Glass Enamel Research Articles

Effect of P2O5 addition on Li2TiO3 crystallization with opacification of white single-layer glass enamel coatings

The mutual effect of the components of enamel on its whiteness is examined. Effect of P 2 O 5 on the process of opacification of white single-layer enamels is studied. It is established that Li 2 TiO 3 plays the main role in the mechanism of crystallization.

Use of additions of ferroelectric substances to improve the dielectric properties of glass enamels

It is shown that there is promise in introducing ferroelectric additives to glass enamel coatings to improve their dielectric characteristics. The limits of the additive introduced for low-alkali borosilicate enamel are determined. A comparative table of properties of the initial and composite enamels is presented. The dielectric properties of the new material are determined and it is determined that the additive does not dissolve in the glass enamel.

Use of titanium dioxide for the development of antibacterial glass enamel coatings

It is shown that titanium dioxide is useful for developing antibacterial glass enamel coatings. Antibacterial powder (filler) was synthesized on the basis of hydroxyapatite modified with titanium oxide, and its phase composition was investigated. It was established that the composite glass enamel coatings studied are characterized by a substantial antibacterial and antifungal effect from 70 to 90% with synthesized inorganic filler content from 1 to 5% with Ti4 + /(Ti 4+ + Ca 2+ ) ratio equal ratio 0.04 - 0.07.

Antibacterial composite glass coatings for protecting special-purpose steel panels

It is confirmed that glass enamel coatings are promising for antibacterial protection of steel panels. A methodological approach is developed for obtaining antibacterial composite glass coatings. A glass matrix with a programmed structure, bactericide nanopowders of zinc phosphate, and composite glass coatings based on them have been obtained on the basis of the system R2O – RO – TiO2 – P2O5 – SiO2. The composition of a coating with the maximum antibacterial effect with respect to E. Coli bacteria is determined.

On‐site analysis of Chinese Cloisonné enamels from fifteenth to nineteenth centuries

AbstractA selection of 22 rare Chinese cloisonné enamels, from fifteenth century to nineteenth century A.D., has been studied on‐site in the storage rooms of the musée des Arts décoratifs in Paris. The Raman signatures of the transparent and/or opacified glass matrix are discussed and compared with those that were previously recorded on glazed pottery, enameled and stained glasses. Enamels mostly belong to lead‐based potash‐lime glasses. Three different compositions, lead‐potash‐lime (fifteenth, sixteenth, eighteenth and nineteenth century), soda‐rich (sixteenth–seventeenth century) and soda‐lime (seventeenth century) are identified according to the wavenumber maxima of the SiO stretching and bending multiplets. Most of the pigment signatures are similar to those recorded on ceramic glazes and glass enamels, which proves the link between the technologies but a specific opacifier is observed: fluorite (CaF2). Naples Yellow pigment variations give characteristic signatures. Additionally, a comparison is made with Limoges enamels (sixteenth–nineteenth century A.D.). Copyright © 2009 John Wiley & Sons, Ltd.

Effect of semiconducting titanium dioxide on the resistivity of a composite glass enamel coating

It is shown that the electric conductivity of TiO2 (rutile) can be increased by doping it with oxides of elements possessing higher valence. Adding semiconducting TiO2 to glass enamel slip makes it possible to decrease the resistivity of a composite coating considerably.

On‐site analysis of Limoges enamels from sixteenth to nineteenth centuries: an attempt to differentiate between genuine artefacts and copies

AbstractA selection of 15 painted enamels, most of which belong to Limoges productions, from 1500 to 1900 A.D., has been studied on‐site in the storage rooms of musée des Arts décoratifs in Paris. The Raman signatures of the transparent and/or opacified glass matrix are discussed and compared with those which were previously recorded on glazed pottery, enamelled and stained glasses as well as Chinese cloisonné enamels. Analysed enamels mostly belong to soda‐lime‐based glass. Three types of compositions such as soda‐lime (fifteenth to sixteenth century), soda‐rich (fifteenth, sixteenth/nineteenth centuries) and lead‐potash‐lime (sixteenth and nineteenth centuries) are identified on the basis of the Raman signature of the glaze according to the wavenumber maxima of the SiO stretching and bending multiplets. The pigment signatures are similar to those recorded on ceramic glazes and glass enamels, which proves the similarity of the technologies. Cassiterite as an opacifier and hematite red and Naples yellow pigment variations give characteristic Raman signatures. The presence of lead arsenate as a pigment opacifier in nineteenth‐century samples is confirmed. Attempts are made to establish tools for the differentiation between genuine artefacts and nineteenth‐century restoration or fakes. Copyright © 2010 John Wiley & Sons, Ltd.

