IR@CGCRI - Central Glass and Ceramic Research Institute (CSIR)
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In Vitro and In Vivo Bone Regeneration Assessment of Titanium-Doped Waste Eggshell-Derived Hydroxyapatite in the Animal Model
No full textInthis work, a titanium-doped hydroxyapatite (HAp) scaffold wasproduced from two different sources (natural eggshell and laboratory-gradereagents) to compare the efficacy of natural and synthetic resourcesof HAp materials on new bone regeneration. This comparative studyalso reports the effect of Ti doping on the physical, mechanical,and in vitro as well as in vivo biological properties of the HAp scaffold.Pellets were prepared in the conventional powder metallurgy route,compacted, and sintered at 900 & DEG;C, showing sufficient porosityfor bony ingrowth. The physical-mechanical characterizations wereperformed by density, porosity evaluation, XRD, FTIR, SEM analysis,and hardness measurement. In vitro interactions were evaluated bybactericidal assay, hemolysis, MTT assay, and interaction with simulatedbody fluid. All categories of pellets showed absolute nonhemolyticand nontoxic character. Furthermore, significant apatite formationwas observed on the Ti-doped HAp samples in the simulated body fluidimmersion study. The developed porous pellets were implanted to assessthe bone defect healing in the femoral condyle of healthy rabbits.A 2 month study after implantation showed no marked inflammatory reactionfor any samples. Radiological analysis, histological analysis, SEManalysis, and oxytetracycline labeling studies depicted better invasionof mature osseous tissue in the pores of doped eggshell-derived HApscaffolds as compared to the undoped HAp, and laboratory-made samples.Quantification using oxytetracycline labeling depicted 59.31 & PLUSMN;1.89% new bone formation for Ti-doped eggshell HAp as compared toTi-doped pure HAp (54.41 & PLUSMN; 1.93) and other undoped samples. Histologicalstudies showed the presence of abundant osteoblastic and osteoclasticcells in Ti-doped eggshell HAp in contrast to other samples. Radiologicaland SEM data also showed similar results. The results indicated thatTi-doped biosourced HAp samples have good biocompatibility, new bone-formingability, and could be used as a bone grafting material in orthopedicsurgery
Machine Learning-Assisted Design of Na-Ion-Conducting Glasses
No full textAsan alternative to liquid electrolytes, all-solid-state sodium-ionbatteries are receiving significant attention due to their potentialfor improved safety and efficiency. Here, we propose a combined experimentaland machine learning (ML) approach for discovering glass electrolyteswhile also providing insights into the role of different glass components.Specifically, we experimentally prepare and measure the ionic conductivityof 27 glass compositions of the sodium aluminophosphate glass family.Further, we train ML models on this dataset to predict the ionic conductivity,which exhibits excellent agreement with the experimental results.We interpret the composition-conductivity relationship learnedby the ML model using Shapely additive explanations (SHAP), whichreveals the role played by the glass components in governing the conductivity.Employing these observations, glass compositions with improved conductivityvalues are predicted and experimentally validated. The results corroboratethe insights from SHAP analysis and enable optimized glass formulationsin real-world experiments. This demonstrates how ML tools can significantlyaccelerate the discovery of Na-ion-conducting glass electrolytes
Evolution of microstructure, magneto-structural transformation, and magnetocaloric effect in(Fe72-0.9xNi8-0.1xCo8)Zr7B4Cu1Gax (0 <= x <= 6 at. %) alloys
No full textWe report the evolution of microstructure, magnetic properties, and magnetocaloric effects in a series of (Fe72-0.9xNi8-0.1xCo8)Zr7B4Cu1Gax (0 gamma-Fe transformation occurred in the range of 691-733 K in arc -melted ingots (AMIs), whereas the same occurred at 660-723 K in as-spun ribbons (ASRs). The Curie temperature of gamma phase lies in the range of 1126-1140 K and 1106-1126 K for AMIs and ASRs, respectively. Addition of Ga reduces the saturation magnetization and induce nanocrystallization in ASRs. A second-order magnetic transition has been identified in x = 0 ASR using Arrott plot exhibiting magnetic entropy change (|Delta SM|) of 0.973 J/kg.K at T gamma C under magnetic field of 0.976 T. The refrigeration capacity of x = 0 and x = 6 ASRs has been estimated to be 12.78 J/kg and 22.98 J/kg, respectively, at 0.976 T
SiO2 Nanoparticles Incorporated Poly(Vinylidene) Fluoride Composite for Efficient Piezoelectric Energy Harvesting and Dual-Mode Sensing
