scholarly journals Characterization of photocatalytically active coatings based on TiO2/Zn-Al layered double hydroxide on ceramic tiles

2013 ◽  
pp. 181-190 ◽  
Author(s):  
Tatjana Vulic ◽  
Ognjen Rudic ◽  
Jonjaua Ranogajec
Keyword(s):  
Photocatalytic Activity ◽  
Molecular Mass ◽  
Point Of View ◽  
The Self ◽  
Ceramic Tiles ◽  
Peg 4000 ◽  
Degradation Reaction ◽  
Self Cleaning ◽  
Double Hydroxide

The self-cleaning function (photocatalytic activity and surface hydrophilicity/hydrophobicity) is of great importance for ceramic tiles from both economic and environmental point of view. This research is focused on the preparation of suitable photocatalytic suspensions studying the influence of the photocatalyst powder amount and the molecular mass of polyethylene glycol (PEG) on the self-cleaning properties of the suspensions deposited on the ceramic tile surface. Photocatalysts based on Zn-Al double layered hydroxides with TiO2 as active component, were synthesized and used for the preparation of the suspensions. The coated tiles prepared using smaller photocatalyst amount and the highest investigated molecular mass of PEG (PEG 4000) showed the highest photocatalytic activity in the Rhodamine B degradation reaction, as well as the appropriate surface properties.

Testing of Photocatalytic Activity of Self-Cleaning Surfaces

2010 ◽  
Vol 68 ◽  
pp. 126-134 ◽  
Author(s):  
Urška Lavrenčič Štangar ◽  
Marko Kete ◽  
Urh Černigoj ◽  
Vilma Ducman
Keyword(s):  
Terephthalic Acid ◽  
Catalyst Layer ◽  
The Self ◽  
New Method ◽  
Solid Polymer ◽  
Solid Catalyst ◽  
Ceramic Tiles ◽  
Standard Methods ◽  
Self Cleaning ◽  
Fatty Deposit

Due to relatively successful application of TiO2 photocatalysis in the field of self-cleaning surfaces, a reliable and appropriate quantitative method for determining the self-cleaning efficiency of the products (photocatalyst films on different supports) should be widely recognized and established. Currently, the two standard methods are based on photobleaching of methylene blue aqueous solution in contact with thin solid catalyst layer, and on photodegradation of a solid fatty deposit (e.g. stearic acid) over catalyst layer followed indirectly by water contact angle (CA) measurements. Another method proposed recently is based on the entrapment of an organic dye in a solid polymer matrix deposited over the photocatalyst layer. Upon illumination, the dye (e.g. resazurin) is reduced by the photogenerated electrons to the form of a different colour or to the bleached form. Recently, a new method for determination of self-cleaning activity of photocatalytic surfaces was developed in our laboratory. It is based on the deposition of a transparent solid layer comprising terephthalic acid over the photocatalytic surface. When such a system is irradiated, among the other degradation products also a hydroxyterephthalic acid is formed due to a reaction between photoexcited TiO2 and terephthalic acid. Hydroxyterephthalic acid is a highly fluorescent molecule and can be easily detected by HPLC-FLD or spectrofluorimeter. Many different samples were tested using this method and using the standard method based on photodegradation of a solid fatty deposit over the catalyst layer. Regarding the sample (substrate) type, the focus was given to the self-cleaning ceramic tiles coated with TiO2-SiO2 thin films that were produced in cooperation with the major manufacturer of floor ceramic tiles in Slovenia, Martex d.o.o.. In case of self-cleaning ceramics and some other sample types, the advantages of the new method over standard methods were highlighted and critically evaluated.

