Iranian Journal of Chemistry and Chemical Engineering
Year:2024 | Volume:43 | Issue:1|Papers Count:33

Over the past two decades, there has been a rapid growth of research on nanotechnology in construction materials. This study presents a timely and comprehensive review that focuses on investigating the effects of incorporating various nanoparticles into cementitious, polymeric, and composite materials commonly used in the construction and architecture sectors. The primary objective is to critically analyze the potential benefits and limitations associated with the addition of nanoparticles, particularly in enhancing mechanical performance, durability, functionality, and sustainability. The study methodology involves an extensive analysis of published literature on nanoparticles applied in construction materials. The impact of nanomaterials on properties, including compressive strength, fracture toughness, stiffness, self-sensing capability, resistance to environmental degradation, antimicrobial effects, and recyclability is thoroughly examined. The findings reveal significant progress in demonstrating the capabilities of nanomaterials in tailoring the properties of cementitious composites, coatings, and plastics. However, challenges persist in such areas as dispersion, agglomeration, predicting long-term performance, toxicity evaluation, and feasibility assessment. Recommendations are provided, which focus on evaluating durability under in-service conditions, developing sustainable manufacturing methods, and establishing standardized protocols for material preparation and testing. The outcomes emphasize the need for a holistic approach that considers technical, environmental, economic, and social factors to facilitate the widespread adoption of nano-engineered materials. This comprehensive review serves as a valuable reference for researchers, engineers, architects, and construction professionals interested in understanding the current state-of-the-art, limitations, and future outlook on the integration of nanoparticles in construction applications.

Zinc oxide (ZnO) is a mineral compound commonly found as a white powder that is insoluble in water. It has a wide range of applications in various industries, including tile and ceramic manufacturing, glass production, rubber and lubricant production, paint formulation, adhesive and sealant production, battery manufacturing, food products, and medicine, such as wound dressings and dental materials. Additionally, ZnO nanoparticles are used in bone regeneration in conjunction with other ceramic nanoparticles and batteries. While ZnO can occur naturally, it is typically chemically synthesized to obtain an off-white crystalline powder. When heated, it temporarily changes color to yellow but returns to its original white color upon cooling. One practical method for achieving high energy storage capacity is to use oxygen from the air as the cathode (positive electrode) and a metal like zinc or aluminum as the anode (negative electrode) in a cell. In such a cell, the proportion of the oxygen cathode naturally decreases compared to the existing anode. There are various methods for producing ZnO, including direct, indirect, wet chemical, and laboratory synthesis. ZnO possesses unique properties such as antibacterial and anti-ultraviolet radiation properties, as well as high heat capacity, making it highly desirable for diverse industrial applications. This review paper specifically focused on synthesizing ZnO nanoparticles using the co-precipitation method, followed by characterization using X-Ray Diffraction (XRD) and Scanning Electron Microscope (SEM) analyses. The Transmission Electron Microscopy (TEM) images of the synthesized nanoparticles revealed their spherical and occasionally rod-shaped morphology, with particle sizes ranging between 30-50 microns. Zinc oxide nanoparticles are extensively used in cosmetic products such as face powder, lipstick, and creams due to their moisturizing, antibiotic, and deodorant properties. They are also employed as additives in oil, glue, and drying agents, as well as catalysts in methanol synthesis. Moreover, zinc oxide is commonly included in sunscreens due to its ability to reflect ultraviolet rays and its anti-sebum effects. Various methods, including sol-gel, precipitation, hydrothermal, microemulsion, Chemical Vapor Deposition (CVD), and biological approaches, can be employed to synthesize ZnO nanoparticles.

The use of metallic 3D printers in medical manufacturing has enabled the creation of complex medical products customized to each patient's specific anatomical information through CAD/CAM. This technology has allowed the examination of three-dimensional (3D) bone scaffolds as models for human bone geometry. Gradually, 3D printing has become a promising tool for creating grafts and scaffolds for bone tissue engineering, particularly in orthopedic fractures. The present study explores the use of a medical-grade titanium alloy coated with chitosan containing wollastonite nanoparticles (WS-NPs) at varying concentrations (0, 5, 10, and 15 wt%) to fabricate a 3D porous metallic scaffold using Selective Laser Melting (SLM). Materials characterization was performed using Scanning Electron Microscopy (SEM) and X-Ray Diffraction (XRD) analysis, while mechanical tests were conducted to determine the compressive strength, fracture toughness, elastic modulus, and Poisson ratio of the samples. The study involved fabricating a 3D porous metallic scaffold using SLM and a medical-grade titanium alloy coated with chitosan containing wollastonite nanoparticles (WS-NPs) at varying concentrations (0, 5, 10, and 15 wt%). The samples were characterized using SEM and XRD analysis, and mechanical tests were conducted to determine their properties. The samples were also subjected to a Simulated Body Fluid (SBF) and phosphate-buffered saline (PBS) test to evaluate their bioactivity and biodegradation rate, as well as an MTT toxicity test. The feasibility of the prostheses was tested for 1, 3, 7, and 14 days, and the results were analyzed. The SEM images and XRD analysis showed the surfaces of scaffold parts produced in nanometer dimensions, confirming the corresponding coating as well as the phases in the scaffold. The sample containing 10 wt% WS-NPs had the highest elastic modulus of about 420 MPa and compressive strength with a coating containing 10 wt% WS-NPs in a chitosan matrix. The results showed that the percentage of porosity changed from 52% to 48% in sample 2 and sample 3, respectively, as the compressive strength increased. The third sample exhibited promising biological behavior for orthopedic applications. The objective of this work is to fabricate and characterize a 3D porous metallic scaffold coated with chitosan containing wollastonite nanoparticles for bone tissue engineering applications. The study successfully fabricated a 3D porous metallic scaffold using SLM and a medical-grade titanium alloy-coated with chitosan containing wollastonite nanoparticles (WS-NPs) at varying concentrations. The results demonstrated that the sample containing 10 wt% WS-NPs had the highest elastic modulus and compressive strength. The third sample exhibited potential for orthopedic applications due to its promising biological behavior. 

