Journal of Applied Research of Chemical -Polymer Engineering

Abstract The rise of bacterial infections has become a serious problem in human societies. As a result, the development of nanocomposite materials based on biocompatible and non-hazardous materials, besides having antimicrobial and biocompatibility or non-cytotoxicity, associated with unique structural properties, possesses a great importance. Research approach: In this study, bacterial cellulose (BC)/polypyrrole (PPy) and zinc nanoparticles (ZnO), which simultaneously have antimicrobial properties and cell proliferation, were introduced as a new generation of nanocomposite scaffolds produced by freeze-drying. To begin with, ZnO with different weight percentages of 1%, 3% and 5% was added to BC and then PPy in the amount of 2 mmol was embedded in the structure by in situ polymerization. FESEM images proved that the nanofibrous and porous structure of BC was also preserved in the presence of PPy and ZnO. However, after adding PPy and ZnO, they formed a dense structure and microstructure of grape clusters. By adding 2 mmol PPy into BC and upon in situ synthesizing, the tensile strength and Young modulus of BC were significantly reduced to 71 MPa and 2.5 GPa, respectively. On the other hand, with the addition of ZnO nanoparticles, the mechanical properties significantly increased (both of Young modulus and tensile strength compared to BC/PPy samples) due to the compaction of the nanocomposite aerogel’s structure and the formation of the interface of ZnO nanoparticles with both polymers of BC and PPy. The observation of the inhibition zone in the culture medium containing two gram-positive and negative bacteria, well proved the antibacterial ability of ternary nanocomposite scaffolds. The results of MT9 related to L929 on aerogels showed that by adding 3% of ZnO nanoparticles, adhesion and cell proliferation increased significantly during different days of 1 day, 5 days and 7 days of culture.

Abstract Research Subject: One of the important methods in the treatment of skin wounds is the use of wound dressings. Recently, the use of polymer-based wound dressings has become increasingly common. The use of natural polymers is very important in wound dressings. The aim of the present study is to design and manufacture a polyvinyl alcohol/aloe vera wound dressing with the capability of healing skin wounds.
Research Approach: The electrospinning method was applied to prepare the samples. Aloe vera gel was first extracted, purified, and powdered by freeze-drying. In all samples, the amount of polyvinyl alcohol and aloe vera powder was fixed at 8 wt.%. This value was selected empirically based on the quality of the produced fibers. Different samples including different amounts of polyvinyl alcohol and aloe vera were produced and their properties including morphology, tensile strength, swelling, degradability, and antimicrobial properties were investigated.
Main Results: The results showed that the dropless random oriented fibers with uniform diameter were produced. The diameter increased with increasing aloe vera contribution, which was attributed to an increase in viscosity due to the presence of aloe vera. With increasing aloe vera contribution in the samples, tensile strength decreased and the elongation percentage increased. The swelling behavior of the specimens was evaluated by measuring the weight of the specimens in a simulated skin environment and the results showed that the presence of aloe vera increased the hydrophilic properties of the specimens. Antimicrobial activity of the samples against two gram-positive Staphylococcus aureus and Gram-negative Pseudomonas aeruginosa was investigated using the disk diffusion method and it was found that the presence of Aloe vera in the samples brought antimicrobial activity against Pseudomonas aeruginosa. Finally, the findings of this study confirm the feasibility of using polyvinyl alcohol /aloe vera for the production of the electrospun wound dressing.

