Effect of Ground Tire Rubber on Mechanical Properties of Low Density Polyethylene

This research explores the effect of ground tire rubber (GTR) on the mechanical properties of LDPE. This thermoplastic-elastomer blend sets the composition of ground tire rubber and low-density polyethylene (LDPE/GTR). The blend was prepared in different proportions and was processed in a compression molding machine. The optimum operating conditions of the blend set to be 220℃ temperature and pressure varied from 150-200 bars. Different parts per hundred rubber (phr) samples were obtained under these conditions, including 1 phr, 2 phr, 3 phr, 4 phr, and 5 phr. After that, the mechanical properties of the blend were examined concerning various compositions. Different testing methods were used to determine the mechanical properties of the thermoplastic-elastomer blend, which include tensile strength, flexural strength, and Izod impact. The results obtained from these tests show that tensile strength and modulus decreases by increasing the rubber content. However, impact strength and percentage elongation increase by increasing the rubber content. This enhancement in impact and percentage elongation may be suitable for the applications in gymnasium mat and automobile industry.

Ion-selective Electrodes Based on PVC Membranes for Potentiometric Sensor Applications: A Review

Ion-selective electrodes (ISEs) are potentiometric sensors used to measure some of the most critical analytes in environmental laboratory. Recently ion sensors are taking place of various analytical techniques, as they provide a convenient and fast method of electroanalysis. Ion-selective electrodes are simple, relatively inexpensive, robust, durable, and ideal to be used for the detection of heavy metal ions. Important characterisctics of ISEs are selectivity, response time, detection limit, working range, effect of pH etc. Lot of research work is being done for the formation of ISEs by using polymeric membrane incorporated with ionophores or electroactive material. Various types of Schiff bases, macromolecules and metal complexes may be used as ionophores along with plasticizer, ion-excluder for the membrane preparation. Ion-selective electrodes will be optimized for pH range, selectivity, sensitivity, working concentration range and lifetime before their use as sensor electrode for determining the concentration of ions in solution. Various researchers are working in the field to develop Ion-selective electrodes which shows better selectivity and sensitivity than the previously reported electrodes and can be used as electrocatalysts. These ISEs can be used as electrochemical sensors for the analysis of food products, drinking water, beverages, fertilizers, and for the analysis of sample containing toxic substances.

Effect of Photoconductivity Precursor Volume on Structural, Physical, Electrical and Optical Properties of Thin Layers of Cadmium Oxide (CdO) Nanostructures Produced Using Spray Pyrolysis Technique

Thin layers of Cadmium Oxide (CdO) are produced over glassy substrate by spray pyrolysis technique with precursor volumes of 50, 75 and 100 (ml). FESEM images of samples show the formation of nanometric structures and structural characterization of them resulted from XRD spectroscopy indicate the formation of cubic polycrystalline structure in growing layers with preferred direction of (111). Evaluating the optical properties of samples show that optical band gap of layers is reduced from 3.6 to 3.4 (eV) by increasing the precursor volume and the optical absorption coefficient of samples is in UV region at about 105 (cm-1). Data analysis indicates that the produced sample in volume of 100 mL has the smallest penetration depth (smaller than 200 nm) in UV region. On the other hand, thin layers of Cadmium Oxide (CdO) with various volumes of Cadmium acetate solution (40, 50 and 70 ml) were deposited using spray pyrolysis technique over a glassy substrate. Samples were investigated using FESEM images, XRD and UV-Vis spectra as well as I-V characteristic. It was found that all samples were grew up with polycrystalline nanostructures along the preferred direction of (002). In addition, it was found that grew up sample in the volume of 50 (ml) are of optimum photoconductivity condition in visible range regarding optimum structural (largest crystallite size and lowest crystallite defect density) and optical (smallest band gap and highest light absorption) conditions.