In the present study, polycaprolactone (PCL) nanocomposites were rapidly prepared. PCL nanocomposites were modified with chitosan (CS) biopolymer and Silica Nanoparticles (SNs). The samples were characterized by Fourier Transform InfraRed (FT-IR) spectroscopy for functional groups, Scanning Electron Microscopy (SEM) for size and morphology, differential scanning calorimetry (DSC) for thermal stability, X-Ray Diffraction (XRD) for crystal structure, and tensile analysis for mechanical property. The water absorption and biodegradation analysis were evaluated for the nanocomposites. MTT assay was used to determine the cytotoxicity of nanocomposites for human embryonic kidney cells (HEK293). The antibacterial activity of nanocomposites was measured by the agar disc diffusion method against Escherichia coli (E. coli) as a gram-negative bacterium using the inhibition zone. Spherical silica nanoparticles were confirmed by SEM with an average particle size of 40-50 nm. The presence of functional groups of SNs, PCL, and CS was observed by ATR-FT-IR analysis. PCL crystal plates were identified with XRD analysis. Based on the thermal properties, the increase of silica nanoparticles increased the crystallization enthalpy of polycaprolactone. The increase of silica nanoparticles improved the mechanical properties and more water absorption and degradability. Based on the results, this biocompatible and non-toxic PCL/CS/SN nanocomposite with antibacterial properties improved biological and biomedical applications.

Graphite nanopowders can be prepared by several techniques including graphitization of diamond powder in an inert atmosphere, Chemical Vapour Deposition, Chemical synthesis, etc. In the present work, we present a very economical, simple, less toxic technique for preparing graphite nanoparticles. Graphite nanoparticles were prepared from the graphite present in pencil by hand milling technique using a motor and a pestle. The prepared graphite nanoparticles were used to prepare graphite nanofluids by a two-step method. Nanofluids were prepared by ultrasonication at 42KHz for 20 mins. The hand-milled raw graphite nanopowder was further heat treated at 150̊C, 300̊C, and 450̊C to investigate the effect of temperature on nanosize and dislocation density. The heat-treated nanoparticles were characterized by X-Ray Diffraction studies (XRD) for structural features & UV-Vis spectroscopy for band gap determination. The average size of the nanoparticles varied from 42nm-56nm. The dislocation density of the nanopowders varied from 3.18x1014/m3 to 5.66x1014/m3. The graphite particles heat treated at 450̊C had a size of 52nm and there was no effect on particle size till 300̊C. The band gap of heat-treated nanoparticles varied from 1.18eV at 150̊C to 1.55eV at 450̊C.  0.1 vol% Graphite nanofluids were prepared with water and ethylene glycol as base fluid. Nanofluids prepared from graphite nanoparticles that were heat treated at 450̊C showed the highest stability in comparison to other nanofluids which contain nanoparticles heat treated at 150̊C & 300̊C. The thermal conductivity of nanofluids increased with the heat treatment temperature of nanoparticles from 0.431 W/m-K to 0.436W/m-K for the same volume fraction of nanoparticle (0.1%). This is due to the enhanced surface area of heat-treated nanoparticles evident through XRD studies.

In recent years, there has been extensive research on the synthesis of Chitosan-Tripolyphosphate (CS/TPP) nanoparticles. However, the influence of different parameters and their interactions on nanoparticles is not well known yet. The purpose of the present study is to use machine-learning techniques, Random Forests (RF), and Artificial Neural Networks (ANN), to estimate the size and zeta potential of nanoparticles based on chitosan and tripolyphosphate concentrations, chitosan molecular weight, degree of deacetylation, pH, temperature, stirring rate, and their interactions. Machine-learning algorithms successfully estimated the size and zeta potential of nanoparticles spanning a size range from 50 to 1000 nm. The random forest algorithm had better overall R-squared accuracy of 0.95211 and 0.93978 in comparison to ANN model with R-squared accuracy of 0.94744 and 0.93643 for particle size and zeta potential, respectively. Results depicted that temperature and stirring rate did not have significant effects on the size and zeta potential. On the other hand, CS concentration and pH were the most important parameters on the size and zeta potential, respectively. Furthermore, the results indicated that the primary cause for the unexplained variation in prior studies stemmed from the interactions among parameters. Moreover, a correlation exists between size and zeta potential, attributed to the interaction of attractive and repulsive electrostatic charges, ionic interactions, and the quantity of CS molecules. 

Carbonization of Zea mays roots at 600˚C in the presence of nitrogen atmosphere and its activation at 800˚C under the hydraulic environment for an hour was used for mercury adsorption studies. Activated carbon (AC) was characterized by P-XRD, Raman, SEM, EDX, BET, and pH methods. By the inductively coupled plasma-mass spectrometer technique, mercury adsorption on AC was investigated under optimum conditions (at a pH of 5, 1mg/mL of adsorbent, 10 ppm of mercury, and 60˚C for 60 min). Evaluation of the statistical parameters for non-linear isotherm and kinetic models has disclosed that mercury adsorption on AC obeyed a pseudo-first-order kinetic model and Freundlich adsorption isotherm which was further confirmed by the Sips isotherm at equilibrium. The surface area of AC is 422 m2/g and has shown an adsorption capacity of 40.8 mg/g mercury and 99.43% removal efficiency. The dimensionless separation factor (RL) was 0.018 which pronounces favorable adsorption of mercury. The larger C value (7.3675 mg/g) and not passing the plot through the origin (R2 =0.9872) in Web Morris intraparticle diffusion model evidenced that IPD is not only rate-limiting step and other kinetic models (PFO) were also involved in the mercury sorption on AC. Desorption experiments were carried out in warm water and the percentage of mercury that has been restored was 6% due to the quasi-chemical bond between AC and mercury.

