Mechanical Ball Milling Process Research Articles

Carboxymethyl cellulose enhanced Cr(VI) removal of zero-valent iron via the coating anti-passivation mechanism

Competition for electrons from dissolved oxygen and secondary passivation resulting from the deposition of FeCr hydroxide are two challenges that impede the removal of hexavalent chromium (Cr(VI)) with zero-valent iron (ZVI). In this study, we fabricated micron-sized zero-valent iron modified with carboxymethyl cellulose (CMC-ZVI) via a mechanical ball milling process and demonstrated its improved performance up to eight times for Cr(VI) removal. Owing to the CMC protective film, the inhibition of dissolved oxygen for Cr(VI) removal, aging of ZVI in air, and secondary passivation of ZVI by the deposition of FeCr hydroxides were all inhibited. Even after a week of continuous aging, the CMC-ZVI maintained a stable Cr(VI) removal efficiency of over 50 %. The excellent hydrophilicity of CMC enhanced the interaction of CMC-ZVI with water and Cr(VI), thus improving its capacity for Cr(VI) removal. Furthermore, CMC-ZVI not only proficiently reduced and completely removed the high-mobility Cr(VI) from actual electroplating effluent, but also effectively alleviated the inhibition of Cr(VI) removal via CMC-ZVI by aeration and air aging. The efficiency of CMC-ZVI in removing Cr(VI) from actual electroplating effluent was improved by over 41 times compared to pristine ZVI. This advantage has the potential to make the storage and transportation of ZVI more affordable and convenient and increases its potential for practical applications. This study provides an efficient Cr(VI) removal strategy using ZVI for environmental remediation and a strategy for the production of highly reactive, aging-resistant, easily stored, and transported zero-valent iron with the potential for practical applications.

Composites of equiatomic Y, La, Ce, Nd, and Gd rare earth oxides: Chemical-shift effects and valence spectra

The core-electron and valence spectra of the composites of equiatomic rare earth oxides (equi-REO) were investigated using XPS. Equi-REOs fabricated by annealing at 1600 °C for 10 h after the synthesis by mechanical ball-milling and chemical sol-gel methods, exhibited the FCC bixbyite single phase. It was confirmed that Y and La sites had the higher oxidation state (Y > 3+ and La>3+) than Y2O3 (Y3+) and La2O3 (La3+), respectively, and both Gd and Nd sites had the lower oxidation state (Gd < 3+ and Nd<3+) than Gd2O3(Gd3+) and Nd2O3(Nd3+), one the other hand, in the Ce site, Ce3+ was increased compared to CeO2, and Ce3+ and Ce4+ were mixed. There were a significant changes in the electron DOS associated with O 2p – 4f hybridizations in the equi-REOs compared to the ideal mixture. Finally, we found that the chemical sol-gel process induces more changes of chemical and electronic states of the equi-REO than the mechanical ball milling process.

Oxalic acid modification enables high efficiency and proton conductive of Fe-base amorphous toward acid orange II in wastewater removal

A method involving the application of an elevated proton conductive shell onto Fe-base amorphous alloys (Feam) through the mechanical ball-milling process with oxalic acid dihydrate (OA-BFeam) is presented. The investigation highlights that the resulting Fe2C2O4·shell remarkably enhances the removal rate of acid orange II (AO II) by Feam, exhibiting an approximately 2.17-fold increase. This enhancement is attributed to the superior proton conductivity of the Fe2C2O4 shell in comparison to the iron oxide shell. Consequently, protons can effectively traverse the Fe2C2O4 shell and permeate into the iron core, where they serve as reducing agents to generate H. Simultaneously, the formation of surface-adsorbed Fe2+ occurs rapidly, contributing to a highly efficient AO II removal process across a broad pH range. Additionally, it is noteworthy that OA-BFeam exhibits equivalent efficacy in the removal of both direct and reactive dyes. Overall, this work introduces an environmentally benign surface modification technique for Feam and underscores the influence of proton conductivity on the dye wastewater removal capability of Feam.

