Dheeraj Kumar Gara

The inclusion of the metal based therapeutic ions into bioactive glasses received potential towards tissue regeneration applications due to their excellent biocompatible, mechanical and wear properties. In the current work, one such configuration is chosen, strontium (Sr) and Copper (Cu) ions based bioactive borosilicate glass system i.e., [Formula: see text] with varying composition of Sr and Cu for 0, 1 and 2 wt.%. The glasses were prepared through melt quench process and the as prepared specimens are characterized for their microstructural, mechanical, tribological, biocompatible and biological investigations. The results were found to appealing with microstructure and crystallographic peaks displaying the presence of extracted natural Silica (Si) and Calcium (Ca) powders. Further the same specimens are characterized for their mechanical strength and it was found to be 55.21MPa compressive strength and lowest specific wear rate overall for CuSr-1 wt.% composition. Being CuSr-1% displaying better mechanical properties, the same samples i.e., Cu, Sr for 1wt.%, were investigated for their biocompatible studies through Simulated Body Fluid immersion protocol. The SBF studies indicate the formation of hydroxyapatite that can be inferred from crystallographic peaks and Fourier Transform Infrared Spectroscopy. The samples were also exposed to antibacterial studies against Escherichia coli (E. coli) and Staphylococcus aureus (S.aureus) and are found to exhibit excellent antibacterial activity. The observed selective antibacterial activity highlights the potential of these bioactive glasses as advanced materials for load-bearing orthopaedic implants and bone tissue engineering scaffolds, where the simultaneous requirements of mechanical robustness and antimicrobial efficacy are critical for clinical success.

The composition of constituent elements in bioactive glasses is critical for achieving properties suitable for biological applications. Even minor compositional variations can significantly alter the system’s response. This study investigated silica-based bioactive glasses doped with 2, 4, and 6 wt% bismuth (Bi), utilizing an Analysis of Variance (ANOVA) model with a Central Composite Design (CCD) to examine the influence of compositional changes on structure and properties. Physical properties were characterized using Zeta potential measurements for stability, Scanning Electron Microscopy (SEM) for nanoparticle size, and Brunauer-Emmett-Teller (BET) analysis for porosity. Post-Simulated Body Fluid (SBF) investigations included transmission electron microscopy (TEM) with Selected Area Electron Diffraction (SAED) to observe hydroxyapatite (HA) formation, Energy-Dispersive X-ray (EDX) spectroscopy for compositional analysis, Fourier Transform Infrared (FTIR) spectroscopy to evaluate nanoparticle functional characteristics, and X-ray Photoelectron Spectroscopy (XPS) to determine the oxidation state of Bi. A correlation between physical properties and constituent composition was established through ANOVA. The predicted and actual values were consistent with the selected optimization model. In vitro assays confirmed the bioactivity of the synthesized samples, which were found to be biocompatible and non-cytotoxic for the intended applications.

Thermal cracking of SAE 40 lube oil contamination is a critical process for maintaining the efficiency and longevity of industrial machinery and automotive engines. This study investigates the mechanisms and outcomes of thermal cracking as a method to decompose and remove contaminants from lube oil (SAE40) and investigates the possibility of the use of solid coke produced as residue after the cracking process. The research also examines the optimal conditions for thermal cracking, including temperature ranges, heating rates, and the influence of catalysts. Analytical techniques such as thermogravimetry (TGA), Fourier-transform infrared spectroscopy (FTIR), and thermograms (DSC) are employed to characterize the chemical composition of the solid produced after treatment. This result reveals that the produced coke after the treatment demonstrates the resin capability, and it can be used as a binder or additive in lower temperature applications. This study underscores the potential of thermal cracking as an effective method for recycling contaminated lube oil, thereby contributing to sustainability and cost-efficiency in industrial maintenance practices.

Supercapacitors have garnered substantial interest owing to their capacity to deliver power effectively for short-term applications. However, current supercapacitors suffer from limited stability and low-capacity storage. Metal-organic frameworks (MOFs) have emerged as a promising solution due to their high surface area and abundant active redox sites. MOF-based electrodes combined with aqueous based electrolytes have shown potential to enhance supercapacitor performance. While there is limited literature on MIL-101(Fe) MOF-based electrodes, a comparative study was conducted to investigate the supercapacitor performance of MIL-101(Fe) electrodes synthesized using hydrothermal and microwave-assisted processes. Processing parameters, such as the method used, alter the microstructure, morphology, and uniformity of supramolecular chemistry, impacting electrochemical characteristics. This study aimed to determine the active redox reactions, chemical stability, surface area, adsorption characteristics, and electrochemical characteristics of the electrodes. The electrodes from hydrothermal synthesis [MF(ht)] exhibited excellent electrochemical activity in comparison to the microwave-assisted [MF(m)] electrodes in the three-electrode configuration. At a high current density of 7 A/g, the MF(ht) electrode displayed a remarkable specific capacitance of 775.6 F/g and a good cyclic stability (82% @ 10 A/g) after 5000 galvanostatic charge–discharge cycles. At a current density of 1 A/g, the two-electrode configuration of MF(ht) yielded a high energy density of 74.7 Wh/kg at a power density of 2160 W/kg and a decent cyclic stability after 5000 cycles. The results suggest that the MF(ht) electrodes possess remarkable electrochemical properties that make them a promising candidate for advanced applications in energy storage.

In this work, MoSe₂-WS₂ nanocomposites consisting of WS₂ nanoparticles covered with few MoSe₂ nanosheets were successfully developed via an easy hydrothermal synthesis method. Their nanostructure and photocatalytic hydrogen evolution (PHE) performance are investigated by a series of characterization techniques. The PHE rate of MoSe₂-WS₂ is evaluated under the white light LED irradiation. Under LED illumination, the highest PHE of MoSe₂-WS₂ nanocomposite is 1600.2 µmol g⁻¹ h⁻¹. When compared with pristine WS₂, the MoSe₂-WS₂ nanostructures demonstrated improved PHE rate, which is 10-fold higher than that of the pristine one. This work suggests that MoSe₂-WS₂ could be a promising photocatalyst candidate and might stimulate the further studies of other layered materials for energy conversion and storage.