A Simple and Portable Colorimeter Using a Red-Green-Blue Light-Emitting Diode and Its Application to the On-Site Determination of Nitrite and Iron in River-water

Abstract Spin-states and charge-trappings in blue organic light-emitting diodes (OLEDs) are important issues for developing high-device-performance application such as full-color displays and white illumination. However, they have not yet been completely clarified because of the lack of a study from a microscopic viewpoint. Here, we report operando electron spin resonance (ESR) spectroscopy to investigate the spin-states and charge-trappings in organic semiconductor materials used for blue OLEDs such as a blue light-emitting material 1-bis(2-naphthyl)anthracene (ADN) using metal–insulator–semiconductor (MIS) diodes, hole or electron only devices, and blue OLEDs from the microscopic viewpoint. We have clarified spin-states of electrically accumulated holes and electrons and their charge-trappings in the MIS diodes at the molecular level by directly observing their electrically-induced ESR signals; the spin-states are well reproduced by density functional theory. In contrast to a green light-emitting material, the ADN radical anions largely accumulate in the film, which will cause the large degradation of the molecule and devices. The result will give deeper understanding of blue OLEDs and be useful for developing high-performance and durable devices.

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Optimization and evaluation of a blue light photoinitiating system for textile inkjet printing

Textile Research Journal ◽

10.1177/0040517518783346 ◽

2018 ◽

Vol 89 (10) ◽

pp. 1964-1974

Author(s):

Yi Huang ◽

Guangdong Sun ◽

Yating Ji ◽

Dapeng Li ◽

Qinguo Fan ◽

...

Keyword(s):

Blue Light ◽

Light Emitting Diode ◽

Absorption Efficiency ◽

Polymerization Rate ◽

Nozzle Clogging ◽

Light Emitting ◽

Custom Made ◽

Light Curing ◽

Set Up ◽

Pigment Ink

A blue light curing process was developed to solve the nozzle clogging challenge commonly encountered in conventional textile pigment printing, by using camphorquinone (CQ) and ethyl-4-dimethylaminobenzoate (EDMAB) as a photoinitiator combination and substituting oligomers and monomers for a polymeric binder. High light absorption efficiency was insured by closely matching the spectrum of the photoinitiator with a custom-made blue light light-emitting diode set-up. Kinetic analyses of such a CQ/EDMAB system indicated that the maximum polymerization rate of the monomer was proportional to [PI]0.5 and [I0]0.5, while excessive high photoinitiator concentration (>1 wt%) will decrease the polymerization rate because of the “filter effect.” With optimized blue light curable pigment ink formula and irradiation conditions, the photocurable pigment printed fabrics exhibited uniform and vibrant colors, clear outlines, and excellent wet and dry rubbing fastness of grades 4 and 4–5, respectively.

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Homogeneous ZnO nanowire arrays p-n junction for blue light-emitting diode applications

Optics Express ◽

10.1364/oe.27.0a1207 ◽

2019 ◽

Vol 27 (16) ◽

pp. A1207 ◽

Cited By ~ 7

Author(s):

Mingming Su ◽

Tanglei Zhang ◽

Jun Su ◽

Zhao Wang ◽

Yongming Hu ◽

...

Keyword(s):

Blue Light ◽

Light Emitting Diode ◽

Nanowire Arrays ◽

Zno Nanowire ◽

Light Emitting ◽

Zno Nanowire Arrays

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Determination of 3,4,5-Trihydroxybenzoic Acid Exploiting a Visible-Light-Driven Photoelectrochemical Platform: Application in Wine and Tea Samples

Journal of the Brazilian Chemical Society ◽

10.21577/0103-5053.20210160 ◽

2022 ◽

Author(s):

Kayni Lima ◽

Ridvan Fernandes ◽

Clenilton dos Santos ◽

Flavio Damos ◽

Rita de Cássia Luz

Keyword(s):

Light Emitting Diode ◽

Glass Slide ◽

Experimental Conditions ◽

Amperometric Determination ◽

Light Emitting ◽

Promising Tool ◽

Visible Light Driven ◽

Photoelectrochemical Method ◽

Acid Determination

The present work is based on the development and application of a photoelectrochemical method for the amperometric determination of 3,4,5-trihydroxybenzoic acid in different samples. The method is based on the use of a photoelectrochemical platform based on a glass slide coated with fluorine-doped tin oxide, which has been modified with cadmium sulfide and poly(D-glucosamine) and subjected to a light-emitting diode (LED) lamp. The photoelectrochemical platform was sensitive to the increase of the concentration of the antioxidant 3,4,5-trihydroxybenzoic acid in the solution. Under the optimized experimental conditions, the photoelectrochemical method presented a linear response for a 3,4,5-trihydroxybenzoic acid concentration ranging from 0.2 up to 500 μmol L-1. The method was applied to 3,4,5-trihydroxybenzoic acid determination in samples of wines and teas with recoveries between 95.88 and 101.72%. The results obtained suggest that the developed platform is a promising tool for quantifying the 3,4,5-trihydroxybenzoic acid.

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Determination of Dental Adhesive Composition throughout Solvent Drying and Polymerization Using ATR–FTIR Spectroscopy

Polymers ◽

10.3390/polym13223886 ◽

2021 ◽

Vol 13 (22) ◽

pp. 3886

Author(s):

Arwa Almusa ◽

António H.S. Delgado ◽

Paul Ashley ◽

Anne M. Young

Keyword(s):

Light Exposure ◽

Light Emitting Diode ◽

Attenuated Total Reflectance ◽

Drying Time ◽

Light Emitting ◽

Spectral Changes ◽

One Step ◽

Urethane Dimethacrylate ◽

Kinetics Of

The of this study aim was to develop a rapid method to determine the chemical composition, solvent evaporation rates, and polymerization kinetics of dental adhesives. Single-component, acetone-containing adhesives One-Step (OS; Bisco, USA), Optibond Universal (OU; Kerr, USA), and G-Bond (GB; GC, Japan) were studied. Filler levels were determined gravimetrically. Monomers and solvents were quantified by comparing their pure Attenuated Total Reflectance-Fourier Transform Infra-Red (ATR–FTIR) spectra, summed in different ratios, with those of the adhesives. Spectral changes at 37 °C, throughout passive evaporation for 5 min, then polymerisation initiated by 20 s, and blue light emitting diode (LED) (600 mW/cm2) exposure (n = 3) were determined. Evaporation and polymerisation extent versus time and final changes were calculated using acetone (1360 cm−1) and methacrylate (1320 cm−1) peaks. OS, OU, and GB filler contents were 0, 9.6, and 5.3%. FTIR suggested OS and OU were Bis-GMA based, GB was urethane dimethacrylate (UDMA) based, and that each had a different diluent and acidic monomers and possible UDMA/acetone interactions. Furthermore, initial acetone percentages were all 40−50%. After 5 min drying, they were 0% for OS and OU but 10% for GB. Whilst OS had no water, that in OU declined from 18 to 10% and in GB from 25 to 20% upon drying. Evaporation extents were 50% of final levels at 23, 25, and 113 s for OS, OU, and GB, respectively. Polymerisation extents were all 50 and 80% of final levels before 10 and at 20 s of light exposure, respectively. Final monomer polymerisation levels were 68, 69, and 88% for OS, OU, and GB, respectively. An appreciation of initial and final adhesive chemistry is important for understanding the properties. The rates of evaporation and polymerisation provide indications of relative required drying and light cure times. UDMA/acetone interactions might explain the considerably greater drying time of GB.

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