Ball Milling Treatment Research Articles

Synthesis of titanium oxycarbide in TiO2-C-H2 system

Titanium oxycarbide can be used as a soluble anode to produce sponge titanium in USTB or MER molten salt electrolysis process. However, the key factor of these two processes is to prepare oxycarbide with appropriate C/O ratio and at a low cost as well. This work reported a simple method of preparing titanium oxycarbide from TiO2 in C-H2 system. Based on the prediction of thermodynamic calculations, titanium oxycarbide was prepared successfully at 1400 °C with the molar ratio of TiO2 to carbon exceeding 1:2, and the ideal electrolytic anode (TiC0.5O0.5) was produced at 1400 °C (with a ratio of 1:3 of TiO2 to carbon). Number of parameters (carbon content, temperature, sample's mass, additive (Fe element), and with ball milling treatment) were considered and discussed in the current study. Furthermore, this method can reduce not only the reaction temperature and time, but also the emission of carbon dioxide.

Research on Treatment of Oily Sludge from the Tank Bottom by Ball Milling Combined with Ozone-Catalyzed Oxidation.

Difficult separation of oil–solid phase and high fine content of the recovered oil were two problems in the treatment of oily sludge from the tank bottom by the hot water-based extraction process. To solve the problems, one technology with “ball milling + ozone-catalyzed oxidation” as the core was studied, and the process parameters of ball milling and ozone-catalyzed oxidation were respectively optimized. After ball milling treatment, the oil content of dry oily sludge decreased from 33.9 to 10.2%. Then, an ozone catalytic oxidation treatment technology with aluminum ore as the catalyst was developed to further treat this stubborn oily sludge. Under the optimal conditions, the oil content of oily sludge could be further reduced to 0.28%, which met the treatment and disposal requirements stipulated in GB4284-2018. For further research on the contribution of the catalyst to the ozone catalytic oxidation system, the reaction activation energy and reaction rates of ozone oxidation and ozone catalytic oxidation were compared from the perspective of kinetics. The results showed that, with the catalyst addition, the reaction rate constants increased about three times and the reaction activation energy reduced 82.26%, which showed the effectiveness of the catalyst on the kinetics quantitatively. The combined process with “ball milling + ozone-catalyzed oxidation” as the core can solve the two problems in the treatment of oily sludge from the tank bottom by hot water-based extraction and provides a reference for the harmless and resourceful treatment of oily sludge from the tank bottom.

Surface optimization of detonation nanodiamonds for the enhanced mechanical properties of polymer/nanodiamond composites

The surface of agglomerated nanodiamond (ND) particles was modified with carboxylic acid and ammine moieties using UV/ozone and ball milling methods respectively. The microstructural analysis revealed that the initial agglomerated NDs clusters were predominantly reduced in size with the UV/ozone and ball milling treatments. The UV/ozone and ball mill functionalized NDs were kept for dispersion under observations into ethanol, water and dimethyl sulfonic oxide (DMSO) solvents. The dispersion images satisfactorily showed that all the surface modified NDs samples reveals good dispersion tendency comparatively to pristine NDs whereas, the ball mill treated NDs showed outstanding dispersion behavior rather than all samples. Furthermore, the mechanical properties were investigated using various amounts of surface modified NDs in epoxy matrix. The mechanical properties were checked in terms of ultimate tensile strength (UTS), Percent break strain and Flexural strength. The results of all the mentioned mechanical properties revealed that 0.3 wt% was the optimum amount for getting highest properties. Similarly ball mill treated NDs represented the remarkable enhancements in all mechanical performances comparatively to pristine and UV/ozone treated ND samples.

Study of the Effects Induced by Ball Milling Treatment on Different Types of Hydrocolloids in a Corn Starch-Rice Flour System.

