Fabrication and antimicrobial effects of silver nanoparticle-poly(N-isopropylacrylamide)-poly(ferrocenylsilane) hydrogel composites

2012 ◽  
Vol 1453 ◽  
Author(s):  
Xiaofeng Sui ◽  
Xueling Feng ◽  
Andrea Di Luca ◽  
Clemens A. van Blitterswijk ◽  
Lorenzo Moroni ◽  
...  
Keyword(s):  
Light Emitting Diode ◽  
Light Emitting ◽  
Uv Led ◽  
Hydrogel Network ◽  
Redox Responsive ◽  
Equilibrium Swelling ◽  
Hydrogel Composites ◽  
Equilibrium Swelling Ratio ◽  
Strong Antimicrobial Activity

ABSTRACTNovel hydrogels composed of thermo-responsive poly(N-isopropylacrylamide) (PNIPAM) and redox-responsive poly(ferrocenylsilane) (PFS) macromolecules were formed by photopolymerization. PFS chains bearing acrylate side groups were copolymerized with NIPAM and N,N’-methylenebisacrylamide in tetrahydrofuran in a predetermined ratio under ultraviolet light-emitting diode (UV-LED) irradiation at a wavelength of 365 nm, in the presence of a photoinitiator. Crosslinking occurred smoothly, providing homogeneous hydrogels. The equilibrium swelling ratio, rheology and morphology of these hybrid PNIPAM-PFS-based hydrogels were investigated. In-situ fabrication of silver nanoparticles inside the hydrogel network via reduction of silver nitrate by the PFS chains led to hydrogel composites. These composites showed strong antimicrobial activity while maintaining a high biocompatibility with cells.

scholarly journals Design of a Secondary Freeform Lens of UV LED Mosquito-Trapping Lamp for Enhancing Trapping Efficiency

Crystals ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 335 ◽  
Author(s):  
Wei-Hsiung Tseng ◽  
Diana Juan ◽  
Wei-Cheng Hsiao ◽  
Cheng-Han Chan ◽  
Hsin-Yi Ma ◽  
...  
Keyword(s):  
Light Intensity ◽  
Intensity Distribution ◽  
Light Emitting Diode ◽  
Trapping Efficiency ◽  
Axially Symmetric ◽  
Light Intensity Distribution ◽  
Light Emitting ◽  
Led Light ◽  
Uv Led ◽  
Freeform Lens

In this study, our proposed ultraviolet light-emitting diode (UV LED) mosquito-trapping lamp is designed to control diseases brought by insects such as mosquitoes. In order to enable the device to efficiently catch mosquitoes in a wider area, a secondary freeform lens (SFL) is designed for UV LED. The lens is mounted on a 3 W UV LED light bar as a mosquito-trapping lamp of the new UV LED light bar module to achieve axially symmetric light intensity distribution. The special SFL is used to enhance the trapping capabilities of the mosquito-trapping lamp. The results show that when the secondary freeform surface lens is applied to the experimental outdoor UV LED mosquito-trapping lamp, the trapping range can be expanded to 100π·m2 and the captured mosquitoes increased by about 300%.

Miniaturized UV-LED Array Chip Photochemical Vapor Generator Coupled with Point Discharge Optical Emission Spectrometer for Determination of Trace Selenium

2021 ◽  
Author(s):  
Mengtian Li ◽  
Yi Luo ◽  
Zhirong Zou ◽  
Fujian Xu ◽  
Xiaoming Jiang ◽  
...  
Keyword(s):  
Light Emitting Diode ◽  
Optical Emission ◽  
Nano Tio2 ◽  
Light Emitting ◽  
Uv Led ◽  
Led Array ◽  
Point Discharge ◽  
Photochemical Vapor Generation ◽  
Optical Emission Spectrometer

An ultraviolet light emitting diode (UV-LED) array chip as irradiation source for nano-TiO2 catalyzed photochemical vapor generation (PCVG) was combined with a hollow electrode point discharge microplasma optical emission spectrometer...

Embedded growth of colorful CsPbX3 (X = Cl, Br, I) nanocrystals in metal−organic frameworks at Room Temperature

2022 ◽  
Author(s):  
Chen Chen ◽  
Lei Nie ◽  
Yizhe Huang ◽  
Shuang Xi ◽  
Xingyue Liu ◽  
...  
Keyword(s):  
Light Emitting Diode ◽  
Metal Organic Framework ◽  
Light Emitting ◽  
Confined Growth ◽  
Wide Color Gamut ◽  
Metal Organic ◽  
Interfacial Synthesis ◽  
Novel Strategy ◽  
Lead Halide

Abstract Herein, we develop a novel strategy for preparing all-inorganic cesium lead halide (CsPbX3, X= Cl, Br, I) perovskite nanocrystals (NCs)@Zn-based metal-organic framework (MOF) composites through interfacial synthesis. The successful embedding of fluorescent perovskite NCs in Zn-MOFs is due to the in-situ confined growth, which is attributed to the re-nucleation of water-triggered phase transformation from Cs4PbBr6 to CsPbBr3. The controllable synthesis of mixed-halide based composites with various emission wavelength can be achieved by adding the desired amount of halide (Cl or I) salts in the re-nucleation process. More importantly, the anion exchange reaction is inhibited among various composites with different halogen atoms by being trapped in MOFs. Besides, a white light-emitting diode (WLED) is produced using a blue LED chip with the green-emitting and red-emitting composites, which has a color coordinate of (0.3291, 0.3272) and a wide color gamut. This work provides a novel route to achieving perovskite NCs growth in MOFs, which also can be extended to the other NCs embedded in frames as well.

