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 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.

Self-cleaning treatment on historical stone surface via titanium dioxide nanocoatings

2019 ◽  
Vol 48 (5) ◽  
pp. 404-408
Author(s):  
Pooneh Kardar ◽  
Reza Amini
Keyword(s):  
Titanium Dioxide ◽  
Sol Gel ◽  
The Self ◽  
Architectural Heritage ◽  
Content Type ◽  
Smart Coatings ◽  
Self Cleaning ◽  
Reported Data ◽  
Inductive Property ◽  
Practical Implications

Purpose The purpose of this study is to evaluate the possibility of using titanium dioxide coating in the field of architectural heritage. Design/methodology/approach In this research, a titanium dioxide coating was prepared and then applied to the travertine stone surfaces. The nature of the coating was determined through various observations and analyses. Moreover, the effect of photocatalytic self-cleaning was evaluated using an organic dye (Rhodamine B). Findings The results of XRD, DLS and SEM confirmed the formation of small anatase crystals. The hydrophilic behavior on the surface was observed by coatings based on titanium dioxide. Research limitations/implications The self-cleaning ability of titanium dioxide is due to the synergistic effect of its optical inductive property, which is activated with sunlight. Practical implications The self-cleaning coatings are interested for many industries. The reported data can be used by the formulators working in the research and development departments. Social implications Self-cleaning systems are considered as smart coatings. Therefore, the developing of its knowledge can help to extend its usage to different applications. Originality/value The application of titanium dioxide coating in the field of architectural heritage is a great challenge. Therefore, in this research, a titanium dioxide coating was prepared by sol-gel method and then applied on travertine surfaces and its properties were studied.

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.

Preparation and Characterization of Novel Self-Cleaning Glasses with TiO2 Coatings

2012 ◽  
Vol 573-574 ◽  
pp. 135-139 ◽  
Author(s):  
Yu Mian Liu ◽  
Wei Ping Hu
Keyword(s):  
Environmental Protection ◽  
Ultraviolet Light ◽  
Sol Gel ◽  
The Self ◽  
Formaldehyde Concentration ◽  
Ultraviolet Light Irradiation ◽  
Foundation Base ◽  
Self Cleaning ◽  
Almost All ◽  
Organic Gases

Common glass for architecture had only one function, i.e., transparency and the requirement for indoor health made “environmental protection type” novel glass necessary. In the present study, a novel self-cleaning glass was prepared by sol-gel method. To form self-cleaning glass, common glass was adopted as the foundation base and TiO2 coatings were cover its outside surfaces. The novel glass had little change in shape but alteration to slightly white compared to common glass, thanks to white TiO2. The self-cleaning glass could reduce formaldehyde concentration of air from more than 160 mg•m3 to 0.4 mg•m3 within 60 h, while the common glass could cut down to ca. 30 mg•m3 and reaching equilibrium before 24 h. The removal of formaldehyde by common glass could be owing to adsorption action and slightly gradation by ultraviolet light, and the removal by self-cleaning glass could be mostly assigned to photodegradation by TiO2 when ultraviolet light irradiation. Besides, the self-cleaning glass exhibit 74.99% and 91.60% anti-bacteria rate to Escherichia coli and Staphylococcus aureus, respectively, when common glass was chosen as control. In brief, the self-cleaning glass was proved excellent to remove formaldehyde and inhibit bacteria. As a result of the non-preference of the photodegradtion and anti-bacteria by TiO2, it was believed the self-cleaning glass could remove almost all the kinds of indoor organic gases and inhibit almost all the kinds of bacteria, including some pathogens. The self-cleaning glass had great potential in interior finish application meeting the challenge for environmental protection.

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

Synthesis and Self-Cleaning Property of TiO2 Thin Film Doping with Fe3+, Al3+, Ce3+ Ions

2020 ◽  
Vol 20 (7) ◽  
pp. 4084-4091
Author(s):  
Chun Han ◽  
Lei Zhao ◽  
Manying Zhang ◽  
Lin Pan ◽  
Zhifeng Liu
Keyword(s):  
Thin Film ◽  
Contact Angle ◽  
Water Contact Angle ◽  
Tio2 Thin Film ◽  
Sol Gel ◽  
Molar Ratio ◽  
Water Contact ◽  
Cleaning Performance ◽  
Photogenerated Electrons ◽  
Self Cleaning

Enhancing the response to visible light and inhibiting recombination of photogenerated electrons and holes is a key point for strongly improved self-cleaning performances of TiO2 self-cleaning films. In this work, TiO2 thin film doping with three different ions (Fe3+, Al3+, Ce3+) on glass substrate respectively by sol–gel method to explore the effect of ions on self-cleaning performance of TiO2 thin films. All the prepared samples are characterized by XRD, SEM, UV-Vis and water contact angle tester. Moreover, the self-cleaning mechanism of doping TiO2 thin film is discussed. The water contact angle of TiO2 thin film doping with 9% Fe (molar ratio), 5% Ce and 5% Al are reach at 0°, respectively. In comparison with the water contact angle of pure TiO2 thin film (2.5°), TiO2 thin film doping with metal ions exhibit better self-cleaning property.

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