Xylenol Orange Research Articles

Fabrication and characterization of TiO2-based dye-sensitized solar cells

Dye-sensitized solar cells TiO2 with were fabricated. The phase composition and microstructures of the solar cells were examined by X-ray diffractometry and transmission electron microscopy, and the energy levels of the present solar cells were also discussed. The results show that a solar cell mixed with xylenol orange and rose Bengal shows a higher conversion efficiency compared to solar cells with a single dye. An introduction of amorphous TiO2 layers results in an improvement of the conversion efficiency.

Sm2−xDyxZr2O7 Pyrochlores: Probing Order−Disorder Dynamics and Multifunctionality

The present work involves the synthesis of a series of Sm(2-x)Dy(x)Zr(2)O(7) compounds (0.0 ≤ x ≤ 2.0) by a controlled gel combustion process. The powders were thoroughly analyzed by powder X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy, and diffuse-reflectance UV-visible spectroscopy. The powder XRD studies revealed the system to be single-phasic throughout with retention of pyrochlore-type ordering until 40 mol % of Dy(3+), beyond which the pyrochlore lattice gives way to the defect fluorite structure. Interestingly, Raman spectroscopic studies (as against XRD studies) showed retention of pyrochlore-type ordering throughout the homogeneity range of the compositions studied. This is perhaps the first study that reports retention of a weak pyrochlore-type superstructure in the Dy(2)Zr(2)O(7) system, which was otherwise known to crystallize in the defect fluorite system. The ionic conductivity measurements showed an increase in the activation energy (E(a)) with an increase in the mole percent of Dy(3+) owing to the decreased mobility with an increase in the degree of disorder. The system possesses a tunable band gap with varying amounts of Dy(3+). First-principles calculations were performed to support a decrease in the band gap of the doped system with an increase in the Dy(3+) content. The potential as photocatalysts of some of these compositions was explored, and they exhibited high photocatalytic activity for degradation of xylenol orange, with t(1/2) increasing from pure Sm(2)Zr(2)O(7) to pure Dy(2)Zr(2)O(7).

Removal of Xylenol Orange from Solutions by γ-Cyclodextrin-Grafted Carboxymethyl Cellulose

The potential to remove xylenol orange (XO) from aqueous solutions through adsorption on γ-cyclodextrin-grafted carboxymethyl cellulose (CCMC) was investigated in batch experiments. The effects of contact time, adsorption temperature and initial XO concentration were discussed. Results of batch experiments showed that CCMC exhibited some sorption capacities towards XO. It was found that isotherm fitted Languir and Freundlich models for the adsorption of XO on CCMC. On the basis of the Langmuir analysis, the maximum adsorption capacities were determined to be 29.9, 27.1, 21.9, 16.2 and 16.1 mg of XO per gram of CCMC at 283, 288, 293, 298 and 303K, respectively. The negative values of free energy change indicated the spontaneous nature of adsorption.

Determination of zinc(II) and cadmium(II) as their complexes with Xylenol Orange by capillary elecrophoresis using online preconcentration

A new version of online preconcentration employing the pH-stacking mechanism has been proposed; it has been implemented by the example of a procedure for the capillary electrophoretic determination of trace zinc(II) and cadmium(II) with photometric detection in the visible spectrum region as complexes with Xylenol Orange. The analytical range is 2–400 μg/L for zinc(II) and 1–500 μg/L for cadmium(II).

Formation of complexes on the surface of nanosized europium fluoride

EuF 3 nanoparticles with size of 10–20 nm and the hexagonal crystal structure have been synthesized and characterized. Surface modification of the nanoparticles with 4-(2-pyridylazo)resorcinol and xylenol orange in aqueous media has been examined. The study of formation of Eu(III) molecular complexes in solution and complexes on the EuF 3 nanoparticles surface has revealed some essential differences in the processes, namely much more slow kinetics of interaction of the ligands with the surface Eu(III) ions and enhanced stability of surface complexes.

Voltammetric Detection of Dopamine in Presence of Ascorbic Acid and Uric Acid at Poly (Xylenol Orange) Film-Coated Graphite Pencil Electrode

Poly (xylenol orange) film-coated graphite pencil electrode was fabricated for the detection of dopamine in the presence of ascorbic acid and uric acid in phosphate buffer solution of pH 7. The redox peaks obtained at modified electrode shows a good enhancement. The scan rate effect was found to be a diffusion-controlled electrode process. The electrochemical oxidation of dopamine was depended on pH, and the limit of detection was found to be 9.1×10−8 M. The simultaneous study gave and excellent result with great potential difference between dopamine and other bioactive organic molecules by using both cyclic voltammetric and differential pulse voltammetric techniques. The present modified graphite electrode was applied to the detection of dopamine in the injection samples, and the recovery obtained was satisfactory.

