Glass Coatings Research Articles

Synthesis and Characterization of Composite Coating of Iron Oxide and Bioactive Glass, Coated by Electrophoretic co-Deposition Method for Biomedical Applications

Synthesis and Characterization of Composite Coating of Iron Oxide and Bioactive Glass, Coated by Electrophoretic co-Deposition Method for Biomedical Applications

Structure activity relationship of novel antibacterial phosphonium ionic liquids/organic salts in dispersions and on films: Potential antifouling coating materials

The worldwide increasing threat from drug resistant strains, urge continuous development of novel and effective antibacterial agents to minimize nosocomial infections and associated deaths. In this direction ionic liquids (ILs) or analogous organic salts (OS) have exhibited promising potential due to their ease of designability and tunable properties. Herein, nine structurally different phosphonium based ionic liquids (ILs)/Organic Salts (OS) were developed and investigated for their structural effect on antibacterial activity in dispersions and surface coatings. This study reveals that the structural effect on bactericidal property is reversed in coatings compared to dispersions. The pure aryl phosphonium viz. (tetraphenyl phosphonium [TTP]+) cation based IL of ampicillin (Amp−) demonstrate highest bactericidal effect in dispersion compared to alkyl aryl phosphonium (ethyltriphenyl phosphonium)-ampicillin IL and the least activity was observed for pure tetra alkyl phosphonium (trihexyltetradecyl phosphonium)-ampicillin ILs. However, on coatings the activity was reversed. It is observed that optimum hydrophilic-lipophilic balance of ILs/OS dominated the bactericidal effect in dispersions whereas on coating the most lipophiphilic IL/OS demonstrated highest activity. In dispersions the bactericidal effect is a combined property of the cation and the anion while on glass coatings primarily cationic part dominate the bactericidal effect as the hydrophilic ampicillin anion is attached to the glass surface. SwissADME based skin permeation study indicate good potential of the [TPP][Amp] IL as topical antibiotics with a log Kp of 6.91 cm/s and Log P of 3.62. Thus, the present study reveals the structural effect on antibacterial properties of ILs/OS are system dependent as implied from the investigation of some phosphonium ILs/OS and provides useful information for developing washable transparent antifouling coatings.

Soiling mitigation potential of glass coatings and tracker routines in the desert climate of Saudi Arabia

AbstractHigh levels of airborne dust, frequent dust storms and infrequent rain events are some of the reasons why soiling can drastically reduce the energy yield of photovoltaic modules in desert areas. There are ongoing and increasing efforts to identify appropriate and economically feasible strategies that can be used to mitigate soiling in deserts. Both innovative tracking with adapted resting positions during night and anti‐soiling coatings (ASCs) are considered as potential solutions to reduce soiling. In this study, the individual mitigation potential of both ASC and tracking routines as well as the combination of the two approaches are investigated. For this, outdoor exposure tests were carried out in desert region of Saudi Arabia. Coated and uncoated glass samples were tested in different tilt configurations: fixed, 1‐axis tracking with horizontal stowage (facing the sky) and 1‐axis tracking with vertical stowage during the night. Both methods indicate significant soiling reductions, especially for the combined solution of ASC and tracking with vertical night stowage, where soiling losses can be reduced by up to 85%. In addition, it has been shown that the relative ASC performance can be improved when using vertical night stowage compared to fixed tilt or standard 1‐axis tracking scenarios.

Improving the bond strength of bioactive glass coatings obtained by atmospheric plasma spraying

Bioactive glasses are inorganic biomaterials that can provide a bioactive response and thus favor the successful bonding of orthopedic implants. Some strategies were studied to improve the bond strength of bioactive glasses, such as producing agglomerated bioactive glass powders or designing different coatings combining hydroxyapatite (HA) with bioactive glass. The bioactive coatings were produced by atmospheric plasma spray (APS) onto titanium alloy substrates, and the microstructure and adhesion strength of the developed coatings were evaluated. It was found that a significant improvement in adhesion strength was obtained for the developed coatings, in particular when thermal treatment was applied to pure glass coatings and when HA was part of the coating. The coatings reactivity in simulated body fluid and Tris-HCl solutions was studied. All coatings showed bioactive behavior, but the ones with only an amorphous phase in the upper part of the coating dissolved faster, releasing a larger proportion of Ca ions, which caused faster nucleation and growth of apatite deposits.

