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Showing 649 results for Type of Study: Research Paper

Richa Singh,
Volume 21, Issue 1 (3-2024)
Abstract

Drug-resistance among bacteria is a concerning issue in medical field. Silver nanoparticles (AgNPs) are one of the promising novel nano-antibiotics. In the present study, AgNPs were synthesized using cell-free extract of Acinetobacter sp. challenged with silver nitrate. Preliminary observations done using UV-Vis spectrophotometry at 420 nm. Complete reduction of silver ions to AgNPs was confirmed through cyclic voltammetry. Electron microscopy revealed formation of spherical shaped nanoparticles of size upto 20 nm. These AgNPs were furthr used to determine their effect on activity of various antibiotics against pathogenic bacteria such as Neisseria and Xanthomonas. Higher antibacterial activity of AgNPs was observed against Gram-negative bacteria. Enhanced antibacterial action of AgNPs was observed with selected beta-lactam antibiotics producing upto 3-fold increase in area of zone of inhibition. On exposure to AgNPs, the minimum inhibitory concentration and minimum bactericidal concentration of antibiotics were lowered by upto 2000 times indicating potential synergistic action of AgNPs. This study clearly signifies that the drug, proved to be inefficient due to bacterial resistance, could be made functional again in presence of AgNPs. This will help in development of novel antibacterial formulations containing antibiotics and nanoparticles to combat multiple drug-resistance in microorganisms.
Dipali Potdar, Sushant Patil, Yugen Kulkarni, Niketa Pawar, Shivaji Sadale, Prashant Chikode,
Volume 21, Issue 1 (3-2024)
Abstract

The Nickel tungsten (Ni-W) alloy was electrodeposited on stainless steel (SS) substrate using potentiostatic mode at room temperature. Potentiostatic electrodeposition was carried out by varying the deposition time. The physicochemical properties of Ni-W alloys were studied using X-Ray diffraction (XRD), Electron Microscopy and micro-Raman spectroscopy. Recorded XRD spectra was compared with standard JCPDS card and the presence of Ni was confirmed, no such peaks for W were observed. Further study was extended for micro-Raman analysis. From Raman spectroscopy study the appearance of Ni-O and W6+=O bonds confirms that the Ni-W present in amorphous phase. Several cracks were observed in SEM images along with nanoparticles distributed over the electrode surface. The appearance of cracks may be correlated with the in-plane tensile stresses, lattice strains and stacking faults and may be related to the substrate confinements.
 
Yugen Kulkarni, Niketa Pawar, Namrata Erandole, Muskan Mulani, Mujjamil Shikalgar, Swapnil Banne, Dipali Potdar, Ravindra Mane, Smita Mahajan, Prashant Chikode,
Volume 21, Issue 1 (3-2024)
Abstract

The paper investigates the solar photodegradation of Methylene Blue dye using copper oxide (CuO) thin films synthesized by the Successive Ionic Layer Adsorption and Reaction (SILAR) method. The structural, morphological, and optical characteristics of the CuO thin films have been investigated by employing a variety of methods, such as Fourier transform Infrared (FTIR) spectroscopy, UV-Vis spectroscopy, Scanning electron microscopy (SEM), and X-ray diffraction (XRD). The outcomes showed that CuO thin films with excellent surface shape and a highly crystalline nature had been successfully deposited. Methylene Blue was subjected to solar radiation during its photodegradation process, and the outcomes showed a significant decrease in the dye's concentration over time. To maximize the photo degradation process, the effects of other experimental factors were also assessed, such as the starting concentration of MB, the quantity of CuO thin film, number of SILAR cycles and the pH of the solution. Good photocatalytic activity is demonstrated by CuO thin films produced using the SILAR approach in the solar photodegradation of methylene blue. The development of affordable and ecologically friendly wastewater treatment technology that can use sun energy to break down persistent organic contaminants is affected by these findings.
 
