Ceramic Tile Surfaces Research Articles

Polymer dispersions and their interaction with mortar constituents and ceramic tile surfaces studied by zeta-potential measurements and atomic force microscopy

The interaction between mineral surfaces and organic polymer dispersions with different monomer base and protective colloids as present in tile adhesive mortar systems was investigated by measuring the ζ-potential and by direct observation by atomic force microscopy (AFM). The charge situation of pure mineral powders and pure polymer dispersions as well as their interaction in presence of different cementitious aqueous solutions was studied. The binding of Ca++ ions leads to positive ζ-potentials for quartz or ceramic in calcium containing aqueous solutions and acts as a transmitter of attractive forces. However, the adsorption of sulfate ions may disturb such attraction. The interaction between polymer dispersions and ceramic (polished and original tile) or mica surfaces influenced by the presence of artificial cementitious pore solutions was observed by AFM. A flat index (height/diameter of latex particles in contact with these surfaces) was defined to quantify the polymer–mineral interface affinity. The different flat indices for different polymer–substrate combinations are mainly related to two parameters, the glass transition temperature of the copolymer and the stabilization system (steric versus cationic). Furthermore tapping phase imaging revealed significant heterogeneities in the inner structure of the polymer particles and inhomogeneous distribution at their surface probably related to local variations of the protective colloid, especially polyvinyl alcohol.

Preparation and antibacterial activity of Ag/SiO2 thin film on glazed ceramic tiles by sol–gel method

In the present study, silver-doped silica thin films on glazed surface of ceramic tiles were well prepared by sol–gel method to achieve antibacterial activity. Thermal treatment was done in the air at 1100°C for two hours. The Ag/SiO2 thin films were investigated through Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), X-ray diffraction (XRD) and wavelength dispersive spectrometry (WDS). Atomic absorption spectroscopy (AAS) was used for the quantitative determination of the silver ion concentration being released from Ag/SiO2 films over a 24 day period. The antibacterial effects of Ag/SiO2 thin films against Escherichia coli and Staphylococcus aureus were also examined. From the analysis results, it was found that high temperature treated coating consists of two phases of SiO2 and Ag based on the trapping of the Ag phase in the silica matrix. The presence of Ag elements on the surface of the coated tiles, were also observed. Thermal treatment at high temperatures caused sharp XRD peaks and high crystallinity in this system. Ag+ ions were released constantly and the mean release rate (±SD) was 0.104 ±0.01μg/ml during 24 days. Coating films exhibited an excellent antibacterial performance against both bacterium.

Hydrogen peroxide vapour decontamination of surfaces artificially contaminated with norovirus surrogate feline calicivirus

Noroviruses are a leading cause of gastrointestinal disease and are of particular concern in healthcare settings such as hospitals. As the virus is reported to be environmentally stable, effective decontamination following an outbreak is required to prevent recurrent outbreaks. To investigate the use of hydrogen peroxide vapour to decontaminate a number of surfaces that had been artificially contaminated with feline calicivirus (FCV), a surrogate for norovirus. The surfaces tested were representative of those found in hospital wards. FCV was used to contaminate materials representative of a hospital setting (stainless steel, glass, vinyl flooring, ceramic tile and PVC plastic cornering). The carriers were exposed to 30% (w/w) hydrogen peroxide vapour at 5-min intervals over 20 min, after which postexposure viral titres were measured. Hydrogen peroxide vapour reduced the viral titre by 4 log(10) on all surfaces tested within 20 min of exposure. The reduction in viral titre took longest to achieve on stainless steel (20 min), and the quickest effect was seen on vinyl flooring (10 min). For glass, plastic and ceramic tile surfaces, the desired reduction in viral titre was seen within 15 min of exposure. Hydrogen peroxide vapour allows for large-scale decontamination of areas following outbreaks of infectious organisms. Hydrogen peroxide vapour is effective against FCV and is active on a range of surfaces. Therefore, it may represent a suitable decontamination system for use following a hospital outbreak of norovirus.

Environmental Radioactivity Comparison Study for the Glaze-Clay Surface of Ceramic Tiles by Tracks Technique

TRACKS DENSITY, radon concentration, radon exhalation rates and radium concentration were measured from ceramic tiles for both of glaze and clay by using the track technique, containing CR-39, to estimate the radiation exposure in the vicinity of ceramic tile. For ceramic tiles of wall, the average of tracks density, the radon concentration, radon exhalation rates and radium concentration were found in the range 230-356 tracks.cm

Porcelain tile surface modification with isocyanate coupling agent: interactions between EVA modified mortar and silane improving adherence

