Thin Film Transistor Liquid Crystal Display Waste Glass Research Articles

Synthesis of aluminum-mesoporous MCM-41 humidity control material from thin-film transistor liquid crystal display waste glass and sandblasting waste and its application

The preparation of an aluminum-mesoporous A1-MCM-41 humidity control material (Al-MHCM) by hydrothermally synthesizing a mixture of thin-film transistor liquid crystal display (TFT-LCD) waste glass and sandblasting (SB) waste was studied. The product has a typical mesoporous structure, with a specific surface area of up to 1013m2/g, the pore size distribution calculated is 3–4nm, and the pore volume of 0.97cm3/g. All the aluminum atoms of the product are in the form of tetrahedral aluminum in the framework, which confirms the successful synthesis of Al-MHCM. Results show that when the hydrothermal synthesis temperature is 105°C, the product synthesized from a mixture with a Si/Al molar ratio of 41.8 exhibits excellent performance (91.45m3/m3) in terms of the equilibrium moisture content and moisture adsorption capacity. The results confirm that the equilibrium moisture content of Al-MHCM is better than the rape straw concrete and hemp concrete (9.8–17.8m3/m3), and that of a diatomite/ground calcium carbonate composite aterial (11.7m3/m3). The research results are expected to provide a new technology for synthesizing TFT-LCD waste glass and SB waste into novel high value-added humidity control materials.

ELUCIDATING THE EFFECTS OF NANOSILICA ON THE CHARACTERISTICS OF ALKALI-ACTIVATED THIN-FILM TRANSISTOR LIQUID-CRYSTAL DISPLAY WASTE GLASS

Thin-film transistor liquid-crystal display (TFT-LCD) waste glass can be used as a raw material for producing geopolymers, because it contains large amounts of silicon and aluminum in its amorphous structure. The setting time and compressive strength were evaluated to determine the quality of the geopolymer product with various amounts of nano-SiO2 (0% 3%) and TFT-LCD waste glass replacement (0% - 40%). The microstructures of the samples were characterized using mercury intrusion porosimetry (MIP), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). The highest compressive strength and compact microstructure of the geopolymer was attained by adding 10% waste glass and 1% nano-SiO2. The results demonstrated that adding nano-SiO2 to the geopolymer substantially enhances compactness, improves uniformity, and greatly increases compressive strength. This work offers a low-cost route for fabricating geopolymers, because TFT-LCD waste glass can be used to partially substitute metakaolin in the composition of the geopolymer.

Humidity-conditioning mesoporous molecular sieves synthesized from thin-film-transistor liquid-crystal-display waste glass and SiC sludge

This study characterized the humidity conditioning of Al-MCM-41 mesoporous molecular sieves that were recycled from thin-film-transistor liquid-crystal-display (TFT-LCD) waste glass and SiC sludge and synthesized through alkali fusion and hydrothermal processes. Temperatures of 450–650°C, various liquid: solid ratios (5:1, 10:1, 15:1), and different proportions of SiC sludge in the TFT–LCD waste glass were used. The crystal structures of the Al-MCM-41 were determined using X-ray diffraction. The concentrations of heavy metals leached from the materials were below Taiwan's regulatory thresholds. When the liquid: solid ratio was 10:1 and the alkali fusion temperature was 90, 105, or 120°C, the mesoporous molecular sieves met JIS A1470 intensity building materials specifications (moisture adsorption content > 29 g/m2). Mesoporous molecular sieves recycled from TFT-LCD waste glass and SiC sludge had excellent mechanical properties, making them feasible for use in humidity-conditioning applications. This novel synthesis process could also be employed for other Si-related industrial wastes and be beneficial during the large-scale production of valuable silica-based humidity-conditioning materials for environmental protection applications. © 2017 American Institute of Chemical Engineers Environ Prog, 2017

Performance of Cementitious Composites Incorporating Ground TFT-LCD Waste Glass

Abstract In South Korea, a great amount of thin-film transistor liquid-crystal display (TFT-LCD) waste glass in the form of industrial waste has been produced during the electronic equipment manufacturing process in recent years. This paper presents a detailed experimental study on the performance of mortar specimens replaced partially by TFT-LCD waste glass (TLWG). The replacement level of TLWG was the main test variable. Setting time, compressive and flexural strengths, drying shrinkage, and chloride-ion permeability tests of mortar specimens incorporating TLWG were carried out to evaluate the possibility of recycling TLWG as a cementitious material. In addition, field-emission scanning electron microscope (FE-SEM) investigations were used to observe the effect of TLWG replacement on the microstructural changes of paste samples. From the test results, it was found that higher replacement levels of TLWG (above 20 %) negatively affected the strength, drying shrinkage, and chloride-ion penetrability of mortar specimens because it led to a porous structure in the hardened cement system. On the other hand, because of the pozzolanic activity, the use of TLWG up to a maximum 10 % replacement level was possibly effective in enhancing mechanical properties of mortars. This was verified through the microstructural observations by SEM and energy dispersive spectroscopy (EDS) analysis. Hence, taking into consideration economical and mechanical factors, it can be concluded that appropriate replacement of TLWG as a cementitious material holds promise in the production of concrete, as well as in recycling industrial waste.

