Nm In Ethanol Research Articles

Extraction and characterization of novel alternative cellulosic fiber for sustainable textiles from Aloe barbadensis Miller stems (agricultural waste)

Novel research has been conducted on Aloe vera, focusing on stems fiber (agricultural waste), for the extraction of cellulosic fiber, an area lacking prior scientific exploration. This fiber is being reported for the first time in the scientific community. Aloe barbadensis Miller variety was subjected to various cultivation methods, including the application of inorganic and organic fertilizers, along with the removal of lower leaves to promote stem growth. Stem fibers were extracted using the water retting method and subsequently analyzed. The moisture content was 55.35 % and 6.99 % ash content in the fibers. The bacteriostatic analysis of Aloe vera fibers was assessed against four bacterial strains, with both ethanol and water extracts showing varying degrees of inhibition zones. The UV–Visible spectrum exhibited a distinct λmax at 247 nm in ethanol, while FT-IR analysis provided characteristic peaks at 3759, 1590, 1750, 1663, 1250, 564, SEM images displayed the smooth surface morphology of the fibers, and X-ray diffraction analysis indicated a high degree of crystallinity (78.67 %), suggesting a well-structured and crystalline nature. Energy dispersive X-ray (EDX) analysis was conducted to determine the elemental composition of the fibers, revealing the presence of carbon, oxygen, calcium, and copper, with carbon being the predominant element in cellulose. These results showed promising properties suggesting potential applications in textile industry as an alternative sustainable natural cellulosic fiber.

Highly effective recognition of Fe3+ and lysine based on hydrosoluble N-doped carbon dots

In this study, dual-color nitrogen-doped carbon dots (NCDs) were synthesized using a simple solvothermal method. These fluorescent NCDs displayed excitation-independent emission in red (598 nm in ethanol) and orange (553 nm in water) due to their effect of two different solvents. Both types of NCDs exhibited high stability under UV irradiation for 80 min. The water-soluble NCDs showed excellent sensitivity to Fe3+ ions by the quenching of their photoluminescent (PL) intensity. Quantitative analysis revealed a gradual decline in PL intensity, with a low detection limit of approximately 0.97 µM. Interestingly, the quenched fluorescence of NCDs caused by Fe3+ could be restored by the addition of lysine to the (NCDs + Fe3+) solution, with an estimated detection limit of about 0.37 µM. This phenomenon could be explained in the terms of non-radiative electron/hole recombination, leading to aggregation through efficient photo-induced electron transfer (PET). Utilizing their high selectivity and sensitivity, these NCDs served as “On-Off-On” switches and were successfully employed for the detection of Fe3+ in real water samples, contributing to environmental safety and control efforts.

INCREASING THE EFFICIENCY OF USING WOOD BIOMASS BY PROVIDING SPECIAL PROPERTIES

Background. The search for ways to use logging waste is a distinct scientific direction, due to the large number of their permanent formation. The importance of such studies is associated with the need to reduce the loss of valuable wood raw materials in the form of logging waste. One of the possible ways of using waste from logging industries is the production of wood chips using a mobile complex of machines with its further recycling into a wood-fiber semi-finished product. Wood-fiber semi-finished product is, as it is known nowadays, one of the environmentally friendly types of insulation and finishing materials. A significant limitation in the use of wood fiber in various types of production is low fire and bio-resistance. As a consequence, imparting specific properties to a wood-fiber semi-finished product in the form of fire and bio-resistance is an acute problem of the modern wood processing industry.
 Purpose. Synthesis of 4-azofunctionalized pyrazoles with perfluoroalkyl substituent by cyclocondensation of polyfluorinated beta-diketones to confer special properties to the wood-fiber semi-finished product.
 Materials and methods. The 1H, 13C NMR and 1H-13C HSQC spectra were registered at the Krasnoyarsk Regional Center for Collective Use of the FITC KNC SB RAS on a Bruker Avance III Fourier spectrometer with a frequency of 600 MHz equipped with sensitive helium probes with a diameter of 5 mm and 1.7 mm. TMS is used as an internal standard. Chromato-mass spectra were obtained using ISQ 7610 Single Quadrupole GC-MS and Shimadzu LC/MS-2020 instruments. Methyl alcohol was used as the mobile phase. IR spectra were recorded on the FT-801 (FT-801) SIMEX IR Fourier spectrometer with a spectral range from 450 to 5700 cm-1. UV spectra were recorded on a HELIOS OMEGA spectrophotometer equipped with a tungsten-halogen lamp in quartz cuvettes with a diameter of 1 cm at a concentration of 1·10-4 mol/l for 200-400 nm and a concentration of 1·10-2 mol/l for 400-800 nm in ethanol. Melting temperatures were determined in open capillaries on a PTP device (TU 25-11-1144-76).
 Results. 3 new compounds were synthesized: 3(5)-(thiophene-2-yl)-4-nitroso-5(3)-(trifluoromethyl)-1H-pyrazole, 3(5)-phenyl-4-nitroso-5(3)-(trifluoromethyl)-1H-pyrazole and 3(5)-(naphthalene-2-yl)-4-nitroso-5(3)-(trifluoromethyl)-1H-pyrazole.
 Conclusion. Thus, 3(5)-(thiophene-2-yl)-4-nitroso-5(3)-(trifluoromethyl)-1H-pyrazole, 3(5)-phenyl-4-nitroso-5(3)-(trifluoromethyl)-1H-pyrazole and 3(5)-(naphthalene-2-yl)-4-nitroso-5(3)-(trifluoromethyl)-1H-pyrazole. Complex separable mixtures of substances containing pyrazoline, β-diketone and target nitrosopyrazoles were formed by a single-reactor method. The two-stage method of production proposed by us increases the purity and yield of the target products.

