Browsing by Author "Indrajit Tah"

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Structure-Property Correlation in Ba/Sr-Ca-Mg-Zn-Si-Al-O Glass: Elucidation by Experimental and Molecular Dynamics Simulation Study
(American Chemical Society, 2024) Sushanta Kumar Mohapatra; Indrajit Tah; Margit Fabian; Saswata Chakraborty; Prince Sen; Krishna K Dey; Manasi Ghosh; H.S. Maharana; Annapurna Kalyandurg
Broad band transmitting glasses from visible to mid-infrared with good mechanical strength, chemical durability, glass-forming ability, and thermal stability are preferred for optics and laser technology applications. Generally, low phonon energy glasses possess an extended transmission cutoff toward mid-infrared, but at the same time, retention of other desired properties is challenging for the researchers. In this work, we have shown that mixed alkaline earth (Ba/Sr) would have the potential to improve overall glass properties while retaining its low phonon energy when CaO is partially substituted by BaO/SrO in calcium magnesium zinc silica-aluminate (CMZSA) glass. Quantitative structure analysis of its role in glass properties has been carried out using molecular dynamics (MD) simulation and experimental techniques. This study reveals that Al and Si mainly attained fourfold coordination, while Zn and Mg majorly existed in Al-O-Zn/Mg triclusters. The Ba2+ ions play almost equal roles as charge compensators and network modifiers, while Sr2+ ions play a larger role in charge compensation. As a result, the SrO-added glass leads to the highest bridging oxygens as compared to others and corroborates with improved optical, thermal, and mechanical properties. Hence, the SrO-added glass shows the most stable network connection and improved overall glass properties. © 2024 American Chemical Society.
Tailored Bioactive Glass Coating: Navigating Devitrification Toward a Superior Implant Performance
(American Chemical Society, 2024) Anustup Chakraborty; Subhadip Bodhak; Indrajit Tah; Shashi Kant; Debolina Saha; Krishna K. Dey; Neelima Gupta; Manasi Ghosh; Sucheta Tripathy; Amarnath R Allu; Kaushik Biswas
The development of well-adherent, amorphous, and bioactive glass coatings for metallic implants remains a critical challenge in biomedical engineering. Traditional bioactive glasses are susceptible to crystallization and exhibit a thermal expansion mismatch with implant materials. This study introduces a novel approach to overcome these limitations by employing systematic Na2O substitution with CaO in borosilicate glasses. In-depth structural analysis (MD simulations, Raman spectroscopy, and NMR) reveals a denser network with smaller silicate rings, enhancing thermal stability, reducing thermal expansion, and influencing dissolution kinetics. This tailored composition exhibited optimal bioactivity (in vitro formation of bone-like apatite within 3 days) and a coefficient of thermal expansion closely matching Ti-6Al-4V, a widely used implant material. Furthermore, a consolidation process, meticulously designed with insights from crystallization kinetics and the viscosity-temperature relationship, yielded a crack-free, amorphous coating on Ti-6Al-4V substrates. This novel coating demonstrates excellent cytocompatibility and strong antibacterial action, suggesting superior clinical potential compared with existing technologies. © 2024 American Chemical Society.