Effect of Discharge Duration on Characteristics of FeCrWMoCB Metallic Glass Coatings

Effect of Discharge Duration on Characteristics of FeCrWMoCB Metallic Glass Coatings

Investigation of Scale Formation on Glass Coatings of Pipes

Investigation of Scale Formation on Glass Coatings of Pipes

Nanomechanical surface properties of co-sputtered thin film polymorphic metallic glasses based on Ti-Fe-Cu, Zr-Fe-Al, and Zr-W-Cu

Metallic glasses are amorphous materials that have shown prospects in several applications including biomedical due to their superior and unique mechanical, tribological, and bioactive properties. New functional coatings of thin film polymorphic metallic glasses (Ti-Fe-Cu, Zr-Fe-Al, and Zr-W-Cu) were deposited by co-sputtering of constituents from high purity (99.9%) targets. The thin film metallic glasses were deposited on stainless steel 316 L (SS316L) and titanium alloy (Ti) substrates. Co-sputtering offers tuneable parameters (pressure, power, and time), which fosters high-quality polymorphic films of desired thickness and composition. Surface and nanomechanical properties of the films, including surface morphology, structure, mechanical, and tribological properties were investigated using SEM, AFM, XRD, XPS, nanoindentation, and scratch test. The coated substrates exhibit uniform nanostructured films with surface roughness in the range of 1.5 to 7 nm. The XRD spectra show a dominant amorphous glassy polymorphic feature on both substrates with crystallites size in the range of 65–108 nm. Nanomechanical characteristics of the films suggest high wear resistance with film adhesion strength ranging between 624 - 2159 µN and 2273 - 2978 µN on SS316L and Ti substrates, respectively. Overall, these polymorphic Ti-Fe-Cu, Zr-Fe-Al, and Zr-W-Cu nanostructured uniform films with low surface roughness and high adhesion on SS316L and Ti substrates are potential functional surfaces for biomedical applications.

Antibacterial Activity of a Bioactive Tooth-Coating Material Containing Surface Pre-Reacted Glass in a Complex Multispecies Subgingival Biofilm.

Bioactive materials were developed with the ability to release fluoride and provide some antimicrobial potential, to be widely used in dentistry today. However, few scientific studies have evaluated the antimicrobial activity of bioactive surface pre-reacted glass (S-PRG) coatings (PRG Barrier Coat, Shofu, Kyoto, Japan) on periodontopathogenic biofilms. This study evaluated the antibacterial activity of S-PRG fillers on the microbial profile of multispecies subgingival biofilms. A Calgary Biofilm Device (CBD) was used to grow a 33-species biofilm related to periodontitis for 7 days. The S-PRG coating was applied on CBD pins from the test group and photo-activated (PRG Barrier Coat, Shofu), while the control group received no coating. Seven days after treatment, the total bacterial counts, metabolic activity, and microbial profile of the biofilms were observed using a colorimetric assay and DNA-DNA hybridization. Statistical analyses were applied; namely, the Mann-Whitney, Kruskal-Wallis, and Dunn's post hoc tests. The bacterial activity of the test group was reduced by 25.7% compared with that of the control group. A statistically significant reduction was observed for the counts of 15 species: A. naeslundii, A. odontolyticus, V. parvula, C. ochracea, C. sputigena, E. corrodens, C. gracilis, F. nucleatum polymorphum, F. nucleatum vincentii, F. periodonticum, P. intermedia, P. gingivalis, G. morbillorum, S. anginosus, and S. noxia (p ≤ 0.05). The bioactive coating containing S-PRG modified the composition of the subgingival biofilm in vitro, thereby decreasing colonization by pathogens.

Influence of annealing on microstructure and cavitation erosion resistance of iron-based metallic glass coatings synthesized by HVOF thermal spraying

This study aimed to deposit a novel iron-based metallic glass coating onto 316L stainless steel and analyze the microstructures, phases, mechanical properties, and cavitation erosion resistances of the as-sprayed and annealed coatings. The coatings were annealed at temperatures of 540, 640, and 740 °C, resulting in varying crystal contents. As the annealing temperature increased, the amorphous content of the iron-based coatings decreased from 90% to 62%, 35%, and 29%, respectively, while the microhardness increased from 849 HV0.2 to 944, 970, and 860 HV0.2, respectively. The coating annealed at 640 °C exhibited the best resistance to cavitation erosion, whereas the coating annealed at 740 °C had the poorest resistance. Cavitation erosion always initiated from defects in the amorphous/nanocrystal coatings, such as pores, microcracks, or phase interfaces, and then propagated along these defects, eventually causing the stripping of particles. During cavitation erosion, the well-bound particles fragmented under repeated shocks, and the amorphous phase crystallized into nanocrystals, leading to detachment of particles in small sizes.

