Dye Absorption Research Articles

Influence of Cotton Pre-Treatment on Dyeing with Onion and Pomegranate Peel Extracts.

In this paper the possibility of applying natural dyes on cellulose fibres were researched with respect to the impact of cotton material pre-treatment (scouring, chemical bleaching, mercerization and mordanting), using renewable sources of natural dyes (waste as a source). As mordants, metal salts of copper, aluminium and ferrum were used, and the influence on colour change as well as on fastness properties were analysed. The natural dyes were extracted from onion peel (Allium cepa L.) and pomegranate peel (Punica granatum L.). In spectrophotometric analysis performed of the plant extracts, the onion extract has peaks at 400 and 500 nm, resulting in red-orange colourations and the pomegranate extract shows a maximum at 400 nm, i.e., in the yellow region, which is characteristic of punicalin. Results show significant influence of cotton pre-treatments on colour appearance and fastness properties, caused by pre-treatments affecting the properties and structure of the cotton itself. The positive effect of mercerization on dye absorption and bonding is confirmed. For wash and light fastness properties, more satisfactory results have been obtained for yarns dyed with pomegranate peel natural dye, and the key importance of mordants for fastness properties has been confirmed.

Multi-Stimuli-Responsive Organogel Based on Bisthiourea Compounds for The Removal of Selected Organic Dyes

The self-assembly of a series of bisthiourea containing amino acid side chains has been studied in a large range of organic solvents. Self-assembly is driven mainly by hydrogen bonding groups of thiourea and amino acids moieties. Of all the synthesized compounds, only bisthiourea with alanine side chains, 3.5 formed thermoreversible gel in 50:3 dichloromethane:water mixture at minimum gel concentration of 0.5%. SEM micrographs of the gel showed the formation of entangled cross-linked fibres. The addition of anions such as Cl¯, F¯ and AcO¯ disrupted the gel network of 3.5 thus inducing the gel-sol transition. To investigate the ability of the bisthiourea to form metallogel, metal ions such as Co2+, Cu2+, Ni2+ and Pb2+ were introduced, however, none of them induce the formation of metallogel. In particular, the gels show good performance in the absorption of bromocresol green and Eriochrome black-T at 75% and 61% efficiency, respectively within 24 hours. The good dye absorption properties of gel 3.5 render the potential of bisthiourea gels as new dye absorption materials, which show significant benefit for water pollution treatment.

DLP 3D Printed Textile의 유연성 향상을 위한 모델링 디자인 및 염색성 평가

3D printing has been considered a key technology, leading the fourth industrial revolution. However, 3D printed textile still has a lot of limitations to overcome before it can be adopted as a clothing material in terms of design, flexibility and dyeability. This study aims to provide modeling design for imparting the flexibility and post-dyeing process for 3D printed textiles. The modeling types were designed to test the flexibility of 3D printed textiles. The post-dyeing process was evaluated through dye absorption depending on the resin and modeling types, respectively. The results were as follows: two types of modeling (Modeling A and B) were designed with a ring structure to test the flexibility of the 3D printed textiles. The 3D printed textiles with ringbased structure Modeling A had flexibility regardless of the hardness of resin types. In the dyeability test, softening resin (S-Resin) and hardening resin (H-Resin) were found to have good dyeability with acid dye and direct dye, respectively. The condition of S-Resin with acid dye and H-Resin with direct dye was controlled by dye absorption rate.

Absorption Properties of Polyvinyl Alcohol Films Filled with Nanoparticles Doped with Acridine Orange Dye

Polyvinyl Alcohol (PVA) polymer/ Acridine Orange (AO) dye films prepared via casting technique at room temperature. The effect of adding (Acridine Orange (AO) dye solution, Magnesium Oxide (MgO), and Aluminum Oxide (Al2O3) NPs) to the PVA polymer matrix were studied on the absorption spectra. The effect of AO addition on the absorption spectrum of PVA film is occurrence blue shift (5nm) from 280nm to 275 nm in the PVA and red shift (10nm) from 490nm to be 500 nm for AO maximum absorbance wavelength. The absorbance of AO dye decreases when adding PVA, but increases When the volume ratio of AO dye solution is increased to 0.49 for 18ml, the volume ratio of AO dye solution decreases for 24- and 30-ml volume ratios. Adding NPs led to enhancing the photophysical properties of polymer composite, noted that absorbance of adding alumina nanoparticles more than it is in the case of adding magnesia nanoparticles. Also, there is a 10 nm red shift in AO and a 5 nm blue shift in AO when they are added to the polymer matrix filled with MgO and Al2O3 NPs.