AbstractAdhesion between tiles and mortar is of paramount importance to the overall stability of ceramic tile systems. The interfaces between ceramic tiles and polymer‐modified Portland cement mortar are derived from several physical and chemical phenomena that take place during their formation. From the chemical perspective, weak forces are expected to occur preferably at the tiles and polymer‐modified Portland cement mortar interfaces. Therefore, the purpose of this study was to promote a new chemical functionalization of ceramic tile surfaces by modifying with isocyanate‐trialkoxysilane coupling agent in order to enhance the interfacial adhesion with poly (ethylene‐co‐vinyl acetate), EVA, polymer‐modified mortar. Pull‐off tests and Fourier Transformed Infrared Spectroscopy (FTIR), using the Attenuated Total Reflectance method, were carried out in order to characterize the system. The bond strength results have provided evidence toward improvements in adherence at the tile–polymer modified mortar interface, thus reflecting the development of urethane linkages between silane and EVA polymer, as detected by FTIR. Copyright © 2010 John Wiley & Sons, Ltd.

Survival of Staphylococcus aureus exposed to UV radiation on the surface of ceramic tiles coated with TiO2

The aim of this study was to determine and compare the antimicrobial activity of UV radiation of wavelength 253.7 nm (used in typical germicidal lamps) against Staphylococcus aureus on the surfaces of conventionally produced white ceramic wall tiles (matt and shiny) and the same tiles coated with TiO2 using three different methods: RF diode sputtering, atmospheric pressure chemical vapour deposition (APCVD) and spray pyrolysis deposition (SPD). Results clearly indicate that the bactericidal action of UV radiation is much stronger on the surfaces of tiles coated with TiO2 than on the tiles uncovered. The strongest bactericidal effect of UV radiation was found for film prepared by APCVD. Results of experiments for shiny and matt tiles did not differ statistically. The use of ceramic wall tiles coated with TiO2 films in hospitals, veterinary clinics, laboratories, food processing plants and other places where UV radiation is applied for disinfection should greatly improve the efficiency of this treatment.

Functionalization of ceramic tile surface by soluble salts addition: Part II. Titanium and silver addition

The aim of this study was to assess surface functionalization of industrial ceramic tiles through the addition of soluble salts to improve mechanical properties (scratch and wear resistance) and conductivity, while preserving the aesthetic aspects of the finished product. This objective was pursued through the application of different solutions of titanium and silver with a potential for transformation into titania and silver nanoparticles during the sintering of the material. The solutions, in different concentrations, were applied (300 g/m 2) to unglazed green tiles by air brushing. The resulting products were polished and characterized in terms of microstructural, surface micromechanical, and technological properties based on the UNI EN ISO reference standards. The electrical conductivity deriving from the presence of titania and silver was also established with specific tests. The results were found to correlate with the results obtained from the addition of zirconium solutions as reported in part I of the paper.

Functionalization of ceramic tile surface by soluble salts addition: Part I

The aim of this investigation was the surface functionalization of industrial ceramic tiles by soluble salts addition to improve mechanical properties (resistance to scratch and wear) preserving the aesthetical aspect of the final product. This objective was pursued through the application of different solution of zirconium capable to be transformed in zirconia nanoparticles during the material sintering. The solutions, in different concentrations, were deposited (300 g/m 2) on unglazed green tiles by air-brushing. The obtained products were polished and characterized in terms of microstructure, surface micromechanical and technological properties based on the UNI EN ISO reference rules. The final aesthetical aspect of the products and the obtained hue variation were evaluated by means of UV–vis spectroscopy and colorimetric analysis.

Functionalization of ceramic tile surface by sol–gel technique

The aim of this investigation was the surface functionalization of industrial ceramic tiles by sol–gel technique to improve at the same time the cleanability of unglazed surfaces. This objective was pursued through the design and preparation of nanostructured coating that was deposited on polished unglazed tiles by air-brushing. In particular TiO 2–SiO 2 binary film with 1, 2 or 5 wt% of titania were prepared by using tetraethoxysilane and titania nanoparticles as precursors. The obtained films were characterized by scratch tests to verify the adhesion of the coatings to the polished tiles. To mainly evaluate the effect of the thermal treatment (temperature range 100–600 °C) on the photocatalicity of the coatings, the films were studied under UV exposure by contact angle measurements and cleanability test. Particular attention has been paid to preserve the aesthetical aspect of the final product and the obtained hue variation was evaluated by means of UV–visible spectroscopy and colorimetric analysis.