Characterization of Synthetic Ni(II)-Xylenol Complex as a Photosensitizer for Wide-Band Gap ZnO Semiconductor Electrodes

A synthetic NiIIL(H2O)2complex (L = xylenol orange, 3,3′-bis [N,N-di(carboxymethyl)-aminomethyl]-o-cresol sulphonapthalein (H2O)2), which is a water-soluble dye, has been studied for its photosensitizing properties atn-ZnO semiconductor electrodes prepared by sol-gel techniques. The absorption spectrum of aqueous solution of this complex exhibits a strong peak at 563 nm and a shoulder at 526 nm wavelength of light. The sandwich-type dye-sensitized solar cell using ZnO semiconducting thin film with test dye anchored onto it showed the cell output as follows:VOC=0.506 V,Jsc=1.68 mA cm−2, andFF=0.41under illumination with full spectrum of light (intensity 520 mW cm−2), while on illumination with visible light (λ>420 nm, intensity 480 mW cm−2),VOC=0.506 V,Jsc=1.4 mA cm−2, andFF=0.49were achieved. Maximum incident photon-to-current conversion efficiency for the present system was found to be 8.7% at wavelength (λmax=563 nm).

A comparative study on dissolution rate of sintered (Th-U)O2 pellets in by microwave and conventional heating.

ThO2 with approximately 3% 233UO2 is the proposed fuel for the Advanced Heavy Water Reactor (AHWR) and characterized as a mixed oxide (MOX) fuel. Due to the existence of a single oxidation state, quantitative dissolution of MOX samples like (Th-U)O2 and (Th-Pu)O2 is a challenging task for any analytical chemist. However, dissolution is a pre-requisite for complete characterization of the fuel. The present paper describes a detailed study carried out on the comparison of dissolution of sintered (Th-U)O2 mixed oxide pellets, in 16 M HNO3 using microwave and conventional heating techniques, under reflux conditions. The study was carried out with variation of parameters such as concentration of HF and UO2 substitution in the MOX solid solution. The concentration of dissolved U and Th was determined by modified Davies and Gray potentiometric titration and Th-EDTA complexometric titration using xylenol orange as the titration end point indicator respectively. Experimental results clearly indicate that the microwave heating assisted dissolution rate is 2 to 3 times higher than the conventional infrared heating assisted dissolution rate, for sintered pellets. The concentration of HF is a critical parameter, an excess leads to precipitation of insoluble ThF4. The concentration of HF was optimized to 0.025 M. Experimental results also clearly show that at this concentration of HF in 16 M HNO3, a higher substitution of UO2 in MOX solid solution also facilitates the dissolution process. Different trace metal impurities were determined in the MOX samples after dissolving by microwave and infra red heating techniques and it was observed that the results are comparable.

Indicator approach to develop a chemosensor for the colorimetric sensing of thiol-containing water and its application for the thiol detection in plasma

A strategy for the determination of the presence of thiol-containing amino acids was successfully established by simply assembling copper chloride and xylenol orange (3,3'-bis[N,N-bis(carboxymethyl)aminomethyl]-o-cresolsulfonephthalein trisodium salt; XO) in a 1 : 1 molar ratio in quasi-physiological water solution (pH 6.0). The copper(II)-XO ensemble was highly selective for thiol species such as cysteine, homocysteine, and glutathione without interference from other amino acids and could quantitatively detect thiol in the range from 10 to 200 μM with a linear relationship having an average molar absorbance constant of 6530 L mol(-1) cm(-1) in pure water. The whole recognition process for thiol gave rise to a rapid visual color change from purple-red to yellow which can be observed simultaneously with the naked-eye.

