scholarly journals Water-Soluble Chemical Vapor Detection Enabled by Doctor-Blade-Coated Macroporous Photonic Crystals

Sensors ◽  
2020 ◽  
Vol 20 (19) ◽  
pp. 5503
Author(s):  
Min-Fang Wu ◽  
Hui-Ping Tsai ◽  
Chia-Hua Hsieh ◽  
Yi-Cheng Lu ◽  
Liang-Cheng Pan ◽  
...  
Keyword(s):  
Photonic Crystals ◽  
Color Change ◽  
Chemical Vapor ◽  
Peak Shift ◽  
Water Soluble ◽  
Hydroxyethyl Methacrylate ◽  
Vapor Detection ◽  
Doctor Blade ◽  
Reflection Peak ◽  
Wide Range

Water-soluble chemicals, involving a wide range of toxic chemicals in aqueous solutions, remain essential in both daily living or industrial uses. However, most toxicants are evaporated with water through their use and thus cause deleterious effects on the domestic environment and health in humans. Unfortunately, most current low-dose chemical vapor detection technologies are restricted by the use of sophisticated instruments and unable to promptly detect the quantity of diverse toxicants in a single analysis. To address these issues, this study reports the development of simple and fast chemical vapor detection using doctor-blade-coated macroporous poly(2-hydroxyethyl methacrylate)/poly(ethoxylated trimethylolpropane triacrylate) photonic crystals, in which the poly(2-hydroxyethyl methacrylate) has strong affinity to insecticide vapor owing to a favorable Gibbs free energy change for their mixing. The condensation of water-soluble chemical vapor therefore results in a significant reflection peak shift and an obvious color change. The visual colorimetric readout can be further improved by increasing the lattice spacing of the macroporous photonic crystals. Furthermore, the dependence of the reflection peak position on vapor pressure under actual conditions and the reproducibility of vapor detecting are also evaluated in this study.

scholarly journals Development of Highly pH-Sensitive Hybrid Membranes by Simultaneous Electrospinning of Amphiphilic Nanofibers Reinforced with Graphene Oxide

2019 ◽  
Vol 10 (2) ◽  
pp. 23 ◽  
Author(s):  
Mohsen Gorji ◽  
Ali Sadeghianmaryan ◽  
Hossein Rajabinejad ◽  
Saman Nasherolahkam ◽  
Xiongbiao Chen
Keyword(s):  
Graphene Oxide ◽  
Response Time ◽  
Color Change ◽  
Fiber Diameter ◽  
Chemical Vapor ◽  
Ph Sensitive ◽  
Solution Ph ◽  
Vis Spectroscopy ◽  
Wide Range ◽  
Nanofibrous Membranes

Nanofibrous-based pH sensors have shown promise in a wide range of industrial and medical applications due to their fast response time and good mechanical properties. In the present study, we fabricated pH-sensitive sensors of nanofibrous membranes by electrospinning polyurethane (PU)/poly 2-acrylamido-2-methylpropanesulfonic acid (PAMPS)/graphene oxide (GO) with indicator dyes. The morphology of the electrospun nanofibers was examined using scanning electron microscopy (SEM). The effect of hydrophilic polymer ratio and concentration of GO on the sensing response time was investigated. The sensitivity of the membranes was studied over a wide pH range (1–8) in solution tests, with color change measured by calculating total color difference using UV-vis spectroscopy. The membranes were also subjected to vapor tests at three different pH values (1, 4, 8). SEM results show the successful fabrication of bimodal fiber diameter distributions of PU (mean fiber diameter 519 nm) and PAMPS (mean fiber diameter 78 nm). Sensing response time decreased dramatically with increasing concentrations of PAMPS and GO. The hybrid hydrophobic/hydrophilic/GO nanofibrous membranes are capable of instantly responding to changes in solution pH as well as detecting pH changes in chemical vapor solution in as little as 7 s.

scholarly journals Clairvoyant Melon Maturity Detection Enabled by Doctor-Blade-Coated Photonic Crystals

Sensors ◽  
2021 ◽  
Vol 21 (21) ◽  
pp. 7046
Author(s):  
Yi-Cheng Lu ◽  
Liang-Cheng Pan ◽  
Yao-Wei Lei ◽  
Kun-Yi Andrew Lin ◽  
Hongta Yang
Keyword(s):  
Photonic Crystals ◽  
Color Change ◽  
Stop Band ◽  
Blue Shift ◽  
Ethanol Vapor ◽  
Doctor Blade ◽  
Color Changes ◽  
Reliable Assessment ◽  
Fruit Maturity ◽  
Brix Value

Climacteric fruits are harvested before they are ripened to avoid adverse damages during transport. The unripe fruits can undergo ripening processes associated with rind color changes on exposure to ethanol vapors. Although rind coloration is a common indicator showing fruit maturity, the attribute does not provide reliable assessment of maturity especially for melons. Herein, we report the achievement of sensitive and reversible melon maturity detection using macroporous hydrogel photonic crystals self-assembled by a roll-to-roll compatible doctor-blade-coating technology. The consumption of applied ethanol vapor during melon ripening results in less condensation of ethanol vapor in the pores (250 nm in diameter), leading to a distinct blue-shift of the optical stop band from 572 to 501 nm and an obvious visual colorimetric readout from yellow green to blue. Moreover, the dependence of the color change on Brix value within the melon has also been evaluated in the study.