Self-oscillation of 3D trapped bubbles

In this study, we focus on the trapping and self-oscillation of microbubbles in ethanol using a low-power continuous-wave laser. The microbubble formation is achieved by heating of ethanol by light absorption (λ = 658 nm) at silver nanoparticles deposited on the distal end of a multi-mode optical fiber. Subsequently, a second low-power continuous-wave laser (λ = 1,550 nm) coupled to a single-mode optical fiber is used to trap the microbubble. To trap the microbubble, the red laser is turned off after its generation, and immediately the trapping laser is activated. The bulk light absorption at λ = 1,550 nm in ethanol modulates the surface tension of the bubble wall, creating a 3D potential well that effectively traps the bubble. Once the bubble is trapped, random variations in the bubble's radius led to instabilities in the trap, triggering the microbubble oscillation. The trapped bubble tends to oscillate along the light propagation between two points of quasi-steady-state equilibrium. These bubble oscillations result from the opposing competing forces: a changing-direction Marangoni force and drag forces and the upward buoyancy force. To explain the self-oscillation, we present a simple model that qualitatively describes the main features observed in the experimental data.

Method Development and Validation for the Simultaneous Estimation of Pregabalin, Methylcobalamin and Nortriptyline in Sustained Release Tablet Dosage Form Using UV-Spectrophotometry

To method develop and validate simple, linear, rapid, cost effective, precise, accurate and economical for the simultaneous estimation of Pregabalin, Methylcobalamin and Nortriptyline in sustained release tablet dosage form using UV-Spectrophotometry. The drug obeyed the Beer’s law and showed good correlation of concentration with absorption which reflect in linearity. The UV- Spectroscopic method was developed for estimation of Pregabalin, Methylcobalamin and Nortriptyline in sustained release tablet dosage form and also validated as per ICH guidelines. The method is based on measurement of absorbance at three wavelengths 219 nm, 222 nm, and 239 nm in Ethanol and distilled water. Linearity graph of Pregabalin, Methylcobalamin and Nortriptyline were found to be linear in the concentration ranges of 30-150 µg/ml, 0.6-3.0 µg/ml and 2-10 µg/ml. The correlation coefficient (R2) values at three wavelengths 219 nm, 222 nm, and 239 nm for Pregabalin are 0.9996, 0.9929, and 0.9996; for Methylcobalamin (R2) values are 0.9998, 0.9991, and 0.9997; for Nortriptyline (R2) values are 1.0, 0.9992 and 0.9997. The low % RSD values indicate method to be accurate and precise. The % recoveries of Pregabalin, Methylcobalamin and Nortriptyline were in the range of (99.30%-1-1.61%), (98.89%-100.02%) and (99.69%-100.23%) which was within standard acceptance limits. All other validation parameters were performed by following respective ICH guidelines.