Sandesh Jirage, Kishor Gaikwad, Prakash Chavan, Sadashiv Kamble,
Volume 21, Issue 1 (3-2024)
Abstract

The Cu2ZnSnS4 (CZTS) thin film is newly emerging semiconductor material in thin film solar cell industry. The CZTS composed of economical, common earth abundant elements. It has advantageous properties like high absorption coefficient and best band gap. Here we have applied low cost chemical bath deposition technique for synthesis of CZTS at low temperature, acidic medium and it’s characterization. The films were characterized by different techaniques like X-Ray diffraction, Raman, SEM, Optical absorbance, electrical conductivity and PEC study. The X-Ray diffraction, Raman scattering techniques utilized for structural study. The XRD revels kasterite phase and nanocrystalline nature of CZTS thin films. These results and its purity confirmed further by advanced Raman spectroscopy with 335 cm-1 major peak. The crystallite size which was found to be 50.19 nm. The optical absorbance study carried by use of UV-Visible spectroscopy analyses its band gap near about 1.5 eV and its direct type of absorption. The electrical conductivity technique gives p-type of conductivity. The scanning electron microscopy (SEM) study finds it’s rock like unique morphology. The EDS technique confirms its elemental composition and it’s fair stoichiometry. The analysis of PEC data revealed power conversion efficiency-PCE to 0.90%.
The Cu2ZnSnS4 (CZTS) thin film is newly emerging semiconductor material in thin film solar cell industry. The CZTS composed of economical, common earth abundant elements. It has advantageous properties like high absorption coefficient and best band gap. Here we have applied low cost chemical bath deposition technique for synthesis of CZTS at low temperature, acidic medium and it’s characterization. The films were characterized by different techaniques like X-Ray diffraction, Raman, SEM, Optical absorbance, electrical conductivity and PEC study. The X-Ray diffraction, Raman scattering techniques utilized for structural study. The XRD revels kasterite phase and nanocrystalline nature of CZTS thin films. These results and its purity confirmed further by advanced Raman spectroscopy with 335 cm-1 major peak. The crystallite size which was found to be 50.19 nm. The optical absorbance study carried by use of UV-Visible spectroscopy analyses its band gap near about 1.5 eV and its direct type of absorption. The electrical conductivity technique gives p-type of conductivity. The scanning electron microscopy (SEM) study finds it’s rock like unique morphology. The EDS technique confirms its elemental composition and it’s fair stoichiometry. The analysis of PEC data revealed power conversion efficiency-PCE to 0.90%.

Avinash Ramteke, Pradnya Chougule, Pranali Chavan, Amit Yaul, Gourav Pethe,
Volume 21, Issue 1 (3-2024)
Abstract

Nickel doped CoMn ferrites with high magnetization were synthesized by double sintering solid state route with compositions of Co0.7-xNixMn0.3Fe2O4 with x = 0, 0.05, 0.1 and 0.15. Theoretical Cation distribution for cubic spinel ferrites was suggested on basis of electrical configuration expectations and cation site preferences. Cation distribution suggested was in good agreement with experimental results obtained from VSM and XRD. Values of theoretically calculated magnetic moment, coercivity and magnetization are in good agreement with experimental data obtained from VSM. Maximum saturation magnetization of 37.7emu/gm is obtained for sample Co0.7Mn0.3Fe2O4 at magnetic field of 5K Oe. Magnetostriction was found to increase with increasing magnetic field (from 1KOe to 5KOe.) Maximum magnetostriction of 84ppm was observed for sample Co0.7Mn0.3Fe2O4 at 5KOe. Maximum magnetization of magnetoelectric composites with 30% Co0.7-xNixMn0.3Fe2O4 – 70% PbZr0.48Ti0.52 was found to be 7.4 emu/g for composition with x = 0.
 