Hydrolytic hydrogen production behavior in NaCl solution of Mg and Mg-GO composite synthesized by mechanochemical reaction

With the help of the mechanochemical reaction (MCR) strategy, the composition optimization, structure regulation and surface modification of metallic Mg are realized by introducing GO in the high energy mechanical ball milling process to enhance the hydrogen production performance in NaCl solution. The synthetic process of Mg and Mg-GO composite by MCR is systematically optimized and the microstructure evolution as well as the hydrolytic hydrogen production behavior are investigated. Phase composition optimization and microstructure regulation can be effectively implemented during the MCR process. The response rate of the repeated hydrogen-filling MCR sample is faster than that of the single hydrogen-filling MCR sample. The hydrogen production rates at 298 K of 4, 8, 12, 16 and 20 h MCR Mg with repeated H2-filling can reach to 922, 934, 890, 917 and 1131 mL/g/min, respectively. The internal microstructure refinement, surface modification, moderate activity, appropriate particle size, surface defects and reasonable mass transfer channels of MCR 8 h Mg-GO composite are the reasons for the fast rates and high yields of hydrolytic hydrogen production. 365.3, 864.4 and 933.8 mL/g H2 can be produced by 8 h MCR Mg-GO composite within 1, 3 and 10 min, respectively. The hydrogen production rate of 8 h MCR Mg-GO composite is as high as ∼600 mL/g/min. Mechanochemical reaction strategy with catalyst is a useful method to improve the hydrolysis hydrogen production performance of metallic Mg when well matched with the added catalyst.

Effects of silicon concentration on the magnetic and structural properties of nanostructured Fe-Si alloy synthesized by ball mill process

This study aims to elaborate on the production of a nanostructured Fe-Si alloy with varying silicon concentrations and how it can enhance the magnetic properties of the alloy. In order to achieve this, the mechanical alloying technique was employed to create the nanostructured alloy. After the mechanical ball milling process, the morphological, structural, and magnetic properties of the alloy were thoroughly analyzed using advanced techniques such as scanning electron microscopy (SEM) coupled with energy-dispersive spectroscopy (EDS), X-ray diffraction (XRD), and vibrating sample magnetometer (VSM). The results from these techniques revealed significant changes in the properties of the alloy. One of the major findings of this study was the appearance of Fe3Si phase, commonly known as Suessite, after the mechanical milling process. This indicates that the milling process caused a transformation in the crystal structure of the alloy. Additionally, an increase in silicon concentration led to a reduction in crystallite sizes, which was observed through the XRD analysis. Furthermore, the lattice strain and lattice parameters of the alloy were observed to increase with increasing silicon concentration until it reached 3%. After this point, the value of the lattice parameter remained constant, indicating that further increases in silicon concentration did not significantly impact the lattice structure of the alloy. The FTIR analysis revealed the presence of a distinct band at 1070 cm−1, indicating the occurrence of stretching vibrations associated with Fe-Si bonds. The milled samples exhibit improved magnetic properties, with increased saturation magnetization values observed as the silicon concentration increased.

A Ternary Nanocomposite Based on Nano-Bimetallic Platinum/Nickel Decorated on Multi-Walled Carbon Nanotubes for Flow Injection Amperometric Detection of Promethazine

We propose a nano-bimetallic platinum/nickel composite on multi-walled carbon nanotubes (nano-Pt/Ni@MWCNT) composite as electrode material, which was prepared via a simple pyrolysis method followed by a mechanical ball-milling process. Results showed that the nano-Pt/Ni particles could be anchored on the surface of the MWCNT, which was confirmed by multiple characterizations. The nanostructure of the synthesized composite provides a large specific surface area to expose a large number of active sites and the resulting enhanced electrical conductivity ultimately improves the electrocatalytic activity towards promethazine (PMZ). Furthermore, a nano-Pt/Ni@MWCNT/GCE coupled flow-injection amperometric system was used to electrochemically determine PMZ. The proposed sensor also demonstrated potential in analysis in cases involving a large number of samples, which can be rapid analysis with a high sample throughput of around 60 samples h−1. Linearity of response was shown from 0.10 to 100 μM and from 100 to 1000 μM PMZ. The detection limit was 0.03 μM and the limit of quantification was 0.11 μM. The proposed method demonstrated excellent reproducibility (RSD = 1.02%, n = 6), repeatability (RSD = 1.44%, n = 25), operational stability (RSD = 2.02%, n = 100), and interference tolerance. The viability of the nano-PtNi@MWCNT/GCE was demonstrated for the detection of PMZ in spiked saliva, urine, and beverage samples, with recoveries from 95.7 ± 0.7 to 105 ± 2%.