Electrochemical oxidation methods are simple, use very few extra reagents, and are both technically and economically viable technologies that can be used for the treatment of various industrial effluent streams including olive wastewater. The treatment is based on the direct anodic oxidation method in which the pollutants are adsorbed on the anode surface and then reduced by the electron transport reaction. In this study, the effect of different catalysts on the treatment of olive wastewater is carried out by using electrocatalytic methods. Initially, TiO2/AC, V2O5/TiO2/AC, WO3/TiO2/AC, and V2O5/WO3/TiO2/AC catalysts were prepared by a sol-gel method. Then, the removal of different pollutants such as color, phenol, lignin, and Chemical Oxygen Demand (COD) was investigated by using different experimental electrochemical processes. In the electrocatalytic oxidation process, synthesized catalytic materials were used as particle electrodes (working electrodes) with the graphite electrodes in an electrochemical cell. The treatment process was optimized by investigating the effects of different parameters, for example, treatment time, catalyst type, catalyst amount (as solid/liquid ratio), voltage, the amount of supporting electrolyte (NaCl), and suspension’s pH. The V2O5/TiO2/AC catalyst exhibited the highest percentage of removal under all experimental conditions, with a significant effect of voltage on the removal capacity observed (82.95% for lignin and 74.42% for COD). While the pH effect showed limited influence on the removal performance, higher yields were observed in acidic conditions. The electrocatalytic reaction involves various steps such as adsorption, nano adsorption, electrooxidation, and electrocatalytic oxidation. The individual effects of these steps were also investigated, resulting in percentage color removals of 25.58%, 51.72%, and 72.42%, respectively. When the data were evaluated in terms of kinetics, it was seen that the data provide a first-degree agreement of over 90 % in all experimental parameters and the removal rate constants of low molecular weight substances may generally be higher than the others. Despite its significant lignin removal efficiency, the catalytic process mentioned above yielded lower values compared to other catalytic methods. Additionally, it was observed that the phenol concentration increased as a result of this process. This suggests that for the catalytic oxidation of olive wastewater effluent, the preliminary treatment using an electrocatalytic process is found to be more effective. The synergistic combination of these processes was more effective than the individual process.

The present study aims to determine the photocatalytic degradation efficiency on organic Methylene Blue (MB) dye by using Mg0.5Co0.5Al0.5Fe1.5O4 spinel ferrite nanoparticles as a photocatalyst. All metal nitrates and sodium hydroxide were used as raw chemicals in the co-precipitation method for the synthesis of Mg0.5Co0.5AlxFe2-xO4 (x = 0.0, 0.1, 0.3, 0.5, 0.7, 0.9 mole %) spinel ferrites nanoparticles. The synthesized nanoparticles were characterized by X-Ray Diffraction (XRD), Field Emission Scanning Electron Microscope (FE-SEM), Energy Dispersive Spectrometer (EDS) mapping, Fourier Transform InfraRed (FT-IR), PL photoluminescence spectra, UV–Visible spectroscopy and N2 absorption-desorption isotherm method. XRD confirms the spinel cubic structure of spinel ferrite nanoparticles. Interplanar distance (d) and crystalline size (D) are calculated by using Bragg’s equation and Scherrer’s relationship respectively. SEM and EDS confirmed the morphological and elemental analysis of spinel ferrites. UV spectrum of the synthesized photocatalyst was studied and compared the energy band gap between the undoped, Mg-doped, and Mg-Al-doped cobalt spinel ferrites. PL photoluminescence spectra were analyzed to investigate the transfer, relocation, and recombination process of charge carriers. The surface area of the synthesized photocatalysts was in the range of 26.38-32.47 m2/g. The photocatalysis of Mg-Al doped cobalt spinel ferrite nanoparticles were carried out for the degradation of MB dye under visible light irradiation. The amount of photocatalyst (spinel ferrite) used, duration under irradiation, pH level, starting dye concentration and H2O2 concentration were all factors in the photocatalytic degradation of MB dye. The maximum percentage degradation (%) of MB dye was analyzed and calculated at pH 9. The MB dye (20 ppm) was maximum degraded by 2 g/L of spinel ferrite nanoparticles in 120 min. of visible light irradiation.

This study focuses on evaluating the electrocoagulation process as a method for the treatment of real municipal wastewater using aluminum plate electrodes as an anode in a batch electrochemical reactor. An attempt was made to model the Chemical Oxygen Demand (COD) removal and Electrical Energy Consumption (EEC) as a function of the critical operating variables for the determination of optimal conditions statistically. The initial pH, current, and reaction time were selected as key independent variables in a five-level Central Composite Design (CCD); at the same time,  COD removal efficiency and EEC were considered as the response function. At the optimum conditions proposed by CCD (pH=6.2, I=0.025A, and T=46 min), a maximum COD removal efficiency of 85.7% with electrical energy consumption of 0.151 kW h/m3 was achieved. In addition, the operating costs, energy; and electrode consumptions at optimum conditions were calculated to be 0.1127079 $/m3, 0.151 kWh/m3; and 0.026 kg/m3, respectively. These results presented here prove that the EC process has good performance and great potential for efficient treatment of real municipal wastewater.

