Iranian Journal of Materials Science and Engineering

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The field of nanomaterial has greatly advanced in the last decade following a wider range of applications in the fields of electronics, automobiles, construction, and healthcare due to its extraordinary and ever-evolving properties. Synthesis of the nanomaterial plays a crucial role in redefining the current engineering and science field. At the same time, procuring an environment-friendly end product through eco-friendly solutions and sustainable processes is the key to many global problems. Green synthesis of nanomaterials like graphene and its derivatives involves mild reaction conditions and nontoxic precursors because it is simple, cost-effective, relatively reproducible, and often results in more stable materials. This paper primarily focuses on the green synthesis of graphene and its derivatives (graphene oxide & reduced graphene oxide) and geopolymers; a green technology for preparing graphene reinforced geopolymer composites. Various methods used globally for green synthesis of graphene and geopolymer are briefly discussed and this paper tries to integrate these two areas for a green end product. Possible applications of these green composites are also discussed to provide insights on the current growth and developments. 

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Graphene oxide (GO) and reduced graphene oxide (rGO) is a semiconductor device which finds its many applications in the various electronic devices. In the present study GO and rGO thin sheets have been grown over Si wafers using Hummer’s and modified Hummer’s method and a comparison in the properties of the coatings have been carried out. The morphology of the sheets characterized by SEM revealed similar transparent sheet like structure for both the chemical synthesis. The diffraction pattern of GO and rGO prepared with modified Hummer’s method showed peak shift to lower diffraction angle from 9.96 ^o to 9.63 ^o and 26.4 ^o to 26.3 ^o respectively. The diffraction peaks were observed at diffraction phase of 001 and 002 crystal plane. FTIR spectra revealed presence of oxygen functional groups in GO thin sheets whereas peaks for oxygen functionalities are absent in rGO. The polarization curve indicated similar corrosion resistance of GO and rGO thin sheets grown under Hummer’s and modified Hummer’s. Capacitive property of rGO is better than GO as observed by the electrochemical analysis of GO and rGO..Graphene oxide (GO) and reduced graphene oxide (rGO) is a semiconductor device which finds its many applications in the various electronic devices. In the present study GO and rGO thin sheets have been grown over Si wafers using Hummer’s and modified Hummer’s method and a comparison in the properties of the coatings have been carried out. The morphology of the sheets characterized by SEM revealed similar transparent sheet like structure for both the chemical synthesis. The diffraction pattern of GO and rGO prepared with modified Hummer’s method showed peak shift to lower diffraction angle from 9.96 ^o to 9.63 ^o and 26.4 ^o to 26.3 ^o respectively. The diffraction peaks were observed at diffraction phase of 001 and 002 crystal plane. FTIR spectra revealed presence of oxygen functional groups in GO thin sheets whereas peaks for oxygen functionalities are absent in rGO. The polarization curve indicated similar corrosion resistance of GO and rGO thin sheets grown under Hummer’s and modified Hummer’s. Capacitive property of rGO is better than GO as observed by the electrochemical analysis of GO and rGO.

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Residual stress measurement is of utmost importance for the safety and reliability of engineering components and has been an active area of scientific research. Relaxation techniques such as hole drilling, slitting and ring core method are widely applied semi destructive techniques for residual stress measurements in polymer composites. This article reviews the recent literature on the measurement of residual stress in polymer composite by employing the above-mentioned relaxation techniques. This article summarizes the categories of residual stresses, causes of formation, techniques of measurements and also briefly outlines the chronological developments of the Hole drilling and slitting method. The article also provides a comparative summary of these relaxation methods.

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Copper oxide (CuO) nanostructure particles were prepared using KOH/NaOH catalyst by low cost precipitation method and characterized by powder X-ray diffraction (PXRD), scanning electron microscope (SEM) and energy dispersive X-ray spectra (EDX) analysis. The photocatalytic dye degradation study of pure CuO nanostructure particles are analysed against two azo dyes (Direct black 38 (Black-E) and Congo red) under ultraviolet (UV) and solar irradiation. The release of major active species (*OH) in the photocatalytic degradation by as prepared CuO nanostructure particles were investigated by photoluminescence (PL) spectra with two different excitation wavelength (325and 355nm). The band gap of CuO nanostructure particles was calculated from diffuse reflectance spectra. The photocatalytic effect of CuO nanostructure particles is confirmed from the UV – Vis and photoluminescence spectra and also, further confirmed from the kinetic studies under UV and solar radiations. The photocatalytic degradation results revealed that 16.35% and 7.5% of black E and Congo red dye was degraded under UV, while it was 47.2% and 17.6% under solar light. The influence of pH on the photodegradation and change in the reaction temperature under solar irradiation were also analysed