A novel sustainable second‐derivative synchronous spectrofluorimetric method for the simultaneous determination of olmesartan medoxomil and rosuvastatin calcium in bulk and formulations: Integrated greenness and whiteness evaluation

AbstractThe present research has established a quick and highly sensitive second‐derivative synchronous fluorometric technique for the simultaneous quantification of a binary mixture of olmesartan medoxomil and rosuvastatin calcium. Simultaneously, the suggested approach was used to detect the synchronous fluorescence intensity of the cited drugs at Δ λ = 80 nm in ethanol to determine the concentrations of olmesartan medoxomil and rosuvastatin calcium at 265 and 240 nm, respectively. Various experimental conditions were tested, and each variable was analyzed and optimized. The calibration graphs were shown to be linear within ranges of 0.1–2.0 and 0.5–6.0 μg ml−1 for each drug concentration, respectively. The newly developed Green Solvents Selecting Tool (GSST) was utilized to assess the solvent's sustainability. Furthermore, the proposed method was found to be environmentally friendly after being evaluated with three different tools [the Green Analytical Procedure Index (GAPI), the Analytical Greenness Metric (AGREE), and the Analytical Eco‐Scale with Eco‐score equal to 95]. The whiteness qualities were also studied using the Red–Green–Blue (RGB12) model, which was recently designed and showed a high score equal to 92.9. The proposed method’s good findings, as well as its ongoing sustainability, simplicity, and economy, stimulate its application in QC laboratories.

3D dynamic tracking Aβ plaques in live brains using vinyl-bridged dyes with two-photon excitation/NIR emission and large Stokes shifts

Real-time studies of biomarkers for neurological disorders present significant opportunities for diagnosing and treating related diseases, and fluorescent probes offer a promising approach to brain imaging. However, intracerebral fluorescence imaging is often limited by blood-brain barrier permeability and penetration depth. Moreover, only very few probes have rapid intracerebral metabolic properties, which are critical for in vivo imaging. Here, we developed a novel class of fluorescent dyes with two-photon excitation and near-infrared (NIR) emission (920/705 nm). The representative WAPP-4 probe exhibits a large Stokes shift (Δλ = 324 nm in ethanol) and excellent blood-brain barrier permeability. Notably, using WAPP-4, we achieved in vivo 3D dynamic imaging of Aβ plaques in the brains of living mice with Alzheimer's disease (AD). In addition, super-resolution imaging showed that WAPP-4 could effectively characterize the distribution and shape of Aβ plaques in isolated brain slices. This study demonstrates that newly developed fluorescent dyes with large Stokes shifts and blood-brain barrier permeability enable real-time imaging of amyloid plaques, which will contribute to the development of other valuable tools for near-infrared imaging and super-resolution imaging in the brain.

Benzanthrone sulfides: synthesis, solvatochromism characterization and analysis of experimental photophysical parameters and theoretical calculations

In this paper the synthesis, characterization, and photophysical properties of benzanthrone-derived sulfides are discussed. The compounds were synthesized using a practical method of nucleophilic aromatic substitution reactions of 3-bromobenzanthrone with thiols. Structural characterization was conducted using nuclear magnetic resonance (NMR) and Fourier-transform (FTIR) spectroscopy and high-resolution mass spectrometry, confirming the chemical structures. The crystal structure of a compound was determined via X-ray diffraction, revealing π-π stacking interactions and intermolecular hydrogen bonding. Photophysical analysis showed solvatochromic effects (emission of light upon excitation from 507 nm in benzene to 591 nm in ethanol) and attributed fluorescence to intramolecular charge transfer. Computational analysis using DFT calculations provided further insights into the compounds' properties, including excited state energies and the potential for efficient intersystem crossing. Overall, the research provides a comprehensive understanding of the newly synthesized benzanthrone alkyl and aryl sulfides as well as a phenylselanyl derivative. The photophysical properties, charge transfer characteristics observed in the compounds and the solvatochromic effects exhibited by the compounds suggest their potential to be utilized for developing sensors for detecting environmental changes, chemical substances or biological targets.

PH regulated lactose inspired fabrication of zinc oxide nanoparticles for insulin sensing by LSPR absorption

Nanostructured metal oxide particles with diversified morphologies are in high demand in nanotechnology. The particle size, shape, and overall geometry mainly depend on the fabrication method. This study reports synthesis of zinc oxide nanoparticles (ZnO NPs) from zinc nitrate hexahydrate [Zn(NO3)2.6H2O] precursor in aqueous media at 65 °C by using lactose from cow milk as a reducing agent and regulating pH from 6 to 10. UV–visible absorption gave maximum absorbance (λmax) at 371–375 nm in ethanol for localized surface plasmon resonance (LSPR), FTIR exhibited bands at ca. 439–481 cm−1 for stretching mode Zn–O bonds, and XRD peaks at 2 θ values at 31.8, 34.45, and 36.28° confirmed the fabricated ZnO NPs. The XRD spectra also indicated that the ZnO crystallite (20–30 nm) has a hexagonal wurtzite structure. The average particle sizes measured by DLS were ca. 50–837 nm, and SEM microphotographs demonstrated the morphology of ZnO NPs with a hexagonal, rod-shaped, or spike-like structure. The ZnO NPs were used to investigate the LSPR absorption at various concentrations of insulin, ranging from 2.5 μM to 50 μM. The ZnO NPs fabricated at pH 7 and 10 showed better insulin sensing performance with high precision. The synthesis approach of ZnO NPs with variable morphologies would play a significant function in biomedical science especially real time monitoring of glucose for efficient management of diabetes.

