Effect Of Preparation Process Research Articles

Effect of preparation process on purity of tricalcium aluminate

In the realm of cement production, traditional fuels are steadily giving way to alternative sources. While this shift yields economic and ecological advantages, it introduces notable technological challenges. Specifically, there is an escalation in certain chemical elements, leading to variability in the mineralogical composition. This variability is subsequently manifested in the characteristics of Portland clinker. It becomes imperative, therefore, to synthesize pure clinker minerals. This synthesis is essential for both understanding their behavior in industrially manufactured cement and creating analytical standards for mineral identification through XRD. The primary focus of the research is on the production of pure tricalcium aluminate, a key clinker mineral, within laboratory conditions. A direct laboratory methodology involving solid-phase synthesis is used. The investigation meticulously tracks the impact of homogenizing the raw material mixture on the resultant mineral’s purity. To achieve this, a high-speed Pulverisette 6 planetary mill is utilized along with two types of grinding bodies. A corundum grinding capsule with corundum grinding bodies is employed to prevent contamination by foreign ions. Simultaneously, a highly efficient steel grinding capsule with steel grinding bodies is utilized. The raw material mixture is then subjected to sintering at six different temperatures ranging from 1 200 to 1 450 °C, and the purity of the produced mineral is quantified using Rietveld analysis. Laser granulometry results indicate a strikingly similar comminution of the raw material in both grinding cases. Iron contamination, as revealed by XRF analysis, is minimal, accounting for only 0.21 %. The purity of 97.6% C3A, is achieved at 1 450 °C using a steel grinding capsule, with 2.4% unreacted lime Conversely, when using a corundum capsule, a purity of 93.6 % is achieved, accompanied by residues of 2.2 % mayenite and 3.8 % lime. This discrepancy may be attributed to an insufficient degree of raw material comminution in the corundum capsule. Intriguingly, a slight iron contamination during the grinding of the raw material mixture exerts a positive influence on purity. In this case, iron acts as a flux, fostering a more favorable reaction of the mineral mayenite. This multifaceted exploration enhances our understanding of clinker mineral synthesis, offering insights into optimizing purity based on grinding methods, sintering temperatures, and the impact of minor contaminants.

Effect of Preparation Process on the Physicochemical Properties of Activated Carbon Prepared from Corn Stalks

The preparation of activated carbon (AC) from agricultural and forestry wastes is one of the effective methods for resource utilization. In this study, AC was prepared from corn stalk (CS) by pyrolysis, one-step activation, and two-step activation to determine the optimum preparation method. Based on this, a single-factor design was used to investigate the influence of activating agents (KOH, NaOH, KOH/NaOH), activation temperatures (600, 700, 800 °C), and activation times (60, 90, 120 min) on the physicochemical properties of AC. The physicochemical properties of AC were characterized by Thermal gravimetric analysis (TGA), Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Scanning electron microscopy (SEM), and Cyclic voltammetry (CV). The results showed that the AC obtained by the one-step activation method (KOH, 800 °C, 120 min) exhibited a rich pore structure and excellent electrochemical properties (Ipa = 159.8 μA, Ipc = −169.5 μA). However, for the two-step activation method, the AC exhibited a poor pore structure and electrochemical properties (Ipa = 130.8 μA, Ipc = −129.9 μA). In addition, one-step activation provides high-quality AC in a shorter activation time than two-step activation.

Spherical TiAl Alloy Powders by PREP: Preparation, Microstructure and Properties

TiAl alloy powders were prepared by plasma rotate electrode pulverization (PREP) with high speed. The effect of preparation process on the microstructure and properties of powders was studied. The results showed that the titanium aluminum powder prepared by PREP method was solid and spherical without satellite powder. The powders had two morphologies: cracked surface and smooth surface. The relationship between particle size and surface morphology was as follows: the smaller the particle size, the smoother the surface. Ti, Nb and Gr elements were uniformly distributed, while Al elements were segregated, but no alloy element loss occurred. The powderswere mainly composed of γ-TiAl and α2-Ti3Al phase and contained a small amount of NbCr2 phase. The average thickness of laminates of α 2+γ was about 0.2μm. Thelamellar thickness of γ phase was about 20nm. The long axis of NbCr2 phase was 200nm, and the short axis was 50 ~ 100nm. The higher the rotating speed of the electrode, the smaller the particle size and the higher the sphericity of the powders. With the increase of plasma generator current, the particle size decreased and the sphericity increased. The yield of - 100 mesh ~ + 325 mesh powders for EBSM molding could reach more than 80.68 %, when42000r / min and 670A process parameters were adopted.