Minimizing Scaling Losses in High-Performance Quantum Dot Luminescent Solar Concentrators for Large-Area Solar Windows.

While luminescent solar concentrators (LSCs) have been researched for several decades, there is still a lack of commercially available systems, mostly due to scalability, performance, aesthetics, or some combination of these challenges. These obstacles can be overcome by the systematic optimization of a laminated glass LSC design, demonstrated herein. In particular, we first show that it is possible to improve optical and electrical efficiencies of an LSC by fine-tuned optimization of the constituent fluorophore-containing interlayer resin. Further still, an increased understanding of commercially available solar cells allows us to establish a direct correlation between the device's optical and electrical efficiency. Next, optical characterization of LSCs of varying sizes allows us to elucidate the main loss mechanisms in our LSCs, as well as ways to mitigate them. Altogether these optimization steps create opportunities for high-performance multi-interlayer LSC devices with demonstrated electrical power conversion efficiency as high as 1.1% to 4.9% at visual light transmission of 74% to 5%. Furthermore, careful examination of different blue-color (red-band absorbing) dyes provides a path for color-tunability of LSC windows toward neutral regimes. Design iterations of multiple device form factors enabled a color-neutral prototype without significant performance losses by separating color-neutralizing and LSC layers into different panes of an insulated glass unit. This work demonstrates the importance of LSC design optimization in achieving high-performance solar window technology with commercially acceptable aesthetics.

New spectrophotometric method for determination of mebendazole by oxidative coupling reaction

A rapid , simple, accurate and sensitive spectrophotometric method was developed for determination of mebendazole ( MBL ) in pure form and in its pharmaceutical dosages. This method depend on oxidation of MBL with excess amount of N-bromosuccinimide ( NBS ) in acidic medium with standing for complete the reaction , and the oxidized MBL coupled with Rhodamine B to get red product related with MBL amount and measuring the absorbance of surplus dye at 570 nm. A linear calibration curve was obtained over the concentration range 2.5 – 30 μg.ml-1 with correlation coefficient of 0.9992. The molar absorptivity and sandell's sensitivity index values were determined to be 1.476 × 104 L.mol-1.cm-1 and 0.02 μg.cm-2. The limit of detection (LOD) and quantification (LOQ) were calculated to be 0.469 and 1.982 μg.ml-1, respectively . The proposed method has been successfully applied to the determination of MBL in available dosage form, the validity proposed method was confirmed by recovery study via standard addition technique.

Direct and Reactive Dyes Recovery in Textile Wastewater Using Calcinated Hydrotalcite

Growing environmental conservation concerns have led researchers to seek the means to treat and recover wastewater. The textile industry dumps vast quantities of wastewater from textile dyes. By means of clays, dye waste can be separated and reused for other industrial processes. Clay absorption varies depending on the type of dye employed because factors like the reactivity of the dye molecule and its size are very important during the absorption process. The absorption capacity of calcined hydrotalcite at several concentrations was compared in a 0.05 g • L-1 solution of four distinct dyes: Direct Blue 199, Direct Red 23, Direct Blue 71 and Reactive Yellow. Dyes have different molecular weights because the weight of reactive dyes is considerably lighter than that of direct dyes, which is why the Lambert-Beer lines of each dye are previously considered. We worked with a 5 g • L-1 clay concentration to introduce the dye into the clay by stirring for 24 h in 100 ml of each dye solution before filtering it and leaving it to dry. In all cases, the dye absorption by nanoclay was nearly absolute and the initial solution was very clean, which are excellent results from the wastewater treatment point of view. Color measurement was performed by a Jasco V-670, double-beam spectrophotometre between 190-2700 nm. Differences in color were calculated and represented in CIE-Lab* color space diagrams. Finally, thermogravimetric (TGA) and X-ray diffraction (XRD) analyses were carried out to ensure both nanoclay-dye interactions and hydrotalcite structure recovery. No large differences were observed under these conditions, which reinforces the idea of using low nanoclay concentrations.