Q-ABSORBANCE RATIO AND VIERODT’S SPECTROPHOTOMETRIC METHOD FOR THE SIMULTANEOUS ESTIMATION OF FAMOTIDINE AND OMEPRAZOLE

Famotidine and omeprazole are the drugs used in the treatment of gastrointestinal disorders. The current work is an analytical method for the simultaneous determination of famotidine and omeprazole and is based on the Q-absorption method and Vierodt’s method. These two methods depend on the isosbestic point and the ?max of one of the two components. The isosbestic point was found to be 295 nm in ethanol. 287nm and 301nm are the ?max of famotidine and omeprazole respectively. The method is validated as per ICH guidelines.

Identification, Determination and Spectral Study

Corona viruses resist many antiviral agents which reduces the antiviral therapies. Remdesivir is an antiviral drug efficient against single-stranded RNA viruses. Analytical determinations of this drug are very benefit in selecting the correct dose and getting real information and formulas of this compound. In this work, remdesivir has been identified at 239 nm in aqueous alkaline (1M NaOH), at 245 nm in ethanol, and at 246 nm. in methanol, it has also been followed at 239 nm using the alkaline medium and determined in injection, the linearity range was from 1to 60 µg/ml with molar absorptivity 2.036×104 l.mol-1.cm-1, and Sandell’s sensitivity index is 0.0295 µg.cm-2, LOD is 0.2613 and LOQ is 0.871 µg/mL. I. R spectrum of solid remdesivir shows band at 1639.96 cm -1 due to the carbonyl group and at 3350.79 cm-1refer to the hydroxy group adjacent to NH2 group which appears at about 3300 cm-1, the aromatic was identified at 1660-2000 cm-1 and C-O of ester at 1153cm-1. These bands in the alkaline medium were slightly shifted to be 1637 cm -1 due to carbonyl group and at 3318 cm-1refer to hydroxy group adjacent to NH2 group which appeared at about 3264 cm-1, the aromatic was identified at 2131 cm-1, and C-O of ester at 1379cm-1.

Preparation of Composite Hydrogels with Silica Nanoparticles by Photoinitiated Polymerization Reaction

In this study, (3-mercaptopropyl) trimethoxysilane (MPTMS) modified silica nanoparticles (SiO2-MPTMS) were successfully prepared. The average size of SiO2-MPTMS nanoparticles was measured by Dynamic Light Scattering (DLS) as 341 nm in ethanol, while Scanning Transmission Electron Microscopy (STEM) analyzes confirmed that the nanoparticles were nano-sized and revealed that their shapes were spherical. Then, 3D nanocomposite hydrogels were prepared by incorporating SiO2-MPTMS nanoparticles in various ratios (0.25, 0.50, 0.75 and 1.0 wt %) into an acrylate resin consisting of N-isopropyl acrylamide (NIPAM) and polyethylene glychol diacrylate (PEGDA; as a crosslinker) by the photoinitiated polymerization reaction with Dimethoxy-2-phenylacetophenone (DMPA; as a photoinitiator). By Thermal Gravimetric Analyzer (TGA) measurements, it was determined that the nanocomposite hydrogels maintained their thermal stability up to 330 0C and the thermal degradation steps were close to each other. Scanning Electron Microscopy (SEM) study showed that the neat and nanocomposite hydrogels’ morphological structures were in the porous and smooth scaffold, and also that the SiO2-MPTMS nanoparticles (0.50 wt %) were homogeneously distributed in the network structures of hydrogels, localized in the bonds.

