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Synthesis methods of chitosan nanoparticles: A review
Biopolymeric nanoparticles are found to be very effective in potential applications in different fields, especially in biomedical field. Chitosan nanoparticles (CSNPs) are one of those kind of nanoparticle with great research potential owing to its nontoxicity, biodegradability, and high permeability. The extraction of chitosan biopolymer and the production of CSNPs are both vibrant research areas. Emulsification, complexing, phase inversion etc. are the conventional synthesis methods; new synthesis methods are being developed to overcome the disadvantages of traditional approaches. Here we provide a glimpse into the methodological and mechanistic underpinnings of the synthesis methods of CSNPs. This chapter provides a complete overview of the synthesis methods used for the production of CSNPs, their benefits, drawbacks, and obstacles, as well as their future prospects. 2025 Elsevier Ltd. All rights reserved. -
Synthesis and Studies on Partially Stabilized Zirconia and Rare-Earth Zirconate Pyrochlore Structured Multilayered Coatings
This work is focused on the thermal fatigue behaviour studies of ceramic coatings, as TBC (Thermal Barrier Coating) system, its importance in determining the thermo-mechanical properties and service-life estimation of the coatings when exposed to elevated operating temperatures. Commercial 6-8%Yttria stabilized zirconia (YSZ) top coat (TC) and NiCrAlY bond coat (BC) in (a) conventional YSZ (BC and TC), (b) multi-layered functionally graded materials (FGM) i.e., BC-blend (50BC+50TC)-(TC) configuration and (c) lab synthesized Zirconia based pyrochlore (Lanthanum Zirconate-LZ) were the coating materials involved. Nickel based super alloy Inconel 718 substrates were coated by using Atmosphere Plasma Spray (APS) system with three different (varying power) plasma spray parameters. All the sides of the 25mm x 10mm x 5mm thick substrates were completely covered with the bond coat and ceramic coating. FGM configuration was spray coated only on one side of the Inconel flat plates. Thermal shock cycle tests were performed on the coated specimen by following the ASTM B214-07 guidelines which comprised of introducing the coated specimen in a muffle furnace at 1150C, held in it for 2 minutes before removing from furnace followed by forced fan air cooling (one shock cycle). The specimen were periodically subjected to visual inspection for faults, before continuing the shock cycles, until the coating flaked off or cracked or detached from substrate. Cross section metallographic samples were prepared and analysed under SEM (Scanning Electron Microscope) and Energy Dispersive spectroscope (EDS) to study the as-sprayed coating morphology and interface quality, measure coating thickness, study defects characteristics and the chemical composition. Crystal structural phases were analysed using X-Ray Diffraction (XRD). 2019 Elsevier Ltd. -
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Synthesis and physico-chemical characterization of ZnS-based green semiconductor: A review
One-dimensional (1D) semiconductor nanostructures have been attracting a great deal of attention because of their excellent electronic and optoelectronic performance. Zinc sulfide (ZnS) nanostructures have attracted increasing attention because of their potential application in both conditional optical devices and new generation of green nanostructure semiconductors because of their special structure-related physical and chemical properties. Synthetic form of ZnS can be transparent, and it is used as a window for visible optics, infrared optics, and functional materials. In this chapter, the detailed studies of synthesis, characterization of crystals, and noncrystalline behavior is reported. The crystal structure of semiconductor and its morphological studies are compared and fabrication methods will be described. The major parameters that influence on ZnS doped with metal ions and rare earth ions and its optoelectronic properties will be carefully analyzed. In addition, the primary application of ZnS micro- and nanocrystals will be described. At the end, the predicted future applications and development directions of doped and undoped ZnS nanocrystals will be given. 2023 Elsevier Ltd. All rights reserved. -
Synthesis and photophysical properties of a novel phthalimide derivative using solvatochromic shift method for the estimation of ground and singlet excited state dipole moments
