scholarly journals Influence of the Addition of TiO2 Nanoparticles on the Self-Cleaning Performance of Cementitious Composite Surfaces

Proceedings ◽  
2020 ◽  
Vol 63 (1) ◽  
pp. 42
Author(s):  
Elvira Grebenișan ◽  
Andreea Hegyi ◽  
Henriette Szilagyi ◽  
Adrian-Victor Lăzărescu ◽  
Brăduț Alexandru Ionescu
Keyword(s):  
Tio2 Nanoparticles ◽  
Organic Molecules ◽  
The Self ◽  
Matrix Degradation ◽  
Cementitious Composite ◽  
Duration Of Action ◽  
Cementitious Matrix ◽  
Cleaning Performance ◽  
The Matrix ◽  
Self Cleaning

The presence of TiO2 nanoparticles in a cementitious matrix induces self-cleaning capacity in the presence of UV radiation by combining two mechanisms: surface hydrophilicity and degradation of the stain agent molecules. Experimental results indicate an increase in surface water absorption and, indirectly, in the degree of hydrophilicity, with the increase in the concentration of TiO2 nanoparticles in the matrix. Degradation of organic molecules, rhodamine B, is dependent on the duration of action and intensity of UV rays and the concentration of nanoparticles in the cementitious matrix. An addition of 3–6% TiO2 is effective and sufficient for a good self-cleaning capacity of cementitious surfaces.

scholarly journals Hydrophobic and Anti-Fouling Performance of Surface on Parabolic Morphology

2020 ◽  
Vol 17 (2) ◽  
pp. 644
Author(s):  
Yu Li ◽  
Shengke Yang ◽  
Yangyang Chen ◽  
Dan Zhang
Keyword(s):  
Contact Angle ◽  
Chemical Oxidation ◽  
The Self ◽  
Separation Performance ◽  
Copper Sheet ◽  
Water Separation ◽  
Cleaning Performance ◽  
Oil Water Separation ◽  
Oil Water ◽  
Self Cleaning

The hydrophobicity and anti-fouling properties of materials have important application value in industrial and agricultural production and people’s daily life. To study the relationship between the unit width L0 of the parabolic hydrophobic material and the hydrophobicity and anti-fouling properties, the rough surface structure of the parabolic with different widths was prepared by grinding with different SiC sandpapers, and further, to obtain hydrophobic materials through chemical oxidation and chemical etching, and modification with stearic acid (SA). The morphology, surface wetting and anti-fouling properties of the modified materials were characterized by SEM and contact angle measurement. The oil–water separation performance and self-cleaning performance of the materials were explored. The surface of the modified copper sheet forms a rough structure similar to a paraboloid. When ground with 1500 grit SiC sandpaper, it is more conducive to increase the hydrophobicity of the copper sheet surface and increase the contact angle of water droplets on the copper surface. Additionally, the self-cleaning and anti-fouling experiments showed that as L0 decreases, copper sheets were less able to stick to foreign things such as soil, and the better the self-cleaning and anti-fouling performance was. Based on the oil–water separation experiment of copper mesh, the lower L0 has a higher oil–water separation efficiency. The results showed that material with parabolic morphology has great self-cleaning, anti-fouling, and oil–water separation performance. The smaller the L0 was, the larger the contact angle and the better hydrophobic performance and self-cleaning performance were.

scholarly journals Sol-Gel Coatings for Subaquatic Self-Cleaning Windows

Crystals ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 375
Author(s):  
Andrew I. M. Greer ◽  
David Moodie ◽  
Graham Kerr ◽  
Nikolaj Gadegaard
Keyword(s):  
North Sea ◽  
Marine Bacteria ◽  
Optical Transmission ◽  
Sol Gel ◽  
Optical Devices ◽  
The Self ◽  
Worst Case ◽  
Airborne Pollutants ◽  
Cleaning Performance ◽  
Self Cleaning

Self-cleaning windows are well known for their ability to function with airborne pollutants, but there is a growing industry for semi-permanent subaquatic optical devices, where the performance of such windows should be considered. Here sol-gel technology is explored as a means of producing self-cleaning, subaquatic, sapphire windows. We demonstrate removal of marine bacteria and, in the worst-case contamination scenario, dead North Sea crude oil (API 35). This greasy contaminant was smeared across the windows to effectively reduce optical transmission strength to just 54%. The titania-based sol-gel-coated windows can restore transmission to within 10% of the clean value in less than one day, unlike standard sapphire windows, which lose 68% transmission following contamination and aquatic submergence over the same duration. A range of theories to enhance the self-cleaning performance of the sol-gel coating were explored, but none of the tested variables were able to provide any enhancement for subaquatic performance.