Ultraviolet light-emitting diode (UV LED) trap the West Indian sweet potato weevil, Euscepes postfasciatus (Coleoptera: Curculionidae)

2012 ◽  
Vol 47 (3) ◽  
pp. 285-290 ◽  
Author(s):  
Masako Katsuki ◽  
Yusuke Omae ◽  
Kensuke Okada ◽  
Toru Kamura ◽  
Takashi Matsuyama ◽  
...  
Keyword(s):  
Sweet Potato ◽  
Ultraviolet Light ◽  
Light Emitting Diode ◽  
West Indian ◽  
The West ◽  
Light Emitting ◽  
Uv Led ◽  
Sweet Potato Weevil ◽  
Euscepes Postfasciatus

A Compact Microcontrolled Microfluidic System for Photometric Determination of Phosphate in Natural Water Samples

2015 ◽  
Vol 68 (7) ◽  
pp. 1108 ◽  
Author(s):  
Osmundo Dantas Pessoa-Neto ◽  
Tiago Almeida Silva ◽  
Vagner Bezerra dos Santos ◽  
Orlando Fatibello-Filho
Keyword(s):  
Light Emitting Diode ◽  
Flow Analysis ◽  
Photometric Determination ◽  
Microfluidic System ◽  
Experimental Conditions ◽  
Light Emitting ◽  
Experimental Parameters ◽  
Led Photometer

A compact environmentally friendly microcontrolled microfluidic device ideal for in situ phosphate determination was developed based on a microsystem based on low-temperature co-fired ceramics (LTCC) coupled to a light-emitting diode (LED)–photometer with a multicommutation flow analysis (MCFA) approach. The experimental parameters of the MCFA analyzer were optimized by chemometric studies. Under the best experimental conditions, limits of detection and quantification of 0.02 mg P L–1 and 0.07 mg P L–1, respectively, and a sampling frequency of 67 h–1 were estimated. Moreover, a low sample consumption of only 60 μL per determination was the other advantage that fully meets the requirements of sustainable research and green chemistry purposes.

scholarly journals 3D Microlithography Using an Integrated System of 5-mm UV-LEDs with a Tilt-Rotational Sample Holder

Micromachines ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 157 ◽  
Author(s):  
Sabera Fahmida Shiba ◽  
Hyeongmin Jeon ◽  
Jong-Soo Kim ◽  
Jong-Eun Kim ◽  
Jungkwun Kim
Keyword(s):  
Light Source ◽  
Light Emitting Diode ◽  
Vertical Direction ◽  
Ultra Violet ◽  
Integrated System ◽  
Sample Holder ◽  
Large Area ◽  
Light Emitting ◽  
Uv Led ◽  
Uv Leds

This paper demonstrates a 3D microlithography system where an array of 5 mm Ultra Violet-Light Emitting Diode (UV-LED) acts as a light source. The unit of the light source is a UV-LED, which comes with a length of about 8.9 mm and a diameter of 5 mm. The whole light source comprises 20 × 20 matrix of such 5 mm UV-LEDs giving a total number of 400 LEDs which makes it a very favorable source with a large area for having a batch production of the desired microstructures. This light source is able to give a level of precision in microfabrication which cannot be obtained using commercial 3D printers. The whole light source performs continuous rotational movement once it is turned on. This can also move up and down in a vertical direction. This multidirectional light source also comprises a multidirectional sample holder. The light source teaming up with the multidirectional sample holder highly facilitates the process of fabrication of a huge range of 3D structures. This article also describes the different levels of characterization of the system and demonstrates several fabricated 3D microstructures including high aspect ratio vertical micro towers, twisted turbine structures, triangles, inclined pillar ‘V’ structures, and hollow horn structures as well.

scholarly journals Reducing the Impacts of Biofouling in RO Membrane Systems through In Situ Low Fluence Irradiation Employing UVC-LEDs

Membranes ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 415
Author(s):  
Philipp Sperle ◽  
Christian Wurzbacher ◽  
Jörg E. Drewes ◽  
Bertram Skibinski
Keyword(s):  
Hydraulic Resistance ◽  
Extracellular Polymeric Substances ◽  
Residual Effect ◽  
Feed Stream ◽  
Membrane Systems ◽  
Light Emitting ◽  
Cycle Arrest ◽  
Uv Led ◽  
Biofouling Control

Biofouling is a major concern for numerous reverse osmosis membrane systems. UV pretreatment of the feed stream showed promising results but is still not an established technology as it does not maintain a residual effect. By conducting accelerated biofouling experiments in this study, it was investigated whether low fluence UV in situ treatment of the feed using UVC light-emitting diodes (UVC-LEDs) has a lasting effect on the biofilm. The application of UVC-LEDs for biofouling control is a novel hybrid technology that has not been investigated, yet. It could be shown that a low fluence of 2 mJ∙cm−2 delays biofilm formation by more than 15% in lab-scale experiments. In addition, biofilms at the same feed channel pressure drop exhibited a more than 40% reduced hydraulic resistance. The delay is probably linked to the inactivation of cells in the feed stream, modified adsorption properties or an induced cell cycle arrest. The altered hydraulic resistance might be caused by a change in the microbial community, as well as reduced adenosine triphosphate levels per cells, possibly impacting quorum sensing and extracellular polymeric substances production. Due to the observed biofilm attributes, low fluence UV-LED in situ treatment of the feed stream seems to be a promising technology for biofouling control.

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