Abstract Research subject: In recent years, there are so many attractions in the field of effective detection and discrimination of volatile organic compounds (VOCs). Detection of VOCs compounds, are very important in many applications and industries such as air pollution control, air quality control, food packaging, food quality control, disease diagnostic, agriculture etc. The sensitivity and selectivity of the prepared sensors to detect of VOCs needs to improve.
Research approach: A conductive polymer composite sensitive layer based on poly (lactic acid) as polymer matrix and multiwall carbon nanotubes as conductive filler was prepared to detect of volatile organic compounds (VOCs). For this purpose the porous sensitive layer was prepared by non-solvent induced phase separation (NIPS) method. In this structure, chloroform (low boiling point temperature) was used as the solvent and ethanol (high boiling point temperature) was used as a non-solvent. The sensitive layer was used to detect of toluene, methanol, and chloroform. The structure and morphology of synthesized layer was investigated by means of scanning electron microscopy (SEM) and BET test.
Main results: The investigation indicated that the phase separation method induced the open cell morphology into the conductive composite. The BET results showed that the specific surface area of composite increased to 22.3 m²/gr. The experimental results showed that the response properties of porous layers was improved dramatically in comparison with dense layers. It was related to the increase of specific surface area of polymer composite and therefore the increase of diffusion coefficient of analyte molecules into the polymer matrix. Finally the sensitivity and selectivity of porous sensitive layers was investigated based on Flory-Huggins interaction parameter.

Abstract Research subject: Selectivity and permeability are the major parameters of polymeric membranes in gas separation process. Hence, nowadays in order to improve aforementioned parameters, modification and enhancement issues for such membrane have been highly noticed.
Research approach: In this study, in order to improve the performance of polymeric membranes, the two-component blend membranes containing Pebax^®1657 and PVA were synthesized for CO₂ separation. The effect of different PVA concentrations within the Pebax matrix on structure, morphology and gas separation properties of resultant membranes was investigated. The chemical bonds, crystallinity and cross-sectional morphology studied through, Fourier transform infrared (FTIR), differential scanning calorimetry (DSC) and scanning electron microscopy (SEM), and were utilized.
Main results: The results of the thermal analysis indicated an increase in crystallinity and also glass transition temperature in presence of 5 – 15 wt.% PVA, while the membrane crystallinity decreased by increasing the PVA content up to 20 wt.%. FESEM images demonstrated a uniform cross-section without any cracks and defects for neat Pebax membrane but by adding PVA to Pebax matrix, appeared cracks and cave structures on the cross- section of blend membranes. The CO₂/CH₄ separation performance of membranes was measured using a constant volume set up at 30°C and feed pressure of 2, 6 and 10 bar. The obtained results revealed that the CO₂ permeability in blend membranes improved as the PVA content increased within the membrane. The best obtained CO₂ permeability was 204.64 Barrer which gained by Pebax/PVA (20wt.%) at feed pressure of 10 bar. Moreover, the highest selectivity of CO₂/N₂ for blend membrane with 15 wt.% of PVA was about 100.21 at 10 bar and 30°C.

Abstract Research Subject: In this paper, the adsorbents used to remove lead ion using adsorption operation have been reviewed.
Research Approach: The types of adsorbents used to remove lead ions, the modifications of adsorbents, adsorption conditions, isotherms and adsorption capacity of adsorbents have been investigated and compared based on the literature survey.
Main Results: Modification by impregnation of functional groups has a significant role in increasing the adsorption capacity. The pH of the solution plays an important role in the adsorption of lead ions and generally the adsorption capacity increases by increasing the pH of the solution. Langmuir's isotherm model has been more consistent with the equilibrium data. Among the reviewed adsorbents, carbon-based adsorbents such as activated carbon and graphen-oxide, modified by chemicals such as ammonium persulfate or polyamines, show higher adsorption. Also, biomasses due to their abundance and low prices have the potential to be used as lead ion adsorbents.

Abstract Abstract
Research Subject: Sulfide removal from sour water is essential, before reuse or release of sour water into the environment. Regarding the high costs of traditional methods, biological removal can be used as a reliable alternative.
Research Approach: Biological sulfide removal from sour water was investigated in a batch reactor using Thiobacillus sp. as a dominant species of a mixed culture. A conceptual model was developed to describe the process of H₂S removal from sour water in the batch reactor. The model considers H₂S and O₂ transfer between liquid and gas phases, biological oxidation of H₂S to sulfate and elemental sulfur, and chemical oxidation of H₂S to thiosulfate in the liquid phase. The governing equations were derived using the principles of mass conservation and biochemical reactions. Several batch runs were performed to obtain experimental data on the variation of sulfide, sulfate, thiosulfate, and oxygen concentrations in the system as a function of time, and an algorithm was devised to use the method of Particle Swarm Optimization together with the numerical solution of the model equations to estimate biokinetic parameters. Additional batch runs under different conditions were performed to verify the accuracy of the model. These results indicated reasonable accuracy of the model to predict the performance of a batch reactor for the removal of H₂S from sour water. The novelty of this model is considering different pathways for sulfide oxidation which includes product selectivity.
Main Results: The maxim specific oxygen uptake rate (SOUR=OUR/X) is one of the most important parameters in the evaluation of the biological activity of the microorganisms. The calculated value for this parameter was almost constant (16 mg DO g^-1 VSS min^-1) during all sulfide oxidation tests indicating that the maximum specific oxidation capacity of the biomass is independent of substrate and biomass concentration. Results exhibited bacteria prefer to partially oxidized sulfide to elemental sulfur, however this preference is a function of dissolved oxygen and substrate availability.

