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Printed Edition of the Special Issue Published in Coatings

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Bacterial biofilm characterization and microscopic evaluation of antibacterial properties of a photocatalytic coating protecting building materials. Bacterial biofilm characterization and microscopic evaluation of antibacterial properties of a photocatalytic coating protecting building materials. Coatings 2018,8, 93.

Evaluation of Semi-Intensive Green Roofs with Drainage Layers Made Out of Recycled and

  • Introduction
  • Materials and Methods
  • Results
  • Discussion
  • Conclusions

Dead loads of green roof systems were determined as approximate cost per square meter. On the other hand, Figure 7 summarizes the behavior of the green roof prototypes for the intense rainfall condition (simulating a rainfall rate of 49 mm/h).

Table 1. Summary of works related to the use of recycled materials in green roofs.
Table 1. Summary of works related to the use of recycled materials in green roofs.

Effect of Hygrothermal Aging on Hydrophobic Treatments Applied to Building Exterior Claddings

Materials and Methods 1. Materials

The drying kinetics of the samples were verified according to the recommendations of RILEM [28] and UNI [29], which take into account the initial drying (based on the slope of the initial drying curve) and the drying index (DI). After accelerated aging tests, untreated samples show a significant reduction in capillary water absorption (approximately 44%), which can be attributed to the modification (destruction) of capillary pores (typically observed in altered and decayed materials) [36].

Table 2. Chemical and physical characteristics and amount of product used in the application of the hydrophobic products.
Table 2. Chemical and physical characteristics and amount of product used in the application of the hydrophobic products.

Evaluation of the Antibacterial Activity of a Geopolymer Mortar Based on Metakaolin

Results and Analysis

Table 4 shows the results of the initial standardization test for GP and mGP with the three bacteria tested. In the case of geopolymer with TiO2 nanoparticles (GP), the standardization results were satisfactory for E.

Table 2. Chemical composition of metakaolin (MK) and glass waste (wt.%).
Table 2. Chemical composition of metakaolin (MK) and glass waste (wt.%).

Conclusions

The properties of Nano Silver (Ag) geopolymer as antibacterial composite for functional surface materials.Matec. The Properties of Nano TiO2-Geopolymer Composite as a Material for Functional Surface Application.MATEC Web Conf.

Fire Protection Performance and Thermal Behavior of Thin Film Intumescent Coating

Experimental 1. Materials

One of the most widely accepted and internationally recognized fire testing equipment is the cone calorimeter. The experimental data of the coating sample was calculated based on the average of three tests [33].

Table 1. Specifications of experimental materials.
Table 1. Specifications of experimental materials.

Results and Discussion 1. Bunsen Burner

This shows that the thickness of the carbon layer influences the fire-resistant effect of the coating. The properties of the charred structure are related to the fire resistance of the sample [36,37]. Figure 6 shows the curves of total heat dissipated (THR) against time of the intumescent coating samples.

Samples Y and Z showed a highly significant improvement in THR reduction with the addition of the new ES bio-filler. This can be attributed to the physical and chemical integration of the flame retardant ingredients. The inclusion of the ES bio-filler in the foaming formulation resulted in good thermal resistance and fire resistance.

Figure 4. The expansion rate and thickness of char layer of intumescent coating samples.
Figure 4. The expansion rate and thickness of char layer of intumescent coating samples.

Coating of Polyetheretherketone Films with Silver Nanoparticles by a Simple Chemical Reduction

Results and Discussion 1. X-ray Diffraction (XRD)

Figure 1b shows the X-ray diffraction patterns of the samples coated with two layers of silver. The evolution of the PEEK coating is identified by increasing the concentration of silver nanoparticles. AFM images of PEEK/Ag systems obtained with two silver layers are shown in .

In the same way, samples coated with two layers of silver have higher RMS values ​​according to the amount of silver nanoparticles deposited on the surface of the polymer [55]. The amount of nanoparticles deposited on both sides of the polymer has a derivative in the antibacterial properties. The intensity of the silver signals in the diffractograms increased with the amount of silver nanoparticles deposited.