Detection of Galactose and Glycerophospholipids by Galactose Biosensors and Advancement Their Proficiency Using Berkelium Colloidal Nanoparticles and Poly(3,4-Ethylenedioxythiophene)-Poly(Styrenesulfonate)-Based Biosensors

In the current paper, galactose-oxidase enzyme is used as stabilization medium due to its more proficiency, ability for more accurate controlling the enzyme reaction, protecting against wasting of enzyme as well as simple and easy use and exchange of enzyme medium after performing some levels of surface modification and developing multi-walled carbon nanotubes (MWCNTs) on Berkelium plate. For better connecting and stabilizing the enzyme on the medium, the prepared medium is washed by high concentration sulfuric acid and nitric acid and a large volume of deionized water and for protecting enzyme from devastating effect of Berkelium and prohibiting them to become inactive, surface is covered with cystamine before stabilization. Regarding the large size of galactose-oxidase enzyme compared to surface of medium, a connective material with amid at one end and pyrine at the other end is used as transfer agent and for stabilizing this connection, the prepared medium is placed into dimethylformamide (DMF) solution for a couple of hours. Activity of stabilized enzyme at 460 (nm) wavelength recorded by spectroscope was depicted against time to evaluate its stability in various times. The prepared medium, which have a large amount of galactose-oxidase enzyme, can be used as electrode in sensors. Furthermore, galactose-oxidase electrochemical sensor is one of the best methods for detecting low amount of galactose and applying Berkelium colloidal nanoparticles as a supplementary material in the structure of biosensor can be effective for advancement its proficiency and optimum proficiency. On the other hand, in the current study, electrode biosensor entitled as modified carbon paste electrode with Berkelium colloidal nanoparticles (Bknano/CPE) is produced by carbon graphite powder, paraffin oil and Berkelium colloidal nanoparticles (24 nm) and it is compared with carbon paste electrode (CP). In semi-permeable membranes, a combination of 1 (ml) of 0.1 (M) phosphate buffer with specified pH and 10 (mg) of galactose-oxidase enzyme is placed around each electrode. In the same potential of 0.7 (V), biosensors are tested with galactose in concentration range of (0-1) (mM) and various amounts of pH (4,6,8) which lead to producing the maximum current and tracing galactose in pH=6 and concentration of 1 (M) as the optimum condition. Currentmetry induced from both biosensors are compared and it is confirmed that using Berkelium colloidal nanoparticles in the structure of (Bknano/CPE) electrode leads to increasing the conductivity and currentmerty of biosensor. In addition, qualitative and quantitative measurement of food components is of great importance due to high cost of traditional methods, in addition to tendency for more accurate and sensitive detecting of these components. galactose and glycerophospholipids are such compounds that they frequently measure. Various methods are used to detect these food elements. However, the necessity for accurate measurement of these two compounds with high sensitivity, especially for food health issue, leads to developing biological methods, especially biosensors. Among them, biosensors based on conductive polymer nanostructures, especially Poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate), have been recently interested due to their unique characteristics. The current paper aims to introduce and investigate the previously performed studies about Poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate)-based biosensors for detecting galactose and glycerophospholipids.

S. cerevisiae Outer and Inner Membranes are Compromised upon Benzyl Alcohol Treatment

Although there are innovations in the treatment of diseases caused by fungi and medicines with multiple targets have been developed, the search for a drug with a broad spectrum and without any side effects continues to date. It is generally accepted that determining the cellular target responsible for the toxic effect opens up new possibilities for the development of new drugs. Especially the effects of antifungal agents on the surface components of the fungal cell, on cell wall synthesis and the identification of the target site are crucial in antifungal drug development. Thus studies on the fungal cell membranes in connection with the antifungal agents, aim to develop new strategies for the therapy of fungal infections. Antifungal agents targeting fungal cell wall and cell membrane components have increased in importance in clinical studies. In this study, understanding the mechanism of action of benzyl alcohol, a known membrane fluidizer, and the determination of its cellular targets are aimed. We have shown that in the presence of sorbitol, the osmotic stabilizer, benzyl alcohol becomes less effective against yeast cell. Moreover, benzyl alcohol disrupts cell membrane, causing leakage of ions to the extracellular medium. Nuclear membrane is distorted upon treatment of yeast cells with benzyl alcohol. Thus, we conclude that both outer and inner yeast cell membranes are compromised by the action of benzyl alcohol.