Effect of Preparation Processes on Structural Thermal Stability and Collision Energy Dissipation of Common Antirelaxation Coatings on Quartz Substrates.

Paraffin and octadecyltrichlorosilane (OTS) coatings can alleviate collisions between alkali-metal atoms and cell walls and then prolong the atomic spin-polarization lifetime. The surface structure and collision effects of these antirelaxation coatings, as well as the methods to avoid antirelaxation invalidity, have been the focus of researchers. This study investigated the thermolability of coating surface structure and the collision interactions between alkali metal atoms and coatings, considering the influence of various coating preparation factors, where this collision interaction is indirectly analyzed by measuring the collision energy dissipation between an atomic force microscopy (AFM) probe and the atoms on the coating surface. We found that appropriate evaporation time, carbochain length, and postannealing process can enhance the thermostability of the paraffin coating and eliminate its morphological defects. Furthermore, the OTS/water concentration, the soaking time, and the type of solvent have different levels of influence on the cluster formation and the thermostability of the OTS coatings. Moreover, the antirelaxation performance of coatings has been shown to be characterized by counting the energy dissipated when the AFM probe collides with the antirelaxation coating, replacing the conventional light-atom interaction- based method for measuring the relaxation characteristics, but requiring specific coating preparation factors to be maintained.

Preparation of K2Fe[Fe(CN)6] nanoparticles by improved electrostatic spray assisted precipitation technology as potassium-ion battery cathodes

Prussian blue analogues, which have a stable structural framework and larger ion migration channels, are currently one of the most potential cathodes for potassium ion batteries. However, Prussian blue-based materials are susceptible to preparation conditions, resulting in vacancy defects and crystal water in structures, which seriously restricts the exertion of electrochemical properties. Herein, a novel preparation technology-an electrostatic spray assisted coprecipitation way protected by inert atmosphere is proposed and applied to the synthesis of K2Fe[Fe(CN)6] materials. The effects of preparation process on the crystallinity, microstructure and potassium storage performances of K2Fe[Fe(CN)6] are systematically discussed. The results prove that K2Fe[Fe(CN)6] synthesized by the new preparation process has good crystallinity (K1.56Fe[Fe(CN)6]0.89·□0.11·1.86 H2O), small particle size (~20 nm) and high specific surface area (104.31 m2 g−1), and finally exhibits excellent electrochemical performance, including an superb cycling stability of 89 mAh g−1 after 503 cycles at 0.5 C and rate capability of 82 mAh g−1 at 10 C. In addition, this preparation technology also provides a new strategy for the microstructure and performance optimization of other Prussian blue-based materials.

Effect of Preparation Process on Microstructure and Mechanical Properties of Metal Hollow Sphere Composites (Mhscs)

Effect of Preparation Process on Microstructure and Mechanical Properties of Metal Hollow Sphere Composites (Mhscs)

Nitrogen-doped porous carbons with high surface area for capacitive deionization

Heteroatom-doped porous carbons have become a hot research topic because of their excellent physicochemical properties and wide applications. The efficient and simple production of these materials is of great practical and scientific significance. Herein, nitrogen-doped porous carbons have been prepared by means of in-situ polymerization of pyrrole monomer and subsequent carbon dioxide activation. It is found that the preparation processes of polypyrrole polymers play an important role in fabricating high-quality porous carbons. The effect of preparation processes (changes in oxidants during the polymerization of pyrrole monomer) on the morphology, structure, and capacitive deionization performance of porous carbons has been studied systematically. The porous carbons with high specific surface area (1610 m2 g−1) exhibit good electrochemical behaviors and capacitive deionization performance. The capacitive deionization results demonstrate that the as-prepared nitrogen-doped porous carbons have a high electrosorption capacity of 13.5 mg g−1 and excellent regeneration performance in 500 mg L−1 NaCl solution. These results demonstrate that the resultant porous carbons are promising electrode materials for capacitive deionization application.