Figure 2a shows the infrared spectra of PEEK polymer substrates with 1 coating layer. The Fourier transform infrared (FTIR) spectrum of the original PEEK film shows a band at 1647 cm −1 of the conjugated ketone stretch (C=O), the bands at 1587, 1480 and 141
Figure 2a shows the infrared spectra of PEEK polymer substrates with 1 coating layer. The Fourier transform infrared (FTIR) spectrum of the original PEEK film shows a band at 1647 cm −1 of the conjugated ketone stretch (C=O), the bands at 1587, 1480 and 141

Biofilm Formation of a Polymer Brush Coating with Ionic Liquids Compared to a Polymer Brush Coating

Figure 4 shows optical microscopic images for the surface of DEMM polymer brush samples after biofilm formation by E. Figure 5 shows optical microscopic images for the surface of PMMA polymer brush samples after biofilm formation (with these same bacteria). The DEMM polymer brush as a liquid ionic polymer brush was investigated in terms of biofilm formation and antifouling effect.

The DEMM polymer brush coating tended to form biofilms on the surface more than the PMMA polymer brush specimens. Nucleic acids in biofilms can be confirmed more frequently for DEMM polymer brush coating specimens. Brush coating of ionic liquid type polymer can change their polar characteristics leading to the anti-fouling effect of future material surfaces.

Figure 1. Optical microscopic images for N,N-diethyl-N-(2-methancryloylethy)-N-methylammonium bis(trifluoromethylsulfonyl) imide (DEMM-TFSI) specimens (a) before and (b) after selling process.
Figure 1. Optical microscopic images for N,N-diethyl-N-(2-methancryloylethy)-N-methylammonium bis(trifluoromethylsulfonyl) imide (DEMM-TFSI) specimens (a) before and (b) after selling process.

Anti-Fouling Ceramic Coating for Improving the Energy Efficiency of Steel Boiler Systems

Material and Methods

To estimate the thermal conductivity λ(W/m·K) of a sample, the thermal diffusivity (mm2/s), density ρ(g/cm3) and specific heat Cp(J/g·K) of the sample must be known. A top view of the surfaces (Figure 8) showed that a lot of ash was attached to the entire surface of the uncoated steel (Figure 8a). In contrast, almost no contaminant ash adheres to the entire surface of the coated steel (Figure 8b);

The thermal conductivity of the uncoated steel was ~5 W/mK less than that of the coated steel at 800◦C. Figure 10b shows the thermal conductivity of the ceramic coating itself and the ash-deposited sample. The ceramic coating showed a significant improvement in the boiler's thermal conductivity at high temperature (800◦C).

Table 2. Some properties of chosen binders and fillers (manufacturer’s data).
Table 2. Some properties of chosen binders and fillers (manufacturer’s data).

Size Distribution of Contamination Particulate on Porcelain Insulators

  • Size Distribution Characteristics of Adhered Particle 1. Measurement Method
  • Motion Characteristics of Particle
  • Simulation Model
  • Influence of Different Factors on Particle Adhesion
  • Conclusions

Therefore, it is necessary to study the size distribution characteristics of contaminated particles on the surface of the insulator. Furthermore, the influence of relative humidity on particle adhesion number was relatively limited when the particle size was smaller than 15μm and larger than 90μm. However, when the particle size was in the range of 20-80μm, the influence of relative humidity on the particle adhesion number was quite significant.

When the wind speed was in the range of 2–6 m/s, there were marked changes in the size distribution of attached particles. However, when the particle size was smaller than 10 μm and larger than 70 μm, the influence of the electric field strength on the adhesion number was very limited. Thus, there are significant size distribution characteristics of contaminated particles on the surface of the porcelain insulator.

Figure 1. Scanning electron microscopy diagram of typical contaminated particle samples: (a) +800 kV (DC);
Figure 1. Scanning electron microscopy diagram of typical contaminated particle samples: (a) +800 kV (DC);

Fouling Release Coatings Based on

Results and Discussion 1. Surface Properties of the Coatings

Experimental determination showed that elastic modulus and Shore hardness decreased with the increase of PSO content. With the increase in the PSO content, the cross-linking density of the coatings decreased, resulting in a decrease in the mechanical properties. In addition, with the increase in PSO content, the crosslinking density of the coating decreased.