Tertiary Amine-Mediated Polyvinyl Alcohol Membrane Over the Porous Support of Polyvinyl Chloride Membrane for CO2 Separation

Great attention has been paid to membrane-based separation technology in various separation fields, including gas separation. It provides the benefits of energy efficiency, environmental friendliness, easy scale-up, and convenience in operation. Different division advancements are being utilized for the expulsion of acid gas carbon dioxide (CO2). The aim of this work is to synthesis the membrane using polyvinyl alcohol (PVA) with treatment (WT) and without treatment (WOT) of the additive that is triethanolamine (TEA), to study the effect of additive on the permeance of membrane towards CO2 and the morphology changes of each membrane. In this research, virgin PVA and PVA with TEA were cast upon the porous support membrane of polyvinyl chloride (PVC). PVA was used as the polymer matrix, and TEA was used as a CO2 facilitating agent. Distilled water was used as a solvent for TEA and PVA in preparing the solution. Dimethyl acetamide (DMAc) and Tetrahydrofuran (THF) were used as solvents for PVC porous membranes. These membranes were tested on CO2 to find out the permeability and flux rates (J). For the morphology of the membrane, we performed SEM; for thermal analysis, we performed DSC and TGA, and for the strength, we performed the tensile test. The results reveal that the presence of TEA changes the morphology and thermal behavior increases the strength and the permeability of CO2. In a nutshell, the presence of TEA enhanced the performance and the morphology of the membrane.

Graphene Membranes: From Reverse Osmosis to Gas Separation

Graphene membrane is a promising technology to help both carbon dioxide separation from flue gas and water desalination. This work reported the importance of membrane separation processes, the evolution of polymeric membranes before the discovery of graphene and how this material fits into this scenario. In addition, reverse osmosis and gas separations have been discussed as promising methods to reduce the occurrence of freshwater scarcity events and slow global warming. For all these separation techniques, the current state of graphene membranes technology and what advances might be brought by such one atom thick skin layer were presented, as well as the results of theoretical and experimental research. Finally, the challenges that still need to be overcome by this innovative technology as well as the perspectives were shown.

Removal of Heavy Metals from Water: Technological Advances and Today's Lookout Through Membrane Applications

Water contamination by heavy metal is a great environmental concern. It leads to many health issues ranging from diarrhoea, vomiting to life-threatening diseases like cancer, lung/kidney damage. This also affects soil biota/plant growth. Metal-ions have a tendency of bio-accumulation, hence pose a major issue upon entry in the food-cycle. Their removal from water is necessary before use for human/agricultural applications. Different methods reported for metal-ion separation are conventional methods viz. chemical-precipitation, ion-exchange, adsorption, coagulation, flocculation, flotation, electrochemical possess good separation efficiency, but the generation of a secondary pollutant, recovery issues restrict their applicability. Hence, there is a need of reliable techno-economical, environment-friendly, sustainable separation, recovery method. Membrane-based methods viz. reverse-osmosis, nano filtration, electrodialysis, ultrafiltration has ability to treat water for heavy metal recovery without chemical contamination. Recovered materials can be recycled/utilized further. Among different membrane-based processes, micellar/polymer enhanced ultrafiltration requires chemical addition and affects purity. Electrodialysis, reverse-osmosis, nanofiltration processes require large energy/operational issues. Hence, simple ultra filtration with membrane modification is preferable as low-energy requirements. This paper discusses details of conventional/advanced methods for heavy metal separation with the fundamental process, parameters, advantages/limitations.