Expanding π-bridge and introducing auxiliary acceptor for realizing panchromatic absorption of the phenothiazine dyes in dye-sensitized solar cells

Dyes with panchromatic absorption of the solar radiation is crucial for the photovoltaic performances of dye-sensitized solar cells (DSSCs). In this paper we have constructed four phenothiazine dyes (PS1, PS2, PID1 and PID2), and applied to fabricate the DSSCs. Some important results have been found: (I) PID1 and PID2 with isoindigo as auxiliary acceptor successfully achieve nearly panchromatic absorption. (II) thieno[3,2-b]thiophene is a better π-bridge than 2,2′-bithiophene in terms of facilitating the intramolecular transport of photoexcited electrons, reducing the dye aggregation and improving the photovoltaic properties of DSSCs; (III) it is surprised that PID1 and PID2 exhibit broader absorption spectra, but achieve lower conversion efficiencies than PS2 with thieno[3,2-b]thiophene as π-bridge; (IV) The low device efficiencies of the isoindigo-based dyes might be due to the strong electron-withdrawing ability of isoindigo moiety, affecting the electron transport. These findings suggest that it might be an effective way to realize panchromatic absorption of the organic dyes by introducing isoindigo as an auxiliary acceptor, and a balanced perspective on the molecular design of dye is necessary to improve the performance of DSSCs.

A neutral zinc(II) metal-organic framework with nanoporous channels for efficient and selective absorption of anionic dyes

One porous metal−organic framework {[Zn(TIA)(DPE)0.5]·3DMF}n (Zn-1) was successfully constructed under solvo-thermal reaction of Zn(NO3)2·6H2O with multifunctional ligand 3-(4H-1,2,4-triazol-1-yl)-isophthalic acid (H2TIA) and linear bridge dipyridyl ethylene (DPE). Polymer Zn-1 characters as a (32,4-c net) 3D skeleton containing uni-dimensional channels, which results in its high efficient adsorption behavior of anionic dyes CR2−, MO–, and EBT–. Especially for the large-size CR2−, it shows the most rapid removal rate. More importantly, it realized good separation effects of mixed anionic and cationic dyes (CR2−/MB+ and MO–/MB+). Such excellent performances of dye adsorption and separation are mainly caused by the uni-dimensional channels of MOF Zn-1 and supramolecular interactions between guest-host, which was supported by ab initio molecular dynamics (AIMD) simulations.

Impact of graphene oxide on visible light photocatalytic performance of graphene oxide/graphitic carbon nitride three-dimensional structure composites

ABSTRACT The non-metallic catalyst graphitic carbon nitride (g-C3N4) has attracted a significant amount of attention due to its excellent photocatalytic performance. The photocatalytic performance of g-C3N4 has been further enhanced by the incorporation of graphene oxide (GO) as a composite catalyst. However, the enrichment and recovery of these two-dimensional composites after photocatalysis is still a difficult challenge. In this work, a visible light responsive graphene oxide/graphitic carbon nitride coated sponge three-dimensional composite (PU-GO/g-C3N4) was prepared by electrostatic self-assembly using polyurethane sponge (PU) as a skeleton and g-C3N4 as a photocatalyst. The degradation rate of rhodamine B (RhB) under visible light was used as an index to evaluate the photocatalytic performance of PU-GO/g-C3N4. The results demonstrate that during the photocatalytic degradation of RhB by PU-GO/g-C3N4, g-C3N4 is the main photocatalyst, while the holes and the superoxide radicals generated by electron excitation are the main agents. As a bridge connecting PU and g-C3N4, GO improves the agglomeration phenomenon of g-C3N4 on PU. Meanwhile, GO has excellent carrier mobility and inhibits the recombination of photogenerated electrons and holes. Moreover, the presence of GO enhances the absorption of light and dyes. Overall, the addition of GO effectively enhances the photocatalytic performance of PU-GO/g-C3N4 due to it enhances dye absorption, improves light energy utilization rate, and expedites transfer of photogenerated electrons. After 5 cycles, PU-GO/g-C3N4 still exhibits an RhB degradation rate of 92.06%, demonstrating good stability and recycling performance. This material shows great promise for practical environmental remediation applications.