Abstract Research subject: In recent years, many attempts have been devoted to industrial usage of bio-based adhesives, as a result of fossil resources shortage and unusual increase in oil-based products prices. Adhesion strength of this category of adhesives, however, needs improvement.
Research approach: In the current study, lap-shear strength of joints made of a natural polymer, Persian gum (PG), exuded from wild almond tree, and three various substrates, glass, poly(ethylene terephthalate), and cellulose fabric, was investigated. Furthermore, in order to prepare powder acrylic adhesive and evaluate its adhesion to aforementioned substrates, the gum dispersion was blended with synthesized poly(methyl methacrylate-co-butyl acrylate) random copolymer containing 30 wt.% methyl methacrylate (MBC30). Molecular interactions in PG, MBC30, and 50 wt. % PG-containing blend were characterized by Fourier transform infrared spectroscopy. Moreover, morphology of blends containing various amounts of PG was evaluated using scanning electron microscopy of their fractured cross sections.
Main results: The textile joint made with PG dispersion in water showed high shear strength of about 340 kPa. However, PG could not form a suitable joint with glass and polyester substrates, as a consequence of its inability to form a homogeneous film, excessive brittleness, and its inability to diffuse and mechanically interlock with the substrates. Results showed that using an adhesive system containing 50/50 PG/MBC30, besides enabling preparation of powder adhesive, shear strength increased to 20, 11, and 14-fold with respect to pristine MBC30 on glass, poly(ethylene terephthalate), and textile substrates, respectively. In other words, shear strength of an adhesive could be improved by promoting the adhesive constituents interactions and subsequent increase in the blend cohesiveness, on the one hand, and increment of its adhesion to substrate, on the other hand. In the current research, Persian gum was introduced as a water-redispersing agent for acrylic pressure-sensitive adhesives and new adhesive systems were invented with usability in cellulose industry.

Abstract Research Subject: Removal of industrial wastewater especially from textile and dyeing factories is always important actions to control of pollutions. Using of polymeric adsorbents is an important method for removal of dyes from industrial wastewater. In this research work, designing and fabrication of PVA-based adsorbent with proper potential for removal of green malachite from industrial wastewater has been reported.
Research Approach: For fabrication of adsorbent 4 wt.% PVA was gelled in the present of 10 wt.% glutaraldehyde as cross-linker and punched. The punched hydrogels were porous with freeze drying method. For improving the adsorption ability, graphene and TiO₂ were used. The adsorption of green malachite with prepare adsorbent was measured timely to determine the optimum percentage of nanoparticles. In addition, the effect of contact time and the presence of UV on the adsorption of pollution was investigated. Finally, the adsorption isotherms and thermodynamics study were investigated in different time.
Main Results: The results of adsorption of pollution with PVA/graphene adsorbent in different times showed that 0.5 wt.% is the optimum loading of graphene in the PVA matrix. This value was 3 wt.% for TiO₂. The adsorption percentage via optimum adsorbent in dark condition showed that one minute after addition of adsorbent the adsorption percent increased to 75% indicating the high capability of the adsorbent in adsorption of tested pollution. The porous structure was confirmed via SEM image. By comparing the correlation coefficient for Langmuir and Freundlich isotherms it was found that Freundlich isotherm has better agreement with the findings of the current study. In other words, adsorption of green malachite with fabricated adsorbent was done multi layered. The thermodynamics studies showed that due to negative value of Gibbs energy the adsorption reaction of green malachite with fabricated absorbent is automatically.