Mutual influence of the components of white single-layer glass enamels on the opacification mechanism

Questions concerning the mutual influence of the components of enamel on the degree its opacification are examined. Experimental results, which are generalized taking account of previously obtained data, are presented.

Enamels in stained glass windows: Preparation, chemical composition, microstructure and causes of deterioration

Stained glass windows incorporating dark blue and purple enamel paint layers are in some cases subject to severe degradation while others from the same period survived the ravages of time. A series of dark blue, green–blue and purple enamel glass paints from the same region (Northwestern Europe) and from the same period (16–early 20th centuries) has been studied by means of a combination of microscopic X-ray fluorescence analysis, electron probe micro analysis and transmission electron microscopy with the aim of better understanding the causes of the degradation. The chemical composition of the enamels diverges from the average chemical composition of window glass. Some of the compositions appear to be unstable, for example those with a high concentration of K 2O and a low content of CaO and PbO. In other cases, the deterioration of the paint layers was caused by the less than optimal vitrification of the enamel during the firing process. Recipes and chemical compositions indicate that glassmakers of the 16–17th century had full control over the color of the enamel glass paints they made. They mainly used three types of coloring agents, based on Co (dark blue), Mn (purple) and Cu (light-blue or green–blue) as coloring elements. Blue–purple enamel paints were obtained by mixing two different coloring agents. The coloring agent for red–purple enamel, introduced during the 19th century, was colloidal gold embedded in grains of lead glass.

Oral bacterial biofilms – history in progress

Oral bacterial biofilms – history in progress

BIOACTIVE GLASS PARTICLES FIELD-ASSISTED SEALING TO TITANIUM IMPLANT GLASS-BASED COATINGS

This paper reports for the first time the use of field-assisted sealing for bioactive implant coating applications. Field-assisted sealing (anodic bonding) of bioactive glass particles to bioinert glass enamel coating of titanium implant was investigated. Biocompatible titanium oxide interlayer was fabricated by deep thermal oxidation of 80 nm thick Ti thin film previously vacuum evaporated onto polished bioactive glass surface. Bioactive glass particle was anodically bonded via the interlayer to polished surface of bioinert glass enamel coating vacuum deposited onto Ti plate at 860°C. A total of 20 min preheating time with constant temperature increase rate, 5 min bonding time, and 100 V DC voltage were applied during field-assisted bond formation at 530°C in air.

Characterisation of an enamelled metallic object found in Guerrero Negro (Baja California) by PIXE and RBS techniques

The coast of Guerrero Negro (Baja California) has been known for a long time by archaeologists for its shipwrecks. Archaeologists are recovering objects that come from sunken Spanish galleons in the colonial period, and reach the American coast in the frontier of the USA with Mexico.An enamelled metallic object was found next to the beach in Guerrero Negro. We have analysed the piece with proton induced X-ray emission (PIXE) and Rutherford backscattering (RBS) in an attempt to establish whether the object could come from one of the colonial shipwrecks and to valuate its cleaning process.Scanning electron microscopy (SEM) and energy dispersive X-ray spectrometry (EDS) have been also performed in three samples taken from the object in order to observe the heterogeneity of the material.The materials found revealed the presence of typical lead–glass enamels from with pigments such as cuprite (red), or lead–tin yellow used in colonial times. The metallic part consisted of brass. As for the cleaning process, the average efficiency considered as the weight% of chlorine removed, was of 83.4% for brass and 100% for enamels.

