A temperature‐responsive polyurethane film with reversible visible light transmittance change and constant low UV light transmittance

2018 ◽  
Vol 136 (9) ◽  
pp. 47140
Author(s):  
Y. Xiao ◽  
B. Wu ◽  
Z. Liu ◽  
L. Jiang ◽  
J. Lei ◽  
...  
2020 ◽  
Author(s):  
Guifang Feng ◽  
Yanhong Hao ◽  
Liang Wu ◽  
Suming Chen

The photocycloaddition of olefins with carbonyls is of fundamental interest and practical importance in C=C bond location in unsaturated lipids. However, the traditional UV light activated [2+2] photocycloaddition reaction suffers side reactions and potential health damage. Here, we reported the first example of visible-light activated [2+2] photocycloaddition of anthraquinone with unsaturated lipids. This reaction showed great capability for locating the C=C bonds in various kinds of monounsaturated and polyunsaturated lipids by combining with tandem mass spectrometry (MS), such as fatty acids, phospholipids and glycerides. Based on this developed reaction, a workflow with liquid chromatography tandem MS method was developed for the global identification of unsaturated lipids in human serum, and 86 of monounsaturated and complicated polyunsaturated lipids were identified with definitive positions of C=C bonds. This approach provides new insights both on the photocycloaddition reactions and the structural lipidomics.


2020 ◽  
Vol 1 (1) ◽  
pp. 30-36
Author(s):  
Shubha Jayachamarajapura Pranesh ◽  
Diwya Lanka

Background: Textile industries discharge harmful synthetic dyes to nearby water sources. These colour effluents should be treated before discharge to reduce the toxicity caused by synthetic colours. Objective: To synthesize visible light active superstructures to reduce water pollution caused by textile industries. Methods: We have successfully synthesized ZnO/Dy/NiO hybrid nanocomposites using waste curd as fuel by a simple combustion method. The obtained material was able to reduce recombination and enhanced the photocatalytic degradation of organic pollutants. The as-synthesized material was characterized by XRD, absorption spectroscopy, FESEM, EDAX, etc. The obtained hybrid nanostructure was used as a photocatalyst for the degradation of methylene blue under sunlight, UV light as well as in dark. Comparative experiments were carried out with a variation of catalytic load, pH, dye concentrations, etc. for a better understanding of the performance of the catalyst at various conditions. Results and Conclusion: The ternary compound shows wide range of absorption by expanding absorption band both in UV and visible regions. ZnO/Dy/NiO hybrid nanocomposites performed well and showed uniqueness in the activity uder visible light.


Materials ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 607
Author(s):  
Yuxi Zhao ◽  
Rongcheng Liu ◽  
Fan Yan ◽  
Dawei Zhang ◽  
Junjin Liu

The windblown sand-induced degradation of glass panels influences the serviceability and safety of these panels. In this study, the degradation of glass panels subject to windblown sand with different impact velocities and impact angles was studied based on a sandblasting test simulating a sandstorm. After the glass panels were degraded by windblown sand, the surface morphology of the damaged glass panels was observed using scanning electron microscopy, and three damage modes were found: a cutting mode, smash mode, and plastic deformation mode. The mass loss, visible light transmittance, and effective area ratio values of the glass samples were then measured to evaluate the effects of the windblown sand on the panels. The results indicate that, at high abrasive feed rates, the relative mass loss of the glass samples decreases initially and then remains steady with increases in impact time, whereas it increases first and then decreases with an increase in impact angle such as that for ductile materials. Both visible light transmittance and effective area ratio decrease with increases in the impact time and velocities. There exists a positive linear relationship between the visible light transmittance and effective area ratio.


2006 ◽  
Vol 11-12 ◽  
pp. 351-354
Author(s):  
Jie Wei ◽  
Xiao Mei Ji ◽  
Xiao Wang ◽  
Xiao Ming Dong

In order to analyze the polarization of Poly(vinyl alcohol) (PVA) film, both the polarizing film and polarizing film exposed to UV light were prepared and investigated by X-ray diffractometer (XRD) and polarized UV-Visible Spectrometer. Through a series of experiments, it was found that the crystallization degree of the unirradiated PVA film was higher than that of the UV-irradiated PVA film. Furthermore, the transmittance of both unirradiated PVA film and UV-irradiated PVA film was selective, different wavelength and different polarizing angles parallelism different light transmittance.