Raman Scattering Enhancement by silver Nanostructures Prepared by Electrical Exploding Wire Technique

This project aims to fabricate nanostructures (AgNPS) using the electrical exploding wire (EEW) technique using Rhodamine 6G dye as the probe molecule, investigate the effect of AgNPS on the absorption spectra and surface-enhanced Raman scattering (SERS) activities, and advance using porous silicon as an active substrate for surface-enhanced Raman scattering (SERS). X-Ray diffraction (XRD) was used to investigate the structural properties of the nanostructures (AgNPs). Field emission scanning electron microscopy (FE-SEM) was used to investigate surface morphology. A double beam UV-Vis Spectrophotometer was used to analyze the mixed R6G laser dye(of concentration 1x M) absorption spectra with the nanostructures AgNPS (of concentration 24x M). A sunshine Raman microscope device (the objective lens used was (50x)). was used to analyze R6G combined with nanostructures Raman spectra. All samples have shown SERS activity that increased with increasing the hot spots. The SERS enhancement factor for R6G dye(of 1x10-6 M concentration) when mixed with (AgNPS) nanostructures has reached to(2.48 x 106) and the lowest detection limit reached to (1 x 10-14 M) at the wave number (1652 cm-1) using excited laser source (λexc. = 532nm)

Synthesis and Application of a Low Dye Absorption Waterborne Polyurethane for Microfiber Synthetic Leather

As increasing attention is being paid to harmful residual dye pollution in the dyeing effluent from the microfiber synthetic leather industry, there is an urgent need to explore innovative ways to alleviate such pollution. Here, a low-polarity waterborne polyurethane (WPU) was synthesized using hydroxyl-terminated polybutadiene (HTPB) and polypropylene glycol (N220) as soft segments to react with –NCO on isophorone diisocyanate (IPDI). The structure and properties of modified waterborne polyurethane were characterized by Fourier Transform Interferometric Radiometer (FTIR), and emulsion characterization was performed, including particle size and zeta potential analysis, tensile test, thermal properties test, and contact angle test. The SEM and alkali reduction rate results showed that increasing the HTPB content decreases the alkali reduction rate by blocking the penetration of corrosive ions by the double bond cross-link structure, but higher HTPB addition (>40%) leads to an enhancement in phase separation, which contributes to an increase in the alkali reduction rate. The results of the UV spectrum analysis showed that when the amount of HTPB added was 50%, the coloration rate reached 81.27% compared with 13.18%, which was 68.09% higher than that of the unmodified microfiber leather. The binding of the dry and wet rubbing color of the modified microfiber leather with the addition of 50% HTPB reached grades of 4–5 and 3–4, respectively, which meets most application requirements without subsequent washing.

Understanding the "Anti-Catalyst" Effect with Added CoOx Water Oxidation Catalyst in Dye-Sensitized Photoelectrolysis Cells: Carbon Impurities in Nanostructured SnO2 Are the Culprit.

In 2017, we reported a dye-sensitized, photoelectrolysis cell consisting of fluorine-doped tin oxide (FTO)-coated glass covered by SnO2 nanoparticles coated with N,N'-bis(phosphonomethyl)-3,4,9,10-perylenediimide (PMPDI) dye and then a photoelectrochemically deposited CoOx water oxidation catalyst (WOCatalyst), FTO/nano-SnO2/PMPDI/CoOx. This system employed nanostructured SnO2 stabilized by a polyethyleneglycol bisphenol A epichlorohydrin (PEG-BAE) copolymer and other C-containing additives based on a literature synthesis to achieve a higher surface area and thus greater PMPDI dye absorption and resultant light collection. Surprisingly, the addition of the well-established WOCatalyst CoOx resulted in a decrease in the photocurrent, an unexpected "anti-catalyst" effect. Two primary questions addressed in the present study are (1) what is the source of this "anti-catalyst" effect? and (2) are the findings of broader interest? Reflection on the synthesis of nano-SnO2 stabilized by PEG-BAE, and the large, ca. 10:1 ratio of C to Sn in synthesis, led to the hypothesis that even the annealing step at 450 °C in of the FTO/SnO2 anode precursors was unlikely to remove all the carbon initially present. Indeed, residual carbon impurities are shown to be the culprit in the presently observed "anti-catalyst" effect. The implication and anticipated broader impact of the results of answering the two abovementioned questions are also presented and discussed along with a section entitled "Perspective and Suggestions for the Field Going Forward."