Friction and wear behaviors of Ni3Al metal matrix self-lubrication composites prepared by laser melting deposition

In order to improve the tribological perofrmance of Ni3Al metal matrix composites, the effects of preparation process on the friction and wear behaviors are investigated. Ni3Al self-lubrication metal composites (NMCs) containing 2.0 wt% graphene nanoplatelets (GNPs) were prepared by laser melting deposition (NA-LMD) and sparking plasma sintering (NA-SPS). Rotating sliding tests under different applied loads are conducted to study the friction and wear behaviors. The results show that, compared with NA-SPS, GNPs can be well integrated with NA-LMD substrate whose microstructure is more compact, which is attributed to the sufficient alloying reaction, as well as the layer and layer deposition principle of laser technology. Due to the excellent toughness and strength, the worn surfaces of NA-LMD after tests exhibit smooth and flat morphologies and have no significant pits and microholes. The more dense and thick tribo-layer without significant material deformation is formed beneath the worn surface of NA-LMD to improve the wear resistance performance. Whereas the mechanical properties of NA-SPS become poor due to the uncompacted microstructure and the existence of microholes caused by insufficient alloying reaction. Therefore, the friction coefficients and wear rates of NA-LMD are lower than those of NA-SPS when under the role of heavy and repeated sliding contact loads.

Effect of Preparation Process on Surface Quality and Microstructure of Titanium Sheet

At present, domestic cold-rolled titanium sheets have many surface defects, which are significantly different from foreign surface quality. This paper mainly studies the differences in the microstructure and performance of titanium plates GR1 and GR2 imported from Japan and domestic titanium plates TA1, and analyzes the causes of surface defects to solve the problem about TA1. The surface properties of different materials were observed. The mechanical properties of the materials were obtained by room temperature tensile test. The surface roughness of the three materials was tested. The microstructure and composition of the three materials were characterized by SEM, EDS and XRD. The results show that the surface of GR1 and GR2 is brighter and has no obvious chromatic aberration. The surface chromatic aberration of TA1 is larger. The mechanical properties of TA1 are the best. The tensile strength and yield strength of rolling are 325.19MPa and 271.17MPa, respectively, and the lateral direction is 329.19MPa and The roughness of 303.15MPa, GR1 and GR2 is slightly lower than that of TA1. The black area on the surface of TA1 is loose and the oxygen content is high. The pole figure of GR1, GR2 and TA1 are obtained. Keywords: Cold-rolled titanium sheets; Chromatic aberration; Mechanical properties; SEM; Texture

Effects of preparation processes on the structure and properties of collagen gel

ABSTRACTIn this study, the effects of collagen self-assembly, drying methods, and reswelling on collagen gel structure and biological properties were determined. The results showed that the self-assembly of collagen improved the regularity and pore size of the collagen gel and promoted collagen gel thermostability and cell proliferation. After drying and reswelling, the main structure of the self-assembly gel was composed of lamellar gel walls, but the gel structure shrank to some extent and pore size was reduced. The structure of the self-assembled gel after drying and reswelling was closely related to that of the drying method.

Medicated Pressure Sensitive Adhesive Patches from STR-5L Block Rubber: Effect of Preparation Process

STR-5L is a high quality block rubber in Thailand that is interesting to apply in medical and pharmaceutical products because it has very low impurity but high uniformity. In this study, medicated pressure sensitive adhesive (PSA) patches were developed by melt blending technique using hydroxyethyl cellulose (HEC) as tackifier and paraffinic oil as softener. Two rolls mill was used to blend all ingredients and the thin PSA patches were rolled out. Various preparation parameters were studied such as initial viscosity of rubber (60 or 80 Mooney viscosity; MV), mastication time (5-20 minutes), step of mixing, mixing time (35-80 minutes) and gap between rollers (0.1-0.4 mm). The suitable processing conditions were optimized. It was found that the rubber having initial viscosity of 80 MV provided better physical properties, for example, higher force T-peel, lap shear strength and shear holding time. Longer mastication time increased the shear holding time of patches. At 70 minutes of mixing time, the patches showed the highest shear holding time and did not leave any residue on the testing equipment surface. Moreover, the shear holding time decreased when the gap between rollers was expanded. Mixing method with the sequential addition of STR-5L, HEC and then paraffinic oil, provided good PSA patches. However, preparation process did not affect the plasticity retention index of PSA patches due to there were not significant change of values when those all parameters were varied. Next, lidocaine or its hydrochloride salt in powder form could be blended into this PSA to be the homogeneous patches. This lidocaine PSA patches for local anesthetics application on the skin would be evaluated in further study.

