Browsing by Author "Sarvesh Kumar Avinashi"

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3D nanocomposites of β-TCP-H3BO3-Cu with improved mechanical and biological performances for bone regeneration applications
(Nature Research, 2025) Sarvesh Kumar Avinashi; Rajat Kumar Mishra; n. Shweta; Saurabh Kumar; Amreen Shamsad; Shama Parveen; Surajita Sahu; Savita Kumari; Zaireen Fatima; Sachin Kumar Yadav; Monisha Banerjee; Monalisa Mishra; Neeraj Mehta; Chandkiram Gautam
Recently, 3-D porous architecture of the composites play a key role in cell proliferation, bone regeneration, and anticancer activities. The osteoinductive and osteoconductive properties of β-TCP allow for the complete repair of numerous bone defects. Herein, β-TCP was synthesized by wet chemical precipitation route, and their 3-D porous composites with H3BO3 and Cu nanoparticles were prepared by the solid-state reaction method with improved mechanical and biological performances. Several characterization techniques have been used to investigate the various characteristics of fabricated porous composites. SEM and TEM studies revealed the porous morphology and hexagonal sheets of the β-TCP for the composite THC8 (82TCP-10H3BO3-8Cu). Moreover, the mechanical study showed excellent compressive strength (188 MPa), a high Young’s modulus (2.84 GPa), and elevated fracture toughness (9.11 MPa.m1/2). An in vitro study by MTT assay on osteoblast (MG-63) cells demonstrated no or minimal cytotoxicity at the higher concentration, 100 µg/ml after 24 h and it was found a more pronounced result at 20 µg/ml on increasing the concentration of Cu nanoparticles after incubating 72 h. The THC12 composite showed the highest antibacterial potency exclusively against B. subtilis. S. pyogene, S. typhi and E. coli. at 10 mg/ml, indicating its potential effectiveness in inhibiting all of these pathogens. Genotoxicity and cytotoxicity tests were also performed on rearing Drosophila melanogaster, and these findings did not detect any trypan blue-positive staining, which further recommended that the existence of composites did not harm the larval gut. Therefore, the fabricated porous composites THC8 and THC12 are suitable for bone regrowth without harming the surrounding cells and protect against bacterial infections. © The Author(s) 2025.
A novel nanocomposite of HAp-TiC-Ag with enhanced mechanical and biological properties for bone regrowth and anticancer applications
(Royal Society of Chemistry, 2025) Sarvesh Kumar Avinashi; Shweta; Rajat Kumar Mishra; Saurabh Kumar; Amreen Shamsad; Shama Parveen; Surajita Sahu; Savita Kumari; Zaireen Fatima; Vijay Pratap; Rupesh Kumar; Monisha Banerjee; Monalisa Mishra; Horesh Kumar; Rakesh Kumar C. Gautam; Chandkiram Gautam
Hydroxyapatite (HAp)-based composites are extensively used in various applications, including bone regeneration, bone implants, catalysis, drug delivery, and cancer treatment, owing to their unique properties such as osteogenesis, osteoconduction, and osteoinduction, as well as their ability to inhibit tumor cell growth. In this study, pure HAp and silver (Ag) nanoparticles were synthesized using microwave irradiation and green synthesis methods, while a solid-state reaction route was employed for the fabrication of HAp-TiC-Ag composites aimed at enhancing their mechanical and biological properties. A range of characterization techniques, including XRD, FTIR, Raman, XPS, DLS, SEM, TEM, and in vitro assays, were used to assess the structural, morphological, mechanical, and biological properties of the composites. The composite HTA6 exhibited excellent mechanical properties, including a high compressive strength (185 MPa), elevated fracture toughness (10.88 MPa m1/2), a moderate Young's modulus (1.08 GPa), and a Vickers hardness (339.65 HV). The cell viability tests demonstrated that HTA6 treatment did not significantly reduce osteoblast cell growth, while significantly inhibiting the proliferation of cancer cells. Additionally, the composite showed good biocompatibility, displaying non-cytotoxicity in D. melanogaster and strong antibacterial activities against the tested bacteria. These findings suggest that HTA6 is a promising candidate for applications in bone regeneration and cancer treatment. © 2025 The Royal Society of Chemistry.
