Increase In Additive Concentration Research Articles

Preparation and characterization of nano‐filled polypropylene dielectric films

AbstractModified copper calcium titanate (MCCTO) or functional activated carbon (FANC) particles were added to functional polypropylene (FPP) or heat‐treated polypropylene (HTFPP) matrix to improve the performance of FPP as dielectric films. By testing and characterizing the prepared FPPwxMCCTOy, FPPwxFANCz, FPPwxMCCTOyFANCz and HTFPPwxMCCTOy, HTFPPwxFANCy and HTFPPwxMCCTOyFANCz films, It is found that the dielectric constant and discharge energy density of each FPPwxMCCTOy, FPPwxFANCz, HTFPPwxFANCz and HTFPPwxFANCz films reach the maximum when the MCCTO and FANC loads are close to 8 and 6 wt% respectively. FPPwxMCCTO8FANCz and HTFPPwxMCCTO8FANCz series films also obtain the maximum dielectric constant and discharge energy density at FANC load approaching 6 wt%. The discharge energy density of HTFPPw86MCCTO8FANC6 film prepared properly is 3.2 J/cm3, which is more than 3 times higher than that of FPP. When MCCTO and FANC loads are ≦8 and 6 wt% respectively, with the increase of additive content, More dense distribution of MCCTO and FANC was observed in FPPwxMCCTOy(or HTFPPwxMCCTOy), FPPwxFANCz(or HTFPPwxFANCz) and FPPwxMCCTO8FANCz(or HTFPPwxMCCTO8FANCz) series film sections. In this paper, we propose possible explanations for the apparent improvement in dielectric constant, discharge energy density and heat resistance of capacitive films after appropriate heat treatment or addition of appropriate MCCTO and/or FANC loads.

Influence of layered conductive coatings on electrochemical characteristics of NaFe(SO4)2cathode material

Rising production and consumption, and the high cost of lithium salts increased the price of lithium-ion batteries. Sodium-ion batteries are a promising replacement as safer and cheaper. However, the cathode materials for these batteries have low conductivity, which critically reduces their capacity. Modification with conductive additives is one way to solve this problem. Since a large electronic contact area of the active material with the conductive coating is required, the main candidates for such additives are materials with a layered structure. The purpose. To study the influence of layered conductive additives on the performance and kinetic parameters of eldfellite-structured cathode material. Methodology. By cyclic voltammetry and galvanostatic methods, it is found that as the 2D material additive concentration increases, the active material’s performance characteristics initially increase and then decrease, which is related to the sodium ions diffusion rate through the coating layer. Results and discussion. As a result of the modification effect evaluation of NaFe(SO4)2 cathode material with eldfellite structure by layered conductive coatings: graphite, molybdenum disulfide and MXene (Ti3C2Tx), it was determined that for each material there is a certain optimal concentration at which peak currents, capacitance and diffusion coefficient are maximized and resistance is minimized. The optimum additive quantities are 0.5% for MoS2 and MXene, and 0.2% for graphite. Conclusion. The influence of the concentration of 2D conductive coatings on the electrochemical properties of NaFe(SO4)2 intercalation material is shown.

An Adhesion Improvement of Low-Density Polyethylene to Aluminum through Modification with Functionalized Polymers.

An interfacial adhesion improvement between low-density polyethylene (LDPE) and aluminum (Al) foil is an important challenge in designing multilayered packaging (TetraPak packaging type) due to insufficient inherent adhesion between both untreated materials. Therefore, extra adhesive layers are often used. The hydrophobic character of LDPE is responsible for poor adhesion to Al and can result in delamination. This study deals with the comparative study of the bulk modification of LDPE with various commercially available adhesive promoters with different chemical compositions to increase LDPE's adhesive characteristics and ensure good adhesion in LDPE/Al laminates. A copolymer of ethylene and methacrylic acid; a terpolymer of ethylene, maleic anhydride, and acrylic ester; or maleated polyethylene (PE) were used as adhesive promoters, and their effect on adhesion improvement of LDPE to Al was investigated. The best adhesion improvement was observed in LDPE-modified samples with maleated PE, while 0.1 wt.% additive content significantly increased peel resistance (from zero to 105 N/m). An additional increase in additive content (0.5 wt.%) in LDPE led to stronger adhesion forces than the cohesion forces in Al foil. Adding 0.5 wt.% of maleated PE into LDPE improved the LDPE/Al laminates' adhesion and can be applied in multilayered lamination applications.