No full textFlexible electronic skins (e-skins) have a wide range of applications in health monitoring, human-machine interfaces, and robotics. Herein, a novel architecture of e-skins with a combination of multimode measurement and low-cost implementation is proposed. A single electronic skin layer is used to integrate both the pressure and temperature sensing properties. An e-skin membrane is first developed with poly(vinylidene) fluoride incorporated with silicon dioxide nanoparticles. When combined with electrodes, this simple architecture allows the implementation of multimode pressure and temperature sensing. This e-skin exhibits excellent pressure sensitivity with a response time of 1.6 ms. This sensing performance can be attributed to the uniform distribution of the embedded nanoparticles, leading to an enhancement of the electroactive beta phase. This e-skin generates a voltage, from the finger movements, that can be used to detect precisely the minute changes of the finger movement. This electronic skin demonstrates the detection of a linear range of temperature which can be attributed to the phonon-assisted hopping mechanism. A 4 x 4 pressure sensing array is demonstrated, which is able to map the inserted pressure as well as temperature stimuli. Thus, this study provides a new conceptual design for the next-generation green electronic skins
Magnetron sputtered films prepared from sintered Ti-based target and evaluation of tribological properties under the ball on disc condition with varying thickness and load
No full textThe hard nanocomposite coatings comprised of titanium, silicon, boron, and carbon (Ti-Si-B-C) and titanium, silicon, boron, carbon, and nitrogen (Ti-Si-B-C-N) were deposited on SS 304 substrate using magnetron sputtering technique. The tribological properties of these Ti-Si-B-C and Ti-Si-B-C-N coatings were explored with the variation of load (200-600 g) and thickness (3-25 mu m) against high strength steel ball using a ball on a disc tribometer. The nanoindentation technique was used to investigate the wear tracks and its consequent effect on the mechanical behaviour of uncoated and coated films. The analyses of the phases, microstructure, states of valence, shift of electron, and elemental compositions of the coatings were carried out by HRTEM, FESEM, AFM, XPS, EDX, and Raman spectroscopy techniques, respectively. The 2D cross-sectional profiles and 3D topographies of the wear tracks were explored using a 3D profilometer. All these studies established that the 10 mu m thick titanium-based sputtered nanocomposite coatings on SS 304 are efficient wear-resistant materials that showed excellent protection of the substrates from wear up till application of 500 g load. A good correlation between the composition, structure, properties, and processing of materials has been discussed based on the obtained wear behaviour
Low Expansion Glass-Ceramics Using Industrial Waste and Low-cost Aluminosilicate Minerals: Fabrication and Characterizations
No full textThe recycling of the wastes towards value added product development has become a prime challenge. In this work, a low thermal expansion glass-ceramic material based on ternary LAS (Li2O-Al2O3-SiO2) system has been prepared by adopting meltquenching route using industrial waste (blast furnace slag) and low-cost aluminosilicate minerals (China clay and pyrophyllite) at relatively low melting temperature (similar to 1450 degrees C). A part of the precursor powder for pristine glass has also been prepared by sol-gel processing utilizing Li2CO3 and Al(NO3)(3).9H(2)O to obtain better homogeneity in the glass composition vis-a-vis glass-ceramics at lower melting temperature. Thermal properties of the material have been characterized to optimize the nucleation and crystallization temperatures for converting glass to glass-ceramics. Phase structure and surface morphology of the glass-ceramics have been analyzed by X-ray diffraction (XRD) and field emission scanning electron microscopy. XRD study reveals the presence of lithium aluminosilicate as a major phase at the crystallization temperature of 730 degrees C. The developed glass-ceramics show a low thermal expansion coefficient (CTE) value of (19 +/- 0.5)x10(-7)/degrees C in the temperature range of 30 degrees-500 degrees C. The present work can unfold an avenue towards conversion of waste into wealth in the form of low CTE glass-ceramics for possible application as cook-top plate of LPG gas oven
Amphiphilically engineered sodium deoxycholate based nanocomposite hydrogels with strong bactericidal and water absorption characteristics
