Preparation and Characterization of Biocement Mortar Containing Silane-treated Nano-Si3N4 Prepared from Rice Husk Ash

Silicon - This present study aims to develop an eco-friendly high performance biocement using rice husk biomass derived nano Si3N4. The main aim of this study was to investigate the significant...     

Crystallization Kinetics on Melt Spun and HPT-Processed Zr62Cu22Al10Fe5Dy1 Metallic Glass

Metallurgical and Materials Transactions A - The influence of conventional and accumulative HPT (Acc. HPT) process on structural properties of Zr62Cu22Al10Fe5Dy1 metallic glass (MG) phase is...     

Photocatalytic Activity of Pure and Zinc Doped Tin Oxide Nanoparticles Synthesized by One Step Direct Injection Flame Synthesis

A very simple and rapid Direct Injection Flame Synthesis (DIFS) method is effectively used to synthesize pure tin oxide (SnO₂) and zinc doped tin oxide (Zn:SnO₂) nanoparticles from the metallic tin (Sn) and zinc (Zn) powders for the photocatalytic degradation of methylene blue (MB) dye. The DIFS nanoparticles were characterized using XRD, Raman, UV–Vis, FESEM, PL and EDX studies. The X-ray diffraction analysis indicated that the synthesized SnO₂ and Zn:SnO₂ nanoparticles have pure tetragonal phases and their average crystallite size decreases when Zn was doped with SnO₂. Raman study confirmed the various mode of vibrations and the crystal structure of the synthesized nanoparticles. Purity, atomic percentage and chemical composition were analysed using Energy dispersive X-ray analysis and found to be free from impurities. The band gap energy increases from 3.5 to 3.6 eV upon doping which was revealed from the UV–Visible spectroscopic analysis. Photoluminescence analysis confirms the red shifted emission for Zn:SnO₂ due to the oxygen deficiency. The CIE chromaticity (x,y) for SnO₂ and Zn:SnO₂ was calculated from the emission spectra and the co-ordinates represents blue and violet region respectively. Field Emission Scanning Electron Microscopy analysis showed that the pure SnO₂ nanoparticles have irregular, agglomerated, nanoflowered and nanoclustered formation whereas Zn:SnO₂ nanoparticles has more crystalline, cubical and nanoflake structure. The photocatalytic activity was enhanced due to the presence of Zn in SnO₂ under UV light irradiation. The efficiency of MB degradation by SnO₂ was found to be 82% and enhanced to 88% upon doping. Thus the Zn doped SnO₂ nanoparticles synthesized by DIFS was found to be an effective photocatalyst than the pure SnO₂.

     

Rapid Magnetically Directed Assembly of Pre-Patterned Capillary-Scale Microvessels

Capillary scale vascularization is critical to the survival of engineered 3D tissues and remains an outstanding challenge for the field of tissue engineering. Current methods to generate micro-scale vasculatures such as 3D printing, two photon hydrogel ablation, angiogenesis, and vasculogenic assembly face challenges in rapidly creating organized, highly vascularized tissues at capillary length-scales. Within metabolically demanding tissues, native capillary beds are highly organized and densely packed to achieve adequate delivery of nutrients and oxygen and efficient waste removal. Here, two existing techniques are adopted to fabricate lattices composed of sacrificial microfibers that can be efficiently and uniformly seeded with endothelial cells (ECs) by magnetizing both lattices and ECs. Ferromagnetic microparticles are incorporated into microfibers produced by solution electrowriting and fiber electropulling. By loading ECs with superparamagnetic iron oxide nanoparticles, the cells could be seeded onto magnetized microfiber lattices. Following encapsulation in a hydrogel, the capillary templating lattice is selectively degraded by a bacterial lipase that does not impact mammalian cell viability or function. This study introduces a novel approach to rapidly producing organized capillary networks within metabolically demanding engineered tissue constructs which should have broad utility in the fields of tissue engineering and regenerative medicine.