Investigation of ball-milling process on microstructure, thermodynamics and kinetics of Ce–Mg–Ni-based hydrogen storage alloy

Aiming at improving hydrogen storage performance of Mg-base alloy, the Mg90Ce3Ni7 alloy is prepared by medium-frequency induction melting and following mechanical ball-milling process. X-ray diffraction analysis reveals that the ball-milling Mg90Ce3Ni7 alloy is composed of Mg, Mg2Ni and CeMg12 phases, whereas subsequent milling induces grain refinement and the formation of amorphous phase. In addition, the extension of ball-milling time also not further improve the thermodynamic properties, whereas has a very significant effect on the kinetic properties, which is mainly attributed to the change of microstructure of the alloy by ball milling process. The ball-milling not only creates the nanocrystalline and amorphous structures, but also refines the particle size of the alloy. This is beneficial to the nucleation and diffusion of the alloy during reversible hydrogenation reaction. Concretely, the ball-milling time enhances the kinetics of hydrogen absorption at low temperature, especially for the alloy milled for 20 h, in which can absorb more than 3.5 wt % H2 over 30 min at 100 °C. Meanwhile, the ball-milling time enhances the kinetics of hydrogen desorption. It leads to effectively reducing the dehydrogenation activation energy to 72.2 kJ/mol H2, which allows the alloy can release more than 5 wt % H2 in 10 min at 280 °C. The work provides a scientific way to promote the practical application of Mg-based hydrogen storage alloy.

Ball milling synthesis and optical properties of Na and Bi ions Co-doped double perovskite Cs2AgInCl6

Double perovskite Cs2AgInCl6 is a new direct band gap semiconductor material. Compared with traditional perovskite CsPbX3 (X = Cl, Br, I), double perovskite Cs2AgInCl6 has good stability and wide fluorescence half peak width. This study reports the mechanochemical synthesis, characterization and application of a lead-free double perovskite Cs2AgInCl6 doped with Na and Bi ions. It was found that through a facile room temperature mechanical ball milling process, the double perovskite structure can be obtained within 30 min. Then, Na and Bi ions were used to dope to optimize its luminescence properties. By this synthesis method, the sample with the best doping ratio obtained in the experiment is Cs2Ag0.7Na0.3In0.9Bi0.1Cl6 with the photoluminescence quantum yield (PLQY) of 32.7%. The X-ray diffraction (XRD) and photoluminescence (PL) results show that Na and Bi ions can promote the crystallization and optimize the luminescence properties of Cs2AgInCl6. The theoretical calculation results show that both conduction band minimum (CBM) and valance band maximum (VBM) of Cs2Ag0.7Na0.3In0.9Bi0.1Cl6 are flat, which is favorable for the generation of self-trapped excitons. Packaging Cs2Ag0.7Na0.3In0.9Bi0.1Cl6 sample on an ultraviolet (UV) LED chip, and a warm white LED with good performance can be obtained, which shows a bright potential application in the field of white LED.

Investigation on mechanochemically modified calcium‐based adsorbent for flue gas HCl removal

AbstractFor purpose of reducing chlorine ions entering the wet flue gas desulfurazition (WFGD) tower to realize the WFGD waste water sequestration and the gypsum upgrading, a technical method of adsorbent injection into flue gas to remove HCl was proposed in this work. A new NaOH‐modified CaO (CA‐MC‐NA) was prepared by the mechanochemical ball milling method as a superior adsorbent for HCl removal in flue gas. The influence of particle size and Na doping on the dechlorination efficiency and chlorine capacity was investigated in a fixed bed reaction system. The experimental results demonstrated that the HCl removal performance is improved significantly under proper particle size and Na doping, as manifested by the experiment results that the chlorine capacity increases from 27.18 to 38.36 mg/g by simple mechanical ball milling, while it surprisingly reaches 75.36 mg/g by doping 5 wt.% NaOH. The surface physicochemical characteristics was explored by combined sample characterization of BET, XRD, SEM, elemental mapping, and particle size distribution. Dechlorination mechanism of the adsorbents were deduced and discussed. It shows that the mechanical ball milling process reduces the particle sizes to the submicron scale that induces the break and reconstruction of molecular interfacial bonds. It also increases the oxygen defects on the adsorbent surface. The doping of NaOH does not change the crystal structure of the dechlorinator, and Na ions can be chemically loaded over CaO in the form of ionic bonds. Free oxygen atoms or adsorbed oxygen molecules could combine with dissociated hydrogen atoms thus forming hydroxide radicals, which enhances the alkalinity of the adsorbent and boosts the removal of hydrogen chloride.

