UV-LED Lamp Research Articles

Towards smart personalized perspiration analysis: An IoT-integrated cellulose-based microfluidic wearable patch for smartphone fluorimetric multi-sensing of sweat biomarkers

Practical obstacles, such as intricate designs and expensive equipment/materials, in the fabrication of wearable sweat sensors, have limited their feasibility as a personalized healthcare device. Herein, we have fabricated a cellulose-based wearable patch, which further paired with a smartphone-based fluorescence imaging module and a self-developed smartphone app for non-invasive and in situ multi-sensing of sweat biomarkers including glucose, lactate, pH, chloride, and volume. The developed Smart Wearable Sweat Patch (SWSP) sensor comprises highly fluorescent sensing probes embedded in paper substrates, and microfluidic channels consisted of cotton threads to harvest sweat from the skin surface and to transport it to the paper-based sensing probes. The imaging module was fabricated by a 3D printer, equipped with UV-LED lamps and an optical filter to provide the in situ capability of capturing digital images of the sensors via a smartphone. A smartphone app was also designed to quantify the concentration of the biomarkers via a detection algorithm. Additionally, we have recommended an Internet of Things (IoT)-based model for our developed SWSP sensor to promote its potential application for the future. The field studies on human subjects were also conducted to investigate the feasibility of our developed SWSP sensor for the analysis of sweat biomarkers. Our findings convincingly demonstrated the applicability of our developed SWSP sensor as a smart, user-friendly, ultra-low-cost (~0.03 $ per sweat patch), portable, selective, rapid, and non-invasive healthcare monitoring device for immense applications in health personalization, sports performance monitoring, and medical diagnostics.

Assessment of photocatalytic performance of Fe/N-TiO2 photocatalysts prepared by liquid phase plasma process

Abstract To improve the photocatalytic performance of TiO2 photocatalysts, a new method, liquid phase plasma (LPP) method, was used to introduce nitrogen and iron oxide. Interstitial or substitutional nitrogen and Fe3+ iron nanoparticles were impregnated on the surface of TiO2 by LPP reaction without additional chemical reduction agent and the amount of iron of modified TiO2 photocatalysts was affected by the amount of initial precursor. The adsorption edge of modified TiO2 photocatalysts was shifted to the visible region in proportion to the amount of nitrogen and iron oxide, and the band gap energy was decreased, and the photocatalytic activity was confirmed by PL and EPR analysis. The photocatalytic activities of modified TiO2 photocatalysts were measured under UV and blue LED lamps and compared with pure TiO2 powder (P-25). The modified TiO2 exhibited better photocatalytic degradation performance than pure TiO2 under blue LED light conditions, but exhibited low degradation activity under UV LED light conditions. Through GC–MS analysis, it was found that the methylene blue was finally decomposed into an inorganic substance through intermediates such as benzene sulfonic acid and phenol by OH radicals. From these results, we found that the modified TiO2 photocatalysts can be easily prepared using the LPP method and can be used in the visible region.

A Study on the Environmentally Collection of Insects

Because of global warming, global temperature such as greenhouse effect is rising every year. Increasing temperature will have a pernicious impact on the reproductive rate, population and habitat of the insects. As the temperature rises, the abundance of algae and plankton creates an optimal environment for the insects to reproduce. Because of the larvae and carcas of midges, micro disk filter in filtration facilities are blocked. The SS treatment efficiency has been reduced by the blocked membrane, which leads to a blurred discharge water, causing difficulties in maintenance of the treatment process. It was treated with pesticides that contain chemicals to prevent mass reproduction, but they have a huge adverse effect on the ecosystem. To solve this problem, an insect collector using 365 nm, UV LED lamps was designed in an environmentally friendly way using the properties of multi-faceted. The effect on the water flow of the filtering facility was using the properties of multi-faceted. The effect on the water flow of the filtering facility was analyzed by capturing and removing insects according to temperature and humidity changes through the installation of insect collector at the T-P treatment facility. The over-replicated carcass were captured using eco-friendly devices without the use of chemicals. The midges captured by device reduced the membrane obstruction of the filtering facility, resulting in a 69% increase in SS removal effciency, and were effective in improving the overall discharge water of the facilities. Key words: Gloal warming, Midge, UV lamp, Insect collector, Collecting method

가정용 초음파세정장치적용을 위한 자외선 LED와 자외선 램프의 살균 효과에 관한 연구

가정용 초음파세정장치적용을 위한 자외선 LED와 자외선 램프의 살균 효과에 관한 연구

A hybrid photoelectrocatalytic/photoelectro-Fenton treatment of Indigo Carmine in acidic aqueous solution using TiO2 nanotube arrays as photoanode

