scholarly journals Studying the Influence of Mica Particle Size on the Properties of Epoxy Acrylate/Mica Composite Coatings through Reducing Mica Particle Size by the Ball-Milled Method

Coatings ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 98
Author(s):  
Yaling Da ◽  
Jianxing Liu ◽  
Zixian Gao ◽  
Xiangxin Xue

In this work, a series of epoxy acrylate (EA)/mica composite coatings were synthesized through introducing mica powders of different particle size into epoxy acrylate coatings and using an ultraviolet (UV) curing technique to investigate the influence of mica particle size on the coatings. Mica powders of different particle sizes were obtained by ball-milling for 4, 8, 12, 16, and 20 h with a planetary high-energy ball mill. The particle size and morphologies of ball-milled mica powders were characterized by laser particle size analyzer and scanning electron microscopy (SEM). The results indicated that planetary ball-milling reduced the particle size of mica powders effectively. Mica powders that were un-ball-milled and ball-milled were added into the epoxy acrylate matrix by a blending method to synthesize the organic-inorganic UV curable coatings. The optical photographs of the coatings showed greater stability of liquid mixtures with smaller particle size fillers. The chemical structures of EA/mica composite coatings were investigated by Fourier transform infrared spectroscopy (FTIR), and the conversion rate of C=C bonds was calculated. The results indicated that the C=C conversion of coatings with mica powders of smaller particle sizes was higher. Tests of mechanical properties and tests using electrochemical impedance spectroscopy (EIS) showed that pencil hardness, impact resistance, and coating resistance were improved due to the reduction of mica powders particle size.

2019 ◽  
Vol 20 (1) ◽  
pp. 43-48
Author(s):  
S Supriyono ◽  
B Susilo

The objective of this study is to characterize bamboo tutulcharcoal particles produced by High Energy Ball Milling (HBEM)shaker type.The HEBM process was conducted in the stainless steel vialsfor 2 million cycles at 900 motor RPM. The ball milling diameter was 1/4 inch made from steel.Therefore, perhaps the final particle sizewill be determined byempty space of the vial for the movement of the balls. In this study, the empty space is varied for 1/2, 1/3, 1/4, and 1/5 of vial volume. Particle Size Analyzer (PSA) is used to have the particle sizes and SEM-EDX is used to have surface morphology of the particle. The average final particle sizes are 547.8 nm, 522.9 nm, 422.7 nm, and 739.4 nm for 1/2, 1/3, 1/4, and 1/5 empty space of vial respectively. The surface morphologies of the particles are determined by fracture mechanism as they can be seen on the SEM results. Based on the results, it can be said that there is no correlation between the particle size and the empty space of the vial. As long as there is space for movement of the milling balls, the collision occurs and the reduction of the particle also happens.


2019 ◽  
Vol 20 (2) ◽  
pp. 41-46
Author(s):  
S Supriyono ◽  
B. Susilo

The objective of this study is to characterize bamboo tutul charcoal particles produced by High Energy Ball Milling (HBEM) shaker type. The HEBM process was conducted in the stainless steel vials for 2 million cycles at 900 motor RPM. The ball milling diameter was 1/4 inch made from steel. Therefore, perhaps the final particle size will be determined by empty space of the vial for the movement of the balls. In this study, the empty space is varied for 1/2, 1/3, 1/4, and 1/5 of vial volume. Particle Size Analyzer (PSA) is used to have the particle sizes and SEM-EDX is used to have surface morphology of the particle. The average final particle sizes are 547.8 nm, 522.9 nm, 422.7 nm, and 739.4 nm for 1/2, 1/3, 1/4, and 1/5 empty space of vial respectively. The surface morphologies of the particles are determined by fracture mechanism as they can be seen on the SEM results. Based on the results, it can be said that there is no correlation between the particle size and the empty space of the vial. As long as there is space for movement of the milling balls, the collision occurs and the reduction of the particle also happens.


Author(s):  
Malcolm Stein ◽  
Chien-Fan Chen ◽  
Matthew Mullings ◽  
David Jaime ◽  
Audrey Zaleski ◽  
...  

Particle size plays an important role in the electrochemical performance of cathodes for lithium-ion (Li-ion) batteries. High energy planetary ball milling of LiNi1/3Mn1/3Co1/3O2 (NMC) cathode materials was investigated as a route to reduce the particle size and improve the electrochemical performance. The effect of ball milling times, milling speeds, and composition on the structure and properties of NMC cathodes was determined. X-ray diffraction analysis showed that ball milling decreased primary particle (crystallite) size by up to 29%, and the crystallite size was correlated with the milling time and milling speed. Using relatively mild milling conditions that provided an intermediate crystallite size, cathodes with higher capacities, improved rate capabilities, and improved capacity retention were obtained within 14 μm-thick electrode configurations. High milling speeds and long milling times not only resulted in smaller crystallite sizes but also lowered electrochemical performance. Beyond reduction in crystallite size, ball milling was found to increase the interfacial charge transfer resistance, lower the electrical conductivity, and produce aggregates that influenced performance. Computations support that electrolyte diffusivity within the cathode and film thickness play a significant role in the electrode performance. This study shows that cathodes with improved performance are obtained through use of mild ball milling conditions and appropriately designed electrodes that optimize the multiple transport phenomena involved in electrochemical charge storage materials.