The effects of ball milling treatment on both the structure and properties of guar gum (GG), tara gum (TG), and methylcellulose (MC) were analyzed prior to assessing their potential interactions with starch components when they are used alone or in blends in a corn starch–rice flour system. X-ray diffraction profiles showed that the ball milling caused a reduction in the crystallin domain and, in turn, a diminished viscosity of the GG aqueous solutions. Despite an increase in its viscosity properties, effects on TG were minimal, while the milled MC exhibited reduced crystallinity, but similar viscosity. When both milled and un-milled hydrocolloids were individually added to the starch–flour system, the pasting properties of the resulting mixtures seemed to be affected by the type of hydrocolloid added rather than the structural changes induced by the treatment. All hydrocolloids increased the peak viscosity of the binary blends (especially pure GG), but only milled and un-milled MC showed values of setback and final viscosity similar to those of the individual starch. Ball milling seemed to be more effective when two combined hydrocolloids (milled GG and MC) were simultaneously used. No significant differences were observed in the viscoelastic properties of the blends, except for un-milled GG/starch, milled TG/starch, and milled MC/milled TG/starch gels.

Effect of tantalum on phase transition and thermal stability of metastable tungsten tetra-boride

Decomposition of WB4 into WB2 at temperature higher than 1200 °C makes the preparation of pure bulk WB4 ceramic difficult. Doping of the third element was reported to be an effective way for thermal stability improvement of ceramic materials. In the present work, the nearest element of W, tantalum (Ta), was introduced into tungsten boride synthesized by a combination of high energy ball milling and thermal treatment with (W:Ta):B= (2/3:1/3):4.5 & 5. The phase composition, chemical state of each element, and thermal stability of the as-synthesized samples were investigated. Results show that, with W:Ta molar ratio of 2/3:1/3, ei, 2:1, when the (W + Ta):B = 1: 4.5, about 49.5% mass fraction of WB4 phase was maintained successfully after being thermal treated at 1500 °C for 1 h, compared with pure WB22 phase obatined by the Ta-free sample. Increasing B content in raw materials to (W + Ta):B = 1:5, the mass fraction of WB4 phase was increased to 97%, while the only phase can be detected in the Ta-free samples is also WB2. The significantly improved thermal stability of WB4 can be mainly attributed to the completely dissolve of Ta into the W-B system. It was also found that the oxidation resistance of the W-B system was increased with the introduction of Ta.

High-Yield Production of Few-Layer Graphene via New-fashioned Strategy Combining Resonance Ball Milling and Hydrothermal Exfoliation.

Graphene shows great potential applications in functional coating, electrodes, and ultrasensitive sensors, but high-yield and scalable preparation of few-layer graphene (FLG) by mechanical exfoliation method is still a formidable challenge. In this work, a novel two-step method for high-yield preparation of FLG is developed by combining resonance ball milling and hydrothermal treatment. During the resonance ball milling process, the utilization of magnetic Fe3O4 nanoparticles as a new “particle wedge” is beneficial to facilitate fragment and delamination of graphitic layers. In addition, further hydrothermal treatment can enhance ball milling product (BMP) exfoliation because of the shear force driven by the Brownian motion of various molecules at high temperature and high pressure. As expected, the two-step method can have high exfoliation efficiency up to 92% (≤10 layers). Moreover, the FLG nanosheet ink can easily achieve the formation of FLG coatings on the surface of various substrates, resulting in good electrical conductivity, which possesses potential applications in various fields including functional coating, energy storages, and electrochemical sensors, etc. Our work provides a new-fashioned strategy for mechanical large-scale production of graphene.

Physical modification of Thai rice starch and its application as orodispersible film former

The objective of this study was to investigate the application of the physically modified rice starch (MRS) produced by alcoholic-alkaline (MRS-AA) and planetary ball-milling (MRS-BM) methods as an ODF film former. Rice starch was isolated from Thai rice grain. XRD and ATR-FTIR results confirmed crystallinity loss of MRS. MRS-AA exhibited prominently the greater swelling capacity, whereas MRS-BM exhibited prominently the greater cold water solubility. The starch-based orodispersible films (ODFs) with acceptable film and mechanical properties were successfully prepared using solvent casting method. MRS-based ODFs exhibited the greater flexible behaviors but lower disintegration time compared with the native system. Desloratadine loaded MRS-BM-based ODFs disintegrated within 62.3 ± 23.1 s, with more than 95% dissolution within 10 min. In conclusion, the ball-milling treatment resulted in the preferable MRS suitable for use as an ODF film former. This study therefore provides a glimpse into the use of physically modified starch as an ODF film former.