Evaluation of the Role of the Activating Application Method in the Cold Sintering Process of ZnO Ceramics Using Ammonium Chloride.

The influence of the method of applying the activating additive ammonium chloride and its concentration on the density and microstructure of zinc oxide ceramic obtained by cold sintering at 244 °C was investigated. The activating agent was applied by two methods: impregnation and subsequent autoclave treatment. When the powder was activated by the impregnation method, the crystal sizes remained at the initial level of 0.17-0.19 μm. After the autoclave treatment, the crystal sizes increased to 0.31-0.53 μm. Samples of cold sintering ZnO with relative density up to 0.96 and average grain sizes 0.29-0.86 μm were obtained. ZnO powders and ceramic samples were analyzed using SEM, TGA/DSC, and XRD to reveal the effect of the powder activation method and cold sintering conditions on the material microstructure. The effect of ammonium chloride concentration on grain growth and microstructure of ceramic samples is shown. It was found that the average grain size of ceramic samples with an increase in additive concentration passes through a minimum. In cold sintering of the autoclave activated powder, the effect of reducing the average grain size was observed. The results of this work are discussed on the basis of the idea of the solid-phase mobility of the crystal structure arising when interacting with an aqueous medium.

Enhanced properties of single-layer particleboard made from oil palm empty fruit bunch fibre with additional water-soluble additives

The efficacy of additional water-soluble additives was studied relative to the physical and mechanical properties of particleboards produced from oil palm empty fruit bunch (OPEFB). Polyethylene glycol, acrylamide, and acrylic resin were selected as water-soluble additives for use in the OPEFB particleboard production process. The effects of the three additives at two different concentrations (2% and 4% of dry OPEFB mass) on the particleboard properties were evaluated. Addition of water-soluble additives increased the performance of the OPEFB particleboard. The additive concentration has a significant effect on the properties of the particleboard. With the increase of additive concentration, the internal bonding and modulus of rupture value increased while the thickness swelling and water absorption decreased. Particleboards with an additional 4% of acrylamide or polyethylene glycol achieved the highest modulus of rupture (22 MPa), highest internal bonding strength (1 N/mm2), and lowest thickness swelling (9%). All the particleboards produced with 4% of water-soluble additive achieved the standard requirements of JIS A 5908:2003 for physical and mechanical properties.

Experimental study of food waste powder FWP influence on compressive and wear behaviour of polyester composite

Composites reinforced by natural fillers approved to have good tribological properties which essentially required in industrial applications demand specific friction coefficient and wear resistance such as flooring materials and brake pads materials…etc. Food wastes powder (FWP) such as crusts are abundant and possess good mechanical properties, these materials evaluated to assess the possibility of using (Polyester/FWP) as a new engineering material with enhanced mechanical properties. In this research, (UPE/FWP) composites prepared by Hand lay-up molding. Compression and wear behavior of UPE composites reinforced with different types of food waste powder FWP have been investigated. Matrix polyester reinforced with four types of FWP (Coconuts Shells, Chestnuts shells, Egg shells, and Pistachio shells) proposed as new engineering materials with enhanced mechanical and frictional properties. The utilize particles size vary between (713.9, 1094.7, 1060.4 and 543.7) nm respectively. Mixing concentration ratio utilize were (2 and 4 wt %) for all. The results showed that all four types of FWP have improved the mechanical and tribological behavior of UPE composites with mild variation. Both, coconuts and chestnuts particles have the significant effect on the compression strength (C.S.), 4wt% ratio present the higher (C.S) value measured for all (FWP) used and the performance increase gradually as filler contain increased. Also, the value of Young’s Modulus observed to be increased as the (FWP) increases and the best value observe at 4wt% (UPE/coconuts shell and UPE/chestnuts shell) composites. Wear rate (W.R.) results present a noticeable reduction during the increase of additive concentration with mild variation. FWP acts as a good reinforcement with polyester composite so the wear resistances consequently increase.