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Fossil fuels served as the main source of energy throughout the 1800s when the industrial revolution got underway. Countries started aiming for carbon-neutral footprints and lowered emissions as environmental degradation became more apparent. Numerous research projects have been undertaken to discover a photovoltaic device that can replace conventional silicon (Si)-based solar cells. Dye-sensitized solar cells (DSSCs) have undergone extensive research during the past three decades. Due to their straightforward preparation process, low cost, ease of production, and low toxicity, DSSCs have seen extensive use. The reader will be able to comprehend the numerous types of TCO layers, physical methods for depositing metal oxide on TCO thin films, materials for fabricating the various DSSC layers, and the various types of dyes included in DSSC as well as their components and structures. The reader's ability to construct the DSSC, gain a general understanding of how it operates, and increase the effectiveness of these devices' potential growth and development paths are all aided by this review. For these technologies to be debated and shown to be appropriate for a breakthrough in consumer electronics on the market, manufacturing, stability, and efficiency improvements must also be addressed in the future. An overview of current DSSC prototype development and products from major firms is presented.
 

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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.
 

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Biogenic synthesis of papain-conjugated copper metallic Nanoparticles and their antibacterial and antifungal activities Papain metallic conjugated nanoparticles (Papain-CuNPs) were synthesised using Papain and CuSO4.5H₂O. Papain-CuNPs were characterized using UV-visible spectroscopy, FT-IR, HR-TEM, XRD, FE-SEM, zeta potential, and a zeta sizer. The antibacterial activity of papain-CuNPs against human infectious microorganisms (Citrobacter spp, Pseudomonas aeruginosa and Candida albicans) was investigated. The mechanism of action of papain-CuNPs was evaluated using FE-SEM and HRTM. UV spectroscopy confirmed the plasma resonance (SPR) at 679 nm, which indicated the formation of papain-CuNPs. The FT-IR spectrum absorbance peaks at 3927, 3865, 3842, 3363, 2978, and 2900 cm^-1 indicate the presence of O-H and N-H of the secondary amine, and peaks at 1643 and 1572 cm^-1 represent C=O functional groups in Papain-CuNPs. EDAX analysis confirmed the presence of copper in the papain-CuNPs. The zeta potential (-42.6 mV) and zeta size (99.66 d. nm) confirmed the stability and size of the nanoparticles. XRD confirmed the crystalline nature of the papain-CuNPs. FE-SEM and HRTM showed an oval structure, and the nano particles' 16.71244–34.84793 nm. The synthesized papain-NPs showed significant antibacterial activity against clinical P. aeruginosa (15 mm). MIC 125 µg/ml) showed bactericidal activity against P. aeruginosa and the mechanism of action of Papain-NPs was confirmed using an electron microscope by observing cell damage and cell shrinking. Papain-CuNPs have significant antibacterial activity and are thus used in the treatment of P. aeruginosa infections

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The composite solid polymer electrolyte films were prepared by doping nano-sized Fe₂O₃ particles on PVB (Polyvinyl Butyral) complexed with NaNO₃ salt by solution casting technique. FTIR, XRD, and SEM methods characterized these electrolyte films. The Fourier Transform Infrared Spectroscopy and X-ray diffraction methods reveal the structural and complexation changes occurring in the electrolytes. The surface morphology of the electrolyte film was examined using the SEM (Scanning Electron Microscope) technique. The PVB+NaNO₃+Fe₂O₃(70:30:3%) electrolyte shows a moderate ionic conductivity of 2.51×10⁻⁵ S cm⁻¹ at ambient temperature (303 K). AC impedance spectroscopic analysis evaluates the ionic conductivity of the produced polymer electrolyte. Wagner's polarisation technique was applied to study the charge transport characteristics in the electrolyte films. The investigation revealed that ions constituted the majority of the transport carriers. An Open Circuit Voltage (OCV) of 2.0V and a Short Circuit Current (SCC) of 0.8 mA were found in the discharge characteristics data for the cell constructed with the polymer electrolyte sample.