This research seeks to synthesize the metal-organic framework, MOF-235, catalyst and their effectiveness in the wet oxidation of methylene blue removal under room temperature conditions. We used SEM, EDX, TEM, and FT-IR techniques to investigate the structural and physical characteristics of the synthesized catalyst. The results showed that the sample was well synthesized. Response Surface Methodology (RSM) is applied to optimize the efficiency of the methylene blue removal process. Four key parameters including pH, temperature, the dosage of catalyst, and contact time are investigated. The contact time data was used to detect the kinetics of the process. The quadratic model was applied for analysis of variance and optimal test conditions for the process were calculated at a catalyst amount of 0.015 g, pH value of 7.3, a temperature of 37.6 oC, and reaction time of 58 min. It was found that the confirmation of the experimental results was obtained and in these optimal conditions, the maximum removal was 89.93%. Results of the process kinetics showed that it fitted both kinetic models. The present study showed that MOF-235 catalyst could remove methylene blue dye and can be applied to separate and remove such pollutants from aqueous solutions.

In the present work, Hydrothermal-liquefaction (HTL) reaction was investigated for kitchen waste at different temperatures of 150-250 oC both in the presence and absence of hydrogen gas for the conversion of biodegradable kitchen waste into the liquid products in the high-pressure autoclave (batch reactor). Then the best conditions were evaluated in the presence of HZSM-5 and a composite meso/micro-porous silica-based HZSM-5M catalyst. It was observed that HTL in the presence of hydrogen gas and composite catalyst results in a higher yield of bio-oil as compared to HTL without hydrogen gas and catalyst. The highest liquid product yield was observed with 20 bar hydrogen (cold conditions) at 225 0C in the presence of catalyst HZSM-5M (64 wt %) with 10 wt % HZSM-5M catalyst.

In the present work (E)-4-((4-(benzyloxy) benzylidene) amino)-N-(5-methylisoxazol-3-yl) benzenesulfonamide (L1) and (E)-N-(5-methylisoxazol-3-yl)-4-((4-nitrobenzylidene) amino) benzenesulfonamide (L2) have been successfully prepared in alcoholic medium with Hydrochloric acid HCl as a catalytic agent. L1 and L2  have been characterized by elemental analysis, FT-IR, 1H NMR, 13C-NMR, SM, and UV-visible spectroscopy. Theoretical calculations were performed at the DFT level of theory using the B3LYP functional and the 6-31G (d, p) basis set, and electronic properties were calculated using the Time-Dependent Density Functional Theory (TD-DFT) method. In addition to the optimized geometrical structure, Frontiers molecular orbital HOMO/LUMO and NBO charges have been investigated to describe the chemical reactivity of the compounds. The vibrational wavenumbers were calculated and they correlated well with the experimental data. The antibacterial activity of the ligands was tested. The results revealed that the synthesized compound exhibited good to moderate antibacterial activity. Furthermore, interactions between synthesized compounds and bacterial proteins were evaluated by molecular docking while pharmacokinetics and toxicity were studied by ADMET analysis.

To enhance the effectiveness of medicinal medicines and minimize side effects, the expansion of an intelligent oral drug delivery system that is sensitive to the pH in the human body is a critical need. Here, pH-sensitive nano molecular imprinted polymers (NMIPs) were synthesized as a drug carrier to release mesalazine in the colon. A precipitation polymerization process was employed to synthesize the NMIPs using mesalazine (MZ), methacrylic acid (MAA), ethylene glycol dimethacrylate (EGDMA), and azobisisobutyronitrile (AIBN) as a template, functional monomer, cross-linker, and radical initiator, respectively. The preparation conditions of the MIPs were optimized by the Response Surface Methodology (RSM) based on the Central Composite Design (CCD) by investigating the effect of two main factors as Molar ratio of drug/monomer and the Molar ratio of monomer/cross-linker. The predicted data are in admissible assent with the empirical data using RSM (R2 = 0.9729). The optimum molar ratio of the template: monomer: cross-linker was achieved 1:2:10. The synthesized nanopolymers were characterized by Fourier Transform InfraRed (FT-IR) spectroscopy, Scanning Electron Microscopy (SEM), Transmission Electron Microscope (TEM), Brunauer Emmett Teller (BET), X-Ray powder Diffraction (XRD) and Thermo Gravimetric Analysis (TGA). The NMIP-loaded release with MZ was investigated in vitro and shown to an extremely pH-dependent. The desorption process showed that the drug desorption was minor in simulated gastric fluid (pH = 1.2), In contrast, in the simulated colon fluid (pH = 7.4), it was sustained and represented a great method for delivering colon-specific medication. These polymers showed 10.35% and 99.16% drug release at pH 1.2 and 7.4, respectively. According to kinetic investigations, the drug's release rate closely matches the first-order equation. The results demonstrate that the NMIPs can be used as a pH-responsive oral delivery system to deliver drugs to target organs in a regulated manner.