Analysis of the interface zone between the glass ionomer and enamel and dentin of primary molars

Restoring carious teeth is one of the major dental treatment needs of young children. Conventional glassionomer materials are frequently used as filling materials in contemporary pediatric dentistry. The objective of this study was to evaluate the restorative and prophylactic efficacy of the newly marketed glass ionomer, Fuji Triage (GC, Tokyo, Japan), through morphological analysis of the interface zone between the material and the enamel and the dentin of primary molars and to determine the extent of the ion exchange at the interface zone. The sample consisted of 5 extracted intact first primary molars in which glassionomer had been used as filling material after standard class I cavity preparation. The material was placed according to the manufacturer's instructions and teeth were placed into dionised water prior to experiment. Six sections of each tooth had been examined using scanning electron microscopic and electron dispersive spectroscopic techniques (SEM/EDS). The parameters for evaluation included: morphological characteristics of the interface zone and the extent of the ion exchange between the material and the tooth structures Results were statistically analyzed using descriptive statistical methods. SEM/EDS analysis revealed the presence of the chemical bonding between the glass ionomer and the enamel and dentin, 5 and 15 ?m in width, respectively. Ion exchange has not been detected in the enamel at the EDS sensitivity level. Strontium and fluor penetration has been detected in dentin. The ion exchange and chemical bonding formation justify the usage of the conventional glass ionomer materials for restorative procedures in primary molars.

Colorimetric characteristics of colored single-coat enamels

Compositions for single-coat glass enamels that allow obtaining a wide color range of coatings with sufficiently good surface quality for steel articles were developed. Different dyes were tested. Properties of the coatings such as the chemical stability, adhesive strength, gloss, and thermal stability were investigated and the firing temperature range, 670–740°C on average, was determined. The colorimetric characteristics of single-coat enamels were calculated. The enamel coatings obtained can be used in mass production.

Effect of alkali metal oxides on the properties of titanium containing glass enamels

The effect of the ratio of three alkali oxides on the physical and chemical properties of titanium-containing enamels has been investigated and their optimal concentrations have been determined. Acid resistant enamel for steel utensils has been developed.

Highly reliable energy-efficient glass coatings for pipes transporting energy carriers, liquids, and gases

Comparative characteristics of known materials which are used to increase the longevity of steel pipes are presented. It is shown that glass enamel coatings provide effective protection from corrosion. The physical and technological characteristics of fused frits (water resistance, impact strength, microhardness) fall within the GOST 24405-80 limits.

Glass enamel for steel based on diatomite material

The possibility of replacing quartz sand for melting enamel frit by natural diatomite rock is investigated. It is established that the use of local diatomite as the silica material in melting enamel frits is a promising trend in enameling technology. The properties of frits based on diatomite materials are similar to the properties of the reference low-melting frit F-1; they have have slightly lower softening and melting temperatures, and their technological characteristics are within the limits specified by GOST 24495-80 for undercoat enamel on steel.

Tinted one-coat glass enamels for steel

A basic formula for one-coat glass enamel is developed, which makes it possible to obtain a wide color range of coatings for steel products with good surface quality. A number of ionic colorants is tested, mainly compounds of d-and f-elements. The properties of coatings are studied: chemical resistance, adhesion strength, luster, and heat resistance. Their firing temperature is determined. The obtained glass enamels can be used in industrial production.

Formation and spectral properties of silver clusters in sintered glass composites

Thermally induced diffusion of neutral silver and silver cations in sintering glass composites is investigated, with particular attention being given to ion-exchange process with float glass substrate. The aim of this study was to identify the main mechanism of high-temperature discoloration of black glass enamel with silver overprint. Numerical simulations of ion-exchange (silver and sodium ions) process provide an explanation for the observed anomalous silver concentration profile and the particle distribution near the glass interfaces. Numerical simulations of the reflectance spectra are in agreement with experimental observations.

Alkaline Titanium-Silicate Glasses for White Glass Enamels with Enhanced Corrosion Resistance

The properties of alkali borotitanium-silicate glasses with different content of boron, titanium, and lithium oxides are investigated. It is indicated that glasses with a low content of B2O3 (8 – 10%) can be used to produce white glass-enamel coatings that have enhanced corrosion resistance and low leachability of the coating components in acetate solutions.