Reprocessing waste things into a functional product gives two-edged benefits, an eco-friendly environment and waste management. Nowadays, Ceramic materials based on calcium phosphates, which include Nanohydroxyapatite (nHAp) and Tri-calcium Phosphates (TCP) were extensively used in biomedical applications for their outstanding biocompatibility and bioactivity properties. In this work, nHAp (pure) and its polymeric composites were prepared through the precipitation method using the coral skeleton as a calcium precursor. Besides, to change the surface functional characteristics, the polymers were utilized as a capping agent. The synthesized samples were examined by spectrographic tools such as XRD, FT-IR, SEM/EDAX, TG-DTA, XPS and HR-TEM to find the phase, functional groups, size, morphology and thermal stability together with phase transition as well as bonding types which present in the prepared samples respectively. In addition, Simulated Body Fluid (SBF) analysis, antimicrobial assay and hemolytic test were intended to test the apatite-forming ability, antimicrobial effectiveness and hemocompatibility of the prepared samples. Therefore, the present findings suggest the possibility of developing novel HAp polymeric nanocomposites that exhibit improved biocompatible, osteoconductive which impersonates the structure of natural human bone. So, that can use for making bone and dental implants using corals skeleton as a precursor at a lesser cost.

The necessity and usage of hydroxyapatite in the form of bone and dental substitutes are increasing day by day. Hydroxyapatite derived from natural biomaterials promotes better osteointegration and biocompatibility with host bone. The present investigation aims to compare the properties of three distinct naturally occurring calcium precursors (seashells, coral skeletons, and eggshells) derived from nHAp/PVA composites (Polymeric composites). All the prepared samples were examined through characteristic instruments such as XRD (X-ray diffraction), FT-IR (Fourier Transform Infrared) Spectroscopy, TG-DTA (Thermogravimetric-Differential Thermal Analysis), SEM/EDAX (Scanning Electron Microscopy/Energy Dispersive X-Ray Spectroscopy), and XPS (X-Ray Photoelectron Spectroscopy). Furthermore, the samples were subjected to the Simulated Body Fluid (SBF), Hemocompatibility and Antimicrobial assay to find the Bioactivity, Hemocompatible and Antibacterial efficiency of the samples. The surface morphology of seashell nHAp/PVA shows a spherical shape while coral and eggshell-derived nHAp/PVA exhibits rod-shaped morphology. However, the achieved particle is found to be in the range of 32 to 41 nm. Also, coral-derived nHAp/PVA composites show a maximum crystallinity of 83.7% with a minimum weight loss of about 49.96%. This study demonstrates that among the prepared samples, coral nHAp/PVA performs better, but in terms of availability, seashell/PVA takes the lead with good results in all aspects. Though the eggshell nHAp/PVA satisfies several characteristic studies, it shows less stableness on TG-DTA. This study suggests that both Seashells and Corals can be utilized as calcium precursors in the making of quality hydroxyapatite that can be further processed in the making of hard tissue replacements/substitutes.

The need and significance for quality bone graft substitute increases due to the worldwide increment in the health problems such as osteoporosis, accidental loss and teeth decay etc. Nowadays, nanohydroxyapatite and its polymeric composites are effectively used as bone grafts and dentin. In this work, nanohydroxyapatite (nHAp) and surface-modified nanohydroxyapatite were synthesized through the precipitation method using bio-wastes (eggshells) as a Calcium precursor. The polymers Polyethylene glycol (PEG) and polyvinyl acrylate (PVA) were used as surface modifiers to control the particle size. The prepared samples were analyzed through X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FT-IR), Thermogravimetric Differential Thermal Analysis (TG-DTA), Scanning Electron Microscopy (SEM), High-Resolution Transmission Electron Microscopy (HR-TEM) and X-ray Photoelectronic Spectroscopy (XPS). Also, the samples were subjected to simulated body fluid analysis, antimicrobial and hemolytic assay to analyze the apatite forming ability and hemolytic nature. The XRD, SEM and HR-TEM results show the crystallite and particle sizes are about 41 nm, 57 nm and 66.6 nm (rod-shaped) respectively. While the EDAX spectra show the presence of Calcium, Phosphate, Oxygen and Sodium in the prepared sample. However, the FT-IR spectra confirm the presence of OH, PO43-, and CO32- functional groups in the sample. The thermogram depicts the stability of nHAp/PVA composite is better than nHAp without polymer. This study reports that reprocessing of eggshells to nHAp and its composites paves the way to recover the ecosphere and the obtained value-added product, which may use in making a promising material for bone implants, dental fillers and coatings at low cost.

In this work, pure ZnO nanoparticles were prepared by the method of solid state reaction in different temperatures using zinc acetate as a pioneer material. The synthesized ZnO nanoparticles were charac-terized by the various spectrographic tools. The crystallinity nature and lattice parameters are studied through the XRD patterns and the average crystallite size is found to be 34.5 nm. The absorption peak in the FTIR spectra confirms the presence of functional group, whereas a UV-Vis spectrum is used to determine the optical properties of the sample. Furthermore, surface morphology, electronic structure and the magnetic properties of the ZnO nanoparticles were studied by using the SEM, Photoluminescence and VSM studies respectively. This particular method of synthesis is simple and easi-est method to obtain the pure ZnO nanoparticles with high crystallinity in nature. The obtained ZnO, have potential, engineering applications as materials for UV filtering shields with high transparency, lumines-cent materials without any toxic nature.Copyright (c) 2022 Elsevier Ltd. All rights reserved.Selection and peer-review under responsibility of the scientific committee of 2022 International Confer-ence on Recent Advances in Engineering Materials.

Recycling of massive waste into valuable products promotes two in one advantages of waste recovery and a pollution-free environment. Preparation of Nanohydroxyapatite (nHAp) and its polymer composites using waste sea shells (natural precursor) are effectively useful in making artificial bone implants, bone cement, and toothpaste additives. The present work is focused to obtain nHAp with good crystalline nature and better biocompatibility using Meretrix Meretrix Clam shells as raw materials by the Co-precipitation method. To enhance the physio-chemical properties, polymers were used as capping agents. The functional group, particle size, thermal stability, phase transition, surface morphology, and electronic transition of atoms of the synthesized samples have been analyzed by spectrographic tools such as FT-IR, XRD, TG/DTA, FESEM/EDAX, XPS and HR-TEM with EDAX mapping respectively. Furthermore, the bacterial sensitivity of the sample against bacteria, the efficiency of the sample towards the formation of an apatite layer over the surface and its hemocompatibility nature were studied by antibacterial, SBF analysis and hemolysis assay respectively. This method of synthesis is free from hard chemicals and harmful by-products. Thus, the report of the present study suggests that it is promising to achieve nHAp with enhanced surface modification which indirectly promotes bone-bonding capability with natural living bone.

Nowadays, Semiconducting thin films are the efficient candidates for good optical and electrical properties. In this study, the thin films of pure V2O5 together with 2 different molarities were prepared through the method of spray Pyrolysis. The prepared thin films were characterized by spectrographic tools such as XRD, FT-IR, UV-Vis and Hall effect to study their, crystalline nature, Functional group, band gap, resistivity, conductivity and mobility of the flow of electrons respectively. The structural morphology of the synthesized thin films was discussed through the micrographic image obtained from Scanning electron microscopy together with their surface occupancy plots. The obtained minimum crystallite size is about 26.8 nm for 4% molarities. The morphological and structural studies show enhanced results for 4% sample which makes it a viable candidature for optical and electrical applications.