scholarly journals Titanium Dioxide Nanotube-Based Oxygen Indicator for Modified Atmosphere Packaging: Efficiency and Accuracy

Materials ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 2410 ◽  
Author(s):  
Junwei Wen ◽  
Shuting Huang ◽  
Yu Sun ◽  
Zhengjie Chen ◽  
Yixiang Wang ◽  
...  
Keyword(s):  
Titanium Dioxide ◽  
Modified Atmosphere Packaging ◽  
Wide Band ◽  
Crystal Form ◽  
Tio2 Nanotube ◽  
Hydroxyethyl Cellulose ◽  
Modified Atmosphere ◽  
Destructive Testing ◽  
Wide Band Gap ◽  
Pet Film

Colorimetric oxygen indicators can be applied for non-destructive testing in packaging; especially in modified atmosphere packaging (MAP). In this paper; titanium dioxide (TiO2) nanotube; which is used as a semiconductor photocatalyst in oxygen indicators; was synthesized via a microwave-assisted hydrothermal method. X-Ray Diffraction (XRD) was used to analyze its crystal form and Scanning Electron Microscope (SEM).to characterize its morphology. Its properties were studied using Brunauer-Emmett-Teller (BET), Diffuse Reflection Spectrum (DRS), and Bluebottle experiments. The results showed that the synthesized TiO2 nanotube was a mixture of rutile and anatase; with a specific surface area of 190.35 m2/g; and a wide band gap of 3.34 eV. Given the satisfactory performance; the TiO2-based oxygen indicator was prepared and combined with glycerol; methylene blue; and hydroxyethyl cellulose (HEC). The oxygen indicator demonstrated excellent photocatalytic performance and effectively avoided excitation by visible light. We studied the rheological properties; thixotropic properties; and wettability of the indicator. The results demonstrated the printability of the indicator solution; which was then printed in the polyethylene terephthalate (PET) film by screen printing and applied to MAP. The application results showed that the prepared oxygen indicator was able to provide visual support to judge whether the packaging was intact and the food was safe.

scholarly journals EFFECT OF SUNLIGHT ON THE ELECTRICAL CHARACTERISTICS OF THE HETEROSTRUCTURE TITANIUM DIOXIDE/SILICON

Doklady BGUIR ◽  
2019 ◽  
pp. 136-143
Author(s):  
A. A. Kuraptsova ◽  
A. L. Danilyuk ◽  
A. A. Leshok ◽  
V. E. Borisenko
Keyword(s):  
Titanium Dioxide ◽  
Wide Band ◽  
Charge Carriers ◽  
Electrical Characteristics ◽  
Wide Band Gap ◽  
External Bias ◽  
Modeling Process ◽  
Semiconducting Metal Oxides ◽  
The Difference ◽  
Sun Light

Electrical characteristics of the heterostructure titanium dioxide/silicon illuminated by the sun light were theoretically modeled. The modeling process includes consideration of generation of the charge carriers and their transport through the practically important heterostructure n-TiO2/p-Si. The current through the structure under small external bias up to 0.6 V was found to depend nonlinearly on the light wavelength. It is controlled by the movement of the electrons from silicon to the titanium dioxide. The highest current corresponds to the wavelengths of about 600 nm. The results obtained are explained by the difference in the absorption coefficients and reflectivity of titanium dioxide and silicon which determine generation of nonequilibrium charge carriers in the heterostructure n-TiO2/p-Si. It was demonstrated that under illumination of the unbiased heterostructure with the light of 500–600 nm the generated electrons freely move from the titanium dioxide to silicon while the movement of holes is blocked. It helps to concentrate electrons in the relatively thin nearsurface layer of titanium dioxide and use them for catalytic purification of water and air by oxidation of organic pollutants at its surface. The regularities observed are important in the detailed analysis of electronic processes at the surface of wide band gap semiconducting metal oxides and their practical application in photocatalytic processes.