This article reports the synthesis of TiO2 nanotube arrays (TiO2 NTs), grown by Ti anodization, and their use as photoanode in a hybrid photelectrocatalytic (PEC)/photoelectro-Fenton (PEF) treatment of Indigo Carmine solutions in sulfate medium at pH3.0. The anode was combined with an air-diffusion cathode that ensured continuous H2O2 electrogeneration. Comparative trials by electrochemical oxidation with electrogenerated H2O2 (EO-H2O2), electro-Fenton (EF) and PEF with Pt anode were made. The photoanode was stable operating up to 3mAcm−2 with irradiation from a 36-W UV LED lamp, showing photoelectroactivity from an anodic potential (Ean) of +0.20V, as determined by cyclic voltammetry. At 3mAcm−2, color removal by EO-H2O2 with Pt and PEC with TiO2 NTs was very slow, being much faster in EF, PEF and PEC/PEF due to main role of OH formed from Fenton's reaction upon addition of Fe2+. The absorbance and dye concentration decays agreed with a pseudo-first-order kinetics, yielding a slightly lower rate constant for decolorization because of the formation of colored products. The mineralization ability increased as: EO-H2O2≪EF≪PEF<PEC/PEF. The holes photogenerated at the TiO2 NTs surface had higher oxidation ability than OH formed at the Pt surface from water discharge. In PEC/PEF, a slower mineralization was found at 2mAcm−2, although the final mineralization percentage was similar to that attained at 3mAcm−2. Both, SO42− and NH4+ ions were released during the treatments, along with isatin-5-sulfonic and formic acids as main products.

Compact UV LED Lamp with Low Heat Emissions for Biological Research Applications

Much biomedical research focuses on the effects of UV light on human cells. UV light sources are a prerequisite for such research. This paper presents the design and achieved performance of a UVA (Ultraviolet A: 320–400 nm) and a UVB (Ultraviolet B: 290–320 nm) LED-based lamp suitable for use in bioassays, as well as inside an incubator. Numerical simulations were used to optimise the number, layout and output power of LEDs to achieve good irradiance homogeneity while maintaining low costs. Design was optimised for the efficient transfer of generated heat away from the irradiated samples through the heatsink at the back of the lamps. The average irradiance of the target surface by the UVA lamp was 70.1 W/m2 with a maximum deviation of 4.9%, and the average irradiance by the UVB lamp was 3.1 W/m2 with a maximum deviation of 4.8%. With the UVA and UVB lamps, the temperature of samples undergoing irradiation in the incubator rises from 37 to 42 °C within 40 and 67 min, respectively. This by far exceeds the required UV irradiation time in most cases. Tests on Jurkat and HEK-293 cell cultures confirmed the suitability of our lamps for biomedical research.

Enhanced photocatalysis by depositing ZnO thin film in the inner wall of glass tube

This study provides a new paradigm for the degradation of toxic organic compounds. Zinc oxide thin film was deposited on the inner wall of a glass tube using ultrasonic spray pyrolysis technique and the UV LED lamps were used for photocatalytic application. The atomic force microscopy (AFM) observation showed that the surface morphology of the film is almost homogeneous. The PL spectrum allowed us to confirm that the trapped electrons via defects in the ZnO film increased the photocatalytic activity. UV–vis spectrometry reveals a dye degradation efficiency of 100% which confirm a complete removal of methylene blue (MB) after 240 min.

Two strategies to enhance ungual drug permeation from UV-cured films: Incomplete polymerisation to increase drug release and incorporation of chemical enhancers

UV-curable gels, which polymerise into long-lasting films upon exposure to UVA, have been identified as potential topical drug carriers for the treatment of nail diseases. Limitations of such films include incomplete drug release and low ungual drug permeation. The aim of the work herein was therefore to investigate two strategies, namely: (1) increasing drug release from the film, and (2) increasing nailplate permeability, with the ultimate goal of enhancing ungual drug permeation. To increase drug release via Strategy 1, a UV-LED lamp (whose emitted light was suboptimal for gel polymerisation) was used, and it was hypothesised that such a lamp would result in films that are less polymerised/cross-linked and where the drugs are less ‘trapped’. Indeed, the suboptimal lamp influenced polymerisation, such that the films were thinner, had lower glass transition temperatures and enabled a slightly greater (by 15%) drug release of one of the two drugs tested. However, the greater drug release had only a modest impact on ungual drug permeation. To evaluate Strategy 2, i.e. increase nailplate permeability, chemical ungual enhancers, 2-mercaptoethanol (ME), 2-methyl pyrrolidone (NMP), PEG 200 and water were incorporated within the UV-cured films. These chemicals caused increased ungual drug permeation, with ME showing the greatest (by 140%), and water showing the least (by 20%) increase in the amount of drug permeated by day 30. Surprisingly, these chemicals also caused increased drug release from the films, with ME once again having the greatest effect (by 51%) and water the least effect (by 12%). It seems that these chemicals were increasing ungual drug permeation via their influence on drug release (i.e. via their impact on the film) as well as via their influence on the nail itself. We conclude that, of the two strategies tested, the second strategy proved to be more successful at enhancing ungual drug permeation.