No full textSoft naturally occurring biodegradable low molecular weight (LMW) gels with high water absorption capacity and inherent antibacterial properties are significant for applications in wound healing patches, personal hygiene products and soft tissue regeneration. Herein, we report novel naturally occurring bile acid based nanocomposite hydrogels derived from sodium deoxycholate (NaDC) and reduced graphene oxide (rGO) as well as amphiphilic sodium dodecylsulfate (SDS) modified rGO. Introduction of rGO and SDS-rGO in the NaDC hydrogel induces 7L-7L stacking in the nanocomposite hydrogels as well as enhances H-bonding interactions significantly yielding long range order as reflected by FTIR, sol-gel transition temperature, XRD, rheology and SEM studies. Among pure NaDC, rGO-NaDC and SDS-rGO NaDC xerogels, the latter is found to exhibit more than 10 times increased water absorption capacity compared to the pure NaDC gels which is attributed to the amphiphilic modification imparting increased H-bonding in the corresponding gel. Highest viscosity of SDS-rGO-NaDC hydrogels followed by rGO-NaDC and pure NaDC hydrogels further confirm the improved interactions. The emergence of antibac-terial activity in SDS-rGO gel unlike its precursors as well as pure NaDC and rGO-NaDC gels is assigned to the dehydration induced bacterial cell death resulting from its high water absorption capacity imparted by its enhanced H-bonding. Thus, SDS-rGO NaDC gel obtained through a facile alteration of physical forces exhibiting antibacterial activity along with appreciable water absorption capacity and stability under applied stress in-dicates its strong applicability in biodegradable and biocompatible antibacterial wound healing patches
Properties of Water Atomized 25Cr7Ni Stainless Steel Processed by Laser-Powder Bed Fusion
No full textThe 25Cr7Ni stainless steel is characterized by its two-phase microstructure consisting of ferrite and austenite, contributing to an excellent combination of mechanical and corrosion properties. The present study examined the effects of laser energy density and laser powder bed fusion (L-PBF) process parameters on the physical, mechanical and corrosion properties of a water atomized 25Cr7Ni stainless steel powder processed through L-PBF. The results from the study saw that a combination of L-PBF process parameters (laser scan speed and laser scan spacing at a constant layer thickness) as critical factors affecting the mechanical and corrosion properties of the printed samples. The Archimedes density, mechanical and corrosion properties of samples improved with increase in energy density. The as-printed samples displayed single-phase ferritic microstructure and higher mechanical strength (1050 MPa) compared to wrought, metal injection molded (MIM), powder metallurgically sintered (PM) 25Cr7Ni stainless steel (super duplex stainless steel) alloys. The samples exhibited comparable corrosion resistance to that of a wrought 25Cr7Ni stainless steel despite the presence of only ferritic microstructure
Microwave-assisted synthesis of GdOF: Eu3+/Tb3+ ultrafine phosphor powders suitable for advanced forensic and security ink applications
No full textThe rare-earth-doped inorganic ultrafine oxyfluoride host matrices in forensic science, especially in latent fingerprint detection and anti-counterfeiting applications, were still unexplored and may replace the existing technology owing to its high sensitivity. Herein, GdOF: Eu3(+)/Tb3+ ultrafine red and green phosphors were synthesized via a rapid, green microwave-assisted hydrothermal method at 150 circle C. The phosphors synthesized by this novel method possess good luminescent intensity for the hypersensitive D-5(0)-> F-7(2) transition of Eu3+ and D-5(4)-> F-7(5) transition of Tb3+ ions as compared to the phosphors prepared via other conventional methods such as co-precipitation synthesis, sol-gel synthesis, and microwave-assisted co-precipitation synthesis. Further, an enhancement in the luminescent intensity of the ultrafine phosphor was noticed when the microwave parameters and pH values were tuned. The optimized red and green phosphors having high luminescence intensity, good color purity, and high quantum yields of 89.3%, and 71.2%, respectively, were used for the visualization of latent fingerprints on various substrates. These promising phosphors exhibited excellent visualization regardless of the background interference and limit the risk of duplication and are highly reliable. The security inks developed using these phosphors are highly efficient for anti-counterfeiting applications. These multifunctional properties of investigated phosphors can be explored for security applications. (c) 2023 Elsevier Inc. All rights reserved