Doping impacts of La2O3 on physical, structural, optical and radiation shielding properties of (30-x)BaCO3-30TiO2-40SiO2-xLa2O3 (0 ≤ x ≤ 6) glasses for optoelectronic applications
(Institute of Physics, 2023) Rajat Kumar Mishra; Savita Kumari; Shweta; Prince Sen; Sarvesh Kumar Avinashi; Zaireen Fatima; Harel Thomas; Manasi Ghosh; Krishna Kishor Dey; Chandkiram Gautam
Herein, synthesis of novel barium silicate glasses doped with La2O3 in the system (30-x)BaCO3-30TiO2-40SiO2-xLa2O3, BTSL (0 ≤ x ≤ 6) via fast melt-quenching technique was carried out. Further, to confirm the amorphous behaviour of prepared glass samples, x-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM) were carried out. The density of all prepared glasses was determined using Archimedes’ principle and found to be in an increasing manner. To investigate the doping influence of La2O3 on the glasses, few more physical properties like molar volume (Vm), polaron radius (rp), and field strength (Fs) were also studied and found to be increased due to incorporation of La2O3 into BTSL glassy system. Moreover, to explore the structural, functional, and bonding mechanism of the glasses, FTIR, Raman and 29Si-MAS-ssNMR spectroscopies were performed. Further, to investigate the numerous optical parameters, UV-visible spectroscopy was executed, and energy band gaps were found in the decreasing manner as increasing the La2O3 concentrations. Additionally, to study the optoelectronic properties, refractive indices (η) and optical dielectric constant (ϵ) were determined and revealed the increasing behaviour and found suitable material for optoelectronic devices. Furthermore, the radiation shielding parameters, mass attenuation coefficient (MAC), linear attenuation coefficient (LAC), etc were determined using Phy-X/PSD software and these parameters are increased owing to the doping of La2O3. Among all fabricated glasses, (30-x)BaCO3-30TiO2−40SiO2−6La2O3, BTS6L glass exhibited outstanding optical and radiation attenuation properties; can be tailored for the fabrication of optoelectronic and radiation protection devices. © 2023 IOP Publishing Ltd.
Enhanced physical and mechanical properties of resin added with aluminum oxyhydroxide for dental applications
(Elsevier Ltd, 2023) Savita Kumari; Ajaz Hussain; Sarvesh Kumar Avinashi; Rajat Kumar Mishra; Jitendra Rao; Sudhakar Behera; Rakesh Kumar Gautam; Chandkiram Gautam
Resin has limited applications however, its composites with metal oxides exhibited improved characteristics for numerous applications such as dental restoration, dentures etc. Herein, various compositions were fabricated by substituted aluminum oxyhydroxide (AlOOH) into resin via a scalable heat cure process. For phase identification and structural study, XRD and FT-IR techniques were employed. As increasing the content of AlOOH into the PZ {Poly (methyl-methacrylate)-zirconia, (PMMA-ZrO2)} matrix, the percentage of crystallinity and the crystallite size were also estimated and varied from 14.8 to 18.4 and 1.48 nm–1.82 nm respectively. Moreover, to reveal the surface morphology, optical and mechanical behaviour of fabricated nano-composites, the SEM, UV–Vis and Universal testing machine (UTM) were also performed. The direct, indirect band gap, urbach energy of the fabricated composites were noticed within the range of 5.14 ± 0.005–5.19 ± 0.005 eV, 5.31 ± 0.005–5.35 ± 0.005 eV, and 189 ± 3.78–69.6 ± 1.39 eV respectively. The skin depth of the nanocomposites were also studied, the cut-off energy and cutoff-wavelength are 5.66 eV and 220 nm. However, the compressive strength, flexural strength, and the lowest friction coefficient value at 1 m/s sliding speed of the best composite sample (PZA15) are 85.2 MPa, 56.7 MPa and 0.311. The highest flexural modulus (846 MPa) of the PZA15 were determined using the 3-point bending test. Further, to check the biocompatibility of these resin-based composites the MTT assay was carried out. The synthesized composite (PZA15) was found to be highly biocompatible with enhanced mechanical and tribological performances. © 2023 Elsevier Ltd and Techna Group S.r.l.