scholarly journals Synthesis and photocatalytic activity for TiO2 nanoparticles as air purification

2018 ◽  
Vol 162 ◽  
pp. 05006 ◽  
Author(s):  
Adawiya Haider ◽  
Riyad Al-Anbari ◽  
Ghadah Kadhim ◽  
Zainab Jameel
Keyword(s):  
Contact Angle ◽  
Titanium Dioxide ◽  
Tio2 Nanoparticles ◽  
Sol Gel ◽  
Xrd Analysis ◽  
The Self ◽  
Root Mean Square Roughness ◽  
Bacterial Inactivation ◽  
Water Contact ◽  
Self Cleaning

In the present work, titanium dioxide (TiO2) nanoparticles (NP’s) were prepared using sol-gel process from Titanium Tetrachloride (TiCl4) as a precursor with calcinations at two temperatures (500 and 900) °C. The effect of calcinations temperatures on the structural, optical, morphological and Root Mean Square (roughness) properties were investigated by means of Scanning Electron Microscopy, X-ray Diffraction (XRD), and Atomic Force Microscopy (AFM). Bacterial inactivation was evaluated using TiO2-coated Petri dishes. A thin layer of photocatalytic TiO2 powder was deposited on glass substrate in order to investigate the self-cleaning effect of TiO2 nanoparticles in indoor and outdoor applications. Ultra-hydrophilicity was assessed by measuring the contact angle and it evaluated photolysis properties through the degradation of potassium permanganate (KMnO4) under direct sunlight. XRD analysis indicated that the structure of TiO2 was anatase at 500 °C and rutile at 900 °C calcination temperatures. As the calcination temperature increases, the crystallinity is improved and the crystallite size becomes larger. Coated films of TiO2 made the has permeability, low water contact angle and good optical activity. These are properties essential for the application of the surface of the self-cleaning. The final results illustrate that titanium dioxide can be used in the build materials to produce coated surfaces in order to minimize air pollutants that are placed in microbiologically sensitive circumference like hospitals and the food factory.

Photocatalytic Finishing of Cotton Fabrics Based on Nano-Titanium Dioxide and Polyurethane Binder

2014 ◽  
Vol 1033-1034 ◽  
pp. 1227-1234 ◽  
Author(s):  
Penwisa Pisitsak ◽  
Anchalee Porntrirat ◽  
Nisa Boonwang ◽  
Rabchok Thongcharoen ◽  
Nattaya Punrattanasin
Keyword(s):  
Textile Industry ◽  
Fiber Surface ◽  
Aqueous Dispersion ◽  
Cotton Fabrics ◽  
The Self ◽  
Color Strength ◽  
Wash Fastness ◽  
Simulated Solar Light ◽  
Cleaning Performance ◽  
Self Cleaning

In the textile industry, binders are used in fabric finishing processes to promote adhesion between a fiber surface and the particles of desired properties. In this research, a commercial polyurethane binder, Evo®Fin PUS, was used to attach photocatalytic TiO2nanoparticles (Degussa®, P-25) onto a cotton surface, in order to impart self-cleaning properties and to improve wash fastness. The cotton fabrics were finished with the aqueous dispersion of TiO2and the binder, consisting of 2, 4, and 6 % w/v for each component. Finishing was done via a pad-dry-cure process. Then a direct dye (C.I. Direct Blue 199), which was used as a model stain, was dropped onto each sample prior to 24-h illumination with simulated solar light. The self-cleaning properties were triggered by light and evaluated in terms of the reduction in color strength values (K/S) of the stain after exposure. The self-cleaning performance was preserved when the binder was added to the TiO2coating. However, washing reduced the self-cleaning performance of all samples because of the detachment of some TiO2particles, as observed by scanning electron microscopy. Overall, improved wash fastness was observed with the help of binder. Samples were further analyzed for mechanical properties, crease recovery, and drapeability.