In this study, graphene oxide (GO) particles were integrated into a ternary eutectic mixture of capric-lauric-myristic acid (CA-LA-MA) to form a composite material (CA-LA-MA/GO). The GO particles were synthesized using the modified Hummers method, and their size, shape, and morphology were confirmed through XRD and SEM analyses. The ternary mixture was prepared based on theoretically calculated mass ratios and validated using DSC. FT-IR analysis was employed to verify the physical interactions among the precursor components. Notably, the CA-LA-MA/GO composite exhibited thermal decomposition only above 125°C. The phase change temperature demonstrated consistent behavior after the addition of GO, even after undergoing 1000 thermal cycles. Following these cycles, the composite PCM showed a decrease of 5.08% and 3.83% in freezing and melting latent heat, respectively. The thermal conductivity of the composite increased by 36% due to the incorporation of GO, as confirmed by the accelerated melting and freezing processes. Based on these comprehensive findings, it can be concluded that the prepared CA-LA-MA/GO ternary eutectic composite holds great promise for applications such as low-temperature thermal energy storage, thermal energy conservation and management in buildings, and other potential fields.

Powder coatings are fine-ground fused plastic particles that physically resemble sand-containing binders, extenders, pigments, fillers, and leveling additives. In this work, developed powder coating samples that consist of 70 % polyester and 30% epoxy majors were applied by a corona gun and after the application the powder-coated surface was heated in an oven, powdered fine particles were melted and a coating film was developed. The study aims to evaluate the effects of different parameters like particle size distribution, particle moisture content, and particle fluidization value on determining the system transfer efficiency of powder coating for application in the paint industry. The effect of the parameters showed a system transfer efficiency of 80% at 65 micrometer particle size and 0.25% moisture content. However, a system transfer efficiency of 83% was noted when the moisture content and fluidization value were studied at 0.25% and 145 respectively. New trends in powder coating production are sustainability, low-temperature cure, and high durability of a coating film as it steers supply chain difficulties and labor shortages, paving the way for a robust and creative future.

This research focused on the eco-friendly enhancement of Acacia Caesia Bark (ACB) fibers through Castor oil treatment. The properties of untreated ACB fibers were compared with Castor Oil Treated Acacia Caesia (COTAC) fibers. Microscopic analysis using scanning electron microscopy revealed the structural changes in the treated fibers. Single-fiber tensile tests were conducted to evaluate their strength. Physical and metallurgical characterization was performed, followed by thermal characterization using Thermogravimetric Analysis. The crystallinity structure of the fibers was assessed using X-ray diffraction, while Fourier Transform Infrared Spectroscopy identified the presence of free functional groups. The results indicated that the Castor oil treatment slightly altered the fiber structure while significantly improving their tensile strength. The ultimate goal of this research was to explore the potential of using Castor oil treatment as a means to enhance the properties of ACB fibers and promote their application in eco-friendly natural fiber-reinforced polymer composites.

Extrusion, injection molding, calendaring, and thermoforming are just a few of the processing techniques utilized in the plastics industry. Gas-assist injection molding plays a crucial role in this equipment. The advancement of standard injection molding is represented by this apparatus. Parts with thin wall thickness and hollow sections can be manufactured using this method. Use this strategy to save between 30% and 35% of the material. In this procedure, gas is first introduced after a brief shot of material is injected. The remaining portion of the cavity is filled in by injecting gas. The hollow section is described in detail by the gas core. In gas-assist injection molding, the geometry of the gas channel design is also very important. There is a wide variety of materials available for polymeric applications. Different polyamide materials, including polypropylene, polycarbonate, high-impact polystyrene, and polyethylene terephthalate (PET), can be processed using gas-assisted injection molding. Talc-filled polypropylene has been chosen for this study's simulation and experimental work. For simulation purposes, Moldflow plastic insight is utilized. Moldflow plastic insight was used to simulate the tensile samples, and gas-assist injection molding was used to create the experimental models. Simulation and experimental results are used to measure the wall thickness and gas penetration depth. The validation was then checked by comparing these results.

Coffee contamination by Ochratoxin A (OTA) is becoming the main global emerging threat to its quality. The main objective of this study was to determine the levels of Ochratoxin A in coffee beans and brewed coffee samples. Twenty samples of coffee beans and brewed were each randomly collected from coffee stores and street coffee vendors, respectively. The levels of OTA in the coffee samples were determined using High-Performance Liquid Chromatography  (HPLC) with a Fluorescence Detector (FD). The calibration curve for the analyte was linear in the concentration range of 1mg/L - 15mg/L (R2 = 0.997) and 1mg/kg - 15 mg/kg for green coffee beans (R2 = 0.998). The mean concentration of OTA in brewed and coffee beans composite samples was found to be 1.92 μg/L ± 0.07μg/L (n=10) and 1.52 μg/kg ± 0.28 μg/kg (n=10), respectively. The Limit of Detection (LOD) and Limit of Quantification (LOQ) of the method calculated from the calibration curves were 0.76 μg/kg, 0.69 μg/L and 2.31 μg/kg, 2.07 μg/kg for green coffee bean and brewed samples, respectively. The precision of the method expressed in percent Relative Standard Deviations (RSD) of the recoveries was less than 20 % and the mean recovery was 76.28 % – 106.57%. Even though the concentrations of OTA in studied samples didn’t exceed the maximum residue limit set by international organizations, a positive result signals coffee pollution by these toxic substances and careful monitoring is essential to improve the quality of coffee and halt their health and economic effects.