Abstract Research Subject: Nowadays, application of biosurfactants in microbial enhanced oil recovery (MEOR) have aroused much attention and several investigations have been conducted on this field. But their performance in comparison to synthetic surfactants in enhanced oil recovery has little been studied. Most of these researches are limited to comparison of one produced biosurfactant with only a chemical surfactant. To fill this gap, in this research, the potential use of a rhamnolipid type biosurfactant in MEOR was compared to several conventional synthesized surfactants: SDS, SDBS, CTAB and DTAB.
Research Approach: Since the main goal of this research is the comparison between produced biosurfactant and conventional chemical surfactants in oil recovery, several flooding tests were conducted and involved mechanisms were investigated. All of tests were conducted in an oil wet glass micromodel saturated with heavy oil at ambient condition. Injected solutions were prepared at critical micelle concentration of surfactants. During the flooding tests, high quality pictures were taken with a camera connected to the computer to monitor the motion of injected solution in the micromodel.
Main Results: 40% oil recovery was achieved after biosurfactant flooding while SDBS, SDS, CTAB and DTAB resulted 36%, 34%, 32% and 29% oil recovery, respectively. For mechanistic study, the surface tension (ST) and viscosity measurements were performed and contact angle was determined. The surface tension reduction, wettability alteration towards more water-wet condition and increasing the ratio of injected fluid viscosity to oil viscosity were dominant mechanisms. The rhamnolipid was more effective than other surfactants in reduction of surface tension and altering the wettability towards favorable water-wet conditions. It decreased the surface tension of water from 72 to 28 mN/m, which was the least comparing to other surfactants and increased the capillary number about 19.4 times greater than in water flooding. Additionally, it changed the contact angle from 106 to 6, 94.3%, the widest change among applied surfactants.

Abstract Abstract Research Subject: Other waste incinerators and other high-temperature systems designed to dispose of garbage are referred to as heat treatment systems. The burning of waste materials, such as garbage, converts them into ashes collected on the waste floor, exhaust gases, very small particles and, most importantly, heat, which can be used to generate electrical power. Research Approach: In this research, firstly, the energy and exergy efficiencies of a waste incineration cycle, along with utilization of Lorestan petrochemical waste as an additional fuel for waste incineration, are investigated. In this way, the amount of energy needed to produce the required water vapor to disable the catalyst Ziegler-Nata was calculated for the production of linear stylistic polyethylene. Subsequently, a simple model for the inactivation reaction of Ziegler-Nata catalysts was presented using the steam generated by the waste incinerator, and then the mathematical equations for these reactions were obtained using the primary reaction law. By introducing these reactions into the reaction model, a new equation for the reaction model was obtained that covers the moments after the time of deviation to an acceptable level. This indicates the overcoming of inactivation reactions on the reactions of active centers production in the final stages of the reaction. Main Results: The energy and exergy efficiencies of the waste incineration cycle along with the use of Lorestan petrochemical waste as an additional waste gas were investigated and thus the amount of energy needed to generate steam to disable Natal Ziegler catalysts in the production of linear linear polyethylene was calculated. To initiate this, the combined cycle was proposed and its energy and exergy efficiencies were investigated. Also, by changing the key components such as the ammonia solution composition, the ammonia distillation temperature and the input and output pressures of turbine, a way to achieve the energy needed to generate the steam needed to deactivate the Nitra zigzag catalyst in the production of linear linear polyethylene was developed.