1969 ◽  
Vol 54 (5) ◽  
pp. 636-649 ◽  
Author(s):  
John Nolte ◽  
Joel E. Brown

The spectral sensitivities of single Limulus median ocellus photoreceptors have been determined from records of receptor potentials obtained using intracellular microelectrodes. One class of receptors, called UV cells (ultraviolet cells), depolarizes to near-UV light and is maximally sensitive at 360 nm; a Dartnall template fits the spectral sensitivity curve. A second class of receptors, called visible cells, depolarizes to visible light; the spectral sensitivity curve is fit by a Dartnall template with λmax at 530 nm. Dark-adapted UV cells are about 2 log units more sensitive than dark-adapted visible cells. UV cells respond with a small hyperpolarization to visible light and the spectral sensitivity curve for this hyperpolarization peaks at 525–550 nm. Visible cells respond with a small hyperpolarization to UV light, and the spectral sensitivity curve for this response peaks at 350–375 nm. Rarely, a double-peaked (360 and 530 nm) spectral sensitivity curve is obtained; two photopigments are involved, as revealed by chromatic adaptation experiments. Thus there may be a small third class of receptor cells containing two photopigments.


2018 ◽  
Vol 85 (13) ◽  
pp. 1203-1217 ◽  
Author(s):  
Ketsuda Kongsawatvoragul ◽  
Saran Kalasina ◽  
Montakan Suksomboon ◽  
Nutthaphon Phattharasupakun ◽  
Juthaporn Wutthiprom ◽  
...  

2018 ◽  
Vol 53 ◽  
pp. 01013
Author(s):  
Nan Zhang ◽  
Mengyuan Xu ◽  
Ning Li

The existing building energy-saving reconstruction has a large area in our country. If the performance indexes such as the shading coefficient, visible light transmittance and hardness of the coating heat-insulating glass are in the condition of reaching the specification, and it can meet the needs of energy conservation and reform in building, it is a suitable technology for economic application.


2014 ◽  
Vol 886 ◽  
pp. 183-186
Author(s):  
Xiao Dong Zhang ◽  
Sha Sha Wei ◽  
Shou Zhi Pu

An unsymmetrical photochromic diarylethene 1-(2-methyl-1-phenyl)-2-[2-methyl-5-(4-formylphenyl)-3-thienyperfluoroyclopentene (1o) was designed and constructed successfully. Its photochromic properties were examined. The results showed that the compound exhibits good photochromism with UV/Vis light irradiation. The diarylethene 1o changed the color from colorless to blueviolet upon irradiation with 297 nm UV light, in which absorption maxima were observed at 549 and 581nm in hexane and PMMA films, respectively.The photochromic cyclization/cycloreversion kinetics of 1o in hexane were determined by UV-Vis spectra upon alternating irradiation with UV and appropriate wavelength visible light.


2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Lei Li ◽  
Sunil K. Sahi ◽  
Mingying Peng ◽  
Eric B. Lee ◽  
Lun Ma ◽  
...  

2020 ◽  
Author(s):  
Katie Rykaczewski ◽  
Corinna Schindler

<div> <p>One of the most efficient ways to synthesize oxetanes is the light-enabled [2+2] cycloaddition reaction of carbonyls and alkenes, referred to as the Paternò-Büchi reaction. The reaction conditions for this transformation typically require the use of high energy UV light to excite the carbonyl, limiting the applications, safety, and scalability. We herein report the development of a visible light-mediated Paternò-Büchi reaction protocol that relies on triplet energy transfer from an iridium-based photocatalyst to the carbonyl substrates. This mode of activation is demonstrated for a variety of aryl glyoxylates and negates the need for both, visible light-absorbing carbonyl starting materials or UV light to enable access to a variety of functionalized oxetanes in up to 99% yield.</p> </div> <br>


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