Properties of different particle size of recycled TFT-LCD waste glass powder as a cement concrete binder

In the high-tech industry in Korea, the use of thin-film transistor liquid-crystal display (TFT-LCD) glass products has increased significantly in recent years and large amounts of TFT-LCD waste glass are produced during the manufacturing process. The use of recycled waste glass in Portland cement and concrete has attracted a lot of interest worldwide due to environmental concerns, and the increased cost of disposing of used glass. This research studied the effect of different particle size of grinding TFT-LCD waste glass proportions on binder in cement mortar. Experiments were conducted to determine the optimal replacement content and particle type to ensure that the quality of concrete products is maintained. The results indicate that the use of TFT-LCD waste glass powder as an admixture for cement mortar was efficient in reducing alkali–silica reaction (ASR) expansion and increasing workability. The compressive strength of mortars with TFT-LCD waste glass was also improved compared with that of normal mortar, due to the increased amount of calcium silicate hydrates created by pozzolanic reaction. But it was apparent that the properties of workability, compressive strength and ASR were different significantly with particle size of TFT-LCD waste glass powder.

A study of the possibility of using TFT-LCD waste glass as an admixture for steam-cured PHC piles

In the high-tech industry in Korea, the use of thin-film transistor liquid-crystal display (TFT-LCD) glass products has increased significantly in recent years and large amounts of TFT-LCD waste glass are produced during the manufacturing process. This research studied the effect of TFT-LCD waste glass proportions on binder in mortar when added with an appropriate amount of activator. Experiments were conducted to determine the optimal replacement content to ensure that the quality of prestressed high-strength concrete (PHC) products is maintained. The results indicate that the use of TFT-LCD waste glass powder as an admixture for PHC piles was efficient in reducing alkali–silica reaction expansion and increasing workability. The compressive strength of mortars with TFT-LCD waste glass was also improved compared with that of normal mortar, due to the increased amount of calcium silicate hydrates created by pozzolanic reaction between the waste glass and activator. In field tests, the compressive strength of a PHC pile with TFT-LCD waste glass powder was about 3 MPa higher than that of a normal PHC pile. Guidelines are suggested for the recycling of TFT-LCD waste glass in steam-cured concrete products such as PHC piles.

Production of insulating glass ceramics from thin film transistor-liquid crystal display (TFT-LCD) waste glass and calcium fluoride sludge

Abstract This study investigated the feasibility of producing insulating glass ceramic from thin film transistor-liquid crystal display (TFT-LCD) waste glass and calcium fluoride sludge by vitrification and ceramization processes. This study also explored the effects of MgO as a modifying agent on the flexural strength and dielectric constants. Five different mixing ratios of waste and MgO were analyzed. The major mixture composition is CaF2–MgO–SiO2–Al2O3. In the experiments, the initial glasses were obtained by vitrifying mixtures and then heating the initial glasses to produce glass ceramics. The mixture in which the proportion of TFT-LCD waste glass to calcium fluoride sludge was 7 to 3, with 5 wt% MgO added, underwent complete densification at a relatively low temperature (780 °C). Compared to other mixtures, its flexural strength (140 MPa) was higher, and its dielectric constant (6.4 at 1 MHz) was lower. With increasing MgO content, the initial glasses exhibited lower crystallization temperatures. The results also indicate that densification is considerably hindered by the onset of crystallization, resulting in a decrease in the apparent density and flexural strength. The results demonstrate that the TFT-LCD waste glass with calcium fluoride sludge as the fluxing agent and MgO as the modifying agent can be used as a raw material for producing insulating glass ceramics.

Effect of composition on characteristics of thin film transistor liquid crystal display (TFT-LCD) waste glass-metakaolin-based geopolymers

By 2013 the demand for thin-film transistor liquid-crystal display (TFT-LCD) panels will be approximately 364millionm2, or approximately 9.8×106ton. According to the Waste Electrical and Electronic Equipment directive, electrical and electronic equipment waste must be reused and recycled to reduce the amount of e-waste deposited in landfills. TFT-LCD waste glass comprises mainly SiO2 and Al2O3 and can be used to produce geopolymers. This study investigates the effects of the solid/liquid and SiO2/Na2O ratios on the properties of metakaolin-based geopolymers. Recycled TFT-LCD waste glass (0–40%) replaces metakaolin, thereby reducing the amount of metakaolin produced. This study tests samples to determine their quality, including setting time and compressive strength. These tests include mercury intrusion porosimetry, Fourier transform infrared spectroscopy, and scanning electron microscopy. Results indicate that TFT-LCD waste glass consists of SiO2 and Al2O3. The geopolymer based on 10% waste glass and 90% metakaolin had a compressive strength of 62MPa after 60days of curing. The geopolymerization products filled the pores, producing a denser structure. TFT-LCD waste glass has the potential to partially replace metakaolin as a geopolymer material because of its useful mechanical characteristics.