This study was conducted to determine the mechanical and physical features of the gelatin film containing C. aurantium Essential Oil (CEO) and the effect of this film on the chemical and sensory properties of the shrimp were investigated. Evaluation of physical properties including moisture content (7.22%), water vapor permeability (0.46 ×10-11 g/ m s Pa), and solubility (10.46%) in water showed that adding 5% of CEO improves the physical properties of the film. Based on the scanning electron microscope images, the CEO led to the creation of pores and heterogeneous phases on the surface of the gelatin film. In addition, the CEO led to an increase in elongation at break and a decrease in the tensile strength of the gelatin film. Elongation at break and tensile strength of the gelatin film containing 5% CEO was 15.54% and 31.61 MPa, respectively. Investigating the chemical properties of shrimp showed that pH, Peroxide Value  (PV), and total volatile nitrogen (TVB-N) of samples treated with gelatin film containing CEO were preserved in an acceptable range during storage. During the storage, the lowest pH (7.57), TVB-N (18.09 mg/100 g), and PV (1.9 meq O2/kg) values were observed in the samples coated with 5% CEO, which confirms the ability of the film enriched with CEO to increase the shelf life of shrimp. In addition, the evaluation of sensory features showed that the shrimp wrapped with gelatin film enriched with CEO had a higher overall acceptance than the control sample. Based on the results, the gelatin film containing CEO can be introduced as an environmentally friendly active packaging with the potential to increment the shelf life of marine products.

In this research, we have investigated the dominant intermolecular forces governing the behavior of binary systems composed of methylcyclohexane (MCH) and n-alkanols (ranging from 1-pentanol to 1-decanol) within the temperature range of 293.15 K to 323.15 K. The properties under consideration include the mutual and thermal diffusion coefficient, separation ratio, and Soret coefficients. The Soret coefficient for MCH was determined to be positive, indicating an enrichment of this molecule in the colder regions of the liquid mixture. Furthermore, the thermal diffusion coefficients for the binary solutions were found to be positive, exhibiting a decreasing trend with increasing temperature. Interestingly, the separation ratio parameter for all the aforementioned solutions showed a positive correlation with the carbon atom content of the alkanols, suggesting that longer alkyl chains lead to higher values of the separation ratio. These findings point to the reinforcement of molecular forces with increasing alcohol chain length. In light of these results, our study highlights the significant impact of molecular structure on intermolecular forces in binary mixtures, specifically emphasizing the role of alkyl chain length in influencing their thermal behavior. Moreover, we discuss the advantages of our new method in comparison to previous approaches for calculating the thermal properties of such mixtures. The novel methodology presented here holds promise for furthering our understanding and applications in the field of chemistry.

Cereal products such as bread contain low concentrations of riboflavin, which is lost during bread production because of sodium bicarbonate in bread or exposure to light after production. Microencapsulation can be a suitable method to increase the stability of riboflavin in bread. The objective of this study was to investigate the effect of yeast Saccharomyces cerevisiae cells in plasmolyzed and non-plasmolyzed forms as a carrier for protecting riboflavin to enrich Lavash and Barbari bread containing sodium bicarbonate and compare it with a control sample (Lavash and Barbari containing free riboflavin). 1 g of plasmolyzed and non-plasmolyzed yeast Saccharomyces cerevisiae cells containing microencapsulated riboflavin was added to Barbari and Lavash dough (containing 0.3% and 0.5% sodium bicarbonate). The results showed that microencapsulation of riboflavin could increase its stability compared to free riboflavin in Lavash and Barbari. The stability of microencapsulated riboflavin in the plasmolyzed yeast cells was significantly higher (p<0.05) in the Barbari sample than in Lavash. The texture and volume of bread were more affected by 0.5% sodium bicarbonate. At this concentration, the specific weight of samples decreased over time. The Barbara sample enriched with microencapsulated riboflavin in the yeast cell with 0.3% sodium bicarbonate was given the highest aroma, taste, color, and total acceptance scores. Also, using microencapsulated vitamins in plasmolyzed and non-plasmolyzed yeast cells in Lavash and Barbari resulted in higher sensory scores than free (non-encapsulated) vitamins. Therefore, using plasmolyzed yeast cells could protect them from external factors and increase the stability of riboflavin against the harmful effect of sodium bicarbonate; Moreover, it could develop desirable texture and nutritional properties in the product.

Experimental measurement and modeling of the solubility of drugs in supercritical carbon dioxide have gained significant attention in the recent past. It is well known that the task of measuring solubility at desired conditions is a mammoth task; hence, modeling is essential. Further solubility is precisely needed in the process of micronizing drug particles with supercritical carbon dioxide (SC-CO2). In order to achieve this, a proper model is required, which will be utilized in predicting the solubility data at desirable experimental conditions. This work focused on the development of new solubility models based on solid-liquid equilibrium criteria. For validation, we have used existing solubility data for several drugs that fall under the antilipemic, NSAID, antibiotic, and anti-cancer groups. The proposed models were compared to three existing density models to determine their efficacy, further, the thermodynamic quantities such as total enthalpy of reaction, vaporization, and solvation of the compounds were calculated from existing models. Finally, we have reported a statistical comparison of the models considered in this study.

One of the most important thermodynamic properties of a solution is solvent activity, which indicates intermolecular interaction and deviation from the ideal state. Four different temperatures (298.15, 308.15, 318.15, 328.15) Kelvin and a concentration range of 0.001 to 0.1 weight fraction at eight different concentrations were used to measure the water activity of solution PVP (K30) +  by VPO method in the experimental part. Besides the VPO direct method, solvent activity was determined through viscosity measurements. In this method, the viscosity of PVP solution (K30) + H2O, at the mentioned temperatures and in the concentrations of 0.013, 0.025, 0.050, 0.075, 0.100, 0.150, 0.200 Polymer weight fractions were obtained. Then for the prediction of solvent activity, using viscosity data a new model was proposed through the use of Eyring’s absolute rate theory and Flory Huggins’s model in combination. Water activity in thermodynamic modeling was calculated for two PVP solutions, K30+ and K15+, using four thermodynamic models with varying approaches, including ASOG, NRTL, NRTL-NRF, and Flory-Huggins. Fminsearch, Genetic Algorithm (GA), and Particle Swarm Optimization (PSO) were the three algorithms used for optimizing the thermodynamic model parameters. The results of the used models and the presented model in this work have revealed that it is consistent well with the experimental data. AAD% is about 0.5% for the four reported models and 0.9% for the presented model.