A one pot synthesis and characterization of intrinsically fluorescent cross-linked polyphosphazene nanospheres

Novel inorganic-organic hybrid highly crosslinked and fluorescent polyphosphazene nanospheres were prepared via a one pot polycondensation polymerization method. Fluorescein and 4,4′-diaminodiphenylmethane were used as organic monomers in the synthesis of the nanospheres. The crosslinked structure of the nanospheres was formed with inorganic octachlorocyclotetraphosphazene rings. The characterization of the prepared nanospheres was performed by SEM, EDX, solid-state 31P-NMR, FTIR, XPS, XRD, DLS, and UV-vis techniques. The average particle size of the nanospheres was determined to be 343 nm. The fluorescence properties of the nanospheres were investigated. When they were excited at 470 nm, the nanospheres exhibited a fluorescence emission at 520 nm in ethanol. However, they did not show fluorescence emission at solid state. The nanospheres exhibited maximum emission at pH 9.0. The synthesized nanospheres have excellent photostability in 60 minutes at pH 9.0 owing to the crosslinked and inorganic-organic hybrid structure.

The Role of Polyvinylpyrrolidone as a Potential Fluorophore for the Detection of Nitroaromatic Explosives

Background: Detection of explosives (Nitroaromatic compounds) is one of the major issues faced in global security and, to date, remains a challenge even though some materials are developed for their detection. This study introduces the use of polyvinylpyrrolidone (PVP), a nonconjugated conducting polymer, as a potential fluorophore for sensing nitroaromatics. The stimuliresponse of fluorescence of PVP on interaction with energetic nitroaromatics was investigated in the present study. Methods: Fluorescence quenching studies of 5% PVP was carried out by the addition of varying concentration of quenchers (m-dinitrobenzene, trinitrobenzene and 2,4,6-trinitrophenol). To study the effect of different solvents on fluorescence quenching, two different solvents were used, i.e., water and ethanol. The quenching studies of PVP with dinitrobenzene and trinitrobenzene were carried out in ethanol and 2,4,6-trinitrophenol was carried out in the water. Results: The maximum emission peak intensity of PVP was observed at 445 nm in ethanol and 420 nm in water, which was quenched upon the gradual addition of quenchers. This shift in maximum peak intensity of PVP was understood from the change in the solvent polarity. UV-Visible and FTIR studies were also carried out to understand the nature of interaction taking place between the quenchers and PVP. The limit of detection (LOD) was observed as 1.8x10-3 M, 2.5x10-6 M, and 3.9x10-6 M for picric acid, dinitrobenzene and trinitrobenzene, respectively. Conclusion: The results envisage PVP as a potential candidate for sensing energetic nitroaromatics with good sensitivity.

Development and Validation of an analytical method for the determination of Ofloxacin and Benzyl alcohol in a Pharmaceutical mixture

The aim of the study is to develop a validated, rapid, simple and low-cost method for estimating ofloxacin and benzyl alcohol in a combined dosage. Materials and methods: Materials which were used ofloxacin pure substance and benzyl alcohol pure substance which were determined by UV spectrophotometer using ethanol 95% as a solvent and a blank. Results and discussion: Ofloxacin shows the absorption maxima at 300.0 ± 2.0 nm in ethanol 95% with an apparent concentration absorptivity of (30 to 90) µg/ml and benzyl alcohol shows the absorption maxima at 312.0 ± 2.0 nm in ethanol 95% with an apparent concentration absorptivity of (60 to 200) µg/ml, it was found that in the selected range of application of the method there is a directly proportional relationship between the concentration of ofloxacin and benzyl alcohol respectively, in the measured samples and the analytical signal, linear dependence is characterized by high correlation coefficients (R> 0.999)for both of drugs, which is considered acceptable for establishing strict linearity. Conclusion: The method has been verified as it has been proven simple, fast, accurate and low-cost method and does not require any expensive equipment for the analysis of Ofloxacin and benzyl alcohol separately and in a pharmaceutical mixture.

Heterocyclic Schiff Bases of 3-Aminobenzanthrone and Their Reduced Analogues: Synthesis, Properties and Spectroscopy

New substituted azomethines of benzanthrone with heterocyclic substituents were synthesized by condensation reaction of 3-aminobenzo[de]anthracen-7-one with appropriate aromatic aldehydes. The resulting imines were reduced with sodium borohydride to the corresponding amines, the luminescence of which is more pronounced in comparison with the initial azomethines. The novel benzanthrone derivatives were characterized by NMR, IR, MS, UV/Vis, and fluorescence spectroscopy. The structure of three dyes was studied by the X-ray single crystal structure analysis. The solvent effect on photophysical behaviors of synthesized imines and amines was investigated. The obtained compounds absorb at 420–525 nm, have relatively large Stokes shifts (up to 150 nm in ethanol), and emit at 500–660 nm. The results testify that emission of the studied compounds is sensitive to the solvent polarity, exhibiting negative fluorosolvatochromism for the synthesized azomethines and positive fluorosolvatochromism for the obtained amines. The results obtained indicate that the synthesized compounds are promising as luminescent dyes.