ON PRODUCTION POSSIBILITY TITANIUM DIOXIDE POWDER SYNTHESIZED BY DYNAMIC PLAZMA METHOD

2020 ◽  
Vol 11 ◽  
pp. 21-26
Author(s):  
A. A. SIVKOV ◽  
◽  
YU. N. VYMPINA ◽  
A. S. IVASHUTENKO ◽  
I. A. RAKHMATULLIN ◽  
...  
Keyword(s):  
Titanium Dioxide ◽  
Alternative Energy ◽  
Wide Band ◽  
Coarse Fraction ◽  
Wide Band Gap ◽  
Plasma Dynamic ◽  
Dynamic Synthesis ◽  
Titanium Dioxide Powder ◽  
Dioxide Powder ◽  
Photocatalytic Material

These days, environmental pollution problems are relevant, therefore, the problems associated with photocatalysis as a direction for the future development of alternative energy are solved by many world scientists. Titanium dioxide TiO2 is known to be a photocatalytic material with many unique properties. However, its use is limited due to its wide band gap and the high recombination rate of electron pairs. The method of direct plasma dynamic synthesis of dispersed titanium dioxide was proposed. It was established that the synthesized product consisted of two fractions which had different sizes: a coarse fraction with particle sizes from ~10 microns to ~100 microns and a fine one - from ~10 nm to ~1 micron. It was also revealed that fractions mainly consisted of two TiO2 crystalline modifications: anatase and rutile with tetragonal syngony.

scholarly journals Broad-Spectrum Antimicrobial Effects of Photocatalysis Using Titanium Dioxide Nanoparticles Are Strongly Potentiated by Addition of Potassium Iodide

2016 ◽  
Vol 60 (9) ◽  
pp. 5445-5453 ◽  
Author(s):  
Ying-Ying Huang ◽  
Hwanjun Choi ◽  
Yu Kushida ◽  
Brijesh Bhayana ◽  
Yuguang Wang ◽  
...  
Keyword(s):  
Titanium Dioxide ◽  
Potassium Iodide ◽  
Environmental Remediation ◽  
Titanium Dioxide Nanoparticles ◽  
Wide Band ◽  
Dependent Manner ◽  
Wide Band Gap ◽  
Content Type ◽  
Uva Light ◽  
Bacteria And Fungi

ABSTRACTPhotocatalysis describes the excitation of titanium dioxide nanoparticles (a wide-band gap semiconductor) by UVA light to produce reactive oxygen species (ROS) that can destroy many organic molecules. This photocatalysis process is used for environmental remediation, while antimicrobial photocatalysis can kill many classes of microorganisms and can be used to sterilize water and surfaces and possibly to treat infections. Here we show that addition of the nontoxic inorganic salt potassium iodide to TiO2(P25) excited by UVA potentiated the killing of Gram-positive bacteria, Gram-negative bacteria, and fungi by up to 6 logs. The microbial killing depended on the concentration of TiO2, the fluence of UVA light, and the concentration of KI (the best effect was at 100 mM). There was formation of long-lived antimicrobial species (probably hypoiodite and iodine) in the reaction mixture (detected by adding bacteria after light), but short-lived antibacterial reactive species (bacteria present during light) produced more killing. Fluorescent probes for ROS (hydroxyl radical and singlet oxygen) were quenched by iodide. Tri-iodide (which has a peak at 350 nm and a blue product with starch) was produced by TiO2-UVA-KI but was much reduced when methicillin-resistantStaphylococcus aureus(MRSA) cells were also present. The model tyrosine substrateN-acetyl tyrosine ethyl ester was iodinated in a light dose-dependent manner. We conclude that UVA-excited TiO2in the presence of iodide produces reactive iodine intermediates during illumination that kill microbial cells and long-lived oxidized iodine products that kill after light has ended.

scholarly journals Photocatalytic Applications of Titanium Dioxide (TiO2)

