Bactericidal efficiency of UVA-active titanium dioxide thin layers on bacteria from food industry environments

Abstract In this study titanium dioxide nanopowder has been manufactured and examined. Nanocrystalline TiO2 powder has been obtained by hydrolysis and peptization of a solution of titanium isopropoxide and isopropanol. Subsequently, produced powder has been subjected to structural analysis by using a transmission electron microscope, X-ray diffractometer, and Raman spectrometer. For comparison purposes, a commercially available titanium dioxide powder (i.e. titanium white) was also used. Thin layers have been made from this powder and further have been examined by using a UV/VIS spectrometer. Completed research shows the nanocrystalline structure of obtained layers and their good properties such as absorbance at the range of wavelength equal 200 - 1000 nm.

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Preparation of bone-implants by coating hydroxyapatite nanoparticles on self-formed titanium dioxide thin-layers on titanium metal surfaces

Materials Science and Engineering C ◽

10.1016/j.msec.2016.02.053 ◽

2016 ◽

Vol 63 ◽

pp. 172-184 ◽

Cited By ~ 29

Author(s):

W.P.S.L. Wijesinghe ◽

M.M.M.G.P.G. Mantilaka ◽

K.G. Chathuranga Senarathna ◽

H.M.T.U. Herath ◽

T.N. Premachandra ◽

...

Keyword(s):

Titanium Dioxide ◽

Metal Surfaces ◽

Thin Layers ◽

Titanium Metal ◽

Hydroxyapatite Nanoparticles ◽

Bone Implants

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Optically Transparent Titanium Dioxide Particles Incorporated in Poly(hydroxyethyl methacrylate) Thin Layers

The Journal of Physical Chemistry C ◽

10.1021/jp803194p ◽

2008 ◽

Vol 112 (50) ◽

pp. 19979-19985 ◽

Cited By ~ 25

Author(s):

Václav Štengl ◽

Vendula Houšková ◽

Snejana Bakardjieva ◽

Nataliya Murafa ◽

Vladimír Havlín

Keyword(s):

Titanium Dioxide ◽

Thin Layers ◽

Hydroxyethyl Methacrylate ◽

Optically Transparent

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Food Additive Titanium Dioxide and Its Fate in Commercial Foods

Nanomaterials ◽

10.3390/nano9081175 ◽

2019 ◽

Vol 9 (8) ◽

pp. 1175 ◽

Cited By ~ 8

Author(s):

Ji-Soo Hwang ◽

Jin Yu ◽

Hyoung-Mi Kim ◽

Jae-Min Oh ◽

Soo-Jin Choi

Keyword(s):

Particle Size ◽

Titanium Dioxide ◽

Particle Size Distribution ◽

Size Distribution ◽

Food Industry ◽

Food Additives ◽

Intestinal Transport ◽

Nanostructured Particles ◽

Tio2 Particles

Titanium dioxide (TiO2) is one of the most extensively utilized food additives (E171) in the food industry. Along with nanotechnology development, the concern about the presence of nanostructured particles in E171 TiO2 and commercial food products is growing. In the present study, the physicochemical properties of commercially available E171 TiO2 particles, including particle size distribution, were investigated, followed by their cytotoxicity and intestinal transport evaluation. The fate determination and quantification of E171 TiO2 in commercial foods were carried out based on the analytical procedure developed using simulated foods. The results demonstrated that TiO2 is a material mainly composed of particles larger than 100 nm, but present as an agglomerated or aggregated particle in commercial foods with amounts of less than 1% (wt/wt). Titanium dioxide particles generated reactive oxygen species and inhibited long-term colony formation, but the cytotoxicity was not related to particle size distribution or particle type (food- or general-grade). All TiO2 particles were mainly transported by microfold (M) cells, but also by intestinal tight junction. These findings will be useful for TiO2 application in the food industry and predicting its potential toxicity.

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Electrophoretically Deposited Titanium Dioxide Thin Films for Photovoltaic Cells

Australian Journal of Chemistry ◽

10.1071/ch9941869 ◽

1994 ◽

Vol 47 (10) ◽

pp. 1869 ◽

Cited By ~ 49

Author(s):

D Matthews ◽

A Kay ◽

M Gratzel

Keyword(s):

Titanium Dioxide ◽

Dark Current ◽

Photovoltaic Cells ◽

Photovoltaic Cell ◽

Thin Layers ◽

Constant Current ◽

Dye Sensitized ◽

Current Voltage ◽

A New Technique ◽

Titanium Dioxide Thin Films

A new technique for forming porous thin layers of nano -colloidal titanium dioxide on electronically conducting glass was developed. This technique uses constant-current electrophoretic deposition from a dispersion of Degussa P-25 titanium dioxide in 2-methoxyethanol followed by air-drying and annealing. Dye-sensitized TiO2 photovoltaic cells constructed with these films gave current-voltage characteristics comparable with those of films produced by other techniques. A 30 cm2 prototype photovoltaic cell was constructed with electrophoretically deposited TiO2, and tested. Measurement of the dark current and photocurrent enabled the calculation of the light current, and the effect of both the dark current and the series resistance on the cell performance was demonstrated.

