Ball Milling Treatment Research Articles

Effect of demineralization and ball milling treatments on the properties of Arundo donax and olive stone-derived biochar

The structural and physio-chemical properties of biochar are crucial to determining biochar’s quality and the adequate application. Specifically, the large porosity of biochar has been known as a favorable feature, especially for environmental remediation. In this regard, physical and chemical modifications have been used to improve biochar’s porosity which requires high-energy consumption and involves chemical agents. The objective of this study was to prepare biochar with developed porosity using mild treatments. Arundo donax and olive stone were demineralized by a water-washing method. Treated and non-treated biomasses were pyrolyzed, and part of the derived samples was subjected to wet ball milling. Samples were characterized with proximate, Fourier transform infrared, particle size, and physisorption analyses. The effect of demineralization depended on the biomass type, as ash reduction only influenced Arundo donax-derived biochar, which was attributed to the difference in initial ash content that was relatively low for olive stone. The carbonization yield decreased by 46% for the Arundo donax biomass after demineralization. Moreover, demineralization expanded the surface area and total pore volume of the Arundo donax biochar. The ball milling was effective in producing micro-sized biochar particles with a mean size ranging between 30 ± 2 µm and 42 ± 2 µm and between 13 ± 1 µm and 22 ± 2 µm for Arundo donax and olive stone without and with demineralization, respectively. Ball milling increased the surface area of non-demineralized Arundo donax by 47% and demineralized Arundo donax by 124%. Additionally, ball milling increased the surface area of non-demineralized olive stone by 65% and demineralized olive stone by 62%.Graphical abstract

Ball milling treatment of Mn3O4 regulates electron transfer pathway for peroxymonosulfate activation

Heterogeneous metal catalysts have attracted considerable interest in advanced oxidation processes (AOPs) for wastewater treatment by activating peroxymonosulfate (PMS). However, it remains challenging to the rational design of efficient reaction pathway for high-performance contaminants removal by regulating the inherent structure of metal oxides. Herein, a high-energy ball milling method was employed to modulate the electronic structure of hausmannite (denoted as BM Mn3O4), which achieved the switching of singlet oxygen into electron transfer process (ETP)-dominated activation of PMS for efficient removal of bisphenol A - an emerging organic pollutant. The reaction pathway was evidenced through galvanic oxidation process, electrochemical techniques, and in-situ Raman spectroscopy, confirming the electrons transferred from pollutants to metastable PMS* complex with BM Mn3O4 serving as electron shuttle. The ETP mechanism was verified to be closely correlated with decreased eg occupancy of Mn in BM Mn3O4, offering high spatial overlapping with O 2p orbital in PMS for generating PMS* complex. Benefitting from the fine-tuned ETP, BM Mn3O4/PMS system showed enhanced intrinsic activity, higher PMS utilization efficiency, and practical applicability for selective oxidation of electron-rich pollutants. This study provided new insights into rational design of reaction-oriented catalysts for environmental engineering.

Deformation type during the ball milling process: A comparative study of the microstructures formed by ball milling, uniaxial compression, and rolling

The plastic deformation type of metal during ball-milling treatment has not yet been unveiled due to the difficulty in direct observation, and it is also difficult to clarify the deformation behavior even by numerical simulations. A comparative study of the effects of lubrication on the microstructure induced by ball-milling, compression, and rolling was con. Ducted to reveal the deformation type. The deformed flake particle showed a uniform microstructure for the ball-milling treatment with a lubricant. By contrast, the closer the particle surface, the finer the crystal grains were for the treatment without a lubricant. These microstructural features on the ball-milled iron particles were observed in rolled iron sheets, and the effects of the lubricant on the microstructure induced by compression were the opposite. Therefore, we conclude that the type of ball-milling-induced deformation is close to rolling, considering the similarity of the effect of the lubricant on the microstructures.