Impact of Solvents, Magnesium Oxide and Aluminium Oxide Nanoparticles on the Photophysical Properties of Acridine Orange Dye

Absorption and fluorescence spectroscopy techniques were applied to investigate the photophysical characteristics of acridine orange (AO) dye in solvents that included distilled water, dimethyl sulfoxide (DMSO), acetone and ethanol in various concentrations (1×10-4–1×10-6) M. All of the samples were served at room temperature. The relationships between various parameters describing the strength of optical transitions in atoms and molecules were reviewed. This study expresses various viewpoints by describing how concentration and solvent affect the dye's absorption and fluorescence spectra. The absorption spectra of AO exhibit a band at (490 nm), except for DMSO, which shifts more towards red by 5 nm. The fluorescence spectra show a blue shift in AO aqueous solution around 6 nm until (0.5×10-4) M, followed by a red shift at around 7 nm at (1×10-6) M. There is a blue shift in (1×10-5) M for DMSO at around 4 nm, then a 10 nm red shift in higher concentrations as well as a 9 nm red shift in acetone and 6 nm in ethanol. Adding magnesium oxide nanoparticles (MgO NPs) quenched AO in both absorption and fluorescence spectra, whereas maximum fluorescence and intensity increased when aluminium oxide nanoparticles (Al2O3 NPs) were added to the solution. KEYWORDS Laser dye, absorption spectrum, fluorescence spectrum, MgO NPs, Al2O3 NPs

Analytical techniques for the estimation of Celecoxib in capsule dosage form by spectrophotometric method

For the determination of Celecoxib in pure formulations and its pharmaceutical formulations, a simple UV-spectrophotometric method was developed. Celecoxib exhibited maximum absorption at 244 nm in ethanol and obeyed linearity in the concentration range of 0.2-40 μg/ml. The method proposed was validated statistically. With good accuracy, all the proposed methods are simple, selective, reproducible, sensitive and precise. Some of the methods were proved to be superior to most of the reported methods. Many of these suggested prediction methods for chosen drugs, such as Celecoxib, have been successfully implemented either in bulk or in prescription formulations. The suggested methods can be used in bulk and prescription dosage formulations as alternative methods to the recorded ones for the routine determination of selected drugs in the sample.

Analytical techniques for the estimation of Trospium chloride in capsule dosage form by spectrophotometric method

For the determination of Chloride in pure formulations and its pharmaceutical formulations, a simple UV-spectrophotometric method was developed. Chloride exhibited maximum absorption at 280 nm in ethanol and obeyed linearity in the concentration range of 10-70 μg/ml. The method proposed was validated statistically. With good accuracy, all the proposed methods are simple, selective, reproducible, sensitive and precise. Some of the methods were proved to be superior to most of the reported methods. Many of these suggested prediction methods for chosen drugs, such as Chloride, have been successfully implemented either in bulk or in prescription formulations. The suggested methods can be used in bulk and prescription dosage formulations as alternative methods to the recorded ones for the routine determination of selected drugs in the sample.

Synthesis of an Acid-gas Sensing Fluorescence Dye Showing Change of Both Color and Fluorescence Emission Spectrum inside Polyethylenic Fiber on Exposure to Gas Phase Strong Acid for Application to Washable Textile Sensors

A halochromic fluorescence dye was synthesized to fabricate acid-gas sensing textiles. The dye has a maximum absorption at 436 nm and stokes shift of 54 nm in ethanol, which means that it exhibits a typical fluorescence color of greenish yellow. The dye was designed to have good substantivity toward hydrophobic and chemical resistant polyethylenic fibers, such as high molecular weight polyethylene (HMWPE) fibers, by introducing di-butyl and t-butyl groups on coumarin and benzoxazole moieties of the chromophore, respectively. The fluorescence dye showed the change of both color and fluorescence emission properties not only in a solution by addition of hydrochloric acid but also inside the HMWPE fiber on exposure to gas phase hydrogen chloride even at relatively low concentrations. From the repeat test, the sensing performance was maintained reversibly even after 20 repeat cycles of adsorption and desorption of gas phase hydrogen chloride. The HMWPE fabrics dyed with the fluorescence dye can be washable by showing fastness of rating 4–5 to washing.