Structural and electronic properties of defects in semiconductors

1995 ◽  
Vol 53 ◽  
pp. 4-5
Author(s):  
J.L. Batstone
Keyword(s):  
Semiconductor Device ◽  
Chemical Vapor ◽  
Misfit Strain ◽  
Organic Chemical ◽  
Extended Defects ◽  
Transmission Electron ◽  
Semiconductor Thin Films ◽  
Wide Range ◽  
Metal Organic ◽  
Film Substrate

The development of growth techniques such as metal organic chemical vapor deposition (MOCVD) and molecular beam epitaxy during the last fifteen years has resulted in the growth of high quality epitaxial semiconductor thin films for the semiconductor device industry. The III-V and II-VI semiconductors exhibit a wide range of fundamental band gap energies, enabling the fabrication of sophisticated optoelectronic devices such as lasers and electroluminescent displays. However, the radiative efficiency of such devices is strongly affected by the presence of optically and electrically active defects within the epitaxial layer; thus an understanding of factors influencing the defect densities is required.Extended defects such as dislocations, twins, stacking faults and grain boundaries can occur during epitaxial growth to relieve the misfit strain that builds up. Such defects can nucleate either at surfaces or thin film/substrate interfaces and the growth and nucleation events can be determined by in situ transmission electron microscopy (TEM).

Microsponges: An Overview

2017 ◽  
Vol 4 (4) ◽  
Author(s):  
Hamid Hussain ◽  
Divya Juyal ◽  
Archana Dhyani
Keyword(s):  
Controlled Release ◽  
Delivery System ◽  
Oral Delivery ◽  
Active Agent ◽  
Topical Delivery ◽  
Water Soluble ◽  
Wide Range ◽  
Porous Beads

Microsponge and Nanosponge delivery System was originally developed for topical delivery of drugs can also be used for controlled oral delivery of drugs using water soluble and bioerodible polymers. Microsponge delivery system (MDS) can entrap wide range of drugs and then release them onto the skin over a time by difussion mechanism to the skin. It is a unique technology for the controlled release of topical agents and consists of nano or micro porous beads loaded with active agent and also use for oral delivery of drugs using bioerodible polymers.

The content of decenoic acids in drone brood preparations and combined preparations based on it

Biomics ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 389-393
Author(s):  
D.V. Mitrofanov ◽  
N.V. Budnikova
Keyword(s):  
Royal Jelly ◽  
Storage Conditions ◽  
Water Soluble ◽  
Biologically Active Substances ◽  
Biologically Active ◽  
Strict Adherence ◽  
Drone Brood ◽  
Wide Range ◽  
Active Substances ◽  
Melanin Complex

The drone brood contains a large number of substances with antioxidant activity. These substances require stabilization and strict adherence to storage conditions. Among these substances are unique decenoic acids, the content of which is an indicator of the quality of drone brood and products based on it. The ability of drone brood to reduce the manifestations of oxidative stress is shown. There are dietary supplements for food and drugs based on drone brood, which are used for a wide range of diseases. Together with drone brood, chitosan-containing products, propolis, royal jelly can be used. They enrich the composition with their own biologically active substances and affect the preservation of the biologically active substances of the drone brood. Promising are the products containing, in addition to the drone brood, a chitin-chitosan-melanin complex from bees, propolis, royal jelly. The chitin-chitosan-melanin complex in the amount of 5% in the composition of the adsorbent practically does not affect the preservation of decenic acids, while in the amount of 2% and 10% it somewhat worsens. The acid-soluble and water-soluble chitosan of marine crustaceans significantly worsens the preservation of decenoic acids in the product. Drone brood with royal jelly demonstrates a rather high content of decenoic acids. When propolis is introduced into the composition of the product, the content of decenoic acids increases according to the content of propolis.

Influencia de las condiciones de secado solar en la coloración de plantas medicinales

2019 ◽  
pp. 28-34
Author(s):  
Margarita Castillo-Téllez ◽  
Beatriz Castillo-Téllez ◽  
Juan Carlos Ovando-Sierra ◽  
Luz María Hernández-Cruz
Keyword(s):  
Medicinal Plants ◽  
Forced Convection ◽  
Rural Areas ◽  
Color Change ◽  
Drying Process ◽  
Scientific Medicine ◽  
Drying Time ◽  
Bacterial Proliferation ◽  
Wide Range ◽  
Very High

For millennia, humans have used hundreds of medicinal plants to treat diseases. Currently, many species with important characteristics are known to alleviate a wide range of health problems, mainly in rural areas, where the use of these resources is very high, even replacing scientific medicine almost completely. This paper presents the dehydration of medicinal plants that are grown in the State of Campeche through direct and indirect solar technologies in order to evaluate the influence of air flow and temperature on the color of the final product through the L* a* scale. b*, analyzing the activity of water and humidity during the drying process. The experimental results showed that the direct solar dryer with forced convection presents a little significant color change in a drying time of 400 min on average, guaranteeing the null bacterial proliferation and reaching a final humidity between 9 % and 11 %.