Microstructure and properties of Y2O3/Cu composites fabricated by a novel liquid phase in situ reactive synthesis process

Cu–Y2O3 composites were prepared by a secondary mechanical ball milling process and liquid phase in situ reaction and then sintered by the spark plasma sintering (SPS) consolidation technique. The microstructure and mechanical properties were studied using an X-ray powder diffractometer, scanning electron microscope, tensile tester, and Vickers hardness tester. The results showed that the added yttrium was converted into Y2O3, and the obtained Y2O3 nano-particles were uniformly distributed in the copper matrix, their mean size was 5.0 nm, and the cubic Y2O3 phase was coherent with the copper matrix, which indicated (422)Y2O3// (1‾11) Cu and [011‾] Y2O3// [11‾2] Cu orientation relationship. With the addition of Y, the mechanical properties of the composite materials were improved, and the hardness of 10 vol% Y2O3 was increased by 192.0%. Its tensile strength increased by 168.2% compared to pure copper.

Preparation of high-performance Nd–Fe–B magnetic powder by hydrothermal method assisted via ball milling

In recent years, there is an urgent need to improve the preparation process of Nd–Fe–B magnets to obtain magnets with high coercivity and magnetic energy products. In this study, we introduced the mechanical ball-milling process into the chemical preparation process of the magnetic powder, and the as-synthesized magnetic powder has a (BH)max of 5.5 MGOe and a Hc of 4.4 ​kOe. X-ray diffraction and X-ray photoelectron spectroscopy analysis have shown that the milling process does not introduce new impurity phases while also making the raw material powder more refined, which promotes the formation of the main phase Nd2Fe14B. Furthermore, the Henkel plots indicate that the presence of α-Fe is responsible for the increased exchange coupling effect and improved magnetic properties.

Structural, Morphological and Thermal Properties of Nano Filler Produced from Date Palm-Based Micro Fibers (Phoenix dactylifera L.)

In this century, the development of nano-sized filler from biomass material has become the main focus of industries in achieving their final green composite product for a wide range of applications. From a commercial and environmental point of view, fragmentation and downsizing of waste lignocellulosic fibers without chemical treatments into small size particles is a viable option. In this study, an attempt was made to produce nano-sized lignocellulosic fillers from date palm micro fibers via mechanical ball milling process at intense 99 cycles run (equivalent to 25 h). The resultant nanofillers as well as the microfibers were characterized in details by various analytical techniques, including transmission electron microscopy (TEM), scanning electron microscopy (SEM), particle size analysis (PSA), Energy Dispersive X-Ray (EDX), X-ray diffraction (XRD), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC) to assess their structure—property relationship. From microscopy examination, the nanofillers showed a heterogeneous mix of irregular shaped particles, and while having a size ranging of 30–110 nm in width and 1–10 mm length dimensions. Also, the crystallography analysis revealed the crystallinity had mildly declined from microfibers (71.8%) to nanofiller (68.9%) due to amorphization effect. As for thermal analysis, the nanofillers exhibited high heat resistance at 260.8 °C decomposition temperature. Furthermore, the nanofillers also had stable thermo-changing behavior by presenting low heat enthalpy change (40.15 J/g) in its endothermic reaction for breaking organic bonds. The thermal results suggest its suitability for composite fabrication process at high temperature. Thus, the produced nanofillers can be used as a low cost reinforcing agent in the future for versatile polymer-based composite systems.