Simultaneous dyeing and antibacterial finishing of polypropylene using vinyl sulfone dye under supercritical carbon dioxide

Polypropylene fibres are difficult to dye using commonly used techniques due to the high crystallinity and non-polar aliphatic structure, that lack reactive places for dyes in the molecule. Dyeing PP fabric in scCO2 with antibacterial dyes merged the dyeing and finishing methods, resulting in a more productive technique in terms of water and energy consumption. Unmodified polypropylene fabric was dyed with 4-[2-[4-(ethenylsulphonyl)phenyl]diazenyl]-N,N-diethylbenzenamine antibacterial dye under scCO2 medium. The influences of scCO2 working parameters, such as dye concentration, pressure, dyeing time, and temperature, on fabric dye absorption expressed as color strength were studied. The color strength (K/S) was measured as well as CIELAB color parameters. The results were compared with its water dyeing analogue and it was observed that color strength as well as color depth (L) of the samples dyed in scCO2 were noticeably better than its water counterpart. In both scCO2 and water, the fastness properties (washing, rubbing, and light) of the dyed samples were excellent. Antibacterial activity of the dyed polypropylene sample in scCO2 was estimated and the results indicated good antibacterial efficiency.

Mode-dependent dye absorption in phthalocyanine-doped acrylic optical fiber

Phthalocyanine has attractive features as a dopant for plastic optical fibers. Its planar molecular structure and red absorption band are suitable for the design of fiber-optic strain sensors that use the dynamic orientation of dye induced by the deformation of the host matrix. The guidelines to achieve a phthalocyanine-doped fiber with a ruled dispersing manner were investigated. A synthesized fiber using phthalocyanine decorated with tertiary butyl groups showed mode-dependent absorption, which suggested gradual dye distribution in the core radial direction.

Characterization of physicochemical markers for homeopathic medicines and biological supernatant samples

Introduction: Solvatochromic dyes are probes to detect variations on the dipole moment of solvents after the insertion of homeopathic potencies. Recent studies have shown they can be useful tools in laboratory and field studies to detect the activity of homeopathic remedies. Objective: Determine whether solvatochromic dyes can be a diagnostic tool for cells infected by different agents and/or markers to identify the activity of homeopathic medicines. Methods: Ethilicum 1cH, Silicea terra 6, 30, 200cH; Zincum metallicum 6, 30, 200cH and Phosphorus 6, 30 and 200cH were analyzed by pouring the samples (in a 1:60 rate) into a series of seven dyes (rhodamine, ET 33, ET 30, coumarin 7, NN DMIA, Nile red, methylene violet) diluted in absolute ethanol using pre-established working concentrations. Oscillations of dye absorbance were observed at visible light spectrophotometry according to the remedy and potency. Water and succussed water were used as controls. In a second moment, the absorbance profile of the remedies will be compared with those of biological samples (supernatants) and checked with the biological effect previously obtained from each treatment. Supernatants of RAW 264.7 macrophages stimulated by Calmette-Guérin bacilli (BCG) or infected with Encephalitozoon cuniculi will be analyzed. Results: Preliminary results have shown that Silicea terra 6cH, Phosphorus 30 and 200cH and Zincum metallicum 6, 30 and 200cH reduced the absorbance of methylene violet (p=0.01). Repetitions and analysis of supernatants are expected to be performed in the next steps of the study. Future perspectives: Establish a pattern of reactivity of the studied medicines with different dyes and the putative relation with the corresponding supernatants, as an attempt to obtain a “physicochemical signature” for each kind of infection and/or treatment.