A novel phthalimide derivative, 2-{4-[(1H-1,2,4-triazol-1-yl)methyl]phenyl}-1Hisoindole-1,3(2H)-dione (TMPID) containing an isoindole moiety was synthesized by the cyclisation of 2-({4-[(1H-1,2,4-triazol-1-yl)methyl]phenyl}carbamoyl)benzoic acid (TMPCB). The absorbance and fluorescence spectra of the derivative were recorded in fifteen different solvents to investigate their solvatochromic behaviour and dipole moments. Different solvent correlation methods, like the BilotKawski, LippertMataga, Bakhshiev, KawskiChammaViallet and Reichardt methods were employed to estimate the singlet excited and ground state dipole moments. Using multiple regression analysis, solute-solvent, specific and non-specific interactions were analyzed by means of Kamlet-Abboud-Taft and Catalan parameters. Computational studies were performed using time dependent density functional theory (TD-DFT) in order to calculate ground state dipole moment, atomic charges and frontier molecular orbital energies in solvent phase. Experimental and computational studies indicate that the singlet excited state dipole moment of TMPID is greater than the ground state dipole moment. The chemical stability of the derivative was determined by means of chemical hardness (?) using HOMOLUMO energies. From TD-DFT computational analysis, reactive centres in the molecule were evaluated based on molecular electrostatic potential (MESP) 3D plots. 2016 Elsevier B.V. -
Synthesis and Nuclear Magnetic Resonance Studies of 2-Thiophenecarboxaldehyde Nicotinic Hydrazone and 2-Thiophenecarboxaldehyde Benzhydrazone
Synthesis and NMR spectral studies of bidentate N and S heterocycles of 2-thiophenecarboxaldehyde nicotinic hydrazone and 2-thiophenecarboxaldehyde benzhydrazone have been carried out. The compounds, 2-thiophenecarboxaldehyde nicotinic hydrazone and 2-thiophenecarboxaldehyde benzhydrazone were synthesized by reacting stoichiometric quantities of nicotinic hydrazide and benzhydrazide with 2-thiophene carboxaldehyde in methanol in the presence of glacial acetic acid at refluxing temperature. Upon cooling the reaction mixture, the products were obtained as colorless solids. 1H, 13C, 1H-1H COSY, and 1H-13C HSQC experiments have been conducted to characterize the compounds. 2020 Malaysian Institute of Chemistry. All rights reserved. -
Synthesis and Multifaceted Exploration of 4-Phenylpiperidin-4-ol Substituted Pyrazole: Photophysical Insights with Biological Activity
In this study, we successfully synthesized a pyrazole derivative, specifically 4-phenylpiperidin-4-ol substituted pyrazole (CHP), through the reaction of Grignard reagents in combination with pyrazole. This newly synthesized molecule was subjected to a comprehensive evaluation for both its photophysical and biological applications. Notably, CHP exhibited promising invitro antifungal and antibacterial activities, primarily attributed to the presence of the 4-phenylpiperidin-4-ol moiety and resulting component contributed to an enhanced absorption rate of lipids, thereby improving the pharmacological activity of CHP. This correlation between structure and function was further supported by the outcomes of structure-activity relationship studies. Additionally, we conducted in silico studies to examine the molecular interactions of the synthesized molecule with key proteins, including DNA Gyrase, Lanosterol 14 ?-demethylase, and KEAP1-NRF2. The results unveiled robust binding interactions at specific sites within these proteins, indicating potential therapeutic relevance. Furthermore, the photophysical properties of the synthesized compounds were thoroughly investigated using the ab-initio technique. This involved the determination of ground state optimization and HOMO-LUMO energy levels, all calculated with the DFT-B3LYP-6-31G(d) basis set. The assessment of the theoretically estimated HOMO-LUMO value provided insights into the global chemical reactivity descriptors, revealing that the synthesized molecule boasts a highly electronegative and electrophilic index. Taken together, our findings suggest that pyrazole derivatives with 4-phenylpiperidin-4-ol substitutions exhibit promising applications in both photophysical and biological contexts. 2024 Ghaferah H. Al-Hazmi et al., published by Sciendo. -
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Synthesis and electrochemical studies of 1,1-binaphthyl-2,2-diol for aqueous rechargeable lithium-ion battery applications