Wear performance of UHMWPE reinforced with basalt fibre for total disc replacement

For total disc replacement (TDR), wear of the Ultra High Molecular Weight Polyethylene (UHMWPE) bearing surface is the common cause for failure. Wear of UHMWPE plays an important role in determining the life span of TDR implants. In order to obtain materials with improved wear resistance and improved mechanical characteristics basalt fibre of 5wt. %, 10 wt. %, 15 wt. % and 20 wt. % is added with UHMWPE. The wear tests were conducted on a pin-on-disk tribometer. The specimens thus prepared were subjected to hardness tests, tensile testing and wear testing. The results indicated that the hardness increased with increasing percentages of basalt fibre content, and the tensile strength of the specimens increased until 15% of additive content and post that it decreased thereafter, Wear tests indicated a decrease in wear with increase in additive content as the coefficient of friction decreased considerably.

Effect of additive content on the mechanical and thermal properties of pressureless liquid-phase sintered SiC

ABSTRACT Pressureless liquid-phase sintered SiC (LPS-SiC) ceramics fabricated from β-SiC and 1 vol% α-SiC seeds with 3–15 vol% Al2O3-Y2O3-CaO additives were prepared to investigate the effects of additive content on the mechanical and thermal properties. All the specimens consisted primarily of elongated α-SiC grains that were predominantly formed via β to α phase transformation and via the growth of the initially added α-SiC seeds during the sintering. The grain growth and polytypic transformation exhibited diffusion-controlled kinetics. The highest value for fracture toughness (5.4 MPa·m1/2) was exhibited at an additive content level of 7 vol%; this was attributable to the optimal interfacial strength and well-interlocked elongated grains with active crack–microstructure interaction. The specimen with 7 vol% additive content exhibited the highest flexural strength (686 MPa) among the reported pressureless LPS-SiC ceramics, and this was attributable to its high density and the optimal content of soft intergranular phase (IGP). The hardness and thermal conductivity decreased gradually with the increase in additive content, owing to the increased volume fraction of the soft IGP with low thermal conductivity.

Study on the Effect of Si-Al Components in Pulverized Coal Ash on Corrosion in Heating Surface of Biomass Boiler

Pulverized coal ash can be used as an additive to reduce corrosion on heating surface of biomass boiler. Biomass ash and pulverized coal ash were mixed and coated on the metal surface for experiment; the results showed that the corrosion rate of the metal decreases by adding pulverized coal ash. With the increase of additive content, the corrosion gradually reduces. The effect of different pulverized coal ash on corrosion is different, but as the proportion of pulverized coal ash increases, the effect tends to be close. When the molar content of (Si+Al)/(Na+K) is about 2 and the ratio of Si/Al is about 1, the pulverized coal ash additive works best.

Viscosity of Al2O3-water nanofluids

Abstract In many aspects the past decade has proved the rapid development of water based and oil based nanofluids science. Number of research is conducted to estimate the behavior of these fluids in the different thermal equipments. However, nanofluid viscosity deserves much attention during the application of nanofluids. The existing experimental result about the viscosity of nanofluids shows clearly that the viscosity augmented accordingly with an increase of additive concentration and decreased with the temperature rise. In this paper, different characteristics of viscosity of nanofluids are compiled and the viscosities of Al2O3-water nanofluids are estimated by Matlab approximation.