Effect of Silane Coupling Agent on the Self-Cleaning Property of TiO2-Coated Cotton Fabrics

2013 ◽  
Vol 634-638 ◽  
pp. 960-964
Author(s):  
De Yong Wu ◽  
Lian Zhi Wang
Keyword(s):  
Photocatalytic Activity ◽  
Coupling Agent ◽  
Silane Coupling Agent ◽  
Cotton Fabrics ◽  
The Self ◽  
Excellent Photocatalytic Activity ◽  
Silane Coupling ◽  
Self Cleaning ◽  
Good For ◽  
Coated Cotton

Self-cleaning fabrics have been successfully prepared by depositing and grafting TiO2 nanoparticles, and silane coupling agent 3-Aminopropyltriethoxysilane was adopted to improve the photocatalytic activity of self-cleaning fabrics. TEM results showed that the treatment of silane coupling agent is good for increasing the amount of TiO2 particles. The excellent photocatalytic activity of TiO2-coated cotton fabrics is attributed the increase of TiO2 particles and the formation of the TiO2/SiO2 structure.

scholarly journals Preparation and characterization of protective self-cleaning TiO2/kaolin composite coating

2018 ◽  
Vol 68 (331) ◽  
pp. 163
Author(s):  
V. Jovanov ◽  
V. Zečević ◽  
T. Vulić ◽  
J. Ranogajec ◽  
E. Fidanchevska
Keyword(s):  
Photocatalytic Activity ◽  
Composite Coating ◽  
Building Materials ◽  
Support Surface ◽  
Tio2 Content ◽  
Cleaning Efficiency ◽  
Before And After ◽  
Self Cleaning ◽  
Highly Porous

The application of self-cleaning coatings presents one of the most effective ways to protect the surfaces of the building materials. The effect of TiO2/kaolin based coatings applied to three types of substrates: non-porous, porous and highly porous, was investigated. Mechanical activation was applied for the impregnation of the active TiO2 component (in content of 3 and 10 wt. %) into the kaolin support. Surface properties (roughness, hydrophilicity and micro-hardness) and functional properties (photocatalytic activity and self-cleaning efficiency) were studied in order to define the optimal formulation of the applied coatings. The effect of the photocatalytic behavior of the coated substrates in terms of self-cleaning ability was assessed by the photodegradation of Rhodamine B, performed before and after durability tests. The results obtained in this paper showed that photocatalytic activity of the TiO2/kaolin composite coating generally depends on the procedure of TiO2 impregnation into the kaolin clay and the loaded TiO2 content.

scholarly journals SELF-CLEANING GLASS BASED ON ACID-TREATED TiO2 FILMS WITH PALMITIC ACID AS MODEL POLLUTANT

2010 ◽  
Vol 8 (2) ◽  
pp. 200-206
Author(s):  
Nurul Hidayat Aprilita ◽  
Indriana Kartini ◽  
Sofy Herawati Ratnaningtyas
Keyword(s):  
Thin Film ◽  
Photocatalytic Activity ◽  
Palmitic Acid ◽  
Uv Radiation ◽  
Acid Treatment ◽  
Tio2 Films ◽  
Sem Images ◽  
Self Cleaning ◽  
Radiation Time

Preparation and characterization of self-cleaning glass based on acid-treated TiO2 films as well as evaluation on their self-cleaning properties have been carried out. Palmitic acid photodegradation was used as model pollutant. Acid-treated TiO2 powders were deposited on glass surface by using spraying technique. The XRD results showed that acid-treated TiO2 film exhibited decreased anatase crystalline size. The corresponding SEM images showed porous surface morphology. Layer densification was observed as the film thickness increased. TiO2 photocatalytic activity increased as the length of UV radiation increased. Best results were obtained at experimental condition of 35 hours UV radiation time. It is also observed that the thickness of TiO2 layers influenced the efficiency of palmitic acid photodegradation. The film with 1.661 µm thick TiO2 layers and 6.933 mg weight (0.7164 mg/cm2) could degrade 97.54 % mg palmitic acid/cm2 thin film.   Keywords: TiO2 films, acid treatment, self-cleaning glass

scholarly journals Improved Self-Cleaning Properties of Photocatalytic Gypsum Plaster Enriched with Glass Fiber