Recycling thin film transistor liquid crystal display (TFT-LCD) waste glass produced as glass–ceramics

The waste electrical and electronic equipment (WEEE) directives are designed to deal with the rapidly increasing waste stream comprised of electrical and electronic equipment. Recycling electrical and electronic equipment reduces the quantity of waste going to final disposal. The demand for thin film transistor liquid crystal display (TFT-LCD) panels, commonly used in everyday electronic products, is increasing. Conventionally adopted treatments of TFT-LCD waste glass cannot meet WEEE directives. This study adopts the following operating conditions in fabricating glass–ceramics: sintering temperature of 800–950 °C; sintering time of 6 h; and, temperature increase rate of 5 °C/min. The glass–ceramic samples then underwent a series of tests, including the Vickers hardness, water absorption and porosity tests, to determine product quality. The Vickers hardness was 12.1 GPa when fired at 900 °C for 6 h, and density was 2.4 g/cm 3 and water absorption was 0%. Thus, TFT-LCD waste glass can be regarded as a good glass–ceramic material.

Elucidating the hydration properties of paste containing thin film transistor liquid crystal display waste glass

This study discusses the thin film transistor liquid crystal display (TFT-LCD) waste glass-blended cement (WGBC) pastes. It presents their compressive strength, their products of hydration and solid silicates changes. The samples were subjected to Fourier transformation infrared spectroscopy, differential thermal and thermo-gravimetric analysis and 29Si magnetic angle spinning/nuclear magnetic resonance. The experimental XRD results demonstrated the speciation of the TFT-LCD waste glass, and that the major component was SiO 2. At 40% substitution of TFT-LCD waste glass, at 28 days and 56 days, the compressive strength was 35% and 30% lower, respectively, than that of the Portland cement paste. The intensity of the Ca(OH) 2 band at 3710 cm −1 in the 56-day hydrated products of the WGBC pastes that contain TFT-LCD waste glass exhibit comparatively weak peaks suggesting that much Ca(OH) 2 during hydration was consumed. Later, the C S H contents of the WGBC pastes increased, revealing that liberated Ca(OH) 2 was consumed in pozzolanic reactions.

Use of thin film transistor liquid crystal display (TFT-LCD) waste glass in the production of ceramic tiles

In this study, we employ the following operating conditions: varied pressure (25 kgf/cm 2), sintering temperature (900–1200 °C), sintering time (6 h), percentage of thin film transistor liquid crystal display (TFT-LCD) waste glass by weight (0–50%) and temperature rising at a rate of 5 °C/min, to fabricate clay tiles. The sintering characteristics of the clay blended with TFT-LCD waste glass tiles are examined to evaluate the feasibility of the reuse of TFT-LCD waste glass. TFT-LCD waste glass contains large amounts of glass. The TCLP leaching concentrations all met the ROC EPAs current regulatory thresholds. The addition of TFT-LCD waste glass to the mixture, increased the apparent weight loss. The incorporation of 50% TFT-LCD waste glass resulted in a significant increase in the porosity ratio of the specimens compared to the porosity ratio of the ceramic tile containing TFT-LCD waste glass. The main constituent in both the clay tile and the clay with TFT-LCD waste glass samples is quartz. Increasing the temperature resulted in an increase in the flexural strength and resistance to abrasion in the tiles. The porosity ratio decreases as shrinkage increases. The relation between the porosity ratio and the hardness of the tiles used in the study is also shown.

The effect of heating temperature of thin film transistor-liquid crystal display (TFT-LCD) optical waste glass as a partial substitute partial for clay in eco-brick

In order to fulfill the current WEEE directives, the traditional approach to manage thin film transistor-liquid crystal display (TFT-LCD) waste glass is inadequate. It is a serious opportunity to achieve resource conservation, reduction, stabilization and safety of management of TFT-LCD in the near future. To assist in achieving these goals, this study investigated the sintering characteristics and material properties of TFT-LCD waste glass, which can be pulverized and ground and subsequently blended with clay, at various substitution levels (0–40%) and finally fired from 800 °C to 1000 °C to make eco-brick. The brick thus produced was analyzed to determine variations in weight losses on ignition, 24-h absorption, bulk density, shrinkage, compressive strength and microstructure changes. The results for specific gravity, water adsorption, and compressive strength revealed that bricks made from mixtures containing TFT-LCD waste glass met the general requirements for bricks. The advantages of less water absorption, less weight loss on ignition, and a gain in compressive strength in the clay-TFT-LCD waste glass bricks should encourage the use of TFT-LCD waste glass as a brick additive.