Amit Bandekar, Pravin Tirmali, Paresh Gaikar, Shriniwas Kulkarni, Nana Pradhan,
Volume 21, Issue 1 (3-2024)
Abstract

The Mn-Zn ferrite with a composition of Mn0.25Mg0.08Cu0.25Zn0.42Fe2O4 has been synthesized in this study using the chemical sol-gel technique at a pH of 7. The sample was prepared and subsequently annealed at a temperature of 700°C. The nanocrystalline ferrite samples were subjected to characterization using X-ray diffraction (XRD), Fourier transform-infrared spectroscopy (FT-IR), Scanning electron microscopy (SEM), Thermogravimetry (TG), and Differential thermal analysis (DTA). The findings of these observations are delineated and deliberated. The sample's phase composition was verified using X-ray diffraction examination. The crystalline size was determined using Scherrer's formula and was observed to be within the range of 20-75 nm. Two notable stretching bands were seen in the FTIR spectra within the range of 400-650 cm-1. The spinel structure of the produced nanoparticles was confirmed by these two bands. The magnetic characteristics of the powder were examined using a Vibrating Sample Magnetometer (VSM). The presence of M-H hysteresis loops suggests that the produced nanoparticles have superparamagnetic properties, as evidenced by their low coercive force, remanent magnetization, and saturation magnetization values.
 
Eswaran Kamaraj, Kavitha Balasubramani,
Volume 21, Issue 2 (6-2024)
Abstract

Heterostructure photocatalyst of CuWO4 modified SnO2 (CuWO4/SnO2) was fabricated by in simple wet-impregnation process and evaluated via degradation of rose Bengal (RB) under visible light irradiation. The samples had been completely characterized by Ultraviolet-visible diffuse reflectance spectroscopy (UV-vis-DRS), X-ray diffraction (XRD), Scanning electron microscopy (SEM) combined with energy-dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), High-resolution TEM (HR-TEM), X-ray photoelectron spectroscopy (XPS) and Brunauer-Emmett and Teller surface analysis (BET). The result divulged that amongst the catalysts, CuWO4/SnO2 displayed higher photocatalytic activity than CuWO4 or SnO2. The enhanced photocatalytic efficiencies are attributed to the charge transfer from SnO2 to CuWO4 nanoparticles, which efficiently decrease electron-hole recombination energy level. The time required for maximum degradation of rosebengal (RB) under visible light over CuWO4/SnO2 was 180 min. The other parameters such as pH (pH=8), photocatalyst dosage (0.2 g/L) and dye concentration (20 µM) were optimized to achieve high degradation efficiency (98.5%). The excellent photocatalytic activity of CuWO4/SnO2 is due to efficient separation of photogenerated electron-hole pairs. The holes (h+) and superoxide radicals (O2•-) are the reactive species involved in photocatalytic mechanism for gdegradation of RB.
Mohammad Derakhshani, Saeed Rastegari, Ali Ghaffarinejad,
Volume 21, Issue 2 (6-2024)
Abstract

In this research, a nickel-tungsten coating as a catalyst for hydrogen evolution reaction (HER) with different current densities was synthesized and the resulting electrocatalytic properties and morphology were assessed. Linear sweep voltammetry (LSV), electrochemical impedance spectroscopy (EIS), and chronoamperometry in 1 M NaOH were used to evaluate the electrocatalytic activity for HER. By increasing the current density of electrodeposition up to 500 mA/cm2, a columnar morphology was observed. The cyclic voltammetry test (CV) revealed that when the plating current density increases, Cdl has increased from 248 to 1310 µF/cm2 and the active surface area increases 5 times. The results showed that by modifying the coating morphology, the current density of the hydrogen evolution increased up to two times.
 
Muhammad Shahzad Sadiq, Muhammad Imran, Abdur Rafai, Muhammad Rizwan,
Volume 21, Issue 2 (6-2024)
Abstract