Characterization of Cellulose Fibers According to Cellulase-Active Microbial Pretreatment

This study evaluated the effects of microbial (Bacillus subtilis, Bacillus licheniformis) pretreatment and mechanical (ball mill) treatment on the nanofibrillation of cellulose. The optimal growth conditions were identified a B. subtilis (pH 6-8, 25℃ and 100 rpm) and B. licheniformis (pH 7, 35℃ and 150 rpm), respectively. As a result of evaluating microbial reducing sugar production from carboxymethyl cellulose, B. subtilis case showed similar trends at most experimental conditions (pH, temperature and rpm) except for pH 5. The maximum amount of reducing sugar by B. licheniformis was achieved at the culture conditions with pH 7, 35℃ and 150 rpm. There was no change in the crystalline structure of cellulose by ball mill and microbial treatment, but, XRD peaks intensity decreased. Cellulose nanofibers were observed after 6 hours ball mill treatment of alpha cellulose with/without the microbial pretreatment. When applying microbial pretreatment, the cellulose nanofibers produced by the ball mill had more longer in length than those without the pretreatment.

Development of high-efficiency microwave absorption properties of La1.5Sr0.5NiO4 and SrFe12O19-based materials composites

Electromagnetic interference (EMI) and electromagnetic (EM) pollution have gained worldwide attention. High-efficiency microwave absorbing materials (MAMs) as composites with two components of dielectric materials and magnetic materials could be employed to mitigate the undesirable effects of EMI and EM pollution due to their good impedance matching. MAMs have been used for energy harvesting, 5G, information security, reduced radar cross-section, and military technology. La1.5Sr0.5NiO4 (LSNO) and SrFe11.9Cu0.025Co0.025Ti0.05O19 (CCT-SrM5) composites were successfully prepared by ball milling and heat treatment. Structural, morphological, and static magnetic properties significantly changed with the increase of CCT-SrM5 volume in the composites. The compositing also enhanced the EM properties, which resulted in the excellent microwave absorption properties of the composites. The sample of only the LSNO phase (named LS0) showed poor microwave absorption with a minimum reflection loss (RL) of –16.85 dB at 6.96 GHz for t = 6.00 mm. The RL values remarkably increased with the introduction of CCT-SrM5 to the composites. The composites with 60% volume of CCT-SrM5 (LS6) reached a minimum RL of –48.91 dB at 16.96 GHz for a thickness of only 1.75 mm. While the composites with 20% volume of CCT-SrM5 (LS2) had an effective absorption bandwidth (EAB) value of 16 GHz for t = 2.00 mm, which covered all the measured frequency ranges. The achievement of intense RL and ultra-wide EAB values for LSNO/CCT-SrM5 composites proved that these composites were beneficial for practical applications.

A green process for producing xylooligosaccharides via autohydrolysis of plasma-treated sugarcane bagasse

Due to alarming energy consumption and population growth, the transition to a circular economy is being pursued by searching for alternative resources to produce chemicals and energy. In this regard, lignocellulosic biomass, as the most abundantly accessible plant material, is a suitable alternative for satisfying this high demand. Sustainable lignocellulose biorefineries could convert cellulose, hemicellulose, and lignin into high-value products. Most available approaches prioritize cellulose and lignin over hemicellulose. In this work, autohydrolysis treatment of sugarcane bagasse is developed to produce xylooligosaccharides (XOS) with a variable degree of polymerization (2−6) using low-temperature atmospheric-pressure plasma and ball-mill treatment on raw bagasse. The reactive oxygen, ozone, hydronium ions (H3O+), and nitrogen species generated by plasma increase hemicellulose conversion. XOS hydrolysate obtained from plasma pre-treated samples (41.1%) was quantified for xylobiose (12.1%), xylotriose (10.1%), xylotetrose (6.9%), xylopentaose (7.1%), and xylohexaose (4.9%) (6 h of autohydrolysis at 135 °C). Xylan hydrolysate was also yielded 21.2% xylose, and 2.2% furfural, respectively. The entire process (plasma and autohydrolysis) was conducted in water without using any other chemicals. These results suggest the potential role of plasma pre-treatment prior to hydrothermal treatments to selectively produce XOS.

Effect of Ball Milling Treatment on Compositional Gradients in Functionally Graded Materials Fabricated by Centrifugal Slurry Methods

Ceramic-metal functionally graded materials (FGMs) are advantageous to two dissimilar materials joined directly together, which includes smoothing of thermal stress distributions, minimization or elimination of stress concentrations and singularities at the interface corners and increase in bonding strength. In this study, ZrO2/ 304 stainless steel (SUS304) FGMs with continuous gradient manners, not stepwise manners, were fabricated by a combination of centrifugal slurry methods and spark plasma sintering (SPS). The size and surface smoothness of the powders of SUS304 highly affected formation of compositional gradient patterns in the FGMs. Effects of ball milling time and ball sizes on such conditions of the powders as well as compositional gradients in the FGMs were investigated by microstructure observations with element analysis and hardness probing on the cross sections of the FGMs.