Electrochemical hydrogen storage behaviors of as-milled Mg–Ti–Ni–Co–Al-based alloys applied to Ni-MH battery

In the study, the hydrogen storing materials Mg–Ni-based Mg50-xTixNi45Al3Co2 (x = 0, 1, 2, 3, 4) + 50 wt% Ni (named Mg50-xTixNi45Al3Co2 (x = 0–4) + 50Ni) with nanocrystalline and amorphous structures were fabricated by the method of mechanical milling and designed for the negative electrode of Ni–MH batteries. The investigation aims at researching the function of Ti dosage on the electrochemical hydrogen storing characteristics and microstructure of the experimental specimens. The analysis of X-ray diffraction profiles and Scanning Electron Microscope images determines that the experiment specimens contain the major phase Mg2Ni and the minor phase MgNi2. The observation of TEM images reveals a fact that the specimens after ball-milling treatment consist of the nanocrystal and amorphism structures. The electrochemical tests show that as for the samples after ball-milling treatment, the discharge capacities of them gain the utmost value at the first circulate without activation treatment, and the increase of Ti dosage brings on an evident rise in the specimens’ discharge capacity and cycle stability. Concretely, as the Ti content alters from 0 to 4, the discharge capacities of the as-milled (20 h) sample increase from 405.0 to 519.4 mAh/g and capacity retention rate of 100th circulate (S100 = C100/Cmax) augments from 45% to 72%. What’s more, a series of measurements, such as the high rate discharge ability (HRD), the electrochemical impedance spectrum (EIS) as well as Tafel polarization curves etc. show that the electrochemical kinetics performances of as-milled specimens in this experiment have a trend of increasing first and then decreasing with the addition of Ti element.

Nanostructured calcium cobalt oxide Ca3Co4O9 as thermoelectric material. Effect of nanostructure on local coordination, Co charge state and thermoelectric properties

The preparation of pure Ca3Co4O9 materials in the form of dense bodies made of nano-sized grains was investigated by combining a sol-gel route, different thermal cycles, a ball-milling post-treatment and final densification with HP-FAST (High Pressure-Field Assisted Sintering). We found that an effective way for obtaining nano-sized compact bodies with only a marginal increase of the particle sizes of the original powder was the operation of HP-FAST at extremely high pressures (up to 430 MPa) and comparatively low temperatures. A ball-milling treatment before HP-FAST compaction was then required to hinder the large plastic deformation occurring when using these pressures. In contrast, un-milled powders could be densified by HP-FAST only at lower pressure and therefore required higher temperatures, thus losing their nanostructure.For all powders, X-ray absorption spectroscopy assessed a mean Co oxidation state slightly higher than III, coupled to absence of localized Co(II) and presence of localized Co(IV). Ball milling induced a decrease of the mean oxidation state of Co coupled to an increased disorder. The latter effect was confirmed by X-ray Absorption Fine Structure.Nanostructure had a complex effect on the different properties of compact bodies. According to the different conditions of HP-FAST, densities of 75–98% were achieved; the decrease in thermal conductivity was of a factor 2–3, while the electronic transport properties – in particular electrical conductivity – of nano-sized compact bodies were reduced to a larger extent with respect to their micro-sized counterparts. This demonstrates that, for bulk Ca3Co4O9 materials, nanostructure was not an effective approach toward a performing thermoelectric material.

Role of ball milling during Cs/X catalyst preparation and effects on catalytic performance in side-chain alkylation of toluene with methanol

Ball milling modification was performed on Cs/X catalysts before or after cesium ion exchange. Multiple characterization results (such as pyridine-FTIR, XPS, and solid-state NMR) demonstrated that ball milling played a distinct role in these two different preparation procedures of the catalyst. Ball milling performed after the cesium modification has a strong influence on the Cs/X structure and acid–base properties, which results in the enhancement of the catalytic performance for side-chain methylation of toluene with methanol. Detailed studies revealed that ball milling intensified the interactions between oxides and molecular sieves, which not only increased the dispersion of the Cs species but also generated some weaker basic centers. It is proposed that the new basic centers could be Si–O–Cs and Al–O–Cs, which are produced by breaking of the Si–O–Al bonds of the zeolite framework under the synergetic effect of ball milling and alkali treatment. These new active sites may help to promote the side-chain methylation reaction. However, excessive ball milling will lead to the vanishing of zeolite micropores, thus deactivating side-chain methylation activity, which indicates that microporosity plays a key role in side-chain methylation and individual basic centers cannot catalyze this reaction.