Abstract Gel treatment is one of the most promising remedy methods to improve conformance in heterogeneous reservoirs for better sweep efficiency. In this paper, new enhanced preformed particle gels (PPGs) for conformance control at the Balal reservoir are introduced. In these PPGs, three species of 2-acrylamido-2-methylpropane sulfonic sodium salt (AMPSNa), acrylamide (AM) and N-vinylpyrrolidone (NVP) monomers have been used to synthesize via free radical crosslinking polymerization at room temperature using N,N-methylenebis (acrylamide) (MBA) as a cross linker. The swelling properties of the PPGs were enhanced by adding the Nano clay Montmorillonite Na+. A temperature stability agent was also used to make these special PPGs compatible with high temperature and salinity reservoir conditions. Then, PPGs were kept in Balal reservoir conditions in order to study their stability in harsh reservoir conditions. To this end, combination of 50 samples of the preformed particle gel has already been constructed by design of experiment using response surface method, and finally a new model for predicting the swelling ratio of the preformed particle gel based on the weight percentage of material and in different salinity is provided. The results of this research show that the crosslink has more influence on the swelling ratio, and PPG with the optimal formulation will able to guarantee the hard reservoir conditions (temperature 82˚C & salinity 260000ppm).

Abstract The current study is based on synthesis a low cost carbon aerogel with improved properties and thermal insulator approach. In this work cheap novolac resin are used as a raw material for producing polymer aerogel by ambient drying method; then the coal tar pitch is added to samples by immerging them in pitch solution. In next step novolac-pitch polymer aerogels is converted to carbon nano-structure aerogels by pyrolysis heat treatment at inert atmosphere. The results proved, nano-structured aerogels with predictable density will be achieved by this method; also by studying on microstructure and morphology of aerogels it founded these aerogels have high porosity, low density(about 0.1-0.4 g/cm3) and high specific surface area (about 600 m2/g). The charring pitch was a lot and using of it made improved thermal properties that resulted in at least 100s delay in increasing temperature in time-temperature history test; as a result a high performance thermal insulator achieved.

Abstract Due to increase in global demand of propylene, many extensive studies and research have been done to find alternative method for lower energy consumption and efficiency. In this research, gamma alumina is used for molybdenum catalyst base in oxidative dehydrogenation ‎process of propane, in order to produce the propylene. The catalysts are prepared based on wet impregnation method. The analysis of FTIR, XRD, BET, SEM, and XRF are done to evaluate and determine the characteristics of prepared catalysts. Central composition method is employed to study the influence of reaction temperature, molybdenum ‎loading percentage, oxygen to propane ratio, and the effect of interactions between them in propylene ‎production. The molybdenum in the range of 4-16%, propane to oxygen ratio in ‎the range of 1-3%, and temperature in the range of 380-540 ºC are the input parameters of ‎the central composite method. Finally, according to reactor test and analysis of the results of the Design expert software, it is shown that the predicted models for propane conversion, propylene selectivity, ‎and efficiency persentage of oxidation dehydrogenation are about 95%. Maximum of efficiency percentage with a value of 14.02% is obtained at 487 ºC, 11.22% molybdenum‎ percentage, and propane to oxygen ratio of 1.5, which in experimental results, achieving an accuracy of 94% is possible as compared to the optimal design of the test design model.

Abstract In graded structure aerogels, change of pores diameter through the thickness affects the effective thermal conductivity. As the pores diameter is reversely correlated to the density, the effective thermal conductivity of aerogel is often normalized to the density and it is expressed as the B parameter. Lower values of B would be the optimum conditions for the resulting aerogel. The objective of this work is to simulate the heat transfer of the homogenous structures and to compare it with structures that pore diameter vary through the thickness. For this purpose, the structure characteristics and properties of silica aerogel along with the effect of coupling thermal conductivity have to be taken into consideration. Using the COMSOLMultiphysics®software, the heat transfer was modeled for a number of cases, including homogenous structures with minimum density (L), maximum density (H) and for an optimum structure (OPT) having a minimum value of the B parameter. The results were compared to thestructurally graded aerogels in which the density was varied in two fashions, from higher values to lower (HtL) and from lower to higher values (LtH). The change of temperature with time was tracked for all the cases. Results indicated that the minimum value of heat transfer was obtained for the structurally graded aerogel of the type of LtH (a 2-percent increase of efficiency for LtH when compared to the optimum structure (OPT)). Therefore, this structure introduce as the best candidate for producing a thermal insulator.