The constant increase in the utilization of lithium-ion batteries (LIBs) in various field applications, including electrical vehicles and electronic devices, has led researchers to focus on their multiple path developments to obtain new electrode materials. The practical development of these electrode materials, based on organic and inorganic moieties, is challenging for various groups of LIB scientists. The concept of organic electrode materials is highly competitive with inorganic electrode materials because of the accessibility of more active sites with structural diversity, high energy and power density, environmental friendliness potential sustainability, and low cost. Herein, 1,1-binaphthyl-2,2-diol (BINOL) is investigated as an organic electrode material that contains two hydroxyl groups that act as active centers. The oxidative coupling process is employed to synthesize BINOL and so obtained product was characterized by using FT-IR, 1H-NMR and MASS techniques. The electrochemical investigations were carried out using sat. Li2SO4 electrolytic medium at three-electrode cell system. The Cyclic voltammetry (CV) has provided information on the anodic behavior of the material and its stability studied at different scan rates. The battery performance of the cell BINOL | Sat. Li2SO4 | LiMn2O4 by galvanostatic charge-discharge potential limit (GCPL) shows 197/171mAhg?1 specific capacity and 90% columbic efficiency. The electrochemical kinetic obtained by potentiostatic electrochemical impedance spectroscopy (PEIS) shows a semi-infinite diffusion process. 2024 Elsevier B.V. -
Synthesis and crystal structure of 1,7-bis(4-methoxyphenyl)-4-(1,3- dithiolan-2-ylidene)-1,6-heptadiene-3,5-dione
The synthesis and crystal structure of 1,7-bis(4-methoxyphenyl)-4-(1,3- dithiolan-2-ylidene)-1,6-heptadiene-3,5-dione is described. This compound crystallizes in the space group P21 with unit cell parameters a = 14.207 b = 7.752(1) c = 19.473(1) ? = 91.00(3), with two molecules in the asymmetric unit. The ketenedithioacetal functionality present between the carbonyl groups prevents the possibility of keto-enol tautomerization in this compound. The cinnamoyl groups are organized parallel to each other due to the push-pull nature of the ketenedithioacetal functionality. 2010 Springer Science+Business Media, LLC. -
Synthesis and Characterization of WO3 Nanostructures by the Solvothermal Method for Electrochromic Applications
In this study, a tungsten trioxide (WO3) thin film was deposited by direct current (DC) sputtering onto a fluorine-doped tin oxide (FTO) substrate as the seed layer at an oxygen partial pressure of 8 10?4mbar. A simple solvothermal method involving tungsten hexacarbonyl (W(CO)6), ethanol (C2H5OH), and hydrochloric acid (HCl) was used to synthesize vertically stacked nanoscale WO3 hierarchical structures on WO3 seed-layered FTO. After the deposition process, the FTO samples with nanostructures were subjected to annealing in air at 400C for 4 h. After annealing, the surface morphology, structural characteristics, and optical and electrochromic properties of the grown nanostructures were investigated using scanning electron microscopy (SEM), x-ray diffraction (XRD), Raman spectroscopy, UVvisible spectroscopy, and electrochemical analysis. From the XRD analysis, all the diffraction patterns were ascribed to a monoclinic phase. The SEM analysis showed that films grown with 5?L HCl had a nanoflower structure compared to the films grown with 0?L HCl and 20?L HCl. The nanoflower-structured films showed a higher cathodic peak current (?2.22mA), diffusion coefficient (5.43 10?9 cm2/s), and coloration efficiency (23.6 cm2/C). The increased electrochromic characteristics were attributed to the nanostructured films, which enhanced the diffusion of H+ ions by providing a large surface area during the charge transfer process. The Minerals, Metals & Materials Society 2024. -
Synthesis and Characterization of Vanadyl Complexes of Heterocyclic Acid Hydrazones
Two acid hydrazones, Furan-2-carbaldehyde nicotinic hydrazone and Furan-2-carbaldehyde benzhydrazone have been synthesised and they are characterized by elemental analysis, IR, NMR and UV spectral analysis. Vanadyl complexes of these two hydrazones were synthesised and characterised by elemental analysis, IR, UV, EPR, molar conductivity and magnetic susceptibility measurements. Spectral data indicates the square pyramidal geometry for the monomeric ve coordinated oxovanadium (IV) complexes with the general formula [VO(L)(OCH3 )].The vanadium complex of the acid hydrazone was studied for its catalytic activity. The complex was found to be a good catalyst in quinoxaline synthesis. -
Synthesis and characterization of porous, mixed phase, wrinkled, few layer graphene like nanocarbon from charcoal /
Russian Journal Of Physical Chemistry A, Vol.89, Issue 13, pp.2438-2442, ISSN No: 0036-0244. -
Synthesis and characterization of porous, mixed phase, wrinkled, few layer graphene like nanocarbon from charcoal