Effect of preparation process on properties of PLZT (9/65/35) transparent ceramics

Lead lanthanum zirconate titanate (PLZT 9/65/35) transparent ceramics were prepared by different methods. The excellent properties of the ceramics were obtained by partial co-precipitation method and microwave sintering, which reduced the sintering temperature from 1200 to 1000 °C, and shortened the sintering time from 180 to 20 min, compared with the traditional methods. The X-ray diffraction patterns confirm the presence of pure perovskite phase and highly crystalline of PLZT ceramics, i.e. the relative density was up to 96.5%. The dielectric constant of the ceramics were 3895. The hysteresis loop of PLZT ceramics prepared by partial co-precipitation method showed typical quadratic type, which would enable their applications in optical communication switches. The transparency of PLZT ceramics was investigated and the transmittance of 53.8% was obtained in PLZT at 850 nm.

Preparation of carbon foam-loaded nano-TiO2 photocatalyst and its degradation on methyl orange

Photocatalyst is of current interest due to its new technology for environmental pollution. Titanium dioxide (TiO2) is well known as a photocatalyst for the removal of environmental contaminants. In this work, nano-TiO2 photocatalyst was first prepared by sol-gel technique, on the basis of which carbon foam-loaded nano-TiO2 photocatalyst (nano-TiO2/CF) was synthesized by way of impregnating load, baking and forming methods. The effects of preparation processes on the photocatalytic properties of nano-TiO2/CF were investigated. The structures of the prepared nano-TiO2/CF composite were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive spectrometer (EDS). The photocatalytic activity of the prepared nano-TiO2/CF was evaluated by degradation of methyl orange as a model compound under ultraviolet light. Factors of heat treatment temperature, sol concentrations, dipping times, light sources, and the initial concentration of methyl orange on the photocatalytic degradation were studied in details. Results showed that when the concentration ratio of tetrabutyl titanate to absolute ethyl alcohol was 1:8, impregnating load twice, and baking at 500°C, the obtained nano-TiO2/CF photocatalyst exhibited the most desired efficiency in the degradation of methyl orange solution, reaching up to 83–87%.

Effect of Preparation Process on Bending Modulus and Strength of Fiber Tubes in Radial Direction

To explore the effects of preparation process on the mechanical properties of fiber reinforced tubes in radial direction, the closed ring method was applied to assess the elastic modulus and bending strength of GFRP and CFRP prepared by winding method and pultrusion method, respectively. The results indicate that there are two obvious differences between the winding tube and the pultrusion tube: i) the elastic modulus and bending strength of the winding tube for two materials are larger than that of the pultrusion tube. It should be attributed to the position of materials under stress: the former is the fibers while the latter is the matrix; ii) the failure mode for the winding tube is brittle fracture while elastic-plastic fracture is for the pultrusion tube. Compared with other experimental methods, the results of the closed ring method are accurate and reliable, which is demonstrated to be a potential method to evaluate the mechanical properties of fiber tubes in radial direction rapidly and conveniently.

The effect of preparation processes on the physicochemical characteristics and antibacterial activity of chitooligosaccharides

The bioactivities of chitooligosaccharides are markedly influenced by the degree of acetylation, degree of polymerization or molecular weight and pattern of acetylation. Thus, it is crucial to identify reproducible processes that will give rise to well-defined chitooligosaccharides and establish methods for their posterior physicochemical characterization in order to advance in the knowledge of their bioactivity. Chitooligosaccharides were prepared by two different processes. The first used chitosanase enzymatic hydrolysis and the second consisted of a two-step procedure based on chemical hydrolysis followed by chitosanase hydrolysis. Chitooligosaccharides produced in the second process were composed of 63 % of fully deacetylated sequences and inhibited the growth of Escherichia coli and Listeria monocytogenes. Better antibacterial activity was found for those obtained in the first process composed of 27 % of fully deacetylated sequences. Therefore, a low percentage of free amino groups and the presence of acetylated sequences are necessary in these molecules to exert good antibacterial capacity.