As the PSO content increased, the decontamination rate of the coating increased. Then, the antifouling performance of the coatings in the leached PSO phase was also examined. Experimental results of the benthic diatom adhesion test in the leaching phase of PSO.

Table 2. The contact angle and surface free energies of coating samples ( ± SEM (standard error of the mean), n = 6).
Table 2. The contact angle and surface free energies of coating samples ( ± SEM (standard error of the mean), n = 6).

TiO 2 Coating: Synthesis, Physical

Characterization and Photocatalytic Evaluation

Results and Discussion 1. Physical Characteristics

In addition, the morphology of the SiO2@TiO2 coating was observed to be unaffected by the use of sonochemistry. In addition, the diffractogram of the SiO2@TiO2 coating was observed to be unaffected by the use of macroscale sonochemistry. The Raman spectrum of the SiO2@TiO2 nanocomposite showed a decrease in the highest intensity peak of titanium dioxide, while the other peaks were inhibited.

The Raman spectrum of the SiO2@TiO2 coating, without the application of sonochemistry, showed a lower crystallinity for the composite. Table 3 shows the adhesion test results of mortar samples coated using TiO2, SiO2 and SiO2@TiO2. Completed scanning microscopy (SEM), elemental analysis (EDS), transmission electron microscopy (TEM), X-ray diffraction (XRD) and Raman spectroscopy analysis of SiO2@TiO2.

Figure 3. TEM images of the SiO 2 @TiO 2 powder sample (10 × ).
Figure 3. TEM images of the SiO 2 @TiO 2 powder sample (10 × ).

Bacterial Biofilm Characterization and Microscopic Evaluation of the Antibacterial Properties of a

Materials and Methods 1. Bacterial Cultivation

Preliminary measurements of the antibacterial activity were performed on glass microscope slides (26×76 mm2) coated by pipetting the TiO2 coating or the control coating (without TiO2). The role of the pre-irradiation was to increase the antibacterial activity of the coating. 41,42] showed that, for cementitious materials, a low pH of the surface was essential to increase the bioreceptivity of samples.

Direct effect of UV irradiation time on survival of Escherichia coliCIP 53126 expressed as viable log bacteria remaining, light intensity≈2.5 W/m2. Each sample was then inoculated with 300μL of bacterial test suspension adjusted to about 103CFU/mL. No pH jump was detected, indicating that the pretreatment (rinsing) of the cement supports was efficient.

Table 1. Physical characteristics of the VLP5070 (Kronos) TiO 2 particles Description VLP5070
Table 1. Physical characteristics of the VLP5070 (Kronos) TiO 2 particles Description VLP5070

Results and Discussions 1. Antibacterial Activity

In addition, such results could be explained by the encapsulation of TiO2 particles in the organic binder of the coating, which significantly reduces the antibacterial effect. Figure 3 shows the antibacterial activity of the photocatalytic coating (with TiO2) on the membrane after 4 hours of experimentation under UV irradiation, during multiple pre-irradiation of the coating (0 hours, 48 ​​hours, 90 hours, and 109 hours prior to testing). As for the silicate-based coatings, no degradation phenomenon of the coating was observed over time (the same samples were tested after several weeks).

The antibacterial activity experiment performed at low UV irradiation (2.5–3 W/m2) confirmed that the efficiency in bacterial inactivation of the TiO2 coating increased after 48 hours of pre-irradiation. For TiO2-coated samples, one image was taken at the center of the sample (c-1) and another at the edge (c-2). These aggregates may therefore be TiO2 particles that may have participated in cell degradation.