Unravelling the effects of mobile phase additives in supercritical fluid chromatography—Part II: Adsorption on the stationary phase

The mobile phases employed in current practice of supercritical fluid chromatography (SFC) are usually composed of a mixture of pressurized carbon dioxide and a co-solvent. The co-solvent is most often an alcohol and may contain a third component in small proportions, called an additive (acid, base or salt). In the first part of this series, the effects of mobile phase additives on the polarity and apparent pH of the mobile phase were explored. In the present paper, we examine the effects pertaining to adsorption of additives on the stationary phase. Ammonium acetate was selected as a representative case, because it is often employed in current practice. To favour its solubility and further improve chromatographic quality, a small portion of water is also advocated. First, the equilibration time is observed to be largely increased in the presence of an additive, especially when mobile phase compositions containing only low proportions of methanol co-solvent are employed. Secondly, the effects of ammonium acetate are more thoroughly assessed with a modified version of the solvation parameter model (five Abraham descriptors and two descriptors to take account of positive and negative charges on ionizable species). On a hybrid silica stationary phase (ACQUITY UPC2 BEH), the effects of increasing concentration of ammonium acetate (0–25 mM in the methanol co-solvent) are investigated. The retention of acidic species is the most strongly affected, with a continuous retention increase when additive concentration increases. The retention of basic and neutral species is also moderately affected. Then thirty-two stationary phases based on sub-2 μm totally porous particles or sub-3 μm superficially porous particles are characterized with and without 20 mM ammonium acetate and 2% water in the methanol co-solvent. The effects of adsorbed additive on the interaction capabilities are discussed. Finally, the interest of introducing the additive in the dilution solvent, a method that was sometimes recommended to simplify the workflow, is also discussed with a model basic compound.

Influence of graphite on the physical and rheological properties of bituminous binder before and after short-term ageing

Bitumen is commonly used as a binder in the surface course of the flexible pavement. Failures in flexible pavement are mainly due to rutting and cracking distresses that occurs during the service life of the pavement at high and low temperature respectively. To minimize these distresses, there is a need to improve the quality of the bitumen binder. In this study, graphite is considered as potential modifier of the bitumen. The objective of this paper is to investigate the effect of graphite powder on the physical and rheological properties of the bitumen binder before and after being subjected to short-term ageing. Graphite powder was blended in the bitumen in variegated percentages from 5 to 20% with an increment of 5% by weight of bitumen. The samples were simulated to short-term ageing using rolling thin film oven test. Penetration, softening point, rotational viscosity and dynamic shear rheometer tests were performed on these unaged and short-term aged samples. The result indicates an improvement in physical and rheological properties of the bitumen binder as illustrated through decrease in penetration value along with increase in softening point, viscosity and rutting resistance parameter with increase of additive content for both unaged as well as short-term aged samples. The temperature susceptibility and stripping properties of the modified binder also gets improved. However, the addition of graphite resulted in an increase in mixing and compaction temperature. Also, the addition of graphite reduced the degree of ageing of the bitumen binder as indicated through lower penetration ageing ratio, lower softening point increment, lower viscosity ageing index, lower ageing index of rutting factor and an increase in ageing index of loss tangent with increased additive content. The recommended content of graphite as modifier is 8%.

Fabrication of new type of barium ferrite/copper oxide composite nanoparticles blended polyvinylchloride based heterogeneous ion exchange membrane

The current study focuses on the electrochemical, morphological and antibacterial characteristics of a new type of polyvinylchloride based cation exchange membrane modified by BaFe12O19/CuO composite nanoparticles. The used BaFe12O19/CuO composite nanoparticles were synthesized by chemical precipitation technique. The formation of BaFe12O19/CuO was characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and X-ray diffraction (XRD). SEM and scanning optical microscopy (SOM) images also showed relatively uniform structure for the prepared membranes. The membrane water uptake was enhanced up to 14.5% in presence of BaFe12O19/CuO composite nanoparticles. The membrane ion exchange capacity, membrane potential, transport number, surface charge density, permselectivity and ion permeability/flux were also improved sharply by increase of additive concentration up to 2 wt% and then showed decreasing trend by more BaFe12O19/CuO content ratio from 2 to 8 wt%. The membrane areal electrical resistance were decreased significantly from ∼24 to ∼5 (Ω cm2) by using of BaFe12O19/CuO nanoparticles. Moreover, modified membranes demonstrated good ability to removal of E-coli bacteria.