Effect of preparation process on elevated temperature tribological properties of composite polyurea grease

Purpose This paper aims to investigate and prepare the composite polyurea greases with excellent thermal stability and tribological properties. Design/methodology/approach In this paper, composite Ba-based (Ba, barium) tetra-polyurea lubricating greases were prepared with two different methods: mixing Ba-based gelatinizer and tetra-polyurea gelatinizer by a physical method; and introducing barium carboxylate into tetra-polyurea molecules by a chemical method. The properties of the products, such as heat stability, water resistance and friction performance, were analyzed with thermogravimetry, water-resistance test and four-ball friction test. Findings The results indicated that the products obtained by chemically introducing barium carboxylate into tetra-urea molecules showed better elevated temperature tribological properties, and the disadvantages of the polyurea greases with high temperature hardening were also obviously improved. The cone penetration rate at 180°C for 24 h is only 3 per cent. The friction coefficient can be decreased to 0.44 and the last non-seizure load value was increased from 560 N to 1,120 N without any other additives. Originality/value The research is significant because the prepared composite grease showed excellent performances, such as the outstanding thermal stability, water resistance and excellent extreme pressure and anti-wear properties, which may be widely applied in steel, metallurgy, bearings and other industrial fields.

Preparation and desulfurization performance of pyrolusite modified activated coke

In this study, pyrolusite modified columnar activated coke (AC‐P) was prepared through blending coal chars with an additive (i.e. pyrolusite). The effect of preparation process on the properties of obtained activated coke and the effects of operating conditions on desulfurization performance of AC‐P were investigated. The results show that the blending ratio of coal tar and molding pressure could affect the iodine value and drum strength of prepared activated coke. The orthogonal experiment results show that the optimal activation conditions for activated coke were 950°C of activation temperature, 60 min of activation time, and 0.5 of MH2O/MC. When pyrolusite was blended into activated coke, the product yield, iodine value, and desulfurization performance of all AC‐P samples increased significantly. The optimal desulfurization operating conditions were: SO2 concentration at 2000 ppmv, bed temperature at 80°C, O2 content at 8%, water vapor content at 10%, and space velocity at 600 h−1. The results demonstrate that the AC‐P is a kind of very promising adsorbent/catalyst in industrial flue gas desulfurization application due to its low cost and good desulfurization capacity. © 2016 American Institute of Chemical Engineers Environ Prog, 35: 1679–1686, 2016

Effect of Slag Addition on Mechanical Properties of Fly ash Based Geopolymers

This work describes improvement of mechanical properties of alkali activated binders – geopolymers made of fly ash from coal combustion in fusion boiler. The effect of addition of amorphous phase on physico-mechanical properties of geopolymers was examined. The studied properties were: flexural strength, compressive strength and water absorption. Effect of preparation process on the final properties of samples was also discussed. Amorphous phase was added in form of slag from the same coal combustion boiler. Samples were tested after 7, 28 and 90 days. With increasing amount of slag, the ascending trend of compressive strength was observed at the early stages of maturing. Compressive strength values measured after 90 days of maturing were found almost the same for all slag concentrations, and outperformed the compressive strength value of reference sample. On the contrary, the flexural strength was not positively affected by addition of the slag. Regarding the water absorption, the higher the slag addition, the lower water absorption was measured.

Effects of preparation process on performance of rubber modified asphalt

Effects of preparation process on performance of rubber modified asphalt

Effects of preparation process on performance of rubber modified asphalt

The rational utilization of waste rubber tire is essential for the environmental protection. Utilizing rubber particles to modify asphalt can not only improve asphalt performance, but also help the recycling of waste materials. Considering the effect of different preparation process parameters on the performance of rubber modified asphalt, this paper analyzes the effects of the shear temperature, shear time and shear rate on the performance of rubber modified asphalt, and provided a reference for its preparation.