A technique to synthesis wrinkled graphene like nano carbon (GNC) from charcoal is reported in the current study. The charcoal produced by thermal decomposition and is intercalated by Hummers method. It is separated by centrifugation and sonication to get few layer graphene sheets. The structural and chemical changes of the nanostructure is elucidated by Raman spectroscopy, TEM, SEM-EDS and XPS. Raman spectra revealed the existence of highly graphitized amorphous carbon, which is confirmed by the appearance of five peaks in the deconvoluted first order Raman spectra. The SEM analysis reveals the formation of large area graphene sheets with nano-porous structure in it. The TEM/SAED analysis exhibits the presence of short range few layer graphene. 2015 Pleiades Publishing, Ltd. -
Synthesis and characterization of Poly-Vinyl Alcohol-Alumina composite film: An efficient adsorbent for the removal of Chromium (VI) from water
Composite poly vinyl alcohol-alumina films were synthesized by a novel eco-friendly route in the absence of template. The physico-chemical nature of the synthesized film was studied using different characterization techniques. The poly vinyl alcohol-alumina composite film was found to be an efficient adsorbent for the removal of Chromium (VI) at higher concentrations from water. The preparation conditions were optimized to synthesize an efficient adsorbent film for the removal of chromium. The surface properties, chemical composition and amorphous nature of the film confirmed by different characterisation techniques attributes to the chromium removal efficiency of the film. Poly vinyl alcohol-alumina films are economically cheap, easy to prepare, efficient adsorbent for removal of chromium (VI) eco-friendly in nature and reusable with effortless regeneration methods. 2022 -
Synthesis and characterization of heterocyclic derivatives and studies on their photophysical properties
Photophysical properties such as absorption, fluorescence, quantum yields and lifetime of fluorescent heterocyclic compounds have been a subject of extensive research interest. Absorption and fluorescence emission of fluorescent molecules results in electronic transitions between ground and singlet excited state. The bathochromic or hypsochromic spectral shift brings a considerable change in dipole moment of both the electronic states through solute-solvent interactions. We have synthesized some heterocyclic compounds and studied thier photophysical properties. Different derivatives such as Schiff base, chalcone, maleimide and pyranopyrazole were synthesized and characterized by FTIR, 1H NMR, 13C NMR, mass spectrometry and elemental analysis. Photophysical properties of synthesized compounds have been studied through absorption and fluorescence spectroscopy and DFT calculations. We have used solvatochromic approaches such as Bilot-Kawski, LippertMataga, Bakhshiev, Kawski-Chamma-Viallet and Reichardt's solvent polarity parameters to evaluate dipole moments of ground state and singlet excited state of the synthesized heterocyclic compounds. The influence of specific and non-specific interactions on spectral properties was also investigated by using Kamlet-Abboud-Taft and Catalan multiple linear regression equations. X-ray diffraction analysis of hydroxyl Schiff base derivative has been carried out due to the presence of strong inter and intra molecular hydrogen bonding. Solvatochromic analyses of synthesized compounds were done using Bilot-Kawski, Lippert-Mataga, Bakhshiev, Kawski- Chamma-Viallet and Reichardt methods. All Solvatochromic graphs have been plotted for spectral parameters against solvent polarity parameters using Origin 8 software. The obtained experimental results from all methods were compared with theoretical results. The correlation coefficient between microscopic solvent polarity parameter and spectral Stokes-shifts were higher in comparison to bulk solvent polarity functions. Graphs for each molecule provided good correlation based on least square analysis. Dipole moment values of ground and excited states were calculated using slopes of different solvatochromic methods. Higher value of singlet excited state dipole moment indicated that the molecules were more polarised in the singlet excited state. Kamlet-Abboud-Taft and Catalan multiple linear regression (MLR) analyses were used to analyse the solvent effects on absorption, emission and difference in spectral energies of the synthesized molecules. Single point method was used to calculate the quantum yields of the synthesized compounds in ethanol using an ethanolic solution of anthracene as a reference compound. Edwards atomic increment method was applied to calculate the Onsager cavity radii of all the molecules using van der Waals volume. DFT/TD-DFT was used for quantum mechanical calculations of all the molecules. The geometrical structures of the synthesized molecules were optimized using B3LYP/6-311G(d, p) basis set. The positions of HOMO-LUMO orbitals were identified and the band gaps for all the molecules were calculated. Mulliken atomic charges and electrostatic potential surface (MEP) have also been evaluated for all the molecules to identify the ICT pathway and evaluate electrophilic and nucleophilic reactive sites around the molecules . The fluorescence quenching studies of a chalcone derivative by aniline in n-butanol and 1,4-dioxane was performed at 25 ? C which indicated that quenching reactions are diffusion limited. -