The inhibitory effect of xylan on enzymatic hydrolysis of cellulose is dependent on cellulose ultrastructure

The inhibitory effect of xylan on enzymatic hydrolysis of cellulose with different ultrastructure is not clear. In this work, cellulose II, cellulose III, and amorphous cellulose were prepared from cellulose I by NaOH, ethylenediamine, and ball-milling treatment, respectively. Their crystalline structure and enzymatic hydrolyzability were systematically characterized and compared with cellulose I. Furthermore, the inhibitory effect of xylan on cellulose with different ultrastructure was investigated in detail. Results suggested that the enzymatic hydrolyzability of different cellulose increased in sequence from cellulose I (25.4%), cellulose III (41.7%), cellulose II (56.2%) to amorphous cellulose (77.4%) at enzyme loadings of 5.56 mg protein/g substrate. The enzymatic hydrolyzability of allomorphic cellulose was strongly inhibited by xylan, while a little inhibition was observed for amorphous cellulose. It was found that cellobiose released from different cellulose was decreased after the addition of xylan. At the initial hydrolysis stage, the inhibition degree was obviously increased for all of different cellulose, and then, the inhibition degree of cellulose I and cellulose II gradually decreased as enzymatic hydrolysis proceeded, while the inhibition degree of cellulose III and amorphous cellulose had changed a little. In addition, at a longer time of hydrolysis, the inhibition degree was decreased with the increase of cellulase dosage except for cellulose III, which remained approximately unchanged. Overall, this study demonstrated that the inhibitory effect of xylan on cellulose hydrolysis was substantially affected by the ultrastructure of cellulose, and thus it provides new insights for relieving the inhibitory effect of xylan by altering the ultrastructure of cellulose.

High yield solvent extraction of hydrothermal and ball-milling treated lignin prior to enzymatic hydrolysis for co-valorization of lignin and cellulose in Miscanthus sacchariflorus

A lignin extraction procedure was developed for improving extraction yield, mitigating structural changes, and retaining depolymerization performance of the lignin fraction from hydrothermal and ball-milling treated miscanthus. The remaining residues after the lignin extraction process were subjected to enzymatic hydrolysis for evaluating the possibility of producing fermentable sugars. The extraction yield was improved by a factor of 5 due to hydrothermal treatment, and its extract contained approximately 50 g/L of total phenolic compound. The high molecular weight lignin fraction (Mw: 5640–6850 Daltons) was highly dissolved in 80% and 96% dioxane solution, but the low molecular weight part (Mw: 4170–5270 Daltons) was detected regardless of conditions. The major depolymerization products of HML are 4-vinylphenol (6.6 mg/g) and 2-methoxy-4-vinylphenol (4.3 mg/g). 90% of glucose yield was obtained after enzymatic hydrolysis of the extraction residue. Overall, both yields of lignin extraction and enzymatic hydrolysis of residue were improved by combining hydrothermal and ball-milling treatment and changing the solvent combination.

Wafer-like FeSe2-NiSe2/C nanosheets as efficient anode for high-performances lithium batteries

Owing to the high-energy capacity and safety characteristics, transition metal selenides are considered as the promising anode materials for lithium-ion batteries, which has aroused widespread interest in recent years. Thus FeSe2-NiSe2/C multi-layer sheets (FNMS@C) are prepared after hydrothermal process and ball-milling treatment. The layers with large surface area provide low Li-ion diffusion energy barrier to achieve long-cycle and high energy. The FNMS@C electrode shows an excellent rate performance. Moreover it delivers a high reversible capacity of 700.5 mAh g−1 after 100 cycles at 1 A g−1.