Study on electromagnetic wave absorbing properties of nanocrystalline Fe81.5Si3B9P3C1Cu1Ti1.5/Graphene oxide composite

To prevent and control electromagnetic pollution problems, there is an urgent need to develop better wave-absorbing materials. In this study, nanocrystalline alloy/graphene oxide(GO) composite modified powder was obtained on the basis of Fe81.5Si3B9P3C1Cu1Ti1.5 nanocrystalline alloy powder with different weight percentages of GO, which was mechanically mixed by high-energy ball milling treatment, and the microstructure and morphology of the materials and the electromagnetic wave absorption properties were characterized. The results show that the Fe81.5Si3B9P3C1Cu1Ti1.5/GO composite powder has excellent wave absorption performance, and the loss mechanism is magnetic loss including eddy current loss and natural resonance. Defects and groups in GO not only improve the impedance matching characteristics, but also introduce defect polarization relaxation and electron dipole polarization relaxation of the groups, which are beneficial to the penetration and absorption of electromagnetic waves. The minimum reflection loss (RLmin) of the nanocrystalline alloy powder can reach −37.55 dB and the maximum effective absorption bandwidth (ΔfRL<-10dB) can reach 5.95 GHz; the RLmin of the composite powder is as high as −52.55 dB when the GO content is 1.5 wt%, and the widest bandwidth can reach 6.12 GHz at 2.00 mm when the GO content is 0.5 wt%. With the addition of GO, its RLmin increased by 40%. This indicates that the composite material have superior absorption performance compared to a single absorber.

Facile synthesis of C, N, P co-doped SiOx as anode material for lithium-ion batteries with excellent rate performance

SiOx has high specific capacity for lithium-ion batteries, but the rate and the cycling performances need to be further improved to satisfy the needs of the future. In this study, the C, N, P doping SiOx/G@CNP anodes are prepared by a facile ball milling and heat treatment process. The electrochemical performances of SiOx are improved by the synergistic effect of C, N, P doping. The SiOx/G@CNP-2 anode with the addition of 20 wt% phytate shows the best electrochemical performances and maintains a specific capacity of 77.45% after 150 cycles at 0.2 A·g−1. Importantly, it exhibits a remarkable rate performance with specific capacities of 528.2 mAh·g−1 and 370.0 mAh·g−1 even at 3.0 and 5.0 A·g−1, respectively. Artificial graphite and the carbon shell formed by the thermal decomposition of citric acid contribute to the structural stability of SiOx and improve the cycling performance of the material. Moreover, the addition of P element and high content of pyridine N accelerates the rate of Li+ deintercalation, and the conductivity and ion diffusion coefficient of the material are effectively promoted, thus greatly improving the rate performance of the material. This work presented herein provides a simple and feasible method for the preparation of high-performance anode materials.

Ball Milling Treatment of Nb and B Nanoparticles Modified TiAl4822 Composite Powder and Its Effect on Powder Bed Quality and Powder Spreadability in Additive Manufacturing

Ball milling treatment is a low‐cost and achievable large‐scale production method for preparing the composite powder used for the laser powder bed fusion (LPBF) process. For the ball‐milled composite powder, good powder spreadability and composition homogeneity are essential for obtaining the LPBF‐fabricated part with good forming quality. In this article, the Nb and B nanoparticles modified TiAl4822 composite powder with a nominal composition of Ti‐47.53Al‐1.98Cr‐2.81Nb‐0.15B are prepared via ball milling. It is found that the physical properties of the composite powder are more sensitive to the milling time than the milling speed and ball‐to‐powder ratio. Long‐time milling is inclined to cause the formation of broken particles, poor powder flowability, and high oxygen contamination. Besides, the process maps between the ball milling energy E t and particle size distribution width, the static angle of repose, composition inhomogeneity, and oxygen content are established, respectively. Results show that when the applied E t is insufficient or excessive, the degree of sphericity or composition homogeneity always worsens. In these cases, deposition defects such as line or area defects are more prone to occur, due to the enhanced particle rearrangement resistance induced by the addition of nanoparticles.