Abstract In recent years, with the advancement of nanoscience, many scientists have used nano materials to solve existing problems in various sectors of oil industry. Nanofluids made with these materials can facilitate the separation of oil and gas in a reservoir and increase oil recovery factor compared to current methods. Therefore, in this work, the effect of clay nanoparticles on oil recovery factor was investigated. For this purpose, two different base fluids, water and ethanol, were used to disperse the nanoparticles. The effect of adding clay nanoparticles on viscosity changes and interfacial surface tension was determined. Also, in order to investigate the effect of nanoparticle concentration in the base fluid on the ultimate oil recovery factor, nanofluids with 3 and 5 wt% were prepared. Results show that oil recovery factor increases significantly in these conditions by adding them into the base fluid, though nanofluids included clay nanoparticles have less stability. Also, the effect of these nanoparticles dispersed in water is greater than in ethanol. For example, at 5 wt%, oil recovery factor for water based nanofluid was 49.7% and for ethanol based nanofluid was 46%.

Abstract In this research, general performance of Radial basis function (RBF) Artificial neural networks in experimental data on effect of the NiO, WO3, TiO2,ZnO and Fe2O3 nanoparticles in different temperatures and mass fractions on the viscosity of crude oil has been studied. The morphology and stability of the nanoparticles has been analyzed by DLS and TEM analysis, the results showed that the average diameter of the nanoparticles is from 10 to 30 nm which defers for different oxide nanoparticles. The general method for calculating the optimum span of the Isotropic Gaussian function with special algorithm for learning RBF networks, has been presented. This study's results declared that the RBF artificial neural networks, because of having strong academic basis and having the ability to filter the noises, has a good performance. With increase in temperature, the ratio of the viscosity of the nanofluids decreases compering to the viscosity of the basefluid. Also with increase in nanoparticles mass fraction the related viscosity increases boldly. For temperatures higher than 50°C, the related viscosity is less than the viscosity of the basefluid.

Abstract In human-made materials, aerogels have the least thermal conduction coefficient. The least thermal conduction, which aerogels can have, is equivalent to air conduction, about 0.021W/mK. In some applications, lowest conductions is to be needed. In this study, novolac aerogles are used as spacer, for designing and making multilayer super insulators with aluminum foil reflective layers. The performance of these insulators, are extremely depends on density, porosity and the size of pores in aerogel and number of layers in the overall thickness of insulator. In this study, for decreasing effective thermal conduction of multilayer insulations, tow parameters of density of aerogel and ratio of number of layers to thickness of insulator (layer density), are examined in 25 ˚C to 200 ˚C boundary conditions. First, by assessment of aerogel novolac density effect on thermal conduction, aerogel with density of 0.076 g/cm3 was chosen as the best spacer. In the next part, ratio of 25 layer per centimeter of thickness was chosen as the best layer density. Finally, by making multilayer super insulators, based on this results, an insulator with 5×10-4W/mK effective thermal conductivity was obtaind without evacuation of spacer.

Abstract One of the problems for use of rubber in various industries is the surface tension at the surface of rubbers, which results in the crack on the surface, fracture of the rubber and reduces its service life. These tensions are caused by contacting the rubber component with the metal surface and the friction between two surfaces. Roughness of the surface, the composition of the rubber compound, the environmental factors, test conditions and etc. affect the friction between rubbers – metal. Surface roughness plays an important role in sliding between two surfaces and mainly controls friction behavior. On the other hand, roughness effect on the coefficient of friction is controllable using a suitable lubricant. In the present study regarding to the application of JP4 as an aviation fuel, the effect of JP4 fuel as a lubricant was investigated in the reduction of the sliding friction coefficient between the NBR and aluminum surfaces with different roughness. Experimental studies showed, friction coefficient has a good correlation with the mean surface roughness (Ra). By applying JP4 lubricant, the coefficient of friction decreased by about 75%. JP4 fuel as lubricant has changed the trend of varying friction coefficient from decreasing to increasing regard to the surface roughness.

