A new epoxide-mediated route for binary Al2O3-TiO2 aerogels

A new method for the synthesis of binary aerogels Al2O3-TiO2 by epoxide-mediated route was proposed. The synthesis is conducted in DMF solution, the starting materials for the synthesis are aluminium nitrate and titanium chloride. The obtained homogeneous amorphous aerogels possess high surface (250–750 m2/g) and porosity (86–95 %).

Design and simulation of a MEMS MIM capacitive pressure sensor with high sensitivity in low pressure range

In this paper, the improvement of the sensitivity of a capacitive MEMS pressure sensor is investigated. The proposed spring for the sensor can increase the sensitivity. Silicon is used as the substrate and gold and aluminium nitrate are used as the diaphragm and the dielectric layer, respectively. The dimensions of the diaphragm are 150 µm × 150 µm, which is suspended by four springs. The air gap between the diaphragm and the top electrode is 1.5 µm. The proposed structure is an efficient sensor for the pressures in the range of 1–20 kPa. By using the proposed design, the sensitivity of the MEMS sensor in 18 kPa has improved to 663 (× 10−3 pF/kPa).

Mixed-Phase Ion-Exchangers from Waste Amber Container Glass

This study investigated the one-pot hydrothermal synthesis of mixed-phase ion-exchangers from waste amber container glass and three different aluminium sources (Si/Al = 2) in 4.5 M NaOH(aq) at 100 °C. Reaction products were characterised by X-ray diffraction analysis, Fourier transform infrared spectroscopy, 27Al and 29Si magic angle spinning nuclear magnetic resonance spectroscopy and scanning electron microscopy at 24, 48 and 150 h. Nitrated forms of cancrinite and sodalite were the predominant products obtained with reagent grade aluminium nitrate (Al(NO3)3∙9H2O). Waste aluminium foil gave rise to sodalite, tobermorite and zeolite Na-P1 as major phases; and the principal products arising from amorphous aluminium hydroxide waste were sodalite, tobermorite and zeolite A. Minor proportions of the hydrogarnet, katoite, and calcite were also present in each sample. In each case, crystallisation was incomplete and products of 52, 65 and 49% crystallinity were obtained at 150 h for the samples prepared with aluminium nitrate (AN-150), aluminium foil (AF-150) and amorphous aluminium hydroxide waste (AH-150), respectively. Batch Pb2+-uptake (~100 mg g−1) was similar for all 150-h samples irrespective of the nature of the aluminium reagent and composition of the product. Batch Cd2+-uptakes of AF-150 (54 mg g−1) and AH-150 (48 mg g−1) were greater than that of AN-150 (36 mg g−1) indicating that the sodalite- and tobermorite-rich products exhibited a superior affinity for Cd2+ ions. The observed Pb2+- and Cd2+-uptake capacities of the mixed-product ion-exchangers compared favourably with those of other inorganic waste-derived sorbents reported in the literature.

Minimisation of pollution in the cotton fabric dyeing process with natural dyes by the selection of mordant type