The main aim of the present study is to overcome the limitations of the gradient theory for binary mixtures of (CH4+n-alkane). To achieve this aim, the gradient theory of the interface was combined with the perturbed chain statistical association fluid theory equation of state to model the Surface Tension (SF) of the (CH4+n-alkane) system. Two methods were applied to the surface tension calculations. The first method used the constant-value Influence Parameter (IP) while the second method used the Influence Parameter (IP) in terms of the densities of bulk liquid and vapor phases. For accurate prediction of surface tension, the phase equilibrium calculations were improved by fitting binary interaction (BI) parameters. The overall deviation of phase equilibrium calculations was 3.81%. To distinguish the predictive aspects of the model, the binary interaction parameters of the IP were set equal to zero. The results of the model proved that the predictions of both methods agree well with experimental surface tensions, especially for high pressures at which the values of surface tension are very low. The overall Average Absolute Deviations (AADs) were 5.76% and 6.00% for these two methods, respectively. This model is needless of temperature-dependent binary interaction and influence parameters which can be considered as overcoming the limitations of the previous studies.

In this research, natural pozzolanic materials were used in cement production to reduce the emission of CO2 and energy consumption. The rate of substitution of cement with natural pozzolan powder varied from 20% to 50% in 100 samples. Compressive strength tests were carried out on mortar specimens (4×4×16 cm3) after 2, 7, and 28 days. The obtained activity index was approximately 85% and volcanic ash was pozzolan. The compressive strength values changed from 122 to 318 kg/cm2 after 7 days and from 201 to 433 kg/cm2 after 28 days. However, the reduction of CO2 emission with 20% to 50% of additive amounted from 130.74 tons to 419.32 tons of CO2 per ton of clinker. By using 3 to 53% of additives, electricity consumption decreases from 1.89 to 33.39 kWh per ton of clinker. Moreover, this amount of additive can raise energy savings from 99160.8 to 1751841.8 kJ per ton of clinker.

pH neutralization is a highly nonlinear and complex process in chemical reactors. The pH of untreated industrial wastewater affects product quality, soil, and water. Due to its nonlinear characteristics and complexity, pH control is challenging in the process industry. Experimental studies have shown that identifying pH neutralization systems and designing model-based controllers are effective. In this work, we apply an efficient nonlinear prediction model we developed, Least Square Support Vector Machines-Laguerre Hammerstein (LSSVMLH). The VAF (Variance Accounted For) is 92.8186%, and the MSE (Mean Squared Error) is about 0.5406, indicating high confidence in pH neutralization. The identified LSSVMLH model is used to develop Model-Based Controllers (MBCs), namely Hammerstein Nonlinear Internal Model Controller (HNIMC) and Hammerstein Nonlinear Model Predictive Controller (HNMPC) for real-time control of a pH neutralization process. The HNIMC solves the model inversion problem by discarding all positive zeros outside the unit circle to stabilize the system. The experimental results and comparative analysis show that HNMPC and HNIMC have lower ISE and IAE than LMPC and IMC-based Proportional-Integral-Derivative (PID) controllers. The experimental results demonstrate the effectiveness of the model-based controllers in real-time control of a highly nonlinear pH neutralization process.

Considering the limitations of energy consumption and the increasing problems of pollution from low-quality fossil fuels and the need to increase the quality of these fuels by using oxygen additives such as Ethyl tert-butyl ether (ETBE) for their combustion, reviewing and optimizing the production processes of oxygen additives is of great importance. The goal of this study is to simulate-optimize the ETBE production which is used as an oxygenate gasoline additive in the production of gasoline from crude oil. The feed for the ETBE unit comprised two flows of hydrocarbon and ethanol. The Soave-Redlich-Kwong (SRK) equation of state for the vapor phase and the UNIQUAC activity coefficient model for the liquid phase have been used. In this work, at first, the reactive distillation process was simulated by HYSYS software for producing ETBE. Then, the coding was written using MATLAB software and the Genetic algorithm (GA). Both software have been linked simultaneously and the later optimization data was transferred and compared with HYSYS data. The objective function was reflected as the total annual income of ETBE production. The parameters of the objective function were optimized by GA. Optimization was made on decision variables of the objective function which included the output stream temperature of the heater (Tho), input stream temperature of the reactive distillation tower (Tti), output stream temperature of the cooler (Tco), and input stream feed pressure of the distillation tower (Pti). The results of GA optimization show that reboiler duty decreases by 10% as well as total annual profit increases by 15%. Additionally, the comparison of the present work with the findings of researchers reveals a good agreement.

The scrubber of the industrial urea production unit had to be modified after increasing the urea production capacity. It was modified based on the computational fluid dynamics modeling results. Increasing the number of outlet holes in the scrubber’s CAP improved the transient flow of carbamate and scrubber efficiency. In addition, the gas outlet flow rate in the initial design equaled an error level of <1%, while this rate was less than 7% when capacity was enhanced. All measurable parameters were measured and compared before scrubber modification (Plant-0) and after modification (Plant-1). The modification led to an increased average concentration of urea from 71.33 to 71.35 w%, enhanced CO2 purity from 98.81% to 99.09%, a decline in vapor consumed in the studied unit from 104.1 to 100.5 ton/h, and a reduction in the outlet ammonium of Prill tower's synthesis unit from 11.5 to 0.81w% within the two-month interval. Before the modification of the scrubber, ammonium consumption, urea production, and ammonium/urea consumption index equaled 1494.9, 870 ton/day, and 0.5824, respectively, while reached 1503.3, 869.2 ton/day, and 0.5782, respectively after modifications. According to reported values, there was a 1.7 ton/day reduction in ammonium use and an 8.5 ton/day rise in urea production, resulting in considerable savings for the company.