ENHANCING POLYMER-MODIFIED MORTAR ADHESION TO CERAMIC TILE SURFACE BY CHEMICAL FUNCTIONALIZATION WITH ORGANOSILANES

Adhesion between tiles and mortars is of paramount importance to the overall stability of ceramic tile systems. In this sense, from the chemical perspective, weak forces such as van der Waals forces and hydrophilic interactions are expected to occur preferably at the tiles and polymer-modified Portland cement mortar interfaces. Thus, the main goal of this study was to chemically modify the ceramic tile surface through organosilanes aiming to improve adhesion with polymer-modified mortars (PMMs). Glass tile surfaces were treated with five silane derivatives bearing specific functionalities. Fourier transform infrared spectroscopy and contact angle measurements were used for characterizing the novel surfaces produced as the chemical moieties were immobilized onto them. In addition, pull-off tests were conducted to assess the effect on adhesion properties between tile and poly(ethylene-co-vinyl acetate) modified mortar. The bond strength results have given strong evidence of the improvement on adherence at the tile–PMM interface, reflecting the whole balance of silane, cement, and polymer interactions.

Microstructural and mechanical changes by chemical ageing of glazed ceramic surfaces

In the present work, several ceramic tiles, characterised by different glazes, were considered in order to define the role played by the glassy and crystalline phases on the leaching mechanisms and the deterioration of the mechanical properties. The glazed working surfaces were subjected to chemical attack by using a strong basic solution and the chemical analysis of the leached solutions was performed. Before and after the chemical attack, the glazed surfaces of the samples were analysed from both the microstructural and mechanical point of view. In this context, the microstructure was observed by SEM and analysed by X-ray diffraction. In order to define other possible changes, roughness measurements, Vickers hardness and micro-scratch tests were also performed. The results made it possible to deepen the understanding of the mechanisms of elements release caused by the chemical attack and their implications on microstructural and mechanical degradation of the working surface of glazed ceramic tiles.

Chemical functionalization of ceramic tile surfaces by silane coupling agents: polymer modified mortar adhesion mechanism implications

Adhesion between tiles and mortars are crucial to the stability of ceramic tile systems. From the chemical point of view, weak forces such as van der Waals forces and hydrophilic interactions are expected to be developed preferably at the tiles and polymer modified Portland cement mortar interface. The main goal of this paper was to use organosilanes as primers to modify ceramic tile hydrophilic properties to improve adhesion between ceramic tiles and polymer modified mortars. Glass tile surfaces were treated with several silane derivatives bearing specific functionalities. Contact angle measurements and Fourier Transform Infrared Spectroscopy (FTIR) were used for evaluating the chemical changes on the tile surface. In addition, pull-off tests were conducted to assess the effect on adhesion properties between tile and poly(ethylene-co-vinyl acetate), EVA, modified mortar. The bond strength results have clearly shown the improvement of adherence at the tile-polymer modified mortar interface, reflecting the overall balance of silane, cement and polymer interactions.

Indirect effects of the algivorous fishPlecoglossus altivelis altivelison the growth of two insectivorous benthic fish

Summary1. Animals exploiting different resources may nevertheless interact if one species indirectly alters the abundance and distribution of the food of the other. To analyse this indirect effect, we conducted experiments in artificial pools and in the field to investigate the influence of the algivorous fishPlecoglossus altivelis altivelis(known as the ayu) on two species of insectivorous benthic fish,Pseudogobio esocinus esocinusand the gobyGymnogobius petschiliensis.2. In the pool experiments, algal biomass was not correlated with the number of ayu, but the percentage of blue‐green bacteria rose as the number increased. The number of aquatic macroinvertebrates on the upper surface of ceramic tiles placed in the pool bed decreased as the number of ayu increased.3. Although ayu and the benthic species did not interact directly, the reduction in invertebrate abundance on the upper surface of tiles in the pool reduced the growth rate of the benthic insectivores.4. In field experiments, the introduction of ayu into habitats withP. esocinus esocinusorG. petschiliensisreduced the growth rate of these benthic fish. In the field experiment that was carried out over 5 years in theG. petschiliensishabitat, the population density of the goby decreased when ayu were stocked.5. The ayu is a strong interactor or bioengineer in streams, affecting not only benthic algae but also aquatic invertebrates and fishes. We conclude that to predict the outcome of interspecific interactions amongst fishes in streams with high algal production, possible indirect effects must be considered alongside better known direct effects.

A scanner with multi-angle response

The paper shows the design and results from a high speed, high resolution multi-channel scanner that can produce six separate angular outputs over a range of 4°. The design uses an absolute minimum of large optical components to achieve a scan length of 400 mm. Results are shown for ceramic tile surfaces. Speed and quantity of data collected are limited by the digitization electronics and computing available. The image quality is potentially limited by the precision of the scanner prism and by speckle from the monochromatic light source.