Figure 3 presents the antibacterial activity of the photocatalytic coating (with TiO 2 ) on membrane after 4 h of experiment under UV irradiation, for several times of pre-irradiation of the coating (0 h, 48 h, 90 h, and 109 h prior to the test)
Figure 3 presents the antibacterial activity of the photocatalytic coating (with TiO 2 ) on membrane after 4 h of experiment under UV irradiation, for several times of pre-irradiation of the coating (0 h, 48 h, 90 h, and 109 h prior to the test)

Simple Coatings to Render Polystyrene Protein Resistant

Results and Discussion

The typical frequency change over time curves, for the addition of the protein and the subsequent washing step on each tested surface, are shown in Figure 1A. The majority of the surfaces show an initial rapid frequency decrease upon exposure to the protein and a subsequent short area of ​​slower frequency shift as the system reaches saturation. However, we hypothesize that desorption of the Pluronic layer from the polystyrene surface is an additional cause of the continuous upward drift.

It has been found that the initial driving force for adsorption on the hydrophobic polystyrene surface is the displacement of water, followed by the bond strengthening through the functional group interactions [43,44]. Such washout can also be inferred from AFM images of the surfaces (see Figure S1 and Table S1 in Supplementary Materials). The polydopamine intermediate film produced cannot provide the necessary attraction to bind F127 to the surface.

Figure 1. (A) Example QCM-D frequency data comparing BSA (bovine serum albumin) adsorption to the different surface chemistries investigated, namely untreated polystyrene (PS) and polystyrene treated with Pluronic F127 (PS + F127), polydopamine (PS + DOPA)
Figure 1. (A) Example QCM-D frequency data comparing BSA (bovine serum albumin) adsorption to the different surface chemistries investigated, namely untreated polystyrene (PS) and polystyrene treated with Pluronic F127 (PS + F127), polydopamine (PS + DOPA)

Metakaolin-Based Geopolymer with Added TiO 2

Particles: Physicomechanical Characteristics

Materials and Experimental Methodology 1. Materials

A high-purity commercial MK (Metamax BASF, Florham Park, NJ, USA) was used as the primary source or precursor in the production of the geopolymer material, the chemical composition of which is presented in Table 1. This coincides with the percentage of TiO2 reported in the chemical composition of MK (Table 1). In the FTIR spectrum (Figure 3) of the MK, a band at approximately 3437 cm−1 is observed; this corresponds to the asymmetric vibration of OH groups.

The peak located near 687 cm-1 is characteristic of the Ti-O-Ti stretching of the anatase phase, thus confirming the presence of these photoactive species [13]. The mixing process of the solid components (MK and titanium dioxide) and liquids (activator) was carried out in a HOBART Vulcan 1249 mixer. The following techniques were used for the microstructural study of the mixtures: Electron microscopy, FTIR and XRD.

Table 1. Chemical composition of the precursor (MK).
Table 1. Chemical composition of the precursor (MK).

Results and Discussion 1. Fluidity and Setting Time

It is also evident that by increasing the mixture water content, the concentration of ions in the aqueous solution decreases, which decreases the gelation process, in addition to leading to a greater availability of water in the system to be evaporated for the formation of the consolidated structure, which is reflected in an increase in the setting time [15]. In general, an increased proportion of liquid negatively affects the permeable pore content of the mixtures (Figure 6b). Of the different mixes evaluated, those with the lowest water content (L/S = 0.35) showed higher mechanical performance.

Similarly, the presence of the precursor crystalline phase is observed in the GP, which increases with the addition of TiO2 in the material due to its contribution. The FTIR spectra of the synthesized geopolymers are shown in Figure 9, in which no major differences between the non-added and those with 5 wt% and 10 wt% TiO2 added are observed. It is noteworthy that there is no significant difference between the morphologies of the systems with and without TiO2, but the EDS measurements at point 2 of the sample with 10 wt.

Hình ảnh

Table 1. Summary of works related to the use of recycled materials in green roofs.
Figure 8. Average behavior of drained water (mL/min) for typical rain conditions between post-drought and stable cycles.
Figure 9. Average behavior of drained water (mL/min) for intense rain conditions between post-drought and stable cycles.
Figure 10. Temperature behavior during the day for roof prototypes and the environment.
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