Fabrication of bioactive transparent glass ceramics 55SiO2–25Na2O-(15-x)CaO–5P2O5- xZrO2 (0≤x≤6): Physical, structural and in vitro cell viability insights for biomedical applications
(Elsevier Ltd, 2024) Shweta; Rajat Kumar Mishra; Bijay Laxmi Pradhan; Shama Parveen; Priyatama Behera; Sarvesh Kumar Avinashi; Savita Kumari; Zaireen Fatima; Prince Sen; Saurabh Kumar; Monalisa Mishra; Monisha Banerjee; Krishna Kishor Dey; Manasi Ghosh; Chandkiram Gautam
Zirconia (ZrO2) reinforced transparent glass ceramics (TGCs) are excellent materials for enhanced cell viability and biocompatibility for biomedical applications. Herein, ZrO2 doped SiO2–Na2O–CaO–P2O5 base compositions derived from traditional melt-quench technique. The impacts of ZrO2 on the physical, structural, optical, morphological, and biological evaluation were studied. XRD discloses the major phase formation of buchwaldite (CaNaPO4) and disodium calcium silicate (Na2CaSiO4). Density of the TGC samples was calculated and found to be in the range of 2.535–2.910 g/cm3. The optical parameters, and particle size were estimated and analyzed. Herein, ZrO2 plays a significant role as a network modifier and various bond assignments in the glassy network that confirmed by FTIR spectroscopy. Surface morphology and its elemental investigations were also studied using SEM and XPS techniques. Solid state NMR spectrum on 23Na, 29Si, and 31P nucleus were studied for various interactions. Moreover, the cell viability of the fabricated samples on the cancer cells were analyzed and resulted to possess the half maximum inhibitory concentrations (IC50) of the samples were calculated and valued to be 92 to 40 μg/ml respectively. The sample 55SiO2–25Na2O–9CaO–5P2O5–6ZrO2 (BG4) demonstrated a remarkable biological activity for bone regeneration and implants. Further, the cell cytotoxicity was evaluated by performing trypan blue assay, DAPI and DCFH-DA staining on the TGC samples. The data assembled in this research approves the hypothesis that the TGCs represent a feasible material for the biomedical applications for bone and tooth implants. © 2024 Elsevier Ltd and Techna Group S.r.l.
Fabrication, structural, and enhanced mechanical behavior of MgO substituted PMMA composites for dental applications
(Nature Research, 2024) Savita Kumari; Rajat Kumar Mishra; Shama Parveen; Sarvesh Kumar Avinashi; Ajaz Hussain; Saurabh Kumar; Monisha Banerjee; Jitendra Rao; Rupesh Kumar; Rakesh Kumar Gautam; Chandkiram Gautam
The most common denture material used for dentistry is poly-methyl-methacrylate (PMMA). Usually, the polymeric PMMA material has numerous biological, mechanical and cost-effective shortcomings. Hence, to resolve such types of drawbacks, attempts have been made to investigate fillers of the PMMA like alumina (Al2O3), silica (SiO2), zirconia (ZrO2) etc. For the enhancement of the PMMA properties a suitable additive is required for its orthopedic applications. Herein, the main motive of this study was to synthesize a magnesium oxide (MgO) reinforced polymer-based hybrid nano-composites by using heat cure method with superior optical, biological and mechanical characteristics. For the structural and vibrational studies of the composites, XRD and FT-IR were carried out. Herein, the percentage of crystallinity for all the fabricated composites were also calculated and found to be 14.79–30.31. Various physical and optical parameters such as density, band gap, Urbach energy, cutoff energy, cutoff wavelength, steepness parameter, electron–phonon interaction, refractive index, and optical dielectric constant were also studied and their values are found to be in the range of 1.21–1.394 g/cm3, 5.44–5.48 eV, 0.167–0.027 eV, 5.68 eV, 218 nm, 0.156–0.962, 4.273–0.693, 1.937–1.932, and 3.752–3.731 respectively. To evaluate the mechanical properties like compressive strength, flexural strength, and fracture toughness of the composites a Universal Testing Machine (UTM) was used and their values were 60.3 and 101 MPa, 78 and 40.3 MPa, 5.85 and 9.8 MPa-m1/2 respectively. Tribological tests of the composites were also carried out. In order to check the toxicity, MTT assay was also carried out for the PM0 and PM15 [(x)MgO + (100 − x) (C5O2H8)n] (x = 0 and 15) composites. This study provides a comprehensive insight into the structural, physical, optical, and biological features of the fabricated PMMA-MgO composites, highlighting the potential of the PM15 composite with its enhanced density, mechanical strength, and excellent biocompatibility for denture applications. © 2024, The Author(s).