scholarly journals Two-photon polymerization nanolithography technology for fabrication of stimulus-responsive micro/nano-structures for biomedical applications

2020 ◽  
Vol 9 (1) ◽  
pp. 1118-1136
Author(s):  
Zhenjia Huang ◽  
Gary Chi-Pong Tsui ◽  
Yu Deng ◽  
Chak-Yin Tang
Keyword(s):  
Biomedical Applications ◽  
Three Dimensional ◽  
Water Soluble ◽  
Fabrication Technology ◽  
Nano Fabrication ◽  
Two Photon ◽  
Nano Structures ◽  
Wide Range ◽  
Stimulus Responsive ◽  
Two Photon Polymerization

AbstractMicro/nano-fabrication technology via two-photon polymerization (TPP) nanolithography is a powerful and useful manufacturing tool that is capable of generating two dimensional (2D) to three dimensional (3D) arbitrary micro/nano-structures of various materials with a high spatial resolution. This technology has received tremendous interest in cell and tissue engineering and medical microdevices because of its remarkable fabrication capability for sophisticated structures from macro- to nano-scale, which are difficult to be achieved by traditional methods with limited microarchitecture controllability. To fabricate precisely designed 3D micro/nano-structures for biomedical applications via TPP nanolithography, the use of photoinitiators (PIs) and photoresists needs to be considered comprehensively and systematically. In this review, widely used commercially available PIs are first discussed, followed by elucidating synthesis strategies of water-soluble initiators for biomedical applications. In addition to the conventional photoresists, the distinctive properties of customized stimulus-responsive photoresists are discussed. Finally, current limitations and challenges in the material and fabrication aspects and an outlook for future prospects of TPP for biomedical applications based on different biocompatible photosensitive composites are discussed comprehensively. In all, this review provides a basic understanding of TPP technology and important roles of PIs and photoresists for fabricating high-precision stimulus-responsive micro/nano-structures for a wide range of biomedical applications.

Water-soluble polymeric particle embedded cryogels: Synthesis, characterisation and adsorption of haemoglobin

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Kadir Erol ◽  
Melda Bolat Bülter ◽  
Dursun Ali Köse ◽  
Hatice Kaplan Can
Keyword(s):  
Copper Ions ◽  
Langmuir Model ◽  
Water Soluble ◽  
Hydroxyethyl Methacrylate ◽  
Adsorption Ability ◽  
Adsorption Interaction ◽  
Polymeric Particle ◽  
Adsorption Desorption ◽  
Desorption Cycle ◽  
Soluble Poly

Abstract Making cryogels, which are among today’s accepted adsorbents, more functional with different methods, has been one of the subjects spent overtime. In this study, water-soluble poly(maleic anhydride-alt-acrylic acid) polymer embedded in poly(2-hydroxyethyl methacrylate) cryogels. Copper ions were then immobilised to this structure, and this polymer was used for adsorption of haemoglobin from aqueous systems. Adsorption interaction was carried out on an electrostatic basis, and approximately 448.62 mg haemoglobin/g polymer adsorption capacity value was obtained. It was found that the same material has managed to maintain its adsorption ability by 90.3% even after the use of it five times in the adsorption/desorption cycle. The adsorption interaction was determined to be appropriate for the Langmuir model by isotherm studies. The change in Gibbs free energy value was calculated as −2.168 kJ/mol.

scholarly journals Properties of the Biexciton and the Electron-Hole-Plasma in Highly Excited GaN

1997 ◽  
Vol 2 ◽  
Author(s):  
J.-Chr. Holst ◽  
L. Eckey ◽  
A. Hoffmann ◽  
I. Broser ◽  
H. Amano ◽  
...  
Keyword(s):  
Chemical Vapor ◽  
Blue Laser ◽  
Basic Material ◽  
Organic Chemical ◽  
Electron Hole ◽  
Hole Plasma ◽  
Electron Hole Plasma ◽  
Wide Range ◽  
Gain Spectra ◽  
Excitation Processes

High-excitation processes like biexciton decay and recombination of an electron-hole-plasma are discussed as efficient mechanisms for lasing in blue laser diodes [1]. Therefore, the investigation of these processes is of fundamental importance to the understanding of the properties of GaN as a basic material for optoelectronical applications. We report on comprehensive photoluminescence and gain measurements of highly excited GaN epilayers grown by metal-organic chemical vapor deposition (MOCVD) over a wide range of excitation densities and temperatures. For low temperatures the decay of biexcitons and the electron-hole-plasma dominate the spontaneous-emission and gain spectra. A spectral analysis of the lineshape of these emissions is performed and the properties of the biexciton and the electron-hole-plasma in GaN will be disscused in comparison to other wide-gap materials. At increased temperatures up to 300 K exciton-exciton-scattering and band-to-band recombination are the most efficient processes in the gain spectra beside the electron-hole-plasma.

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