UV Lamps Provide Secure and Fast Inspection

UV LED Lamps with UV-formity technology make the inspection faster, easier and fatigue-proof, with more optimal and uniform irradiation

Fluorinated organozirconiums: Enhancement of overcoming oxygen inhibition in the UV-curing film

Organozirconiums had been studied as the peroxyl radical scavenger in UV-curing coatings, which had varied performance in overcoming oxygen inhibition. Herein we modified the complex of zirconium with organic fluorides in order to increase its efficiency of peroxyl radical scavenging. A formulation consists of two conventional monomers (Ebercyl 270 and TPGDA) and an oxygen-sensitive photoinitiator TPO was employed in this study. With different content added in the formulation, the UV-cured coatings had different depth conversion profiles, which were measured by confocal Raman microscopy. Moreover, the standing time for the enrichment of fluorinated organozirconium products to the surface of the coatings and two irradiation sources (Hg-Xe lamp and UV-LED lamp) were adopted to emphasize their properties against oxygen inhibition. Finally, it is shown that fluorinated organozirconiums can lead to tack-free coatings, while the cured films from neat formulation remain tacky.

Characterization and optimization of an inkjet-printed smart textile UV-sensor cured with UV-LED light

For the development of niche products like smart textiles and other functional high-end products, resource-saving production processes are needed. Niche products only require small batches, which makes their production with traditional textile production techniques time-consuming and costly. To achieve a profitable production, as well as to further foster innovation, flexible and integrated production techniques are a requirement. Both digital inkjet printing and UV-light curing contribute to a flexible, resource-efficient, energy-saving and therewith economic production of smart textiles. In this article, a smart textile UV-sensor is printed using a piezoelectric drop-on-demand printhead and cured with a UV-LED lamp. The UVcurable ink system is based on free radical polymerization and the integrated UVsensing material is a photochromic dye, Reversacol Ruby Red. The combination of two photoactive compounds, for which UV-light is both the curer and the activator, challenges two processes: polymer crosslinking of the resin and color performance of the photochromic dye.Differential scanning calorimetry (DSC) is used to characterize the curing efficiency of the prints. Color measurements are made to determine the influence of degree of polymer crosslinking on the developed color intensities, as well as coloration and decoloration rates of the photochromic prints. Optimized functionality of the textile UV-sensor is found using different belt speeds and lamp intensities during the curing process.

LED-UV grafting of vinylsulfone dyes onto photo-oxidized wool fabrics

Photografting coloration of wool was carried out under UV-LED irradiation at room temperature using aqueous vinylsulfone dye solution containing vinylsulfonic acid as a comonomer. UV-LED irradiation of the 395 nm emission is more energy efficient, less damaging to the dyes, and much safer to human eyes compared with polychromatic mercury UV lamps. However, in case of the UV-LED lamps, the wool needs to be photo-oxidized either by UV/ozone or polychromatic UV irradiation before the dye photografting. The surface treatments increased the sulfur and oxygen contents in the modified wool surfaces. While the optimally photografted wool fabrics under the UV-LED lamp yielded a K/S value of 9.9, the K/S of the grafted wool increased to 25.2 and 13.6 after the UV/Ozone or polychromatic UV preoxidation at UV energies of 10.6 J/cm2 and 25 J/cm2 respectively. The color fastness properties of the photografted fabrics were far better than with those of the conventionally reactive-dyed fabrics, implying that the high-molecular-weight photografted dyes seemed to be more durable than the low-molecular dyes.

Preliminary Study on Degree of Conversion of UV Curable Maleinated Acrylated Epoxidised Palm Oil Pressure Sensitive Adhesives Synthesised with Isobornyl Methacrylate Monomer via FTIR-ATR Analysis

UV curable PSA of maleinated acrylated epoxidised palm oil (MAEPO) from palm oil via UV LED lamp has been introduced with the existence of Chivacure 300 as photoinitiator. By involving the isobornyl methacrylate (ISBMA) as a monomer in the PSA formulation, the degree of conversion recorded low percentage of conversion, which was below 50 % although the loading of photoinitiator has been raised to 5 parts per hundred (phr). The ISBMA has affected to the slow curing speed on the maleinated PSA and restricted the conversion of C=C to more than 50 % even though the curing time and photoinitiator loading has been increased up to 300 min and 5 phr. It is expected that the double bonds are still present in the synthesised of PSA which indicated that most molecules were bonded at one end of another in methacrylate group. In the present study, real-time FTIR-ATR spectroscopy was used to follow the crosslinking process of the adhesive and the adhesive properties of the cured coatings.