2021 ◽  
Author(s):  
Atta ul Haq ◽  
Muhammad Saeed ◽  
Samreen Gul Khan ◽  
Muhammad Ibrahim
Keyword(s):  
Water Pollution ◽  
Titanium Dioxide ◽  
Metal Oxides ◽  
Textile Industry ◽  
Photocatalytic Performance ◽  
Wide Band ◽  
Catalytic Performance ◽  
Wide Band Gap ◽  
Rapid Industrialization ◽  
Photocatalytic Applications

Water pollution is one the fundamental problems that have got the serious concerns of the researchers. Water poluution arises due to a number of reasons including domestic, industrial, agricultural, scinec and technology. The textile industry is the main industry that releases the dyes contaminated wastewater to the environment. A varities of protocols have been attempeted for the removal of dyes from aqueous body. Photocatalysis is one of the effective techniques which offer opportunities to overcome the aqueous pollution caused by rapid industrialization and urbanization. The semiconductor metal oxides used as photocatalysts are capable to provide a sustainable and clean ecosystem due to the tunable physiochemical characteristics of semiconductor metal oxides. Titanium dioxide (TiO2) is one of the metal oxides that can be effectively employed as a photocatalyst in the abatement of aqueous pollution due to organic compounds. The catalytic performance of titanium dioxide depends on several parameters like its crystallinity, surface area, and morphology. Titanium dioxide has shown good performance in the different photocatalytic systems, however, the characteristics like wide band gap and low conductivity limit the photocatalytic performance of titanium dioxide. Various attempts have been made to improve the photocatalytic performance of titanium dioxide. Herein, we summarize the various attempts to improve the photocatalytic performance of titanium dioxide in the abatement of aqueous pollution. The attempts made for the improvement of photocatalytic performance of titanium dioxide include modifications in composition, doping of other metal, and formation of heterojunctions with other metal oxides.

Electrical transport in titania nanoparticles embedded in conducting polymer matrix

2015 ◽  
Vol 4 (5) ◽  
Author(s):  
Ashis Dey
Keyword(s):  
Titanium Dioxide ◽  
Band Gap ◽  
Conducting Polymer ◽  
Polymer Matrix ◽  
Electrical Transport ◽  
Wide Band ◽  
Titania Nanoparticles ◽  
Wide Band Gap ◽  
Semiconductor Nanocomposites

AbstractConducting polymer-wide band gap semiconductor nanocomposites are prepared by polymerizing pyrrole in the presence of colloidal titanium dioxide (TiO

TEM and cathodoluminescence of precipitates in II-VI semiconductors

1988 ◽  
Vol 46 ◽  
pp. 488-489
Author(s):  
Joanna L. Batstone
Keyword(s):  
Crystal Growth ◽  
Band Gap ◽  
Local Strain ◽  
Wide Band ◽  
Optoelectronic Device ◽  
Wide Band Gap ◽  
Bulk Crystal Growth ◽  
Transmission Electron ◽  
Device Applications ◽  
Stoichiometry Control

Interest in II-VI semiconductors centres around optoelectronic device applications. The wide band gap II-VI semiconductors such as ZnS, ZnSe and ZnTe have been used in lasers and electroluminescent displays yielding room temperature blue luminescence. The narrow gap II-VI semiconductors such as CdTe and HgxCd1-x Te are currently used for infrared detectors, where the band gap can be varied continuously by changing the alloy composition x.Two major sources of precipitation can be identified in II-VI materials; (i) dopant introduction leading to local variations in concentration and subsequent precipitation and (ii) Te precipitation in ZnTe, CdTe and HgCdTe due to native point defects which arise from problems associated with stoichiometry control during crystal growth. Precipitation is observed in both bulk crystal growth and epitaxial growth and is frequently associated with segregation and precipitation at dislocations and grain boundaries. Precipitation has been observed using transmission electron microscopy (TEM) which is sensitive to local strain fields around inclusions.