Corrosion and electrochemical behavior of water glass coatings embedded with graphite/titanium oxide on 2A12 aluminum alloy

Corrosion and electrochemical behavior of water glass coatings embedded with graphite/titanium oxide on 2A12 aluminum alloy

Particle-Size-Dependent Analysis of the Impact of Temperature, Humidity, and Tilt Angle on Soiling

Natural soiling—the deposition of dust onto surfaces—is a very complex problem and influenced by different factors, such as weather conditions, dust type, or surface properties. To investigate the individual impact of various factors and parameters, laboratory and outdoor soiling tests were performed for uncoated glass samples and glass samples with an antisoiling coating. For this, an advanced experimental setup was used operating at controlled environmental conditions. A detailed microscopic investigation with particle size analysis was performed to better understand the underlying physics of soiling effects and its influencing parameters, including relative humidity, surface temperature, tilt angle, and properties of the sample surface (i.e., glass coatings). Various effects were identified, which must not be neglected for correct interpretation of soiling test results. The article shows that particle rebound, natural convection, thermophoresis, capillary condensation, and adhesion properties of the surface have a substantial impact on soiling.

The Effect of Yttria Stabilized Zirconia on Bonding Strength and Corrosion Resistance of Bioactive Glass Coatings Prepared by Electrophoretic Deposition (EPD) Method

The Effect of Yttria Stabilized Zirconia on Bonding Strength and Corrosion Resistance of Bioactive Glass Coatings Prepared by Electrophoretic Deposition (EPD) Method

INVESTIGATION OF SCALE FORMATION ON GLASS PIPE COATINGS

The results of theoretical and experimental studies of the influence of scale deposits on heat exchange processes in vitrified pipes washed by seawater are presented. Experimental studies have shown that during long-term operation of heat exchangers, minor scale deposits with a layer thickness of up to 0.4 mm are observed on the surface of glass coatings of pipes, while a strong scale layer up to 2 mm thick is formed on the inner surfaces of metal pipes. The practical absence of deposits in vitrified pipes is explained by the increased cleanliness of the glass surface and its resistance to aggressiveness of substances dissolved in sea water. This eliminates the formation of large foci of scale on the glass surface and washing off the formed scale with a stream of seawater.

One-step ball-milling synthesis of cesium tungsten bronze nanoparticles and near-infrared shielding performance

Tungsten bronze (MxWO3) materials have been widely used as thermal insulation for architectural glass because of their higher near-infrared (NIR) light shielding capacity. To solve the problems encountered in solvothermal preparation with high costs and low yields, this study has developed a facile, eco-friendly, effective, but low-cost method, with no need for any annealing process, for promoting the large-scale fabrication of cesium tungsten bronze (CsxWO3, x = 0.32) nanomaterials for potential thermal insulation windows applications. In the proposed ball-milling process, the tungstic acid material could be reduced to hydro tungsten bronze (HxWO3) by cellulose, while the cesium ions (Cs+) could be gradually incorporated into the interspace until the formation of Cs0.32WO3 (Cs/W atomic ratio = 0.32), with an average particle size of ∼33 nm after a 15 h ball-milling process. The reaction mechanism has been investigated in detail via particle structural analysis and optical performance characterization. The obtained Cs0.32WO3 nanoparticles are dispersed in a solution composed of surfactant (s) and polymer (s) which can form a thin film with a thickness of about 2 μm on a glass substrate, by a spinning coating or casting method, to exhibit high visible (Vis) light transmittance (T566nm = 72.6%), and excellent NIR-shielding capability (T1388nm = 5.3%), reflected by good heat-insulating performance in practice use. This work will pave a new path for large-scale production of Cs0.32WO3 nanomaterials with low costs and high performance, beneficial for practical applications in energy-saving glass coatings.

Influence of Polyols on the In Vitro Biodegradation and Bioactivity of 58S Bioactive Sol–Gel Coatings on AZ31B Magnesium Alloys

The mechanical qualities of AZ31B magnesium alloys make them a promising material for biodegradable metallic implants. However, rapid degradation limits the application of these alloys. In the present study, 58S bioactive glasses were synthesized using the sol-gel method and several polyols such as glycerol, ethylene glycol, and polyethylene glycol, were used to improve the sol stability and to control the degradation of AZ31B. The synthesized bioactive sols were dip-coated onto AZ31B substrates and then, characterized by various techniques such as scanning electron microscopy (SEM), X-ray diffraction (XRD) and electrochemical techniques (potentiodynamic and electrochemical impedance spectroscopy), among them. FTIR analysis confirmed the formation of a silica, calcium, and phosphate system and the XRD the amorphous nature of the 58S bioactive coatings obtained by sol-gel. The contact angle measurements confirmed that all the coatings were hydrophilic. The biodegradability response under physiological conditions (Hank's solution) was investigated for all the 58S bioactive glass coatings, observing a different behaviour depending on the polyols incorporated. Thus, for 58S PEG coating, an efficient control of the release of H2 gas was observed, and showing a pH control between 7.6 and 7.8 during all the tests. A marked apatite precipitation was also observed on the surface of the 58S PEG coating after the immersion test. Thus, the 58S PEG sol-gel coating is considered a promising alternative for biodegradable magnesium alloy-based medical implants.

