Eco-Friendly Synthesis of Water-Glass-Based Silica Aerogels via Catechol-Based Modifier

Silica aerogels have attracted much attention owing to their excellent thermal insulation properties. However, the conventional synthesis of silica aerogels involves the use of expensive and toxic alkoxide precursors and surface modifiers such as trimethylchlorosilane. In this study, cost-effective water-glass silica aerogels were synthesized using an eco-friendly catechol derivative surface modifier instead of trimethylchlorosilane. Polydopamine was introduced to increase adhesion to the SiO2 surface. The addition of 4-tert-butyl catechol and hexylamine imparted hydrophobicity to the surface and suppressed the polymerization of the polydopamine. After an ambient pressure drying process, catechol-modified aerogel exhibited a specific surface area of 377 m2/g and an average pore diameter of approximately 21 nm. To investigate their thermal conductivities, glass wool sheets were impregnated with catechol-modified aerogel. The thermal conductivity was 40.4 mWm−1K−1, which is lower than that of xerogel at 48.7 mWm−1K−1. Thus, by precisely controlling the catechol coating in the mesoporous framework, an eco-friendly synthetic method for aerogel preparation is proposed.

The Resource Base of Silica Glass Sand versus Glass Industry Development: The Case of Poland

The production of glass in Poland, especially of container and flat glass, has constantly risen for at least 30 years. New investments in this sector, which have recently been completed or are currently in progress, create optimistic prospects for further development of this industry, whose total annual production capacities in the next few years is expected to exceed 4 million tons. This will result in increasing demand for basic glass-making raw materials, especially high-quality silica sand (glass sand), which can be satisfied almost entirely from domestic sources. Poland as a country with a considerable resource base of these mineral raw materials, has noted a constantly growing production level that currently reaches approximately 2.8 million tons per year. This paper aims to characterize and interpret the development trends in the Polish glass industry in an international context, as well as the resulting increase in demand for glass sand. In this context, an attempt was made to answer questions concerning the sufficiency of the Polish domestic resource base for the production of glass sand. For this study, the leading recent international and Polish analyses, related to glass industry development, the resource base of glass silica sand, and the management of these types of sand, were taken into account, and were complemented by official statistical data and surveying of domestic glass producers. The performed analysis showed that when taking into account the available glass sand resources in developed deposits in Poland, it is possible to continue production at the existing or a slightly increasing level for another 20–25 years. Based on a more comprehensive perspective, however, it would be a good approach to continue providing access to those parts of currently extracted deposits of silica sand and sandstone that are now located outside of the existing exploitation licenses, as well as enabling the development of some satellite deposits in the Tomaszów Basin, which may prove difficult due to environmental factors.

Study of Microleakage between Teeth and Glass Ionomer Cement Modified with 5% Silica from Sea Sand

Glass ionomer cement (GIC) is the most commonly used restoration material because of biocompatible material. GIC is restoration material that can be attached to enamel either to dentin physicochemically. The adhesion properties of teeth to restoration have an effect on marginal adaptation. This causes different attachment values. An alternative difference in attachment can be achieved by adding bioactive glass silica material to glass ionomer cement. The formation of hydroxyapatite can be occurred by bioactive glass silica between the tooth surfaces and the restoration materials and it is been expected to reduce microleakage rates. The purpose of this study was to seen the effect of adding 5% silica nanoparticles from sea sand to the GIC on microleakage rates. In this study, silica was synthesized from sea sand by using coprecipitation method. Specimens were 20 maxillary premolars were classified into two groups which were applied GIC (n=10) and silica 5% modified GIC as restorations (n=10). The specimens were immersed in 5% methylene blue solution for 24 hours, then were observed under stereomicroscope and SEM. There were a difference score microleakage and mean value of distance between silica 5% modified GIC with enamel and dentin had smaller distance, as compared to GIC.

Influence of Glass Silica Waste Nano Powder on the Mechanical and Microstructure Properties of Alkali-Activated Mortars

The recycling of millions of tons of glass bottle waste produced each year is far from optimal. In the present work, ground blast furnace slag (GBFS) was substituted in fly ash-based alkali-activated mortars (AAMs) for the purpose of preparing glass bottle waste nano-powder (BGWNP). The AAMs mixed with BGWNP were subsequently subjected to assessment in terms of their energy consumption, economic viability, and mechanical and chemical qualities. Besides affording AAMs better mechanical qualities and making them more durable, waste recycling was also observed to diminish the emissions of carbon dioxide. A more than 6% decrease in carbon dioxide emissions, an over 16% increase in compressive strength, better durability and lower water absorption were demonstrated by AAM consisting of 5% BGWNP as a GBFS substitute. By contrast, lower strength was exhibited by AAM comprising 10% BGWNP. The conclusion reached was that the AAMs produced with BGWNP attenuated the effects of global warming and thus were environmentally advantageous. This could mean that glass waste, inadequate for reuse in glass manufacturing, could be given a second life rather than being disposed of in landfills, which is significant as concrete remains the most commonplace synthetic material throughout the world.

Study of a silica glass SiO2-Na2O refractive index to fabrication of fiber optic with Brewster method

<p align="justify">One of the critical parameters in the fabrication of fiber optic is refractive index value from the fiber optic material. That is because the main requirement phase of critical angle on the fiber optic waveguide is a core refractive index higher than the cladding. Therefore, refractive index values must be calculated first. The research aim is to study refractive index value of fiber optic material on the fiber optic fabrication. Refractive index value determined by using the brewster method. For this aim, the first step is an establish glass silica to a thin plate. Then thin plate inserts to the sketch of brewster experiment. The brewster method has the aim to determine the reflectance value of the light on transfer magnetic (TM) polarization. The Brewster angle determined by searching the minimum reflectance value of the light on this TM polarization. In this research, the brewster angle obtained by 55.333 degrees. This brewster angle used to calculate the refractive index value from the fiber optic material glass silica. The result of refractive index value at 1.446.</p>