Flowability, binding and release property of “self-lubricating” microcrystalline cellulose

Microcrystalline cellulose (MCC) has been widely used as an excipient in tablets. Silicified microcrystalline cellulose (SMCC) has more application than MCC by using silicon dioxide (SiO2) as a lubricant. However, findings show that the silicon dioxide (SiO2) nanoparticle component is a physiological hazard. In our research, “self-lubricating” microcrystalline cellulose (MCC) was developed by a ball-milling treatment. Commercial MCC and undried MCC with 60% or 80% moisture content were ball-milled for 12 or 24 h. After ball milling, ellipsoid-like particles, with wrinkled surfaces, and a broader particle size distribution resulted in a balance between the flowability and tabletability of the treated MCC. FTIR and XRD analysis showed that cellulose Ⅱ was formed in the undried 60% moisture content MCC after ball milling for 12 or 24 h, which improved the burst disintegration ability of the tablets. In addition, the controlled-released MCC has also been developed. AFM patterns and the angle of repose showed a cohesion phenomenon and some bridges formed between particles of undried 80% moisture content MCC ball-milled for 12 h. Without adding SiO2, our MCC gained improved binding properties, a balance between flowability and tabletability, and a more useful controlled-released ability compared with commercial MCC and SMCC.

Highly Selective Reduction of Nitrate by Zero-Valent Aluminum (ZVAI) Ball-Milled Materials at Circumneutral pH: Important Role of Microgalvanic Cells for Depassivation of ZVAl and N2-Selectivity.

The passivation of zero-valent aluminum (ZVAl) limits its application in environmental remediation. Herein, a ternary composite material Al-Fe-AC is synthesized via a ball-milling treatment on a mixture of Al0, Fe0, and activated carbon (AC) powders. The results show that the as-prepared micronsized Al-Fe-AC powder could achieve highly efficient nitrate removal and a nitrogen (N2)-selectivity of >75%. The mechanism study reveals that, in the initial stage, numerous Al//AC and Fe//AC microgalvanic cells in the Al-Fe-AC material could lead to a local alkaline environment in the vicinity of the AC cathodes. The local alkalinity depassivated the Al0 component and enabled its continuous dissolution in the subsequent second stage of reaction. The functioning of the AC cathode of the Al//AC microgalvanic cell is revealed as the primary reason accounting for the highly selective reduction of nitrate. The investigation on the mass ratio of raw materials manifested that an Al/Fe/AC mass ratio of 1:1:5 or 1:3:5 was preferable. The test in simulated groundwater suggested that the as-prepared Al-Fe-AC powder could be injected into aquifers to achieve a highly selective reduction of nitrate to nitrogen. This study provides a feasible method to develop high-performance ZVAl-based remedial materials that could work in a wider pH range.

Effects of shear emulsifying/ball milling/autoclave modification on structure, physicochemical properties, phenolic compounds, and antioxidant capacity of lotus (Nelumbo) leaves dietary fiber.

Lotus (Nelumbo) leaves are rich in polyphenols and dietary fiber, which have the potential as a high-quality fiber material in functional food. However, lotus leaves exhibit dense structure and poor taste, it is vital to develop appropriate modification methods to improve the properties of lotus leaves dietary fiber. In this study, the effects of three modification methods with shear emulsifying (SE), ball milling (BM), and autoclave treatment (AT) on structure, physicochemical properties, phenolic compounds, and antioxidant capacity of lotus leave dietary fiber (LDF) were evaluated. SEM indicated that there were significant differences in the microstructure of modified LDFs. FT-IR spectra and X-ray diffraction pattern of modified LDFs revealed similar shapes, while the peak intensity and crystalline region changed by modification. SE showed the greatest effect on crystallization index. SE-LDF had the highest water holding capacity, water swelling capacity, and bound phenolic content in LDFs, which increased by 15.69, 12.02, and 31.81%, respectively, compared with the unmodified LDF. BM exhibited the most dramatic effect on particle size. BM-LDF had the highest free phenolic and total phenolic contents in LDFs, which increased by 32.20 and 29.05% respectively, compared with the unmodified LDF. Phenolic compounds in LDFs were mainly free phenolic, and modifications altered the concents of flavonoids. The BM-LDF and SE-LDF exhibited higher antioxidant capacity than that of AT-LDF. Overall, SE-LDF showed better physical properties, and BM-LDF showed better bioactive components. SE and BM were considered to be appropriate modification methods to enhance the properties of LDF with their own advantages.