Inositol hexanicotinate self-micelle solid dispersion is an efficient drug delivery system in the mouse model of non-alcoholic fatty liver disease

Inositol hexanicotinate (IHN) self-micelle solid dispersion (SD) with glycyrrhizic acid (GA) and arabic gum (AG) was prepared by mechanical ball milling process to improve the solubility, stability of amorphous state, and bioavailability of IHN, which enhanced the treatment of IHN on hyperlipidemia and nonalcoholic fatty liver disease (NAFLD). The physicochemical properties of IHN/GA/AG SDs in solid state were characterized by differential scanning calorimetry, X-ray diffraction studies, and scanning electron microscopy. The characteristics of the sample solutions were analyzed by reverse-phase HPLC, particle characterization, critical micelle concentration, and transmission electron microscopy. Further pharmacokinetic study of this SD formulation in rats showed a significant 3.3-fold increase in bioavailability compared to pure IHN. Moreover, biomarkers in serum and liver of NAFLD mice were significantly ameliorated after oral administration of IHN/GA/AG SDs for 15 days. Altogether, these results establish the mechanochemically prepared IHN/GA/AG SDs as an efficacious formulation for the treatment of hyperlipidemia and NAFLD.

Synthesis and electrochemical performance of (100-x)Li7P3S11-xLi3SI composite solid electrolyte for all-solid-state lithium batteries

Li7P3S11 (LPS) solid electrolytes have great advantages, such as high lithium-ion conductivity, and can easily fabricate to make bulk-type all-solid-state lithium batteries. However, LPS has a disadvantage because of large interfacial resistance with lithium, which give a limitation for all-solid-state battery. In this study, (100-x)Li7P3S11-x Li3SI (x=0. 2 and 5) solid electrolyte composites are prepared by mechanical ball milling process. Various physiochemical analysis was carried out to confirm the proper mixing of Li7P3S1 and Li3SI solid electrolytes. The addition of Li3SI solid electrolyte, effectively influence the ionic conductivity and electrochemical properties of the Li7P3S1 solid electrolyte. The prepared Li7P3S11/Li3SI solid electrolyte composites are stable against the lithium metal anode even after 100h charge-discharging process and has stable potential window up to 10V. In particular, 98Li7P3S11-2Li3SI solid electrolyte based ASSLBs shows the highest capacity, of 110mA/g at the current density of 7.5mA g−1 (0.05 C). The charge – discharge cycle stability test also proved the Li3SI mixing to Li7P3S11 helped to maintain the capacity retention value of ∼100 % after 10 cycles. Therefore, the Li3SI into the Li7P3S11 electrolyte helps improve the electrochemical performance.

Microstructure and Dielectric Properties of Naturally Formed Microcline and Kyanite: A Size-Dependent Study

The present article reports the crystal defect-mediated changes in electrical characteristics, especially, dielectric properties, of naturally formed microcline and kyanite in two different size fractions. A facile top-down synthesis approach has been adopted to achieve the nanosized samples. Structural and morphological studies have been carried out using X-ray diffraction, field emission scanning electron microscopy, and Fourier transform infrared spectroscopy. Phase purity and microstructural characteristics of the samples were investigated by performing the Rietveld refinement method. Microstructural analysis reveals that the sample size has been greatly reduced to the nano regime after the mechanical ball-milling process, and the milling process eventually introduced some defects in the nanosized samples. UV–vis spectroscopy reveals the optical absorption characteristics and the band gap values of the samples. A major outcome of the present study is the enhancement of the defect states naturally formed samples using the mechanical milling method and the defect-mediated electrical response with varying temperature and frequency. Remarkably high dielectric permittivity values (77.3 × 103 for AF2 and 8.036 × 103 for KY2) in the nanosamples along with low tangent losses and good industrial feasibility of synthesis make the nanosized samples a potential material for fabricating low-cost energy storage devices.

Electrochemical performance of sulfide solid electrolyte Li10GeP2S12 synthesized by a new method

Solid electrolyte Li10GeP2S12 (LGPS) was successfully synthesized by optimizing the mechanical ball milling process and subsequent heat treatment process using Li, Ge, P and S as raw materials. The synthesis method has the advantages of low cost, simple process, short cycle and high efficiency. The synthesized LGPS possesses regular morphology and uniform particle distribution without agglomeration. Simultaneously, it presents a wide electrochemical voltage window of over 6.0 V (vs. Li+/Li), a low activation energy Ea of 25.5 kJ mol−1 and the room temperature conductivity σLi of 3.27 × 10−3 S cm−1. The synthesized LGPS solid electrolyte exhibits good electrochemical stability and compatibility with lithium metal electrodes, making it possible to apply in all solid state batteries.