Influence of TiO2as a filler into PMMA-ZrO2composites on structural, mechanical and biological properties for denture fabrication
(Elsevier Ltd, 2025) Akhileshwar Gupta; Savita Kumari; Sarvesh Kumar Avinashi; Rajat Kumar Mishra; Rupesh Kumar; Priyatama Behera; Monalisa Mishra; Rakesh Kumar C. Gautam; Saurabh Kumar; Shama Parveen; Jitendra Rao; Monisha Banerjee; Chandkiram Gautam
Polymethyl-methacrylate (PMMA) is widely being used in dentistry, while it has limited mechanical strength. Herein, PMMA composites were fabricated using heat cure technique within a system [(95-x) PMMA + 5 ZrO2 + x TiO2] (x = 8, 6, 4 and 2 wt%) and thoroughly characterized using density measurements, XRD, FTIR, SEM, EDAX, compression tests, 3-point bending, tribological, and hardness tests respectively. Moreover density, crystallite size, percentage of crystallinity, compressive strength, Young's modulus, flexural strength, flexural modulus, modulus of resilience, modulus of toughness, and brittleness coefficient were determined. Composite contains 5 wt% ZrO2and 2 wt% TiO2referred as ZPT2 exhibited the maximum compressive strength. Additionally, flexural strength and flexural modulus were found to be highest for ZPT2. The friction coefficient and hardness were found to be the lowest for ZPT2. In MTT (3-[4, 5-dimethylthiazol-2-yl]-2, 5- diphenyl tetrazolium bromide) assay, MG-63 osteoblast cells were exposed to various concentrations (5–30 μg/ml) of the compounds for 24 h. The results indicated that no significant cytotoxicity was observed for ZPT2. According to the results of the dye exclusion experiment, DAPI (4, 6-diamidino-2-phenylindole), and DCFH-DA (2, 7-dichlorodihydrofluorescein diacetate) staining, ZPT2 did not exhibit cellular damage, genotoxicity and reduced ROS (reactive oxygen species) production at lower concentrations. The combined biological results suggest that oral administration of the ZPT2 sample does not exhibit cytotoxicity and genotoxicity that makes it valuable for dentistry. © 2025 Elsevier Ltd and Techna Group S.r.l. All rights are reserved, including those for text and data mining, AI training, and similar technologies.