Highly thermally conductive polymer-based composites with 3D exfoliated BNNS/functionalized SiC networks prepared by rapid solidification and hot pressing

High thermal conductivity polymer-based packaging materials can achieve effective heat diffusion, which is of great significance for the performance and longevity of electronic devices. Exfoliated boron nitride nanosheets (s-BNNS) containing smaller particle sizes, fewer layers, and more hydroxyl groups were prepared by ball milling and strong ultrasonic treatment in this work. The functionalized SiC (m-SiC) was obtained by ternary blend organic silanol modification, which promoted the compatibility between fillers and fillers, as well as fillers and matrix. By a facile strategy of rapid solidification and hot pressing, s-BNNS were distributed between and on the surface of m-SiC fillers to form m-SiC/s-BNNS/polyamide 6/polyethylene terephthalate (PA6/PET) composite films with 3D thermally conductive networks. The thermal conductivity of m-SiC/s-BNNS/PA6/PET composite reached a superior 6.98 W/(m·K) at a filler loading 85 wt%, which was 124.67% higher than that of SiC/PA6/PET composite without 3D thermal network formation. More interestingly, reverse non-equilibrium molecular dynamics (RNEMD) simulations show that the hybrid SiC/BNNS filler greatly reduces the porosity within the composite compared to only one kind of filler, which in turn improves the composite's thermal conductivity.

Ordered-Range Tuning of Flash Graphene for Fast-Charging Lithium-Ion Batteries

Graphene has yet to be mass produced, so practical fast-charging lithium-ion battery (LIB) prototypes based on graphene are scarce. Graphene suffers from long in-plane and reluctant in-depth lithium diffusion due to its defect-free atomic arrangement, resulting in unsatisfactory rate performance as LIB anodes. In this work, combinatorial flash joule heating and ball milling treatment are implemented to enable gram-scale production of graphene in seconds (known as flash graphene, FG) and in-plane ordered-range modulation of graphene architectures. Following the ball milling, the defect-deficient turbostratic FG is transformed to defect-rich cracked FG (CFG), which has shortened ordered ranges and larger interlayer spacings. The CFG anode outperforms FG, commercial carbon black, and graphite electrodes in terms of specific capacity and rate performance due to open channels and shortened pathways for Li+ transport. Moreover, it shows outstanding cycling stability with a high capacity retention of 99% at the 500th cycle. Furthermore, it works well with the LiFePO4 cathode, enabling fast-charging LIB full battery with a state of charge of 77 and 62% at 2C and 4C, respectively. This research on graphene production and structural engineering provides a practical application for the commercial potential of fast-charging LIBs.

Cathode Properties of xLiF–LiCrO2 Composites (x = 0–1.5) Prepared by Dry Ball-Milling Method for Lithium Ion Batteries

The xLiF–LiCrO2 series, prepared using the dry ball-milling method, was investigated to improve the electrochemical properties of LiCrO2. The addition of LiF to LiCrO2 changed the Cr oxidation state, and its rechargeable capacity increased to greater than that of milled-LiCrO2. The Li–O(F) correlation for xLiF–LiCrO2 was split in two by the dry ball-milling treatment, unlike the case with layered LiCrO2. In addition, the dispersion state of Li and Cr in the particles changed, and part of the Cr oxidation state shifted from +3 to +4 with the addition of LiF to LiCrO2. The reversible capacity increased with increasing x in xLiF–LiCrO2 at x ≤ 0.7, and the number of reacted electrons increased with increasing x in xLiF–LiCrO2. Cr K-edge and L-edge XANES spectra clarified that the charge–discharge reaction for milled-LiCrO2 and xLiF–LiCrO2 proceeds by only Cr3+/Cr6+ redox couples.