Effect of Hydrated Lime and Portland Cement on Asphalt Binders using DSR

Bituminous binder modification has been acknowledged as one of the methods to improve asphalt pavement quality. This study is focussing on investigating the effect of Portland cement and hydrated lime on asphalt pavement of which different percentages (4%, 6% and 8% by weight of bitumen binder) were added to the control 60/70 pen grade bitumen. The effect of the two additives were evaluated through penetration, softening point and dynamic shear rheometer (DSR) tests. Temperature ranges of 20°C - 40°C were used for the DSR rheological testing. The results showed that addition of both hydrated lime and Portland cement had a significant influence on the binder properties. A reduction in penetration and increase in softening point temperature were observed with increase in additive content, this indicates improvement in stiffness and rutting resistance. Also, the DSR rheological analysis shows that the modified binders have higher rutting resistance.

PVC Based Ion-Exchange Membrane Blended with Magnesium Oxide Nanoparticles for Desalination: Fabrication, Characterization and Performance

In this study, polyvinyl chloride (PVC) based nanocomposite cation exchange membranes incorporated with magnesium oxide (MgO0 nanoparticles were fabricated by nonsolvent induced phase inversion method. The additive concentration and electrolyte conditions (concentrations/pH) were investigated. Morphology studies were done using SOM and SEM images exhibited uniform distribution of MgO nanoparticles in the membrane structure. FTIR analysis showed the chemical structure of prepared membrane that demonstrated MgO nanoparticles presence. The hydrophilicity of membranes increased when 0.5-4.0 wt.% of additive were embedded into the polymer matrix. The transport characteristics of prepared membrane were improved by increasing nanoparticle content from 0.5 to 1 wt.%. It was demonstrated that the ionic flux of developed cation exchange membranes improved with an increase in additive content up to 1 wt.%. A considerable reduction was observed in the values of electrical resistance for the prepared membrane containing MgO nanoparticles. Ionic selectivity was enhanced at the more concentered solution and was slightly decreased at higher electrolyte concentration. Moreover, at the electrolyte solution of pH7 the optimal transport properties were achieved for the membranes.

Controllable synthesis of self-assembled MoS2 hollow spheres for photocatalytic application

MoS2 hollow spheres were controllably synthesized with the assistance of surfactant [polyvinyl pyrrolidone (PVP)] through a facile hydrothermal method. Our moderate synthetic route also yielded a large quantity MoS2 nanospheres and nanosheets by adjusting the additive concentration of PVP. The MoS2 nanosheets were synthesized without the addition of PVP. With the gradual increase of additive concentration of PVP, the MoS2 nanosheets assembled into MoS2 nanospheres and the MoS2 nanospheres further assembled into the MoS2 hollow spheres. Meanwhile, a reasonable growth mechanism related to the formation of MoS2 structures was proposed preliminarily. Moreover, the light absorption and photocatalytic properties of synthesized MoS2 structures were investigated. The results indicated that MoS2 hollow spheres exhibited excellent photocatalytic properties, which could be attributed to the unique structure feature, distribution characteristic, abundant of photoactive sites. Thus, it indicated for a huge potential for application in photocatalytic materials, which could solve the water pollution all around the world.