Synergetic impact of MgO on PMMA-ZrO2 hybrid composites: Evaluation of structural, morphological and improved mechanical behavior for dental applications
(Elsevier Inc., 2024) Savita Kumari; Anuj Verma; Rajat Kumar Mishra; Sarvesh Kumar Avinashi; Shweta; Shweta Singh; Priyatama Behera; Jitendra Rao; Rakesh Kumar Gautam; Bijay Laxmi Pradhan; Krishna Kishor Dey; Manasi Ghosh; Monalisa Mishra; Chandkiram Gautam
This work aims to demonstrate the effect of ZrO2 and MgO inclusion into the Poly(methyl methacrylate) (PMMA). To fabricate novel hybrid composites via heat cure method, various composites (PZM2, PZM4 and PZM6) were synthesized in the system [(95-x) PMMA + 5 ZrO2 + x MgO] (x = 2, 4, and 6) respectively. Density of the prepared composites were determined and varying between 1.035–1.152 g/cm3. X-ray Diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) followed by EDAX and mechanical testing were performed to evaluate the fabricated composite properties. Moreover, to explore the structure of the fabricated composites the 13 C CP-MAS SSNMR and 1 H-13 C Phase-Modulated Lee Goldberg (PMLG) HETCOR Spectrum were recorded which clarify chemical shifting and motional dynamics of the composites. Mechanical tests were performed by UTM and the obtained parameters such as compressive strength, Young's modulus, fracture toughness, brittleness coefficient, flexural strength and flexural modulus are found to be in the range of 91–100 MPa, 0.48–0.51 GPa, 9.122–9.705 MPa.m1/2, 0.66–0.815, 51.03–42.78 MPa and 499–663 MPa respectively. Some more mechanical parameters such as proportional limit, elastic limit, failure strength, modulus of resilience and modulus of toughness were also calculated. Furthermore, tribological properties were also determined and the coefficient of friction (COF) was decreased by 17.4 % and 38 % for composite PZM6 at 20 N and 40 N as compared to the composite PZM2 and the lowest wear volume of 1.55 mm3 was observed for PZM2, whereas the maximum volume loss of 5.64 mm3 is observed for composite PZM6. To check out the biocompatibility, cytotoxicity and genotoxicity of the fabricated composites the Trypan-blue assay was also performed for PZM2 and PZM6 composites. Dissection on the gut of larvae was also performed on the both composites followed by DAPI and DCFH-DA staining. Therefore, these synthesized samples can be used for the fabrication of denture materials. © 2024 Elsevier Inc.
Synergistic doping effect of La2O3 on BaO-TiO2-SiO2 glass-ceramics: Evolution of physical, structural, morphological, and dielectric behaviour for electronics applications
(Elsevier Ltd, 2024) Rajat Kumar Mishra; Sarvesh Kumar Avinashi; Savita Kumari; Shweta; Rajbala Nain; Tarun Katheriya; Rakesh Kumar Dwivedi; Shail Upadhyay; Chandkiram Gautam
Herein, numerous investigations such as structural, physical, morphological, optical, and dielectric properties of BaO-TiO2-SiO2 glass-ceramics (GCs) doped with La2O3 were carried out. Various glasses were synthesized within a glass system [(30-x)BaO.30TiO2.40SiO2].x[La2O3], (x=0,2,4, and 6 mol% of La2O3) using a conventional melt-quench method. XRD confirmed the amorphous nature of the glass samples. Differential scanning calorimetry (DSC) was used to identify the glass transition (Tg) and crystallization temperatures (Tc) of the samples. Further, controlled heat treatment of the glasses led to the fabrication of glass-ceramics and their XRD analysis revealed polycrystalline structure, predominantly consisting of a major phase of tetragonal Fresnoite (Ba2TiO8Si2). Furthermore, with the addition of La2O3, the prepared GCs exhibited improved physical properties, including an increase in density (3.783–4.611 g/cm3) and oxygen packing density (81.177–92.303 g-atom/l). Additionally, to study the bonding and structural characteristics, FTIR and Raman spectroscopies were conducted. In order to study the optical properties, UV–visible spectroscopy was executed and showed a reduced indirect energy band gap from 4.290 to 4.220 eV with increasing La2O3. To study the morphological behaviour, SEM and TEM were performed. Eventually, to examine the dielectric characteristics, relative dielectric constant (εr) and dielectric loss (Tan δ) over the glass-ceramics was conducted using a ‘Novocontrol Impedance Analyzer’. The εr and Tan δ values exhibited temperature-dependent behaviour and found to be increased within the frequency range of 1 kHz to 1 MHz. The BTSLC6 glass-ceramic, (24BaO.30TiO2.40SiO2.6La2O3), exhibited a high dielectric constant of ⁓ 9335 and a low dielectric loss of 0.52 at 1 kHz, mainly due to space charge polarization. This makes it a promising candidate for applications in multilayer ceramic capacitors, energy storage, photonics, and electronics. © 2024 Elsevier B.V.
