segment the muscle tissue, and the distribution of resulting T2 values was analyzed. Interdecile range and Pearson Skew were identified as biomarkers to quickly and accurately estimate muscle disease severity in mice. Results The semiautomated segmentation tool reduced image processing time approximately tenfold. Measures of Pearson skew and interdecile range based on that segmentation were repeatable and reflected muscle disease severity in healthy wildtype and diseased mdx mice based on both qualitative observation of images and correlation with Evans blue dye uptake. Conclusion Use of this rapid, non-invasive, semi-automated MR image segmentation and analysis pipeline has the potential to transform preclinical studies, allowing for pre-screening of dystrophic mice prior to study enrollment to ensure more uniform muscle disease pathology across treatment groups, improving study outcomes.

Green Removal of Basic Fuchsin Using Fibers from Reed Leaves

This study investigates the adsorptive capacity of a novel lignocellulosic material derived from reed leaves for the removal of Basic Fuchsin, a cationic dye, from aqueous solutions through batch adsorption experiments. The experimental data showed that the adsorbent demonstrated effective dye removal, with the adsorption kinetics following a pseudo-second-order model and the equilibrium data best described by the Freundlich and Temkin isotherm models. The Langumir model shows the maximum capacity adsorption was 37.59 mg.g-1 Moreover, thermodynamic analysis indicated that the adsorption process was non-spontaneous and exothermic, highlighting the potential for optimizing conditions to enhance dye uptake and sustainability in wastewater treatment applications. In addition, characterization techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM), and Brunauer-Emmett-Teller surface area analysis (BET) confirmed that the adsorbent possessed an amorphous structure with a surface area of 2.42 m².g-1 and the presence of mesoporous features. Lignocellulosic materials such as reed leaf adsorbents, effectively remove hazardous dyes from wastewater offering a sustainable solution to pollution.