Flow-Injection Determination of Iron Based on Its Catalysis on the Oxidation Reaction of Xylenol Orange by Potassium Bromate

A flow injection system is proposed for catalytic kinetic spectrophotometric determination of trace iron(II + III). The involved reaction is based on the catalytic effect of iron(III) on oxidation reaction of xylenol orange by potassium bromate to form a blue-violet complex. Iron(II) is also determined, being oxidized to iron(III) by potassium bromate. The calibration graph is linear in the range of 0.02–10.0 µg l−1 and 10.0–1100 µg l−1. The relative standard deviation is 1.5% for 4.0 µg l−1 iron(III) and 2.3% for 60.0µg l−1 iron(III) (n = 11). The presented system was applied successfully to the determination of iron in natural waters.

Serum paraoxonase and arylesterase activities in iron deficiency anemia during pregnancy

To investigate serum paraoxonase and arylesterase activities, and lipid hydroperoxide levels in pregnant women with iron deficiency anemia. Materials and methods: Paraoxonase and arylesterase activities, and lipid hydroperoxide levels were assessed for pregnant women with iron deficiency anemia (n = 50) and controls (n = 70). Serum basal and salt-stimulated paraoxonase, and arylesterase activities were measured spectrophotometrically. The lipid hydroperoxide levels were measured by ferrous ion oxidation xylenol orange assay. In addition, lipid parameters were determined by routine laboratory methods. Results: Basal and salt-stimulated paraoxonase, and arylesterase activities were significantly lower (P = 0.026, P = 0.031, and P = 0.018, respectively) in pregnant women with iron deficiency anemia when compared to the controls, while lipid hydroperoxide levels were significantly higher (P = 0.004). A significant positive correlation was found between paraoxonase activity and hemoglobin levels (r = 0.329, P = 0.020), while there was inverse correlation between lipid hydroperoxide and hemoglobin levels (r = -0.457, P = 0.001). Among iron deficiency anemia, serum paraoxonase activity was inversely correlated with lipid hydroperoxide levels (r = -0.535, P < 0.001). Conclusion: The findings of the present study have shown that diminished serum paraoxonase and arylesterase activities, and increased lipid hydroperoxide levels may play a role in the early pathogenesis of atherosclerotic heart disease in pregnant women with iron deficiency anemia.

Further studies on the potential contribution of acetaldehyde accumulation and oxidative stress in rat mammary tissue in the alcohol drinking promotion of breast cancer

There is available evidence supporting a positive association between alcohol intake and risk of breast cancer. However, there is limited information regarding possible mechanisms for this effect. Past studies from our laboratory suggest that acetaldehyde accumulation in mammary tissue after alcohol intake may be of particular relevance and that cytosolic and microsomal in situ bioactivation of ethanol to acetaldehyde and free radicals and the resulting stimulation of oxidative stress could be a significant early event related to tumor promotion. In the present studies repetitive alcohol drinking for 28 days was found to produce significant decreases in the mammary tissue content of GSH and alpha tocopherol and in glutathione S-transferase or glutathione reductase activities. In contrast, glutathione peroxidase activity was slightly increased. Malondialdehyde determinations did not show the occurrence of lipid peroxidation while the xylenol orange procedure gave positive results. The mammary microsomal metabolism of ethanol to acetaldehyde was not induced after an acute dose of ethanol or acetone able to induce the activity of its liver counterpart. The cytosolic pathway of alcohol metabolism instead was significantly enhanced by these two treatments. No increased generation of comet images was found either in mammary tissue or in liver under the experimental conditions tested. Results suggest that, while acetaldehyde accumulation in mammary tissue could be a critical event resulting from increasing production of acetaldehyde in situ plus an additional amount of it arriving via blood, other factors such as poor handling of the accumulated acetaldehyde could be also relevant.

Tissue-engineered constructs based on SPCL scaffolds cultured with goat marrow cells: functionality in femoral defects

This study aims to assess the in vivo performance of cell-scaffold constructs composed of goat marrow stromal cells (GBMCs) and SPCL (a blend of starch with polycaprolactone) fibre mesh scaffolds at different stages of development, using an autologous model. GBMCs from iliac crests were seeded onto SPCL scaffolds and in vitro cultured for 1 and 7 days in osteogenic medium. After 1 and 7 days, the constructs were characterized for proliferation and initial osteoblastic expression by alkaline phosphatase (ALP) activity. Scanning electron microscopy analysis was performed to investigate cellular morphology and adhesion to SPCL scaffolds. Non-critical defects (diameter 6 mm, depth 3 mm) were drilled in the posterior femurs of four adult goats from which bone marrow and serum had been collected previously. Drill defects alone and defects filled with scaffolds without cells were used as controls. After implantation, intravital fluorescence markers, xylenol orange, calcein green and tetracycline, were injected subcutaneously after 2, 4 and 6 weeks, respectively, for bone formation and mineralization monitoring. Subsequently, samples were stained with Lévai-Laczkó for bone formation and histomorphometric analysis. GBMCs adhered and proliferated on SPCL scaffolds and an initial differentiation into pre-osteoblasts was detected by an increasing level of ALP activity with the culture time. In vivo experiments indicated that bone neoformation occurred in all femoral defects. The results obtained provided important information about the performance of SPCL-GBMC constructs in an orthotopic goat model that enabled future studies to be designed to investigate in vivo the functionality of SPCL-GBMC constructs in more complex models, viz. critical sized defects, and to evaluate the influence of in vitro cultured autologous cells in the healing and bone regenerative process.