FABRICATION OF PVA/TiO2 NANOFIBERS BY ELECTROSPINNING METHOD AS PHOTOCATALYTIC DEGRADATIO

The nanofiber fabrication process was optimized to determine the effect of stress variations on the morphology and diameter of the nanofibers produced for the absorption of methylene blue dye in water. PVA/TiO2 nanofibers were made using the electrospinning method. The nanofiber fabrication process begins by dissolving 10% PVA with the addition of 0.05 g of TiO2 nanoparticles, the collector tip distance is 15 cm with varying voltages of 12, 15, and 18 kV. PVA/TiO2 nanofiber characterization was carried out using FTIR, SEM, EDS, and UV-Vis Spectrophotometer. The results showed success in forming PVA/TiO2 nanofibers. The nanofibers show a fibrous structures with a diameter of 252 nm for PVA and 237 nm for PVA/TiO2 with a uniform surface and contained TiO2 nanoparticles scattered within the nanofibers. The photocatalytic testing within 5 hours shows that PVA nanofibers can degrade up to 39.29% of the methylene blue dye, while TiO2 powder is up to 55.48%. Hence, the PVA/TiO2 nanofibers can degrade the dye up to 97.02%. The results of good transparency on the UV-Vis Spectrophotometer test are shown in the visible light region caused by the uniform distribution of TiO2 nanoparticles in the nanofiber.

Indirect Spectrophotometric Determination of Mebendazole Using Methyl Orange Dyein the Presence of the Oxidizing Agent NBS

Aim: To develop a swift , simple, accurate and sensitive spectrophotometric method for determination of mebendazole (MBZL) in pure and pharmaceutical formulations. Methods: The suggested method depend on oxidation of MBZL with known excess amount of N-bromosuccinimide ( NBS ) in acidic medium and after reaction is insured to be complete , the surplus NBS is estimated by de colorization of methyl orange (MO) dye and measuring the absorbance of surplus dye at 508 nm. A linear calibration curve was obtained over the concentration range 2.5– 25 μg.ml-1 with correlation coefficient of 0.9997. The molar absorptivity and sandell's sensitivity index values were determined to be 1.505 × 104 L.mol-1.cm-1 and 0.019607 μg.cm-2. The limit of detection (LOD) and quantification (LOQ) were calculated to be 0.3736 and 2.553 μg.ml-1, respectively. The proposed method has been successfully applied to the determination of MBZL in available dosage form, the validity proposed method was confirmed by recovery study via standard addition technique . Keywords: mebendazole ; N-bromosuccinimide ; Determination ;Spectrophotometry ; methyl orange

Determination of Dye Laser Intrinsic Gain Characteristics Using Directly Measurable Quantities.(Dept.E)

The dye laser analysis depends on the gain equation that contains cross sections of the relevant emission and absorption molecular transitions involved in the lasing process. The absorption cross-section σs (v) is directly related to the absorbance curves of the dye. The emission cross-section σem (v) has been derived in terms of directly measurable spectroscopic quantities. The low frequency tail of the absorption curves is minutely diminishing for very dilute solutions(~=10-5 mole/lit) usually used in laser system. This low frequency tail overlaps the operating frequency band of the laser. The linear dependence of the dye absorption on the dye concentration (Beer- Lambert law), is used to solve the low frequency tail problem. The intrinsic gain characteristics are calculated for the dye Rhodamine B and the results are in good agreement with the rep orted experimental results.

Multicomponent interpenetrating metal based Alginate-Carrageenan biopolymer hydrogel beads substantiated by graphene oxide for efficient removal of methylene blue from waste water

Sodium alginate beads are usually prepared in the presence of Ca2+ ions. Here we prepared Graphene oxide based Sodium Alginate-Carrageenan (Ala-Car) hydrogel beads using copper metal ions as ionic crosslinker. The hydrogel beads were prepared by injecting bio-polymers into a beaker containing Cu2+ ions following rapid magnetic bead strategy. The shape and mechanical properties of hydrogel beads were influenced by concentration of copper ions and amount of the biopolymers used. Rheological and textural analysis was carried to investigate the mechanical and deformation studies of the hydrogel beads and the concentration of copper ions was optimized accordingly. Structural and morphological characterization was done by using FTIR and FESEM analysis. The hydrogels showed high removal capacity than the reported hydrogels of sodium alginate for methylene blue (MB) removal. Keeping the dosage of the adsorbent concentration constant (Ala:Car:GO = 2:2:1) and pH 9.2 conditions, percent removal ranged between 70% and 80% at lower concentrations and went upto about 90% at 60 mg/L of the initial dye concentration. As per Langmuir model, maximum adsorption was observed to be 132 mg/g for Ala: Car: GO ratio of 2:2:1. The dye absorption followed langmuir adsorption isotherm. The synthesized hydrogel beads show multi-functionalities (double network of polymers and graphene oxide) as such may potentially be used for removal of harmful dyes from the waste water as well as from aqueous waters.