Finite element analysis for the prediction and optimization of residual stresses caused by laser enamelling

Rapid laser enamelling is applied for sealing ceramic tile grouts. In order to understand the mechanics of microcracks developed and long-term stability of the enamel glaze, finite element analysis of the thermomechanical characteristics is carried out. In the thermal stress analysis, the temperature field is used as a boundary condition to calculate mechanical effects on the material due to thermal strains. A thermoisotropic material model has been defined for five different materials involved in the process. To validate the theoretical predictions, experiments are conducted by the measurements of strain on the ceramic tile surface during laser enamelling with the help of strain gauges. Residual stresses are also determined on the ceramic tile surface with the X-ray diffraction method. The theoretical predictions of the residual stresses are in close agreement with experimental results.

Determination of viscosity

Frits are special glasses used in glaze compositions to cover the surface of ceramic tiles, such as floors, walls, and porcelain tiles. Therefore, glass waste can be used as raw material in the preparation of the ceramic frits for glazes. In this work, frits were formulated by mixture design using 8–15 mass % of laminated glass waste. The waste was added in frit compositions and 40 frits were melted. Test glazes were prepared with the frit compositions and were used to cover ceramic tiles. Using the glass waste, the whiteness, brightness, and Mohs hardness of the test glazes were 93.0, 2.7–91.9 and 4–7, respectively, in comparison to 92.6, 70.1 and 5 for the standard glazes. The Knoop microhardness of the test glazes was 54.5–189.3 (0.53–1.85 GPa) in comparison to 119.8 (1.18 GPa) of the standard. In addition, 92.5% of the test samples were resistant to the chemical attack of NaClO. 84.2% were resistant to HCl, but with differences in appearance of the surface. The coefficient of thermal expansion of the test glazes was 55.6–82.7 ∙ 10−7 °C−1, in comparison to 59.6–75.3 ∙ 10−7 °C−1 the standards. Finally, the results pointed to the feasibility of using ~8 mass % of laminated glass waste in the manufacture of frits used to produce ceramic glazes.

A practical approach to evaluation of the germicidal efficiency of a general purpose military disinfectant.

The bactericidal activity of a general purpose disinfectant consisting of 25% sodium-o-phenylphenolate and 75% sodium-4- and 6-chloro-2-phenylphenolate was evaluated by a simulated in-use, surface-square dilution method. Common floor (asphalt, rubber, and unglazed tiles) and wall (stainless steel tile, ceramic tile, and painted wood) surfaces of various porosities and compositions were selected to simulate actual-use conditions. The method used consisted of inoculating the surfaces of 1-in. square sections of floor and wall covering with a test organism, air-drying the inoculated surface, applying the disinfectant, allowing it to act for 10 min, and recovering the survivors by plating. Confirmatory results of the standard phenol coefficient and use-dilution tests indicated 700 ppm of the disinfectant to be a safe use concentration. The in-use surface-square dilution studies have shown that this is a more than adequate safe concentration for stainless steel, both glazed and unglazed ceramic tile, and nonwaxed surface of asphalt tile. However, concentrations ranging between 2,500 and 6,000 ppm for plastic-fortified rubber tile, 1,500 and 2,000 ppm for waxed asphalt tile, and 2,000 ppm for painted wood were required to achieve 99.9% reduction of either Salmonella choleraesuis or Salmonella schottmuelleri. These results indicate that a disinfectant concentration derived from the Association of Official Agricultural Chemists use-dilution test cannot always be relied upon to provide a dependable index to actual safe use-dilution when a disinfectant is supplied to certain wall or floor surfaces.

A Practical Approach to Evaluation of the Germicidal Efficiency of a General Purpose Military Disinfectant

The bactericidal activity of a general purpose disinfectant consisting of 25% sodium-o-phenylphenolate and 75% sodium-4- and 6-chloro-2-phenylphenolate was evaluated by a simulated in-use, surface-square dilution method. Common floor (asphalt, rubber, and unglazed tiles) and wall (stainless steel tile, ceramic tile, and painted wood) surfaces of various porosities and compositions were selected to simulate actual-use conditions. The method used consisted of inoculating the surfaces of 1-in. square sections of floor and wall covering with a test organism, air-drying the inoculated surface, applying the disinfectant, allowing it to act for 10 min, and recovering the survivors by plating. Confirmatory results of the standard phenol coefficient and use-dilution tests indicated 700 ppm of the disinfectant to be a safe use concentration. The in-use surface-square dilution studies have shown that this is a more than adequate safe concentration for stainless steel, both glazed and unglazed ceramic tile, and nonwaxed surface of asphalt tile. However, concentrations ranging between 2,500 and 6,000 ppm for plastic-fortified rubber tile, 1,500 and 2,000 ppm for waxed asphalt tile, and 2,000 ppm for painted wood were required to achieve 99.9% reduction of either Salmonella choleraesuis or Salmonella schottmuelleri. These results indicate that a disinfectant concentration derived from the Association of Official Agricultural Chemists use-dilution test cannot always be relied upon to provide a dependable index to actual safe use-dilution when a disinfectant is supplied to certain wall or floor surfaces.