Improved Photocatalytic Air Cleaner with Decomposition of Aldehyde and Aerosol-Associated Influenza Virus Infectivity in Indoor Air

ABSTRACTAir pollution caused by fine particulate matter (PM2.5), volatile organic compounds, and bioaerosols is a major environmental risk to health. We developed a photocatalytic air cleaner for reducing the pollution levels of indoor air; we improved the photocatalytic system by using UV-LED for the removal of acetaldehyde and PM2.5 and by reducing the weight and size of the system. The efficiency of photocatalysis depends on the surface area and materials. Therefore, we prepared a nanosized titanium dioxide (TiO2)-coated aluminum plate irradiated by UV-LED lamps (wavelength: 375 nm) as a photocatalytic air cleaner. Passing air continuously through a TiO2-coated aluminum plate (5 × 10 × 1 cm) under black light for 200 min decomposed 90% of 5 ppm acetaldehyde (12.4 µmol h–1) and generated two carbon dioxide molecules (25.43 µmol h–1) at a molar ratio of 1:2, indicating complete decomposition of acetaldehyde with high efficiency. This photocatalytic air cleaner was applied to the decomposition of acetaldehyde and inactivation and removal of aerosol-associated influenza virus. Acetaldehyde (20 ppm) in a 1-m3 cubic space was eliminated in 60 min at a half-life of 8 min. The aerosol-associated infectivity and the RNA genome of influenza virus A/PR/8/1934 (H1N1) produced by a nebulizer in a 779-L cubic space were eliminated within 7 min; however, they were detectable for up to 28 minutes when the functional photocatalytic air cleaner was not used. The presence of intermediate breakdown products of influenza virus indicated that the virus was broken down by photocatalysis. Thus, the photocatalytic air cleaner efficiently decomposed and eliminated organic chemicals, acetaldehyde, and aerosol-associated influenza virus infectivity and viral RNA, indicating that it can clean and detoxify the indoor air in a closed space for maintaining a safer environment.

The investigation of the LED-activated FeFNS-TiO2 nanocatalyst for photocatalytic degradation and mineralization of organophosphate pesticides in water

This study evaluated the preparation and characterization of an efficient doped TiO2 as a novel catalyst for degradation of diazinon model pesticide using LED-activated photocatalysis. TiO2 was doped using N, NS, FeNS, and FeFNS. The FeFNS-doped TiO2 showed the highest catalytic activity in LED/photocatalysis. FeFNS-doped TiO2 is a mesoporous nanocrystal powder with a mean pore diameter of 10.2 nm, a specific surface area of 104.4 m2/g and a crystallite size of 6.7 nm. LED/photocatalysis using FeFNS-doped TiO2 improved diazinon degradation by 52.3% over that of as-made plain TiO2 at an optimum solution pH of 7. The diazinon degradation in LED/photocatalysis using FeFNS-doped TiO2 increased from 44.8% to 96.3% when the catalyst concentration increased from 25% to 300%at a reaction time of 100 min. The degradation and mineralization of diazinon during LED/photocatalysis with FeFNS-doped TiO2 catalyst followed the pseudo-first-order reaction model with the rate constants of 0.973 h−1 and 0.541 h−1, respectively. The FeFNS-doped TiO2 was found to be an efficient catalyst that was photoactivated using UV-LED lamps. LED/photocatalysis with FeFNS-doped TiO2 catalyst is a promising alternative to conventional UV/TiO2photocatalysis for producing free OH radicals for use in the degradation and mineralization of water toxic contaminants.

Hybrid phosphorescence and fluorescence native spectroscopy for breast cancer detection

Fluorescence and phosphorescence measurements are performed on normal and malignant ex vivo human breast tissues using UV LED and xenon lamp excitation. Tryptophan (trp) phosphorescence intensity is higher in both normal glandular and adipose tissue when compared to malignant tissue. An algorithm based on the ratio of trp fluorescence intensity at 345 nm to phosphorescence intensity at 500 nm is successfully used to separate normal from malignant tissue types. Normal specimens consistently exhibited a low I(345)I(500) ratio (<10), while for malignant specimens, the I(345)I(500) ratio is consistently high (>15). The ratio analysis correlates well with histopathology. Intensity ratio maps with a spatial resolution of 0.5 mm are generated in which local regions of malignancy could be identified.

Photogeneration of Heptacene in a Polymer Matrix

Heptacene (1) was generated by the photodecarbonylation of 7,16-dihydro-7,16-ethanoheptacene-19,20-dione (2) in a polymer matrix using a UV-LED lamp (395 +/- 25 nm). Compound 1 showed a long wavelength absorption band extending from 600 to 825 nm (lambdamax approximately 760 nm) and was found to be stable up to 4 h in the polymer matrix. However, irradiation of a solution of 2 in toluene produced only oxygen adducts.