Synthesis of hermetically-sealed graphite-encapsulated metallic cobalt (alloy) core/shell nanostructures

Hermetically-sealed graphite encapsulated cobalt core/shell nanostructures have been prepared by the CO Boudouard reaction using in situ generated cobalt as the catalyst. Only core/shell nanostructures were obtained, rather than a mixture of cobalt nanoparticles with carbon nanotubes or nanofibers. The magnetic cobalt nanoparticles are highly crystallized with a hexagonal-close packed crystal phase (average diameter of ca. 25 nm) and coated with an 8–9 nm thick graphitic shell. The nanostructures have a high saturation magnetization of 85 emu/g and can be easily separated by an external magnet. The creation of the hermetically-sealed graphitic shell not only keeps the magnetic cobalt nanoparticles from reacting with strong mineral acids, but also has biocompatibility and makes further functionalization easy. A pseudo-planar aromatic molecule, xylenol orange, was used as the model molecule because it can be absorbed on the graphitic shell mainly by π–π stacking interaction. This was confirmed by Raman and ultraviolet–visible spectroscopy. Graphite encapsulated Fe 2Co and Fe 0.64Ni 0.36 alloy core/shell nanostructures were also fabricated by this method.

Fricke dosimetry of irradiated sugar by 1H NMR relaxation

Linear dose response in the range 0–30 Gy was observed in spin-lattice and spin-spin relaxation rates of water protons in 10 wt% sugar Fricke solutions at 300 MHz and 25 MHz. Spin-lattice dose sensitivities were higher at 300 MHz (0.058 s−1 Gy−1 with xylenol orange, 0.024 s−1 Gy−1 without) than at 25 MHz (0.047 s−1 Gy−1 with xylenol orange, 0.026 s−1 Gy−1 without), despite slightly less linearity. Spin-spin dose sensitivities at 25 MHz (0.029 s−1 Gy−1 with xylenol orange, 0.033 s−1 Gy−1 without) were slightly higher than corresponding spin-lattice dose sensitivities. Unirradiated sugar was found to accelerate background oxidation in Fricke solution, following a logistic time development curve.

The adsorption of sulphonated azo‐dyes methyl orange and xylenol orange by coagulation on hollow chitosan microsphere

AbstractChitosan (CS) can be used as adsorbent in the treatment of effluents from the textile industry, especially for negatively charged dyes, due to its cationic polyelectrolyte nature. In this work, the adsorption of a model dye, methyl orange, xylenol orange on hollow CS microsphere is analyzed. Adsorption of methyl orange, xylenol orange onto cross‐linked CS is realized by means of analysis of pH influence, agitation time, and initial concentration of the dye. The results obtained from the experiment shows that the adsorption capacities of the two dye‐hollow CS microsphere systems are higher than those stated in other literature using CS particles. The difference in the degree of adsorption may also be attributed to the size and chemical structure of the dye molecule. The results have demonstrated that monovalent and smaller dye molecular sizes have superior capacities due to the increase in dye/CS surface ratio in the system and deeper penetration of dye molecules into the internal pore structure of hollow CS microsphere. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011

A novel method of synthesizing solid phase adsorbent silica modified with xylenol orange: application for separation, pre-concentration and determination of uranium in calcium rich hydro-geochemical samples and sea water—Part 1