Electron microscopic characterization of diamond thin films and substrates for diamond heteroepitaxial growth

1989 ◽  
Vol 47 ◽  
pp. 592-593
Author(s):  
J.B. Posthill ◽  
R.P. Burns ◽  
R.A. Rudder ◽  
Y.H. Lee ◽  
R.J. Markunas ◽  
...  
Keyword(s):  
Thin Films ◽  
Wide Band ◽  
Deposition Process ◽  
Heteroepitaxial Growth ◽  
Electron Microscopic ◽  
Wide Band Gap ◽  
Lattice Matching ◽  
Different Types ◽  
Diamond Thin Films

Because of diamond’s wide band gap, high thermal conductivity, high breakdown voltage and high radiation resistance, there is a growing interest in developing diamond-based devices for several new and demanding electronic applications. In developing this technology, there are several new challenges to be overcome. Much of our effort has been directed at developing a diamond deposition process that will permit controlled, epitaxial growth. Also, because of cost and size considerations, it is mandatory that a non-native substrate be developed for heteroepitaxial nucleation and growth of diamond thin films. To this end, we are currently investigating the use of Ni single crystals on which different types of epitaxial metals are grown by molecular beam epitaxy (MBE) for lattice matching to diamond as well as surface chemistry modification. This contribution reports briefly on our microscopic observations that are integral to these endeavors.

EFFECT OF SODIUM LACTATE ON QUALITY OF LIGHTLY SALTED FISH IN OXYGEN FREE PACKAGING

2017 ◽  
pp. 128-137
Author(s):  
Elena Yuryevna Porotikova ◽  
Boris Lazarevich Nekhamkin ◽  
Mikhail Pavlovich Andreev
Keyword(s):  
Modified Atmosphere Packaging ◽  
Storage Period ◽  
Sodium Lactate ◽  
Vacuum Packaging ◽  
Storage Life ◽  
Clupea Harengus ◽  
Modified Atmosphere ◽  
Salted Fish ◽  
Baltic Herring ◽  
Organoleptic Characteristics

The present article investigates the effect of sodium lactate on microbiological, physico-chemical and sensory characteristics of lightly salted Pacific herring ( Clupea pallasii ) and Baltic herring ( Clupea harengus membras ) during refrigerated storage 5 ± 0.3°C. There have been analyzed different processing methods of lightly salted samples of Pacific and Baltic herring: control (without sodium lactate), and experiment (3% sodium lactate), both in vacuum packaging and modified atmosphere packaging (MAP - 40% CO2/60% N2). For vacuum and MAP there were used bags with low oxygen permeability (3 cm3/m2/day). It was found that 3% sodium lactate keeps firmness of the texture of salted fish muscle and reduces the release of water into the package during storage. Adding 3% sodium lactate reduces the value of the water activity in lightly salted Pacific and Baltic herring by 0.01-0,012 units. The lowest pH (0.02 units) was registered in samples without sodium lactate packed in MAP. Organoleptic signs of spoilage in fish without sodium lactate appeared much earlier, and using 3% sodium lactate both in vacuum and in MAP helped protect and improve organoleptic characteristics of the product during storage. Total biological semination of experimental samples packed in MAP kept at the very low level during the whole storage period, i.e. combined effect of using 3% sodium lactate and MAP inhibited microbial growth. This combination allows to reduce twice the rate of accumulation nitrogen in terminal amino-groups and to increase 1.5-2 times storage life of lightly salted Pacific and Baltic herring, compared to their storage life in vacuum packaging without sodium lactate. The results obtained allow us to recommend using sodium lactate in production of lightly salted fish in oxygen-free packaging, especially in modified atmosphere packaging (40% CO2/60% N2).

Wide Band-Gap Kesterite Thin Films for Photovoltaic Applications

2018 ◽  
Author(s):  
Raquel Caballero ◽  
Leonor de la Cueva ◽  
Andrea Ruiz-Perona ◽  
Yudenia Sánchez ◽  
Markus Neuschitzer ◽  
...  
Keyword(s):  
Thin Films ◽  
Band Gap ◽  
Wide Band ◽  
Wide Band Gap ◽  
Photovoltaic Applications
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