SiO2/TiO2 Antireflective Coatings With Photocatalytic Properties Prepared by Sol–Gel for Solar Glass Covers

2012 ◽  
Vol 134 (4) ◽  
Author(s):  
G. San Vicente ◽  
A. Morales ◽  
N. Germán ◽  
S. Suarez ◽  
B. Sánchez
Keyword(s):  
Organic Molecules ◽  
Sol Gel ◽  
The Self ◽  
Antireflective Coatings ◽  
Solar Systems ◽  
Coated Glass ◽  
Solar Plant ◽  
Self Cleaning ◽  
Promising Development ◽  
Plant Efficiency

The glass covers of solar systems are usually coated with antireflective (AR) coatings on both sides that allow to increase the efficiency of the whole system. At the same time, the accumulation of dust and dirt particles on the surface of the AR coated glass decreases the transmittance of the covers, even to values lower than the uncoated glass. This decrease in the cover transmittance reduces the solar radiation that reaches the absorber and, in this way, a decrease in the solar plant efficiency would be obtained. So, the use of films that combine high transmittance and self-cleaning capacity seems to be a promising development. This paper reports the preparation of sol–gel porous TiO2 and SiO2 bilayers on borosilicate glass. The porosity and thickness of both layers have been optimized in order to obtain the optimal photocatalytic and optical properties. Solar transmittance values of 0.964 were obtained for the TiO2/SiO2 coated glass. The highest value of transmittance reached is 0.993 and it is placed at 600 nm. The self-cleaning properties were evaluated using methylene blue and trichloroethylene (TCE) as model organic molecules using UV-A light. The results showed that the SiO2/TiO2 samples degraded the colorant faster than the SiO2 sample. Moreover, the degradation of TCE in air in a continuous fix bed photoreactor for samples with different TiO2 film thicknesses was also performed. The TCE conversion was found dependent on the TiO2 thickness. Nevertheless, the increase in the thickness of this layer reduced transmittance properties. The study demonstrates that it is possible to combine antireflective and self-cleaning properties in the same material.

scholarly journals Influence of domestic and environmental weathering in the self-cleaning performance and durability of TiO2 photocatalytic coatings

2018 ◽  
Vol 132 ◽  
pp. 96-103 ◽  
Author(s):  
Erika Iveth Cedillo-González ◽  
Virginia Barbieri ◽  
Paolo Falcaro ◽  
Leticia M. Torres-Martínez ◽  
Isaías Juárez-Ramírez ◽  
...  
Keyword(s):  
The Self ◽  
Cleaning Performance ◽  
Self Cleaning

The Photo-Catalytic Activity of Cu2+-Doped TiO2 and Applications in the Self-Cleaning Performance of Textile Wall Fabrics

2012 ◽  
Vol 557-559 ◽  
pp. 1475-1478
Author(s):  
Yan Qin Shen ◽  
Hai Liang Wu
Keyword(s):  
Catalytic Activity ◽  
Visible Light ◽  
Good Combination ◽  
The Self ◽  
Photo Catalytic Activity ◽  
Cleaning Performance ◽  
Nanometer Materials ◽  
Self Cleaning ◽  
Doped Titania

TiO2 photocatalyst and copper-doped titania (Cu/TiO2) photocatalyst were prepared and both photocatalysts were used in the self-cleaning finishing of wall fabrics. XRD showed that the nanometer materials and textile wall fabrics were a good combination. By comparing the self-cleaning effects of two kinds of photocatalysts, the results demonstrate that textile wall fabrics finished with Cu2+-doped TiO2 photocatalyst have better self-cleaning effect under visible light.

Anodic voltammetry of pyrazolone derivatives with the help of the self-cleaning rotating electrode

1987 ◽  
Vol 52 (1) ◽  
pp. 66-71 ◽  
Author(s):  
Vesselin C. Noninski ◽  
Emanuel B. Sobowale
Keyword(s):  
Electrochemical Oxidation ◽  
The Self ◽  
Good Reproducibility ◽  
Rotating Electrode ◽  
Pyrazolone Derivatives ◽  
Self Cleaning ◽  
Anodic Voltammetry

Nine pyrazolone derivatives have been studied by anodic voltammetry using gold self-cleaning rotating electrode (SRE). Voltamograms of good reproducibility are presented. On the basis of voltammetric data a mechanism is proposed for the electrochemical oxidation of sodium 1-phenyl-2,3-dimethyl-4-(N-methylamino)pyrazol-5-one-N-methansulphonate and 1-phenyl-2,3-dimethyl-4-(dimethylamino)pyrazol-5-one in protic medium.

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