Advanced Materials Research Vol. 1185

Abstract: The different characteristics of nanoparticles (NPs) are mostly determined by the sintering process. The goal of the current study is to examine how the sintering temperature affects the optical and structural characteristics of Y₂O₃ NPs made using the sol-gel method. For a competitive study, the synthesized Y₂O₃ NPs were sintered for three hours at 300, 600, and 900°C. The generated Y₂O₃ NPs were sintered for three hours at 300, 600, and 900°C in this work. Samples of Y₂O₃ NPs are designated Y1, Y2, Y3, and Y4, in that order. The cubic structure of Y₂O₃ NPs is confirmed by XRD examination, which also corresponds to JCPDS card No. 083-0927. For Y1, Y2, Y3, and Y4, the crystallite sizes were determined to be 12.58, 12.24, 12.05, and 09.16 nm, respectively. The optical characteristics, such as energy bandgap fluctuations and light absorption, were investigated using UV-Vis spectroscopy. Usually, the absorbance peak shows up between 230 and 250 nm. For Y1, Y2, Y3, and Y4, the energy band gap was determined to be 4.51, 4.40, 4.31, and 4.19 eV, respectively. The vibrational modes of the Y₂O₃ NPs are examined, which provides further evidence of phase purity and structural stability. Increased band gap, better crystallinity, and a lower percentage of oxygen atoms all help the material's mechanical and chemical durability as well as its shine, which makes it more suitable for dental ceramic applications.

Abstract: TiO₂-based photocatalysis has attracted a lot of interest due to its potential to capture solar energy and drive important processes including the breakdown of pollutants and the development of sustainable energy sources. A series of magnesium, zinc, and cobalt nitrate nanocomposite samples with TiO₂ semiconductor nanocomposite samples have been successfully produced by employing a simple and very effective combustion technique with the oxidizing gas urea. Prepared pure TiO₂ nanoparticle was found to have a bandgap of 3.3 eV and a crystalline size of 57.8 nm. For Co, Mg, and Zn doped TiO₂, X-ray diffraction (XRD) studies show cubic, orthorhombic, and tetragonal crystalline structures with crystalline diameters ranging between 37 nm, 46 nm, and 87 nm. Optical study has demonstrated the absorbance, transmittance, and bandgap measurements of Co, Mg, and Zn doped TiO₂. The higher provider density brought on by the Brustein-Moss impact is responsible for the bandgap values' shift to higher energies, which vary from 4.43 eV to 5.35 eV. Visiblei light irradiation was used to measure the degradation of Rhodamine-B (RhB) dye; Co, Mg, and Zn doped TiO₂ explained high photocatalytic activity, which was thoroughly described. The addition of additional energy levels to the TiO₂ bandgap by the dopants results in a wider spectrum of light absorption and more effective use of solar radiation. Here reported the parameters affect how well TiO₂ nanoparticles infused with Mg, Zn, and Co perform photocatalysis.

Abstract: With a high melting point (>2400°C), superior thermal conductivity, and a large band gap (5.8 eV), Y₂O₃ exhibits a high dielectric constant (14–18), a refractive index of ~1.9, and excellent chemical resistance. Its low phonon vibration frequency (~380 cm⁻¹) enables efficient energy transitions for rare-earth (RE) ions, enhancing its suitability as a host for luminescent phosphors. In this study, Y₂O₃ nanoparticles doped with Eu³⁺ and sensitized with either Li⁺ or Bi³⁺ were synthesized via polyol method. A comparative investigation was conducted to evaluate the energy transfer efficiency and luminescence enhancement provided by each sensitizer. Structural and morphological characteristics were examined using X-ray diffraction (XRD) and transmission electron microscopy (TEM), while Fourier-transform infrared spectroscopy (FT-IR) was employed to study absorption features. Photoluminescence (PL) analysis revealed the impact of sensitizer ions on emission intensity, identifying the most effective combination for optimized luminescent performance. These findings demonstrate the potential of sensitized Y₂O₃:Eu³⁺ nanoparticles for advanced luminescence-based applications.

Abstract: This study aims to determine the key thermal parameters of plastic waste degradation, specifically polyethylene terephthalate (PET), polypropylene (PP), and polystyrene (PS), using differential scanning calorimetry (DSC), differential thermogravimetry (DTG), and thermogravimetric (TG) analysis. The thermal stability of these materials was evaluated by analyzing residual solid and wax quantities, conversion percentages, liquid and gas product yields, and process duration. Experiments were conducted at 550–600°C with a heating rate of 50°C/min. Key thermal parameters investigated include onset decomposition temperature, temperature at 50% conversion, completion temperature, maximum DTG temperature, peak DTG value, melting point, and pyrolysis temperature. The activation energy for mass loss was calculated, ranging from 35 to 68 kcal/mol, with PS exhibiting the highest thermal stability (68 kcal/mol). The degradation conversion efficiency ranged from 85% to 99%. Notably, PET pyrolysis produced significantly more solid residues (0.136–0.150 g/g₀) than PP and PS (0.006–0.088 g/g₀). These findings provide valuable insights into the thermal behavior of plastic waste, supporting advancements in waste management and energy recovery applications.