A novel, single-step route has been developed for the synthesis of solid phase adsorbent silica modified with xylenol orange. The addition of cationic surfactant cetyl tri-methylammonium bromide during the synthesis of the adsorbent supports the formation of a stable coating of xylenol orange on silica. The adsorbent showed no signs of degradation in contact with organic solvents and with solutions of varying pH between 1 and 9. This adsorbent has been used for separation and pre-concentration of uranium from hydro-geochemical samples with high calcium content and from sea water. Quantitative sorption of uranium was observed above pH 3 and complete desorption can be achieved using 0.2 M sodium pyrophosphate solution. The uranium content in the extract was determined by laser fluorimetric technique. The equilibration time is 30 min. The sorption capacity of the adsorbent for uranium is 10 mg g−1. An enrichment factor of 50 was obtained by this procedure taking 500 mL of sample solution. Uranium concentrations down to 0.05 ng mL−1 can be determined after pre-concentration using this method. The relative standard deviation at an 0.1 ng mL−1 level is ±15%.

Dielectric Dispersion in KDP Crystals with Complex Organic and Inorganic Impurities

Dielectric properties of KH2PO4 (KDP) crystals doped with complex organic (Amaranth, Chicago Sky Blue, Xylenol Orange) and inorganic (Potassium PentoChloroRuthenate) molecules were analyzed in the frequency range of 10 mHz–10 MHz. A noticeable dispersion in paraelectric phase at 30–80°C is revealed. In some crystals with dyes the deviation of Cole-Cole diagrams from Debye-type relaxation is shown. Conductivity and activation energy of the conductivity mechanism at high temperature are determined.

부유 - 분광광도법에 의한 지르코늄의 극미량 측정

A sensitive and reproducible method for the flotation-spectrophotometric determination of zirconium is reported. The method is based on the complex formation zirconium and xylenol orange (XO) which is floated in the interface of aqueous phase and n-hexane by vigorous shaking. By discarding the aqueous solution and n-hexane, the adsorbed complex on to the wall of a separating funnel was dissolved in a small volume of methanol solvent and its absorbance was measured at 429 nm. The effect of different parameters such as pH, concentrations of HCl, and XO, and volume of n-hexane flotation dissolvent, standing and shaking time were studied. The calibration curve was linear in the range of 7-120 ng of zirconium with a correlation coefficient of 0.9991. The limit of detection (LOD) was 5.8 ng . The relative standard deviation (RSD) for seven replicate measurements of 50 and 110 ng of zirconium were 4.4 and 3.0%, respectively. The method was successfully applied to the determination of zirconium in water samples.

Effect of Dehiscences to the Bone Response of Implants With an Acid-Etched Surface: An Experimental Study in Miniature Pigs

Spontaneous early exposure of submerged implants during the healing phase as a factor for early crestal bone loss around the implants is still being controversially discussed. The aim of this study was to examine the potential impact of dehiscences on the osseointegration process of acid-etched dental implants with a shortened healing period in the maxilla. Five animals received a total of 15 titanium implants 8 weeks postextraction. Eight of these implants were placed in the maxilla to osseointegrate within a shortened healing period of 3 months, whereas the remaining implants were inserted in the lower jaw and served as controls with a regular healing time. Polyfluorochrome sequential labeling with xylenol orange, calcein green, and alizarin complexone was performed 2, 5, and 8 weeks after implant placement. After 12 weeks of unloaded and submerged healing, the animals were killed and the implants removed en bloc. After the processing of the undecalcified PMMA-embedded samples, thin ground sections (40-60 µm) were made. The histomorphometric determination of the bone-to-implant contact (BIC) was calculated using light microscopy. The peri-implant bone apposition rate and the direction of bone growth were determined with the fluorescence microscope. For statistical evaluation, the Mann-Whitney U test, Wilcoxon signed ranks test, and Friedman test were chosen. During the healing period, nonartificial dehiscences were observed at 9 implants. The average BIC was 54.19% (14.51%-68.97%). There were significantly lower BIC rates detected for the cervical part of the implants compared with the middle part. An influence of dehiscences on the osseointegration could not be proven. There were no significant differences between the BIC values of the upper and lower jaw. During the observation period from the third to the eighth week after implantation, the average new bone formation rate was 2.32 µm/d (1.76-2.82 µm/d). During this period, the amount of new bone growth decreased insignificantly. Based on the sequence of the polyfluorochrome labeling, an implantopetal (53.03%) as well as an implantofugal bone growth (46.97%) have been observed. It could be assumed that the acid-etched implants offered a prerequisite to osseointegrate under a shortened healing period. The observed dehiscences seemed not to have compromised the rate of osseointegration.