With increasing energy demand and depletion of fossil fuel resources, it is pertinent to explore the renewable and eco-friendly energy resource to meet global energy demand. Recently, perovskite solar cells (PSCs) have emerged as plausible candidates in the field of photovoltaics and considered as potential contender of silicon solar cells in the photovoltaic market owing to their superior optoelectronic properties, low-cost and high absorption coefficients. Despite intensive research, PSCs still suffer from efficiency, stability, and reproducibility issues. To address the concern, the charge transport material (CTM) particularly the electron transport materials (ETM) can play significant role in the development of efficient and stable perovskite devices. In the proposed research, we synthesized GO-Ag-TiO2 ternary nanocomposite by facile hydrothermal approach as a potential electron transport layer (ETL) in a regular planar configuration-based PSC. The as synthesized sample was examined for morphological, structural, and optical properties using XRD, and UV-Vis spectroscopic techniques. XRD analysis confirmed the high crystallinity of prepared sample with no peak of impurity. The optimized GO-Ag-TiO2 ETL exhibited superior PCE of 8.72% with Jsc of 14.98 mA.cm-2 ,Voc of 0.99 V, and a fill factor of 58.83%. Furthermore, the efficiency enhancement in comparison with reference device is observed which confirms the potential role of doped materials in enhancing photovoltaic performance by facilitating efficient charge transport and reduced recombination. Our research suggests a facile route to synthesize a low-cost ETM beneficial for the commercialization of future perovskite devices.
 
Risa Suryana, Nida Usholihah, Markus Diantoro,
Volume 21, Issue 2 (6-2024)
Abstract

Modifying photo-anode structures in DSSC devices is still challenging in improving efficiency. This study focused on the ZnO rod growth on several porous silicon substrates using the hydrothermal method and determining which porous silicon is appropriate for DSSC applications. The materials used for the growth solution were Zn(NO3)26H2O 0.05 M and C6H12N4 0.25 M. The hydrothermal process was carried out at 90°C for 6 h and then annealed at 450°C for 30 min. SEM revealed that PSi pore influences the structure, diameter, and density of ZnO rods. ZnO structures formed in ZnO rods with a dominant vertical growth direction, ZnO rods with an intersection direction, and flower-like ZnO rods. The diameter of the PSi pore affected the density of ZnO rods grown on the PSi. The average diameter size and the density of ZnO rods vary from 747.66-1610.68 nm and 0.22-0.90 rod/μm2. XRD confirmed the presence of ZnO hexagonal wurtzite, Si cubic, and SiO2 monoclinic. UV-Vis spectrometry characterization results showed that sample reflectance was influenced by ZnO rod density and PSi pitch. The larger density of ZnO rods and the smaller pitch of the PSi pore will lead to lower reflectance. In addition, band gap values were obtained in the 3.06-3.75 eV range. FTIR identified the existence of a ZnO vibration bond, indicating that ZnO was successfully grown on all PSi substrates. The ZnO rods grown on P15S1180 are expected to have more appropriate properties among all five samples for DSSC photoanode.

Seyed Farzad Dehghaniyan, Shahriar Sharafi,
Volume 21, Issue 2 (6-2024)
Abstract

Mechanical alloying was employed to synthesize a nanostructured alloy with the chemical formula of (Fe80Ni20)1-xCrx (x= 0, 4). The microstructural and magnetic properties of the samples were investigated using scanning electron microscopy (SEM), X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDS), and a vibrating sample magnetometer (VSM). Additionally, theoretical calculations were performed using density functional theory (DFT) under the generalized gradient approximation (GGA). Simulations have demonstrated that an appropriate quantity of chromium (Cr) can dissolve within the BCC-Fe (Ni) structure, resulting in a favorable enhancement of the magnetic moment of the lattice. The XRD results indicated that after 96 hours of milling, Fe (Ni) and Fe (Ni, Cr) with a body-centered cubic (BCC) structure were formed. With increasing milling time, the grain size decreased while the microstrain increased. The saturation magnetization (Ms) of Fe80Ni20 composition increased up to 32 hours of milling, but further milling (up to 96 h) resulted in a decrease in the saturation magnetization However, for the (Fe80Ni20)96Cr4 powders, milling up to 64 h caused a reduction in Ms. The coercivity (Hc) trend was different and increased with longer milling times (up to 96 h) for both compositions.
 