Study on Sintering Behavior of Reaction-Cured Glass Coating

High-emissivity coatings constitute an essential component of reusable thermal protection systems, determining the success or failure of hypersonic spacecraft. Reaction-cured glass coating is the basis for all current high-emissivity coatings, and the study of its sintering behavior is of great scientific significance for the development and performance enhancement of the coating. Microstructures and phase compositions of the samples before and after the sintering process were determined using SEM, XRD, and EDS. The sintering temperature, inserting temperature, and heating rate were systematically investigated. The results show that the effects of the sintering temperature, inserting temperature, and heating rate on the coating occur in decreasing order. The optimum condition for coating sintering in this study is an insertion temperature of 1100 °C, a heating rate of 10 °C/min, and a sintering temperature of 1200 °C, and a crack-free and containing SiB4 borosilicate glass coating was successfully prepared.

Modern film coatings for glass and examples of their practical application

The material is devoted to architectural and protective self-adhesive polymer PET films used in the construction of translucent structures and glazing.In the matter of using these materials for more than 20 years of research and observations about professional films, an objective opinion has been formed about professional films as a reliable, durable and highquality product for translucent glazing. But still it is necessary to admit that this product is undervalued in the modern market of services.

High water-stable, hard and strong-adhesive antistatic films from waterborne PEDOT:PSS composites

Electrostatic discharge (ESD) protection is quite necessary for the electronic industry and modern life. Antistatic materials based on poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) have been widely used in these fields such as electronic devices, smart windows, specialty papers, photographic films, glass coatings, fabrics and so on. To solve the critical shortcomings of PEDOT:PSS in high commercial price, high water absorption accompanying dramatically decreased structure stability, mechanical damage vulnerability, and insufficient substrate adhesion ability, etc., herein, we prepared an antistatic PEDOT:PSS/Epoxy films from self-made PEDOT:PSS aqueous dispersion and waterborne epoxy system by facile mechanical mixing and drop-casting on glass substrates. The surface morphology, volume resistivity, surface wettability and water immersion stability of these films were systematically studied. In addition, the substrate adhesion and surface hardness of the films after the introduction of polyhedral oligomeric silsesquioxane (POSS) and silane coupling agent (SCA) in such composite systems were investigated. The optimized PEDOT:PSS/Epoxy/POSS/SCA films exhibited fine antistatic ability, increased hydrophobicity, improved water stability, high hardness (HB) and good adhesion (level 1) on glass substrates. Such conductive films together with their design principle and their environmentally friendly waterborne mother dispersions will promote the further use of PEDOT:PSS in ESD protection materials or others in organic film electronics including vigorously developed flexible and wearable electronic devices.

Plasma Spraying of Kaolinite for Preparing Reactive Alumino‐Silicate Glass Coatings

AbstractThermally treated kaolinite is used to develop a range of alumino‐silicate‐based precursor materials but its behavior during plasma spraying has not been well‐researched. In this study, two types of kaolinite samples were investigated in the form of low defect (KGa‐1b) and high defect (KGa‐2) varieties. The extreme temperatures of the plasma stream (up to 20 000 K) induced flash melting to produce a highly porous alumino‐silicate glass without any crystallization of new Al−Si oxide minerals. The glass is comprised largely of intact or deformed spheres (average diameters 1.14–1.44 μm), which indicates rapid quenching and solidification before impact. The subspherical structures contain up to 40 % closed pore space caused by the rapid escape of water during melting. The low‐density, porous alumino‐silicate glass coatings with predicted specific surface areas (>0.95 m2/g) and hardnesses >1.8 GPa represent a potentially reactive but physically stable substrate ideal for further chemical functionalization.

PEG-functionalized carbazole-based polymers for UV-protected hydrophilic glass coatings

The UV-absorbing and non-fogging glass coatings containing carbazole-based conjugated backbone with different lengths of hydrophilic PEG subunit (KP-PEG) were produced. The characterizations of the polymers were carried out by using different techniques such as FT-IR, 1H NMR, GPC, TGA and DSC. Transmittance and thin-film morphology analyses, which are essential for UV protection and wettability, were investigated by UV–Vis absorption, AFM and TEM techniques, respectively. Transparent thin films prepared by the polymer solutions in chloroform were obtained by spin coating method at a scan rate of 2000 rpm. The wettability performance and antifogging properties of these surfaces were investigated depending on the PEG length in the polymer subunit. The water contact angle of the surfaces was improved to the range between 60° and 29° depending on the amount of PEG group. KP-PEG750 is the best polymer thin film in terms of having the highest roughness, optimum UV absorption and the low contact angle value.