Synthesis and characterization of graphene oxide-based nanofluids and study of their thermal conductivity
(Springer Science and Business Media B.V., 2022) Sachin Kumar Yadav; Diptarka Roy; Anil Kumar Yadav; Pinky Sagar; Sarvesh Kumar Avinashi
In the present research work, we investigated the effect of loading mass concentrations (0.05%, 0.15%, and 0.25 mass %) and temperature (10–50 °C) on the thermal properties of graphene oxide-ethylene glycol (GO-EG) nanofluids. A two-step approach was adopted to prepare the GO-EG nanofluids with different mass proportions without any surfactant. The thermal kinetic analysis was performed by modulated DSC and TGA. Thermal stability and particle size distribution of the nanofluids were monitored by using UV–visible spectroscopy and dynamic light scattering. The experimental findings on the thermal transport characteristics of the as-prepared nanofluid samples are influenced by loading mass concentration, increasing temperature because of the high relative area of dispersed nanoparticles at higher particle concentration, dispersion quality of nanofluids. The thermal conductivity (TC) of GO-EG nanofluid shows an enhancement of 36.72% for (sample no. 3, i.e., GO 3) and shows a semi-linear dependence profile between temperature and TC, with increasing mass concentration due to the decrease in interfacial thermal resistance between GO and EG. The observed results are in good agreement with previously reported literature and reveal the promising prospect for usage as a state-of-the-art heat transport fluid in the coolant industry. © 2022, Akadémiai Kiadó, Budapest, Hungary.
Unveiling of physical, structural, morphological, and electrical properties of Fe2O3doped (30-x)BaO•30TiO2•40SiO2•x[Fe2O3], (0≤x≤6) glass-ceramics potential for energy storage devices
(Elsevier Ltd, 2025) Rajat Kumar Mishra; Sarvesh Kumar Avinashi; Sachin Kumar Yadav; Zaireen Fatima; Rajbala Nain; Rakhi; Savita Kumari; Shweta; Neeraj Mehta; Rakesh Kumar Dwivedi; Chandkiram Gautam
Glass-ceramics with tuneable dielectric properties are increasingly sought after for next-generation multilayer ceramic capacitors (MLCCs) used in advanced electronic applications. However, developing compositions that simultaneously offer high dielectric constants, low dielectric losses, and excellent thermal stability remains a significant challenge. Herein, Fe2O3-doped (30-x)BaO•30TiO2•40SiO2•x[Fe2O3] (0≤x ≤ 6 mol%) glass and glass-ceramics are synthesized using a melt-quenching followed by controlled heat treatment technique. XRD is performed which indicates a transition from amorphous to crystalline structures after heat treatment, with a major phase of tetragonal fresnoite (Ba2TiSi2O8). To check the bonding mechanisms, Fourier transform infrared (FTIR) and Raman spectroscopies are performed. X-ray photoelectron spectroscopy was performed for analysing the elemental composition, and electronic state of a material. However, to study the microstructural behaviour, crystalline nature, and compositional variations, scanning electron microscopy (SEM) and transmission electron microscopy (TEM), followed by energy dispersive spectroscopy (EDS) were also performed. Dielectric properties of the GCs are studied over 10 Hz to 1 MHz. Notably, 24BaO•30TiO2•40SiO2•6Fe2O3(BTSFC6) (x = 6 mol%) sample demonstrates improved dielectric constant (εr = 31740.4) and low dielectric loss (Tanδ = 0.13) at 10 Hz (at 500 °C). The incorporation of Fe2O3not only enhances the AC conductivity but also modifies the electrical relaxation behaviour, as evident from modulus and Cole–Cole plots, which indicate non-Debye-type relaxation and a negative temperature coefficient of resistivity (NTCR) behaviour. Furthermore, hysteresis loop measurements were conducted, revealing that an increase in Fe2O3content in BTSFC glass-ceramics leads to a systematic enhancement in ferroelectric properties and energy storage capacity. This improvement enables material to be tailored for a wide range of applications, from low-loss dielectrics to high-energy storage devices. Therefore, this study demonstrates that strategic Fe2O3doping effectively tailors the structural and dielectric characteristics of barium-titanate silicate glass-ceramics, positioning the BTSFC6 composition as a promising candidate for the fabrication of energy storage devices in demanding thermal and electronic environments. © 2025 Elsevier Ltd and Techna Group S.r.l. All rights are reserved, including those for text and data mining, AI training, and similar technologies.