Reaction sintered zinc oxide incorporated magnesium aluminate spinel from commercial grade oxide reactants

Commercially available fused magnesia and reactive alumina sources were used to develop stoichiometric magnesium aluminate spinel by solid-state reaction sintering technique. Zinc oxide was used as a sintering additive up to 2 wt%. The mixture was compacted using a uniaxial pressure of 150 MPa into pellets and bars. The pressed product was sintered in the temperature range of 1200 to 1600 °C. The dilatometric method was used to evaluate spinel formation with varying amount of zinc oxide. Phase analysis and density study were conducted to study the sintered products. The increase in additive content was found to improve the density and spinel formation in the composition. The dilatometric study showed that addition of zinc oxide reduced the spinel formation temperature and also increased shrinkage at higher temperatures, indicating better sintering. The microstructural study showed dense and compact nature of spinel in the presence of ZnO. One thousand six hundred degrees celsius sintered products were used to study flexural strength and thermal shock resistance.

Fabrication and Characterization of PES Based Nanofiltration Membrane Modified by Zeolite Nanoparticles for Water Desalination

In the present study, mixed matrix PES/zeolite nanoparticles nanofiltration membranes were prepared via the solution casting technique. The effect of zeolite concentration on the PES membrane performance and its properties was studied. Cross-sectional scanning electron microscope (SEM) observations showed that the porosity in the membrane sub-layer was increased with addition of zeolite into the casting solution. Surface SEM images and scanning optical microscope (SOM) images showed the nanoparticles agglomeration in thesurface at high loading rates. Membrane roughness was decreased with the addition of zeolite into the casting solution. Results indicated that the membrane water content was improved initially by using 0.05 wt. % zeolite nanoparticles and then was decreased with further increase in additive concentration. Utilizing zeolite nanoparticles in the casting solution also led to decrease of surface contact angle from 62.02° for PES membrane to 36.87° for membrane filled with 0.1 wt.% zeolite. Moreover, water flux and tensile strength were enhanced with addition of the zeolite (up to 0.1 wt. %) and then were decreased whereas the rejection was decreased just in 0.1 wt. % nanoparticles loading rate. The flux reduction ratio of the prepared membranes was also estimated. Mixed matrix PES/zeolite membranes showed better antifouling properties compared to the PES one.

Liquid-phase assisted flash sintering of SiC from powder mixtures prepared by aqueous colloidal processing

The effects were investigated of the starting particle size (i.e., nanometer or submicrometer powders), content of Y3Al5O12 additives (YAG; in the range 5–20wt.%), and difference of size scales between the two particle types on the liquid-phase assisted flash sintering of SiC from powder mixtures prepared by aqueous colloidal processing. It was found that flash sintering benefits from the refinement of the particles size, the increase in additive content, and the smaller size scale of the particulate additive. It was also found that under the present flash sintering conditions (i.e., 900°C furnace temperature, 13A current, and 50s in flash state) the resulting ceramics are, despite the formation of liquid phase, porous to a greater or lesser extent, and exhibit decreasing porosity gradients from their surface to the centre. These observations are rationalized to extract guidelines for powder batch design contributing to the pressureless ultrafast sintering of non-oxide advanced ceramics.

INDUCED PHOTODEGRADATION EFFECT ON THE FUNCTIONALIZED FE(III) COMPLEX ADDITIVE-POLY(VINYL CHLORIDE) THIN FILM

A complex of Fe(III) with 4-amino-5-(pyridyl)-4H-1,2,4-triazole-3-thiol was prepared and evaluated as a photodegradation for polyvinyl chloride (PVC). Polyvinyl chloride was dissolved in THF solvent (5%, w/w) and functionalized with Fe (III) complex to form PVC films by means of solvent-casting method with a thickness of 40 μm. To study the effectiveness of Fe (III) complex additive, different concentrations (0.01, 0.02, 0.03, 0.04 and 0.05 g) were introduced into the PVC solution. The films’ photodegradation was investigated; the photodegradation activity of the compounds was determined by monitoring the carbonyl group, weight loss method and morphological study with irradiation time. The obtained experimental results showed that the additive behaved successfully as a photoinducer for the degradation process for the PVC films and the photooxidation rate increased with the increase of additive concentration.