Lakshmiprasad Maddi, Srinivas R Gavinola, Atul Ballal,
Volume 21, Issue 2 (6-2024)
Abstract

High thermal conductivity, low coefficient of thermal expansion makes P92 a candidate material for Ultra Super Critical (USC) power plant piping. Microstructural features viz., high dislocation density, lath martensitic microstructure, fine precipitates of M23C6 and MX (X=C, N) contribute towards the high rupture strength. However, most components are typically subjected to multiaxial stress conditions; either metallurgical (weldments), or mechanical (change in the dimension). The present work involves stress rupture testing of circumferential 60° V- notch specimens in the range of 300 – 375 MPa at 650 °C. Notch strengthening effect was observed; with rupture times ranging from 200 – 1300 h. Scanning electron microscopy (SEM) fractography revealed mixed mode of fracture with brittle fracture observed at notch root, while ductile fracture was seen at the centre of the specimen.
 

Fathi Brioua, Chouaib Daoudi,
Volume 21, Issue 2 (6-2024)
Abstract

We have modeled theoretical incident photon-to-current electricity (IPCE) action spectra of poly(3-hexylthiophene) (P3HT) and [6,6]-Phenyl C61 butyric acid methyl ester active layer bulk-heterojunction. By the two-dimensional optical model of a multilayer system based on the structure of Glass substrate / SiO2 /ITO/ PEDOT: PSS /P3HT: PCBM(1:1)/Ca/Al, the optical responses of the device have been computed for different photoactive layer and Ca layer thicknesses to found an optimal structure which allows obtaining the maximum absorption localized in the active layer and high device performance. The electric field intensity, energy dissipation, generation rate, and IPCE have been computed to enhance the device's performance. The finite element method executes the simulation under an incident intensity of 100 mW/cm2 of the 1.5 AM illumination. It was found that the optimum structure is achieved by a 180 nm photoactive layer and 5 nm Ca layer thicknesses.


Rakhesh V, Sreedev P, Ananthakrishnan A,
Volume 21, Issue 2 (6-2024)
Abstract

Organic and Perovskite solar cells have attracted a lot of attention recently since they can be used with flexible substrates and have lower manufacturing costs. The configuration and materials employed in their construction, including the Electron Transport Layer (ETL), active layer, electrode contact, and hole transport layer greatly influence the stability and performance of these solar cells. This research focuses on the simulation of solar cells, specifically utilizing zinc oxide (ZnO) as the electron transport layer. A 0.1 molar ZnO thin film was prepared from Zinc acetate salt and was deposited on a glass substrate using the cost effective Successive Ionic Layer Adsorption and Reaction (SILAR) method. In-depth investigations were carried out on several factors, including structural, surface, optical and numerical analysis. The obtained parameters were utilized in the General-Purpose Photovoltaic Device Model (GPVDM) software to perform numerical simulations of the organic solar cell and Perovskite solar cell. Both Organic solar cells and Perovskite solar cells were designed numerically and through careful observations, electrical parameters like Open circuit Voltage (Voc), Short circuit current (Jsc), Fill Factor (FF), and Power Conversion Efficiency (PCE) were identified. The studies indicate the promising performance of simulated solar cells with SILAR-synthesized ZnO thin film as the ETL.
 
Padmanaban Ramasamy,
Volume 21, Issue 2 (6-2024)
Abstract

The present investigation delves into the friction stir welding of AA5052 and AZ31B alloys, examining the effects of three distinct parameter configurations. A face-centered central composite design, structured to incorporate full replications for comprehensive and reliable analysis, was employed. A pivotal element of this study is implementing an advanced deep neural network (DNN) model. Characterized by its varied activation functions, structural parameters, and training algorithms, this DNN model was adeptly configured to precisely predict the tensile strength and microhardness of the welded joints. This comprehensive examination also included a quantitative assessment of the parameter effects on joint microstructure and mechanical properties. Flawless welds with exemplary surface characteristics were attained through a meticulously optimized set of parameters: a tool rotation speed set at 825 rpm, a tool traverse speed of 15 mm/min, and a shoulder diameter of 18 mm. During the welding process, the formation of intermetallic compounds, specifically Al12Mg17 and Al3Mg2, was observed. An exceptionally refined grain size of 2.23 µm was observed in the stir zone, contributing to the joint's enhanced tensile strength, measured at 180 MPa. The hardness of the specimen fabricated at the high rotational speed is more elevated due to the brittle intermetallic compounds. The better mechanical properties are related to the reduction and distribution of intermetallic compounds formed in the interface zone.  
Alireza Zibanejad-Rad, Ali Alizadeh, Seyyed Mehdi Abbasi,
Volume 21, Issue 2 (6-2024)
Abstract