Low-Cost Raw Materials Synthesized Na 2.9375PS 3.9375Cl 0.0625 Solid Electrolyte

Na3PS4-based materials, which have relatively high conductivities and favorable mechanical properties, make promising Na-ion solid electrolytes for realizing all-solid-state sodium batteries. In this study, Na3-xPS4-xClx solid electrolytes power is prepared by a mechanical ball milling process and subsequent heat treatment process using low-cost Na, NaCl, P2S5 and S as raw materials. In addition, we investigate the conductivity and electrochemical of the composite solid electrolyte with polyethylene oxide-NaClO4. The results show that Na3-xPS4-xClx solid electrolyte heated at 500℃ with polyethylene oxide-NaClO4 exhibits Na-ion conductivity of 8.75×10-4 S cm-1.

Optimization of a nanoparticle ball milling process parameters using the response surface method

Nanocrystalline TiO2-CeO2 powders were synthesized from their TiO2 and CeO2 oxides using mechanical ball milling process. The response surface method is applied to identify optimal parameters for the synthesis of TiO2-CeO2 photocatalyst. Analysis of variance and main effect plot are used to determine the significant parameters and set the optimal level for each parameter. Regression analysis showed good agreement of experimental data with the second-order polynomial model with a coefficients of determination: R2 = 0.991, R2Adj. = 0.940 and R2Pred. = 0.983. Under optimal experimental conditions of TiO2:CeO2 weight percentage ratio 71:29, milling speed 200 rpm, and milling time 115 min the highest photodegradation efficiency was achieved. On the basis of the above statistical analysis, it was found that the band gap energy of TiO2-CeO2 nanoparticles decreases with the increase of the milling speed and milling time with constant TiO2:CeO2 weight percentage ratio. Obtained results suggest that mechanical ball milling process is a rapid, efficient and low energy consumption method to synthesize TiO2-CeO2 photocatalyst.

Ball Milling Synthesis of Silicon Monoxide Anode Materials for Li-Ion Batteries

Li-ion batteries are currently key energy storage devices for various applications such as mobile electronics, electric vehicles, and large-scale energy storage systems. Recently, the global demand for such applications is greatly increasing and in the meantime, high-energy density batteries should be developed to meet the demand. To increase the energy density, the development of high-capacity electrode materials is essential. Currently, graphite is commercially used as anode materials for Li-ion batteries and however, its capacity is limited (theoretical capacity: 372 mAh g­–1). As alternative anode materials, Li-alloy type materials have been intensively investigated to increase the capacity. Among them, Si is one of the most attractive materials because of the high theoretical capacity of 3580 mAh g–1 for Li15Si4 phase. However, it suffers from mechanical degradation caused by large volume change during Li insertion and extraction processes. Recently, silicon monoxide (SiO) materials have attracted great attention due to relatively better cycling stability, which is attributed to the role of oxygen. SiO usually exists in an amorphous form where the oxidation number of Si ranges from 0 to 4. This material can be synthesized by vaporization processes, which is possibly expensive. In this work, SiO materials were prepared by a simple mechanical ball milling process. To improve the electrochemical properties as anodes for Li-ion batteries, carbon incorporation was also performed. The carbon-incorporated SiO materials exhibit the enhanced electrochemical properties.

Biodiesel with nano additives from coconut shell for decreasing emissions in diesel engines

The aim of this work is to decrease emissions in compression ignition engines fueled with diesel and biodiesel blends and also addition of coconut shell (CS) nano particles were prepared by mechanical ball milling process. The organic nano particle was characterized by Transmission Electron Microscopy (TEM), and energy dispersive analysis of X-rays (EDAX) technique. The biodiesel was prepared by using Pungamia pinnata non-edible oil through transesterification process. The average particle size of coconut shell nano particles was found as 20 nm in diameter. Without changing the engine design the performance and emission test was conducted in single cylinder diesel engine with fuels of 100%DF, 20%BD80%DF and 20%BD80%DF with CS.