Abstract Ganoderma lucidum is one of the best-known medicinal mushrooms in the world. It contains substantial amounts of intra- and extracellular secondary metabolites and polysaccharides each with its own specific medicinal and medical uses. The chitin-glucan complex (CGC) is considered one of the important polysaccharides of this fungus. Among the 10 various culture media that were studied, the one containing PDB at 24g/l, peptone at 1g/l, and with the dry weight of cells of 11.6 g/l, the produced CGC of 3.2g/l, and with 27.6 percent CGC in the dry weight of the cells was selected as the suitable culture medium. FTIR analysis was performed for characterization of the produced CGC and its antibacterial properties were studied. The obtained time profile for CGC growth and production was 20 days and, using the logistic growth model and the Lodding-Pipet equation, the calculated specific growth rate of Ganoderma lucidum (μm) and the volumetric productivity for the product were 2.85 g CGC L-1day-and 0.5274 day-1, respectively. The calculations indicated there were high degrees of conformance between the model and the laboratory data related to kinetic characteristics of cell growth (R2= 0.9679) and to CGC production (R2=0.9901). Therefore, the introduced kinetic model can serve as an effective guide to control the fermentation process in industrial production of the valuable CGC polymer.

Abstract Aim: Most scientists are trying to treat cancer, and in this regard were produced numerous anticancer drugs, that adverse effects on non-target tissue. To overcome this, drugs freight to magnetic nanoparticles Chitosan and its carboxymethyl secondary coumpands are biopolymers that are non-toxic, biodegradable therefore found applications in biomedical field. We explain here that glycerol monooleate covered magnetic nanoparticles (GMO-MNPs) capable of transporting hydrophobic anticancer drugs. Method: In the present study, we have expanded 5-fluorouracil (5-FU) that loaded on chitosan MNPs for targeted cancer therapy. Results: The modified nano-adsorbent was then characterized by Fourier Infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), elemental analysis of CHN (9) and thermal weighing analysis (TGA). Lab conditions such as pH, contact time were optimized. To analyze the structure of the sample, X-ray diffraction spectroscopy was used to investigate the magnetic properties of the nanosized particles synthesized by the magnetometer and to detect the phase type formed on the monolayer glycerol matrix network using a polarizing light microscope. Also, the study showed essential oil release in the external environment of 90% for 30 hours. Conclusion: The optimized magnetic nanoparticles according to SEM image, exhibited segregated nanoparticles with sub-spherical smooth morphology and also the high thermal stability of 5-Fluorouracil nanoparticles which indicated a well-established structure of nanoparticles.

Abstract Electronic wastes are known as the most important solid wastes in 21th century. They are producing two or three time faster than other solid waste streams. Many researchers studied bioleaching of e-wastes using Acidithiobacillus ferrooxidans. The presence of alkaline metals cause e-wastes show an alkalinity nature. By adding e-wastes to the environment the pH of solution increases sensibly. Many researchers supposed the optimal pH range of A. ferrooxidans which is 1.5-2.5 as the optimal pH range to reach maximum recovery. So in the bioleaching process by daily pH adjusting in the range and using sensible amount of sulfuric acid, control the pH of solution about 2. In this research two same experiments, just the pH of one of them was adjusted daily, were done. In both experiments the environmental situation including pulp density of 15 g/l, inoculum 10% (v/v), the temperature of 30ºC, and shaking rate of 130 rpm was the same. For 25 days Cu recovery, bacterial count, pH, and Eh were examined. The results showed the maximum Cu recovery at the sample without pH adjusting was about 100% but at the sample with pH adjusting recovery was reduced to 90%. The bacterial count diagram showed the bacterium is well active in both experiments. To maximize recovery, reducing acid consumption, and increasing process economy there is no need to adjust the pH of solution.

Abstract The adsorption of polymeric systems onto reservoir rock through altering the wettability of rock surface improves oil recovery and reduces the unwanted water production. . In this study, the adsorption behavior of dilute polymeric systems based on sulfonated polyacrylamide on the glass particles surfaces (representative of sandstone reservoirs) was investigated and the effect of this phenomenon on changing their surface properties was examined. Results show that crosslinked polymeric samples have lower adsorption on glassy surface comparing with uncrosslinked sulfonated polyacrylamide solution. Furthermore, the contact angle tests results showed that crosslinked samples change the surface property of glass particle less than sulfonated polyacrylamide solution. In addition the Langmuir isotherm model fitted the isotherm data better than the Freundlich model for these dilute polymeric systems. Furthermore, study of the thermodynamic of adsorption showed that their adsorption behavior on glassy surfaces is a spontaneous and exothermic process.