Mössbauer spectroscopy studies on the particle size distribution effect of Fe–B–P amorphous alloy on the microwave absorption properties

An Fe-based nanocrystalline alloy powder is important for application in microwave absorption, and the particle size has a critical impact on the electromagnetic microwave parameters. Therefore, it is necessary to study further the effects of the particle size on such parameters and improve the microwave absorption performance of Fe-based nanocrystalline powers. In this study, Fe–B–P particles were prepared through a synthetic approach consisting of an aqueous chemical reduction and a ball milling treatment. We investigated the effects of ball milling on the microstructure and electromagnetic properties of Fe–B–P particles. The experimental results indicate that the Fe–B–P particles synthesized through an aqueous chemical reduction are amorphous spheres. Fe–B–P particles with an original particle size of 200–1200 nm can be milled into an irregular shape with the size reduced to < 500 nm after 0.5 h of ball milling, and subsequently, the particles become smaller with increases in the milling time, with traces of Fe2O3 generated on the particle surface. The results of the Mossbauer spectra show that a portion of the small particles demonstrate a superparamagnetic property. The volume proportions of the superparamagnetic component increase from 13.1 to 15.8% as the treatment time increases. We measured the permittivity and permeability spectra of Fe–B–P particles within the frequency range of 2–18 GHz. The reflection loss (RL) is − 10 dB for an absorber thickness of 1.7–5.0 mm. The RL is − 20 dB for an absorber thickness of 1.9–2.7 mm. The microwave absorption properties of samples with the same thickness are improved with an increase in the treatment time and are shifted to a higher frequency, which will broaden the bandwidth of the absorption as well.

Engineered phosphorous-functionalized biochar with enhanced porosity using phytic acid-assisted ball milling for efficient and selective uptake of aquatic uranium

The efficient extraction of uranium is challenging for radioactive wastewater treatment. Concerning to the specific coordination of functional groups with radionuclides, the development of ideal sorbents with high surface area, enhanced porosity and abundant functional groups compatibly to uptake uranium selectively is of great significance. Biochar, an attractive material to concentration aquatic targets, exhibits a positive correlation of surface area and pore volume of biochars with pyrolysis temperature, whereas a negative relation of surface functionality with thermolysis temperature. Here we applied a facile and environmental-friendly ball-milling technique to engineer raw biochars in the presence of phytic acid. Ball-milling treatment increased the external surface area of biochars by reducing grain sizes, as well as enhanced the micropore surface area by exposing blocked micropore networks. P-containing moiety was grafted to the surface of biochar matrix successfully. The physicochemical characteristics of biochars enabled a high uptake capacity (128.5 mg/g) and favorable selectivity of U(VI). It suggested that ball-milling of raw biochars with activating solvents could achieve an excellent performance for the efficient concentration of aquatic uranium.

Confinement of Mg Nanoparticles by Bituminous Coal and Associated Synergistic Hydrogen Storage Effect

Using the coking property of bituminous coal, a nanostructured Mg-C composite hydrogen storage material was developed by ball milling and heat treatment. The heat treatment conditions and hydrogen storage behavior of the composite material were investigated. Results show that when the material is heat-treated at 550 °C under Ar atmosphere, the carbon could react with Mg to irreversibly form Mg2C3. When 1.0 MPa H2 was introduced to the heat treatment at 550 °C, the magnesium does not form Mg2C3. The resulting composite material is shown to have a globular bonded structure by scanning electron microscopy, and the Mg nanoparticles are confined by the bituminous coal. Fourier transform infrared spectroscopy and gas chromatography analysis show that the carbon could combine with hydrogen only in the presence of MgH2 under current experimental conditions. The carbon-bonded hydrogen would be released in the form of small molecule hydrocarbons such as CH4, C2H4 and C2H6. Dynamic tests show that coal carbon and magnesium absorb/desorb hydrogen at similar temperatures, which proves that there is a synergistic hydrogen storage effect between magnesium and coal carbon.