Pressureless sintering was employed at 1400 °C to synthesize Ti matrix composites (TMCs) reinforced with in-situ TiB and TiC reinforcements using TiB2 and B4C initial reinforcements. The microstructure and wear behavior of the synthesized composites were evaluated and compared and the results showed that B4C caused the formation of TiB-TiC in-situ hybrid reinforcements in the Ti matrix. Also, TiB was in the form of blades/needles and whiskers, and TiC was almost equiaxed. Moreover, the volume fraction of the in-situ formed reinforcement using B4C was much higher than that formed using TiB2. In addition, although the hardness of the B4C-synthesized composites was higher, the composite synthesized using 3 wt.% TiB2 exhibited the highest hardness (425 HV). The wear test results showed that the sample synthesized using 3 wt.% TiB2 showed the lowest wear rate at 50 N, mainly because of its higher hardness. The dominant wear mechanism in the samples synthesized using 3 wt.% B4C was abrasive and delamination at 50 N and 100 N, respectively while in the samples synthesized 3 wt.% TiB2, a combination of delamination and adhesive wear and adhesive wear was ruling, respectively.

 
Farah Zulkifli,
Volume 21, Issue 2 (6-2024)
Abstract

Researchers are increasingly focusing on green synthesis methods for silver nanoparticles due to their cost-effectiveness and reduced environmental impact. In this study, we utilized an edible bird's nest (EBN), a valuable economic resource, as the primary material for synthesizing silver nanoparticles using only water as the solvent. Metabolite profiling of the EBN extract was conducted using LC-QTOF-MS in positive mode (ESI+), revealing the presence of lipids, glycosides, peptides, polysaccharides, and disaccharides. Upon the addition of silver nitrate to the aqueous EBN extract, noticeable color changes from transparent to brown indicated the successful formation of AgNPs. Subsequent characterization of these silver nanoparticles involved UV-Visible spectroscopy, which revealed an absorption peak at 421 nm. Further characterization was carried out using FESEM, ATR-FTIR spectroscopy, and EDX analysis. The involvement of phenolic agents, proteins, and amino acids in reducing the silver particles was confirmed. The synthesized nanoparticles exhibited a spherical shape, and a particle size ranging from 10 to 20 nm. The presence of elemental silver was confirmed by a strong, intense peak around 3 keV in the EDX spectrum. To assess their potential, the antibacterial properties of the silver nanoparticles against Escherichia coli and Staphylococcus aureus were evaluated using the agar diffusion method.
 
Satish Ahire, Ashwini Bachhav, Bapu Jagdale, Thansing Pawar, Prashant Koli, Dnyaneshwar Sanap, Arun Patil,
Volume 21, Issue 2 (6-2024)
Abstract