Abstract: The discharge of antibiotics such as cefuroxime (CFX) into the environment poses significant risks to human health and aquatic ecosystems due to the emergence of antibiotic resistance. This study evaluated the efficiency of Blighia sapida leave-derived biochar (BSLB) as an eco-friendly and cost-effective adsorbent for removing CFX from aqueous media. Effect of adsorption operating parameters such as BSLB dosage, contact time, temperature, and initial CFX concentration were investigated. Extent of CFX removal was discovered to differ with contact time, adsorbent dose, temperature and initial concentration of drug. Adsorption isotherm and kinetics parameters of the CFX molecule sequestration process were also evaluated Pseudo-second-order kinetics adequately described the adsorption process, which indicates chemisorption is the most plausible mechanism for CFX removal. The Langmuir isotherm model is found to be the best appropriate to describe the adsorption process. The monolayer saturated adsorption capacity of BSLB was found to be 33.50 mg/g. Regeneration experiments demonstrated over 80% efficiency after four cycles, confirming the reusability of the prepared biochar. Therefore, the as-prepared Blighia sapida leave-derived biochar found to be efficient and sustainable biosorbent for the CFX antibiotic removal from liquid phase media.

Abstract: This research investigates the effective moisture diffusivity (D_eff) and energy activation (E_a) as it affects thin layer drying of white yam (Dioscorea rotundata) slices using hybrid drying system under different parameters. These factors helps researchers and food producers to develop optimized drying processes for yam slices in order to minimize drying time, improve energy efficiency, and maintain high product quality. The experimental analysis highlight the interplay between pretreatments (Blanching, B; Sodium metabisulfite, SNa; Neem bark extract, SNBE and Control, C), drying systems (indirect solar drying: ISD and solar-powered hot-air supplemented drying: SPHSD under 0.8 m/s and 1.2 m/s air velocity, and air temperatures of 50 °C, 60 °C, and 70 °C) and slice thickness (5 and 3 mm) on white yam slices during drying. Important data were obtained using Arduino based data logging system for accuracy. Mass transfer during the entire drying of the yam slices took place entirely in the falling drying rate period and was described using Fourier approach based on Fick’s second equation of diffusion. The result demonstrated that D_eff and E_a is significantly affected by petreatment, slice thicknesses, air velocity and drying system. D_eff increased with rising drying temperature and air velocity. However, SPHSD, at 5 mm thickness exhibited a decrease in D_eff compared to 3 mm with values ranging from 1.647 × 10^-10 to 2.790 × 10^-10 m²/s within the investigated parameters. In contrast, ISD and sun-dried yam slices displayed relatively lower and fluctuating D_eff values (not higher than 1.4 × 10^-10), likely due to intermittency in solar radiation. Specific energy consumption varies from 6184.373 J/kg.K to 4620.571 J/kg.K for different thicknesses, temperature and air velocity. Thermal efficiency values which decreases with increased slice thickness ranges from 52.539 % to 39.347 %. Drying efficiency increases with increased temperature and air velocity for SPHSD (87.020 % to 93.169 %) while ISD has the least at 54.196 %.

Abstract: Recently, there has been a growing interest in replacing synthetic fibres with natural fibres in polymer composites due to environmental concerns. This study examined the fibres from the Newbouldia laevis plant for their potential use in lightweight polymer composites, particularly in applications sensitive to strength and temperature. The fibres were extracted from the plant's stem, and various properties such as density, moisture content, moisture regain, and diameter were measured. Chemical analysis revealed the percentages of cellulose, hemicellulose, lignin, extractives, and ash present in the fibres. Furthermore, Fourier transform infrared analysis confirmed the presence of these essential components. Scanning electron microscopy images showed the rough surfaces of the fibres, which enhance the adhesion between the fibre and matrix during the production of polymer composites. Energy dispersive X-ray analysis identified carbon and oxygen as the main elements in the fibres. Thermal analysis provided insights into the thermal stability and maximum degradation temperatures of the fibres. Lastly, a single fibre tensile test was performed to evaluate the tensile strength, elastic modulus, and elongation at break of the fibres using Weibull distribution statistical analysis. The results of this study indicate that Newbouldia laevis fibres could be a promising reinforcement for lightweight polymer composites in strength and temperature-sensitive applications.

Abstract: The construction industry plays a vital role in the economic development and overall progress of any country. Construction activities have significant impact on the economy, but their environmental consequences cannot be overlooked. The excessive use of construction materials particularly cement and steel, which are among the most commonly used construction materials, has become a major environmental concern, as these materials are also key sources of carbon emissions. Moreover, the raw materials required for the preparation of cement and Steel are also depleting at a rapid pace. Therefore, it is necessary to conduct research studies to find new alternative materials which can reduce the consumption of cement and steel in the concrete. Fly ash can be used as binding agent in concrete as it has good cementation properties and is abundantly available. To enhance the mechanical performance of geopolymer concrete (GPC), polypropylene fibers (PPFs) were incorporated in varying ratios (0.5% to 1.5% by volume). The samples were prepared to test the mechanical and durability properties of the concrete. Compressive Strength, Flexural Strength, and Split Tensile Strength test was carried out to conclude the mechanical properties of the geopolymer concrete against different percentages of polypropylene Fiber. Acid attack and rapid chloride permeability tests were conducted out to evaluate the durability of the concrete. The research findings depicted that the greatest compressive strength and split tensile strength are obtained at 1% PPFs GPC. The least amount of chloride penetration was demonstrated by GPC, at 1.5% PPFs.

Abstract: Crystallization of a salt in a porous medium can lead to the generation of stresses on the pore wall. This stress generation mechanism causes the phenomenon of surface heave, i.e. the upward displacement of the porous material surface.This surface heave phenomenon is studied from experiments with random packings of particles (glass beads) confined in a quasi-2D cell when the crystallization of sodium chloride is induced by evaporation. It is shown that the grain size has a significant impact on the surface heave. In addition, it show the existence of an optimal grain size maximizing the heave. This suggest that the bead size dependence is not related to the mechanical aspect of the problem but is rather linked to the impact of the bead size on the morphology and internal properties of the growing subflorescence.