Structural conversion and characterization of Camellia oleifera shell lignin based on mechanochemical-assisted pretreatment

Camellia oleifera shells (COS), are the by-product of Camellia oleifera seed oil processing, and possess a high lignin content (38.6%). However, information on the fundamental chemistry of this lignin is limited. Herein, mechanochemical strategies combining ball-milling with mild acetosolv or alkaline treatment are presented to compare the structural evolution of COS lignins. The mechanochemical processes significantly improve the lignin yield, releasing lignins with high molecular weights (Mw ≈ 7000 mol/g). The COS lignins are GS-type lignins, and G units account for 71.9% of MWL. The synergistic combination of ball-milling and acetosolv treatment led to the cleavage of β-O-4 linkages. In contrast, the alkaline lignin fractions retained a large number of β-O-4 linkages (50.67/100 Ar) and a low phenolic OH content (1.56 mmol/g), indicating that the ball-milling process had little effect on the alkaline lignin structures (typical substructures). In summary, understanding the structural conversion and characteristics of lignins during the combined pretreatments of COS would facilitate the optimization of the pretreatment process and the deconstruction of COS.

Effect of ball milling and solid solution treatment on the microstructure and interfacial behaviors of ZrMgMo3O12p/2024Al composites

ZrMgMo3O12 is a negative expansion material, while 2024Al alloy is a positive expansion material. The difference in thermal expansion coefficients between them will cause thermal mismatch stress at the interface in ZrMgMo3O12p/2024Al composites. Therefore, the interface behaviors of ZrMgMo3O12–Al determine the properties of ZrMgMo3O12p/2024Al composites to a great extent. The effects of ball milling and solid solution treatment on the microstructure and interface behaviors of 10 vol% ZrMgMo3O12p/2024Al composites were studied to improve the reticular microstructure of ZrMgMo3O12 distributed at the grain boundary of the α-Al matrix. The results showed that with increasing milling energy, the microstructure of the composites changed from reticular to equiaxed, and the distribution of ZrMgMo3O12 reinforcements in the matrix was more uniform. The content and size of the primary phase Al2Cu decreased with increasing solid solution treatment time. In addition, only ZrMgMo3O12–Al, Al2Cu–Al12Mo and Al–Al12Mo interfaces can be observed, but it is difficult to observe the interfaces of ZrMgMo3O12–Al12Mo in the composites milled for 12 h and solution treated for 24 h, which is related to the decomposition mechanism of ZrMgMo3O12. The decomposition mechanism is as follows: Al atoms from the α-Al matrix captured O atoms from ZrMgMo3O12 to form Al2O3. ZrMgMo3O12 simultaneously released Mo, Zr and Mg atoms. Mo atoms were enriched and nucleated in situ and precipitated with Al atoms to form the intermetallic compound Al12Mo, while Zr and Mg atoms entered the α-Al matrix to form a solid solution.

Tensile strength and anisotropy of repeated hot-rolled carbon nanotube/aluminum matrix composites

This study aims to strengthen carbon nanotube (CNT)/Al composites, which were fabricated by a combination of spark plasma sintering (SPS) and repeated hot rolling techniques. Dry ball milling was conducted to uniformly disperse CNT in Al powders. The microstructures of the CNT/Al composites including dispersibility of CNT were observed using a scanning electron microscope (SEM) and transmission electron microscope (TEM). Ball milling treatments promoted to reduce the number of CNT aggregations and increase C concentrations in the CNT aggregations in the composites. Anisotropic tensile behavior was also investigated, which demonstrated that the post-SPS repeated hot rolling can highly enhance the tensile strength as well as deformability of the composites.

Structure optimization and electrolyte regulation boost K-storage performance of graphite anode

Modified graphite (MG) with rough edges and reduced crystal particles is developed via ball-milling treatment for commercializable K-storage anode. Importantly, rational electrolyte regulation significantly improves the reaction dynamics as well as reversibility of potassiation/depotassiation behaviors, resulting into a high and stable reversible capacity of 277 mA h g−1 at 200 mA g−1 after 250 cycles in the optimized 3 M KFSI/EC + DEC electrolyte. The enhanced K+-solvents interaction with aggregates (AGGs)-rich solvated structures is revealed to be responsible for the excellent K-storage performance. Furthermore, electrolyte flammability evaluation confirms the remarkably suppressed flammability of the optimized 3 M KFSI/EC + DEC, providing enough security for practical applications of PIBs.