Abstract Hemodialysis is a process of purifying the blood of a person whose kidneys are not working normally. Polyethersulfone membrane has the most application in blood purification because of its unique features, but its hydrophobic nature results in poor biocompatibility. When PES-based membranes are contacted with blood, proteins tend to adsorb onto the polymer surface, and this protein layer causes any adverse effects such as the coagulation of blood cells and platelet adhesion. The biocompatibility of pristine PES membrane can be improved by different modification methods. The aim of this research is to improve polyethersulfone (PES) membrane hydrophilicity and antifouling properties by adding pluronic F-127, poly(ethylene oxide)−poly(propylene oxide)−poly(ethylene oxide) (PEO-PPO-PEO) block copolymer, to the dope solution. In this regard, PPO hydrophobic molecules are bound to PES chains due to hydrophobic–hydrophobic interactions, and membrane hydrophilicity would be improved because of hydrophilic PEO segments. To investigate the effect of adding pluronic F-127 on membrane performance, water contact angle, mechanical properties and filtration tests were carried out. Membranes morphology were characterized by SEM microscopy. Results showed that the addition of pluronic F-127 to the polymeric solution caused permeate flux increase up to 554 L/m²h due to membrane pore size growth and contact angle decrease. Moreover, addition of pluronic F-127 caused a decrease in the tensile strength of the PES/Pluronic F-127 membranes. PES/Pluronic F-127 membranes have improved fouling resistance compared to the pristine membrane.

Abstract Recently, flexible and environmental-friendly aerogel blankets have attracted considerable attention. In this work, the novel silica aerogel/basalt blanket was prepared using basalt fibers via a two-step sol-gel process followed by an ambient drying method and immersing the basalt fiber layer into silica sol. The silica aerogel particles were characterized by FTIR, FE-SEM and nitrogen adsorption analysis. The morphology, hydrophobic properties and surface roughness of neat basalt fiber and its aerogel blanket were also investigated. The density if 0.34 g/cm³, the porosity of 85%, mean pore size of 7±1.5 nm and the surface area of 750 m²/g for the nanostructured silica aerogel particles are obtained. The formation of nanostructured silica aerogel particles on the surface of basalt fibers in the sol-gel process were efficiently occurred leading to a strong hydrophobicity the blanket samples (contact angle of 114°) compared to the hydrophilic neat basalt fibers. The surface roughness of basalt fiber in the blanket samples was increased due to the fiber surface coating with silica aerogel particles. Increasing the sol volume in the synthesis process increased the basalt surface roughness from 3.6μ to 11μ.

Abstract Oil resistant o-rings on the basis of acrylonitrile butadiene rubber (NBR) reinforced by nanoclay were produced via a traditional industrial method in accordance with aviation standard, AMS 7272. The production of nanocomposites comprised the compounding of nanocomposite with optimum mechanical properties and minimum contents of used carbon black and nanoclay, design and manufacturing of the required mold and finally compression molding of the oring. Mechanical and morphological properties of NBR/nanoclay compounds were optimized by introduction of proper contents of a compatibilizer containing a mixture of resorcinol and hexamethylene tetramine through using a master batch production method. The prepared nanocomposites were characterized using X-ray diffraction (XRD) analysis, curing measurements and tensile test analysis. The XRD analysis showed that the compatibilizer facilitates the intercalation of nanoclay silicate layers with the rubber chains which leads to the increase of their basal spacing. The cure characteristics of the nanocomposites showed a decrease of scorch time and increase the cure rate index with the nanoclay loadings. Furthermore, the minimum scorch time and maximum cure rate index could be achieved through using the appropriate content of compatibilizer. The results exhibit that the nanocomposites containing the compatibilizer have higher mechanical properties especially at higher deformations compared to the corresponding uncompatibilized nanocomposites