Hybrid photocatalysts, comprising both inorganic and organic polymeric components, are the most promising photocatalysts for the degradation of organic contaminants. The nanocomposite, Titania-Polyaniline (TiO2-PANI) was synthesized using the chemical oxidative polymerization method. Various characterization techniques were employed to assess the properties of the catalysts. The ultraviolet diffuse reflectance spectroscopy (UV-DRS) analysis revealed that the TiO2 absorbs only UV light while the TiO2-PANI nanocomposite absorbs light from both UV and visible regions. The X-ray diffraction (XRD) results confirmed the presence of TiO2 (anatase) in both TiO2 nanoparticles and TiO2-PANI (Titania-Polyaniline)  nanocomposite. The phases of the catalysts were verified through Raman, TEM, and SAED techniques where all results are in good agreement with each other. The average crystallite size of TiO2 nanoparticle and TiO2-PANI nanocomposite were 13.87 and 10.76 nm. The thermal stability of the catalysts was assessed by the Thermal gravimetric analysis (TGA) technique. The order of the thermal stability is TiO2 > TiO2-PANI > PANI.  The crystal lattice characteristics were confirmed using Transmission electron microscopy (TEM). The surface area measurements were confirmed from the Brunauer-Emmett-Teller (BET) study and were employed for the evaluation of the photocatalytic efficiency of both, TiO2 nanoparticles and TiO2-PANI nanocomposite catalysts. The energy dispersive spectroscopy (EDS) study was employed for elemental detection of the fabricated materials. While Raman spectroscopy was employed for the chemical structure and the phase characteristics of the materials. The standard conditions for the degradation of the CF dye were 8 g/L of catalyst dosage, 20 mg/L of dye concentration, and a pH of 7. The TiO2-PANI nanocomposite exhibited superior efficiency as compared to pure TiO2 nanoparticles, achieving almost 100 % degradation in just 40 minutes.  
Wed Abed,
Volume 21, Issue 2 (6-2024)
Abstract

Silver/polyvinyl alcohol (Ag/PVA) nanocomposites were fabricated via an electrochemical method. Silver nanoparticles (AgNPs) with varying grain sizes were directly synthesized within PVA polymer matrices at deposition times of 15, 30, 45, 60, and 120 minutes. The integration of AgNPs within the PVA matrix was confirmed through Transmission Electron Microscopy (TEM) and optical absorbance measurements. X-ray Diffraction (XRD) analysis demonstrated the face-centered cubic structure of AgNPs. Furthermore, these prepared nanocomposites exhibited significant antibacterial properties against Bacillus subtilis and Pseudomonas pneumonia, as well as antifungal activity against Alternaria alternata. Remarkably, the AgNPs/PVA nanocomposite exhibited outstanding antifungal efficiency, resulting in an impressive inhibition zone of up to 47 mm.
 
Ahad Saeidi, Sara Banijamali, Mojgan Heydari,
Volume 21, Issue 2 (6-2024)
Abstract

This study explores the fabrication, structural analysis, and cytocompatibility of cobalt-doped bioactive glass scaffolds for potential applications in bone tissue engineering. A specific glass composition modified from Hench's original formulation was melted, quenched, and ground to an average particle size of 10 μm. The resulting amorphous powder underwent controlled sintering to form green bodies and was extensively characterized using simultaneous differential thermal analysis (DTA), Raman spectroscopy, and Fourier Transform Infrared analysis (FTIR). After mixing with a resin and a dispersant, the composite was used in digital light processing (DLP) 3D printing to construct scaffolds with interconnected macropores. Thermal post-treatment of 3D printed scaffolds, including debinding (Removing the binder that used for shaping) and sintering, was optimized based on thermogravimetric analysis (TG) and the microstructure was examined using FE-SEM and XRD. In vitro bioactivity was assessed by immersion in simulated body fluid (SBF), while cytocompatibility with MC3T3 cells was evaluated through SEM following a series of ethanol dehydrations. The study validates the fabrication of bioactive glass scaffolds with recognized structural and morphological properties, establishing the effects of cobalt doping on glass behavior and its implications for tissue engineering scaffolds. Results show, Low cobalt levels modify the glass network and reduce its Tg to 529 oC, while higher concentrations enhance the structure in point of its connectivity. XRD results shows all prepared glasses are amorphous nature, and DTA suggests a concentration-dependent Tg relationship. Spectroscopy indicates potential Si-O-Co bonding and effects on SiO2 polymerization. Cobalt's nucleating role promotes crystalline phases, enhancing bioactivity seen in rapid CHA layer formation in SBF, advancing the prospects for bone tissue engineering materials.

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