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Immunoferritin localization of intracellular antigens in positively stained frozen sections

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010008170x ◽

1978 ◽

Vol 36 (2) ◽

pp. 168-169

Author(s):

K. T. Tokuyasu

Keyword(s):

Surface Tension ◽

Water Surface ◽

Thin Layers ◽

The Other ◽

Positive Staining ◽

Frozen Sections ◽

The Past ◽

Ultrathin Frozen Sections ◽

Definition Of

During the past investigations of immunoferritin localization of intracellular antigens in ultrathin frozen sections, we found that the degree of negative staining required to delineate u1trastructural details was often too dense for the recognition of ferritin particles. The quality of positive staining of ultrathin frozen sections, on the other hand, has generally been far inferior to that attainable in conventional plastic embedded sections, particularly in the definition of membranes. As we discussed before, a main cause of this difficulty seemed to be the vulnerability of frozen sections to the damaging effects of air-water surface tension at the time of drying of the sections.Indeed, we found that the quality of positive staining is greatly improved when positively stained frozen sections are protected against the effects of surface tension by embedding them in thin layers of mechanically stable materials at the time of drying (unpublished).

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EELS Measurement of the Local Electronic Structure of Copper Atoms Segregated to Aluminum Grain Boundaries

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100164179 ◽

1996 ◽

Vol 54 ◽

pp. 342-343

Author(s):

S.J. Splinter ◽

J. Bruley ◽

P.E. Batson ◽

D.A. Smith ◽

R. Rosenberg

Keyword(s):

Electronic Structure ◽

Grain Boundaries ◽

Boundary Segregation ◽

Thin Layers ◽

Nominal Composition ◽

Spatially Resolved ◽

Service Lifetime ◽

Heat Treated ◽

Probe Size ◽

Local Electronic Structure

It has long been known that the addition of Cu to Al interconnects improves the resistance to electromigration failure. It is generally accepted that this improvement is the result of Cu segregation to Al grain boundaries. The exact mechanism by which segregated Cu increases service lifetime is not understood, although it has been suggested that the formation of thin layers of θ-CuA12 (or some metastable substoichiometric precursor, θ’ or θ”) at the boundaries may be necessary. This paper reports measurements of the local electronic structure of Cu atoms segregated to Al grain boundaries using spatially resolved EELS in a UHV STEM. It is shown that segregated Cu exists in a chemical environment similar to that of Cu atoms in bulk θ-phase precipitates.Films of 100 nm thickness and nominal composition Al-2.5wt%Cu were deposited by sputtering from alloy targets onto NaCl substrates. The samples were solution heat treated at 748K for 30 min and aged at 523K for 4 h to promote equilibrium grain boundary segregation. EELS measurements were made using a Gatan 666 PEELS spectrometer interfaced to a VG HB501 STEM operating at 100 keV. The probe size was estimated to be 1 nm FWHM. Grain boundaries with the narrowest projected width were chosen for analysis. EDX measurements of Cu segregation were made using a VG HB603 STEM.

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Where’s the fat? Freeze-fracture analysis of ingredient interactions in food systems

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100146084 ◽

1993 ◽

Vol 51 ◽

pp. 48-49

Author(s):

Jean Fincher

Keyword(s):

Lipid Droplets ◽

Food Systems ◽

Food Industry ◽

Freeze Fracture ◽

Food Science ◽

Complex Interactions ◽

Fat Reduction ◽

Important Trend ◽

Conventional Foods ◽

Whipped Cream

An important trend in the food industry today is reduction in the amount of fat in manufactured foods. Often fat reduction is accomplished by replacing part of the natural fat with carbohydrates which serve to bind water and increase viscosity. It is in understanding the roles of these two major components of food, fats and carbohydrates, that freeze-fracture is so important. It is well known that conventional fixation procedures are inadequate for many food products, in particular, foods with carbohydrates as a predominant structural feature. For some food science applications the advantages of freeze-fracture preparation procedures include not only the avoidance of chemical fixatives, but also the opportunity to control the temperature of the sample just prior to rapid freezing.In conventional foods freeze-fracture has been used most successfully in analysis of milk and milk products. Milk gels depend on interactions between lipid droplets and proteins. Whipped emulsions, either whipped cream or ice cream, involve complex interactions between lipid, protein, air cell surfaces, and added emulsifiers.

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