Materials ◽  
2019 ◽  
Vol 12 (3) ◽  
pp. 357 ◽  
Author(s):  
Kamila Zając ◽  
Magdalena Janus ◽  
Antoni Morawski
Keyword(s):  
Mechanical Properties ◽  
Methylene Blue ◽  
Titanium Dioxide ◽  
Photocatalytic Activity ◽  
Glass Fiber ◽  
Glass Fibers ◽  
The Self ◽  
Gypsum Plaster ◽  
Self Cleaning ◽  
Reactive Orange

In the study the self-cleaning properties of photoactive gypsum plasters are presented. The modified gypsum plasters were obtained by addition of 1 and 3 wt.% of nitrogen-modified titanium dioxide (TiO2/N) and 0.1, 0.3, and 0.5 wt.% of glass fiber. The self-cleaning ability of the obtained materials was tested during two dyes decomposition: Methylene Blue (MB) and Reactive Orange (RO). It was found that presence of glass fiber increased photocatalytic activity of modified gypsum plasters, which may be due to the fact glass fiber may act as ducts for light and transport it to sites screened by TiO2 or glass fiber can retard charge recombination. Moreover, unexpectedly the addition of glass fiber did not increase the mechanical properties of modified gypsum plasters, which may be because gypsum does not strongly adhere to the surface of glass fibers.

scholarly journals Evaluation of photocatalytic activity of titanosilicate powders of synthetic origin

2021 ◽  
Vol 12 (2-2021) ◽  
pp. 273-278
Author(s):  
A. V. Tsyryatieva ◽  
◽  
V. V. Tyukavkina ◽  
Keyword(s):  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Phase Composition ◽  
Visible Light ◽  
Specific Surface ◽  
The Self ◽  
Cement Stone ◽  
Light Sources ◽  
Self Cleaning ◽  
Imagej Software

In this work, a comparative study of the photocatalytic activity of synthetic titanosilicate powders with differences in phase composition and specific surface area was carried out. Evaluation of the efficiency of decomposition of the dye methylene blue in the presence of titanosilicate additives in an aqueous medium under ultraviolet and visible light sources is given. The self-cleaning ability of titanosilicate-modified cement stone was studied by exposure to ultraviolet and visible light using ImageJ software. The strength of a cement stone modified with a titanosilicate additive has been determined, and its ability to self-cleaning under the influence of ultraviolet and visible light has been studied.

Characterization of dissolved material during the initial phase of softwood kraft pulping

TAPPI Journal ◽  
2013 ◽  
Vol 12 (1) ◽  
pp. 37-43 ◽  
Author(s):  
HANNU PAKKANEN ◽  
TEEMU PALOHEIMO ◽  
RAIMO ALÉN
Keyword(s):  
Mass Transfer ◽  
Molecular Mass ◽  
Initial Phase ◽  
Degradation Products ◽  
Kraft Pulping ◽  
Reaction Products ◽  
Cooking Temperature ◽  
Molecular Masses ◽  
Aliphatic Carboxylic Acids

The influence of various cooking parameters, such as effective alkali, cooking temperature, and cooking time on the formation of high molecular mass lignin-derived and low molecular mass carbohydrates-derived (aliphatic carboxylic acids) degradation products, mainly during the initial phase of softwood kraft pulping was studied. In addition, the mass transfer of all of these degradation products was clarified based on their concentrations in the cooking liquor inside and outside of the chips. The results indicated that the degradation of the major hemicellulose component, galactoglucomannan, typically was dependent on temperature, and the maximum degradation amount was about 60%. In addition, about 60 min at 284°F (140°C) was needed for leveling off the concentrations of the characteristic reaction products (3,4-dideoxy-pentonic and glucoisosaccharinic acids) between these cooking liquors. Compared with low molecular mass aliphatic acids, the mass transfer of soluble lignin fragments with much higher molecular masses was clearly slower.

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