Synthesis and characterization of graphene oxide and reduced graphene oxide membranes for water purification applications
Graphene oxide and reduced graphene oxide-based laminar membranes have been receiving increased attention for its novel filtration applications. In the present work, graphene oxide (GO) solution is synthesized by modified Hummers method and coated on cellulose nitrate by vacuum filtration technique. Further, reduced graphene oxide (rGO) membranes are fabricated by the controlled reduction of GO membrane using vitamin C solution at 60 C. The formation of GO and rGO is confirmed from Raman, FTIR, and UVVis spectroscopy studies. Morphology and thickness of the membranes are investigated using surface and cross-sectional FESEM images. The filtration study showed that rGO membrane has higher water flux (52 L m?2h?1) than GO (40 L m?2h?1) membrane at differential pressure of 0.3MPa. Moreover, both membranes show congo red rejection of 96%. Prior studies showed that water flux decreased upon reduction of GO membrane which hindered the filtration properties of the membrane. Current work indicates that controlled reduction of GO leads to an enhancement in water flux, maintaining the dye rejection ratio. Graphical Abstract: [Figure not available: see fulltext.] 2023, Qatar University and Springer Nature Switzerland AG. -
Synthesis and characterization of graphene filled PC-ABS filament for FDM applications
Present investigation focuses on development of graphene filled PC-ABS filament for Fused Deposition Modeling applications. Compounding and twin screw extrusion was employed to synthesis graphene filled FDM filament of 1.75mm diameter. Percentage of graphene was varied from 0.1 vol% to 0.25 vol% in steps of 0.05. Developed filaments were subjected to SEM studies, dimensional accuracy and density measurements. In order to achieve filament of 1.75mm diameter, filament extrusion temperature was optimized using Taguchi's L25 orthogonal array, microstructure shows homogeneous dispersion of graphene particles in PC-ABS matrix, density decreases with increased content of graphene particles. 2018 Author(s). -
Synthesis and characterization of flyash reinforced polymer composites developed by Fused Filament Fabrication
Fused filament fabrication (FFF) has seen an upsurge in its utilization towards development of tailored made materials of polymer base. The advancement and diversity in fabricating the polymer composite parts by using FFF has seen the embracement of this technology in wider aspects, ranging from automotive, aerospace, construction and has marched towards day to day requirements. This research article focuses on development of polymer composite; by using flyash (FA), an industrial waste produced during coal combustion, as reinforcement in Acrylonitrile butadiene styrene (ABS) matrix, to study the physical and mechanical properties. FA, which is primarily made up of metal oxides, plays an imperative role as reinforcement. Easily and abundantly available, FA is being used in several applications to reduce the landfills utilization and also helps the environment. In this study FA was added as reinforcement in 5 and 10 wt. % respectively to ABS matrix and was developed into filament of 1.75 mm diameter. The developed ABS + FA polymer composite using FFF, were analyzed for physical and mechanical properties as per American Society for Testing and Materials (ASTM) standards. Microstructure studies were carried out for the developed composite to understand their behavior in enhancing the dimensional accuracy and tensile strength with incremental addition of FA up to 10 wt%. Tensile strength was enhanced by 28.19% and 36.13% for ABS + 5wt. % FA and ABS + 10wt. % FA respectively. Dimensional stability was also enhanced. Similarly, surface roughness analysis was carried out and it was observed to reduce with addition of FA. The surface roughness measurements provided suitable results of decrement by 9.64% and 14.6% for ABS + 5wt. % FA and ABS + 10wt. % FA respectively. Overall, the usage of FA along with FFF, has paved a path in sustainable and green technology in manufacturing. 2022 The Author(s). -
Synthesis and characterization of cyclopentadithiophene and thienothiophene-based polymers for organic thin-film transistors and solar cells /
Macromolecular Research, Vol.26, Issue 10, pp. 1-8, ISSN: 1598-5032