An approach for simulating the initiation of slugs in horizontal pipes is proposed in this research. An analogy is established between the algorithms for solving single-phase problems with discontinuity (Riemann problems) and two-phase slug flow (having a discontinuity in the interface), employing a unique algorithm to solve the conservation equations. Numerical solutions to equations for two-fluid dynamics with transient behavior are obtained by applying a group of conservative shock-capturing techniques. The benefit of utilizing this approach is that the creation of slugs can be computed directly according to the solutions of the differential equations governing the flow field; hence, the location of the interface can be found instantly and without simulation, and the slug regime can be captured automatically. Furthermore, the slug can be captured with low computational cost using a conservative shock-capturing method compared to methods like finite volume. It is demonstrated that the two-fluid model may describe the development of instabilities in stratified flow that give rise to slugs when the mathematical character of the model is hyperbolic. Additionally, the results of numerical modeling and experimental analysis coincide well with the location of slug start. This approach can forecast the flow pattern map and the change from stratified to wavy, and then eventually, slug flow.

Microbial Fuel Cell (MFC) is an emerging, eco-friendly, and cost-effective technique that uses organic substrate as a source of chemical energy for conversion into bioelectricity. However, challenges such as lower power production and inefficient degradation of wastes are required to be overcome for the commercialization of MFC technology. This study investigated the impact of nutrient addition and catholyte buffer on the performance of MFCs using Carbon Felt (CF) and Nickel Foam (NF) as anodes, with and without polyaniline (PANI) modification. A dual chamber MFC was used with a domestic wastewater strength of ~1000 mg/L (COD). The addition of nutrients and catholyte buffer (500 mM) resulted in an increase in power density and COD removal when compared to the control MFC without nutrient addition and with catholyte buffer (100 mM). Further, modification of the CF and NF anode with polyaniline leads to an increase in power generation and COD removal. The highest power density (522.7 ± 24 mW/m2) and COD removal (87%) were observed using PANI@NF as the anode in MFC using nutrients for microbial growth and 500 mM catholyte buffer. The current study is likely to have a favorable impact on the development of a sustainable and environment-friendly method of producing bioenergy.

The gram-negative Escherichia coli (E-coli) and gram-positive Staphylococcus aureus (S-aureus) bacteria may lead to foodborne diseases if they are allowed to enter the bloodstream. The potential risk of bacteria colonization is expected for the consumers of many food products, such as milk, meat, etc. Hence, the separation of these types of bacteria from blood is pivotal for choosing effective treatments. The present study proposes a dielectrophoretic microfluidic device to isolate E-coli and S-aureus bacteria from blood cells using COMSOL Multiphysics 5.6 software. The results demonstrate that the applied potential and frequency, the distance between electrodes, and the buffer-to-sample inlet velocity ratio affect bacterial capture. The present work concludes that the isolation of bacteria from blood cells using the proposed microchip and studied parameters is practical when the blood behaves as a non-Newtonian fluid. Accordingly, the optimal conditions for the complete separation of E-coli and S-aureus bacteria from blood cells can be achieved for the electrode distance of 60 μm, the potential of 100 V, and the frequency of 0.1 MHz when the buffer-to-sample flow rate is 3.   

The bioconversion of sweet sorghum bagasse as lignocellulosic biomass into bioethanol is a complex and challenging process. The present study focuses on optimizing the pretreatment, enzymatic hydrolysis, and fermentation processes during bioethanol production from the bagasse of a drought-tolerant and high-yield sweet sorghum genotype (ISCV 25264). A comparison of acid and alkali pretreatment methods on enhanced enzymatic saccharification of sweet sorghum bagasse indicated that alkali pretreatment with NaOH was more effective. Three independent variables including the NaOH concentration (2-4%), pretreatment time (10-40 min), and pretreatment temperature (80-120°C) were optimized using Response Surface Methodology (RSM) based on central composite design. Pretreatment optimization resulted in a glucose concentration of about 84 g/L during the enzymatic hydrolysis. Afterward, the key variables affecting the hydrolysis process, which included the substrate concentration (5-10%), time (20-70 h), and the temperature (38-50°C) of the hydrolysis reaction were optimized by RSM. Glucose concentration was increased to 93 g/L by using the optimized enzymatic hydrolysis parameters (substrate concentration of 10%, incubation time of 60 h, and incubation temperature of 50°C). Subsequently, Simultaneous Saccharification and Fermentation (SSF) and separate hydrolysis and fermentation (SHF) methods were performed for bioethanol production using Saccharomyces cerevisiae. The results indicated that the ethanol concentration after 48 h was higher under the SHF method (48.714 g/L), compared to SSF (29.582 g/L); however, this method was not commercially attractive due to the much longer total time for bioethanol production. Finally, optimization of the parameters during the SSF process (substrate and yeast concentrations of 30% and 4%, respectively) led to an ethanol concentration of 33 g/L. The optimization of the bioethanol production process in this research has created a platform for pilot-scale studies to investigate the feasibility of bioethanol production from sweet sorghum bagasse at the industrial level.