Purpose This paper aims to select a type of mordant from aluminium salts, namely, aluminium sulphate, aluminium nitrate and polyaluminium chloride (PAC) with the lowest potential for contamination so that their use will minimise pollution from natural dye waste. It also aims to determine the pollution value of natural dye immersion waste from jackfruit wood extract, secang wood, mangsi fruit and several synthetic dyes, to identify potential environmental pollution. Design/methodology/approach Dyeing with natural dyes was performed by exhaust at room temperature by the pre-mordant method, while with synthetic dyes it was performed by exhaust according to the dyeing procedure (reactive, vat and naphthol). The groundwater, mordant solutions, natural dye extract and the waste-water from the natural and synthetic dyes were then tested to determine their biological oxygen demand (BOD5), chemical oxygen demand (COD), total suspended solids (TSS), pH, Al and heavy metal contents such as chromium (Cr), copper (Cu), cadmium (Cd), nickel (Ni), cobalt (Co) and lead (Pb). Findings Aluminium sulphate had the lowest pollution load while PAC had the highest, as aluminium sulphate had a higher BOD5/COD ratio (0.62–0.67) than aluminium nitrate (0.56–0.64) or PAC (0.44–0.54). The dyeing waste from the three natural dyes contained an acidic pH of 3.5–4.2, Al of 75.280–621.34 mg/L, Cr of 0.154–0.215 mg/L and Cu of 0.035–0.072 mg/L. The values of TSS, COD and BOD5 are higher than the quality standards of the waste but are environmentally friendly because the ratio of the BOD5/COD values from the waste ranges from 0.44–0.67. Research limitations/implications The findings indicate that as a mordant, aluminium sulphate results in lower pollution loads than aluminium nitrate and PAC. However, all three mordants contain Cr and Cu, albeit in negligible concentrations. Therefore, it is recommended that future studies strive to identify a mordant that has lower pollution loads and does not contain metals but can increase dyeing results to satisfy consumer requirements. It is the hope that, with the discovery of a new mordant, natural dyes will be the solution for the heavy metal pollution caused by synthetic dyes. Practical implications The use of environmentally-friendly mordants and natural dyes in the Indonesian textile and batik industry will give rise to superior quality eco-textile and eco-batik products. Such environmentally-friendly and high-quality products will not only increase competition and consumer interest but increase product sales as well which will, in turn, increase incomes and the economy. Additionally, an increase in the use of natural dyes by the textile and batik industry will serve as additional income to the communities and farmers from which the raw materials for the natural dyes are sourced thereby creating jobs and increasing welfare. Social implications As environmentally-friendly mordants and natural dyes replace the hazardous and toxic materials currently used in the textile and batik industry, it guarantees the health and safety of its consumers and workers. Furthermore, as the waste-water produced is biodegradable, it reduces river and groundwater pollution. It is, therefore, expected that this information will not only lead to a shift in attitude within the textile and batik industries but the adoption of environmentally-friendly materials, for the sake of the environment, as well as the development of eco-textile and eco-batik products. Originality/value Aluminium sulphate is a mordant type of aluminium salt with a lower potential for contamination than aluminium nitrate and PAC. However, PAC has been discovered to be a mordant for natural dyes, as has the fruit of the mangsi shrub, which has recently been discovered as a naturally occurring blue dye.

Water Pollution in the Arabian Gulf

Arabian Gulf water has been a victim over the years of the Gulf Wars which resulted in the spillage of millions of oil barrels. These have left a significant amount of pollutants that not only affect marine animals but also alter human lives by affecting soils, groundwater systems and environmental sustainability. This study aims to determine major pollutants that are present at the beaches of Abu Dhabi (a part of the Arabian Gulf). The examination of samples from four different locations was made around Abu Dhabi in the United Arab Emirates. These locations included Al Bateen Beach, Saadiyat Beach, Yas Beach and Ras Al Akhdar beach. The methodology included the analysis of pH, salinity, TDS, heavy metal and trace element levels of seawater. The results indicated no presence of heavy metals in any of the four locations. However, there were traces of copper, aluminium, nitrate and magnesium. The results concluded that it is important to maintain the sustainability of Arabian Gulf water because water is the most important natural resource on this planet.

Study of the Optical Characteristics of Aluminim Doped Zno Thin Film

In this work, the study on the influence of the aluminium on the optical properties of ZnO thin film was carried out with a focus on the influence of variation of aluminium ions on the optical behaviour of the ZnO thin film. The film was deposited on the glass substrates by chemical bath deposition technique and aluminium was used in the following varied quantity 0.1, 0.2, and 0.3M to dope the thin films respectively. The solutions were prepared using zinc sulphate, ammonia and Hexamine with aluminium nitrate. The optical characteristics of the film such as the spectral absorbance, reflectance and transmittance within the ultraviolet and near infra-red region of electromagnetic wave spectra were investigated using UV-VIS spectroscopy with the energy band gap found to be in the range of 3.5eV to 3.9eV.