Effect of Ball Milling Treatment on Thermal, Structural, and Morphological Properties of Phosphated Starches from Corn and Pinhão

AbstractIn the previous study, the effect of chemical modification with sodium tripolyphosphate on the properties of corn and pinhão starches was evaluated. However, physical modifications also confer specific characteristics on the starch, diversifying its application. Thus, in this study, thermal (thermogravimetry [TG], differential exploratory calorimetry [DSC]), structural (X‐ray powder diffractometry [XRD], Fourier‐transform infrared [FTIR]) and morphological (field emission gun‐scanning electron microscopy) properties of native and phosphated corn and pinhão starches are evaluated before and after ball milling treatment. In addition, wavelength dispersive X‐ray spectroscopy is applied as a new technique to measure the level of phosphorus and sodium. The incorporation of phosphate groups in starches is confirmed and phosphorus and sodium are reduced after milling. The doubly modified starches show lower moisture retention capacity and lower thermal stability. All treatments reduce the gelatinization enthalpy mainly for double modified starches. Relative crystallinity is drastically reduced after the double modification. Changes in FTIR results are more pronounced after the physical treatment, corroborating with DSC and XRD results. Morphological changes are observed only in the milled samples. Thus, the double modification confer greater changes compared to the isolated modifications.

Operando Observations of Reversible α-BiF3 Conversion in Liquid Electrolyte by Synchrotron Radiation Diffraction and 7Li Nuclear Magnetic Resonance

The electrochemically-driven conversion reaction of BiF3 with Li+ ions is of interest for potential application as a positive electrode system in conversion type rechargeable batteries. Here, we use synchrotron radiation diffraction and 7Li nuclear magnetic resonance (NMR) for complementary operando observations of reversible or quasi-reversible conversion reactions of α-BiF3 nanocomposite electrode at room temperature. The nanocomposite electrode was fabricated by ball milling and subsequent heat treatments. A pronounced XRD peak broadening indicated a disordered fine crystalline state in the electrode. The operando synchrotron radiation diffraction measurements revealed a quasi-reversible smooth crystallographic transformation between α-BiF3 and metallic Bi. The operando 7Li NMR measurement quantitatively showed reversible conversion reactions. The series of in-situ 7Li NMR spectra contained sharp signals from Li+ ions in the electrolyte and a broad signal associated with a solid phase of LiF. These signals followed a stoichiometric relationship that conformed to a three-electron BiF3 conversion pathway.

Energy grass/polylactic acid composites and pretreatments for additive manufacturing

The aim of this study was to find the effect of ball-milling pretreatment of silvergrass and comparing the effects of pretreatment on common lignocellulosic materials such as reed, switchgrass and pennisetum to evaluate the potential of raw materials for additive manufacturing. The size of ball-milled material was much smaller than the nozzle diameter of the 3D printer and the melting point of composite was lower than that of pure PLA according to differential scanning calorimetry. The structure of the surface became smoother distinctly and biomass dispersed better in PLA matrix after ball-milling based on scanning electron microscopy. X-ray diffraction results showed that the ball-milling treatment influenced the performance of the composite by destroying the crystalline region and increasing the amorphous region of raw materials. Besides, the PLA/silvergrass composites possessed better mechanical properties of tensile strength, Young’s modulus and impact strength of 23.1 MPa, 652.9 MPa and 38.67 kJ/m2, respectively. Compared to the composites that were prepared by alkali-H2O2 (AH) and by steam explosion (SE) treatment, the composite that was prepared by acid treatment (AT) exhibited higher tensile strength, Young’s modulus and impact strength of 26.94 MPa, 720.36 MPa and 40 kJ/m2 respectively. Silvergrass/PLA composite shows better thermal stability compared to pure PLA for additive manufacturing. Moreover, AT works as a promising pretreatment method in promoting the properties of wood-plastic composite compared to UT (untreated), AH and SE. The silvergrass/PLA composite could be used for additive manufacturing after ball-milling combined with AT.

Upcycling strategy of grinding swarf by supersolidus liquid phase sintering

Abstract Machining is an important process in the metalworking industry. All machining operations, like milling, turning or grinding, generate large amounts of waste products. Due to the limited resources, it is necessary to find a working recycling strategy and to close the loop in the circular economy. However, there is no recycling strategy for grinding waste. This could be explained by the composition of the grinding waste, called grinding sludge. Therefore, this research deals with the upcycling of the grinding swarf in a PM process. The grinding swarf are characterized by SEM and XRD and processed by a ball mill treatment and a Supersolidus liquid phase sintering process.