2019 ◽  
Vol 7 (2) ◽  
pp. 147-161 ◽  
Author(s):  
Maria L.A.D. Lestari ◽  
Rainer H. Müller ◽  
Jan P. Möschwitzer

Background: Miniaturization of nanosuspensions preparation is a necessity in order to enable proper formulation screening before nanosizing can be performed on a large scale. Ideally, the information generated at small scale is predictive for large scale production. Objective: This study was aimed to investigate the scalability when producing nanosuspensions starting from a 10 g scale of nanosuspension using low energy wet ball milling up to production scales of 120 g nanosuspension and 2 kg nanosuspension by using a standard high energy wet ball milling operated in batch mode or recirculation mode, respectively. Methods: Two different active pharmaceutical ingredients, i.e. curcumin and hesperetin, have been used in this study. The investigated factors include the milling time, milling speed, and the type of mill. Results: Comparable particle sizes of about 151 nm to 190 nm were obtained for both active pharmaceutical ingredients at the same milling time and milling speed when the drugs were processed at 10 g using low energy wet ball milling or 120 g using high energy wet ball milling in batch mode, respectively. However, an adjustment of the milling speed was needed for the 2 kg scale produced using high energy wet ball milling in recirculation mode to obtain particle sizes comparable to the small scale process. Conclusion: These results confirm in general, the scalability of wet ball milling as well as the suitability of small scale processing in order to correctly identify the most suitable formulations for large scale production using high energy milling.


2014 ◽  
Vol 802 ◽  
pp. 125-129
Author(s):  
Heronilton Mendes de Lira ◽  
Pilar Rey Rodriguez ◽  
Oscar Olimpio de Araújo Filho ◽  
Cezar Henrique Gonzalez ◽  
Severino Leopoldino Urtiga Filho

High performance nanostructured light metals and alloys are very interesting for replacing conventional heavier materials in many industrial components. High Energy Ball Milling and Cryomilling are useful techniques to obtain nanocrystalline powders. In this work the effect of several milling conditions such as rotation speed, time, ball to powder ratio and temperature on the crystallite and particle size and morphology in pure aluminum are presented. X-Ray Diffraction, Laser Diffraction and Scanning Electron Microscopy are used. High energy ball milling at ambient and cryogenic temperature of Al powders rapidly leads to a nanometer size down to about 35 nm. High ball to powder ratio promotes both low crystallite and particle size. Small crystallite size like 18 nm and particle size as 4 μm were achieved in the most energetic conditions at ambient temperature. Isopropyl alcohol used as liquid media and protective atmosphere has a strong influence on the results depending on the milling temperature of Al.


2018 ◽  
Vol 941 ◽  
pp. 1990-1995
Author(s):  
Naidu V. Seetala ◽  
Cyerra L. Prevo ◽  
Lawrence E. Matson ◽  
Thomas S. Key ◽  
Ilseok I. Park

ZrB2 and HfB2 with incorporation of SiC are being considered as structural materials for elevated temperature applications. We used high energy ball milling of micron-size powders to increase lattice distortion enhanced inter-diffusion to get uniform distribution of SiC and reduce grain growth during Spark Plasma Sintering (SPS). High-energy planetary ball milling was performed on ZrB2 or HfB2 with 20vol% SiC powders for 24 and 48 hrs. The particle size distribution and crystal micro-strain were examined using Dynamic Light Scattering Technique and x-ray diffraction (XRD), respectively. XRD spectra were analyzed using Williamson-Hall plots to estimate the crystal micro-strain. The particle size decreased, and the crystal micro-strain increased with the increasing ball milling time. The SPS consolidation was performed at 32 MPa and 2,000°C. The SEM observation showed a tremendous decrease in SiC segregation and a reduction in grain size due to high energy ball milling of the precursor powders. Flexural strength of the SPS consolidated composites were studied using Four-Point Bend Beam test, and the micro-hardness was measured using Vickers micro-indenter with 1,000 gf load. Good correlation is observed in SPS consolidated ZrB2+SiC with increased micro-strain as the ball milling time increased: grain size decreased (from 9.7 to 3.2 μm), flexural strength (from 54 to 426 MPa) and micro-hardness (from 1528 to 1952 VHN) increased. The correlation is less evident in HfB2+SiC composites, especially in micro-hardness which showed a decrease with increasing ball milling time.


2009 ◽  
Vol 67 ◽  
pp. 45-51
Author(s):  
Rohit Kumar Gupta ◽  
Vijaya Agarwala ◽  
Sunayan Thakur ◽  
Ramesh Chandra Agarwala ◽  
Bhanu Pant

High energy ball milling (HEBM) had been carried out to produce submicron size titanium aluminide intermetallics (TiAl) using elemental powders of Ti and Al alongwith Ni-P coated graphite. 1% graphite powders was added to stoichiometric composition of Ti48Al and ball milling was conducted for different milling time at varying rpm. The effect of milling time and rpm on particle size has been studied. The prepared samples have been characterized using X-ray diffraction, differential scanning calorimetry (DSC) and scaning elecron microscopy (SEM). Grain size as low as 500 nm could be achieved. Formation of Ti3Al, TiAl and carbon containing intermetallic compounds had been confirmed through X-ray diffraction. Milling time and rpm of mill is found to be important factors which control the final particle size.


2006 ◽  
Vol 45 ◽  
pp. 480-485 ◽  
Author(s):  
V.L. Arantes ◽  
Dulcina P.F. Souza

Tin titanate zirconate (ZTS) is widely known for its good dielectric properties at high frequencies and has been widely employed as a dielectric resonator. ZTS does not sinter easily by solid state difusion and it is necessary to introduce sintering aids capable of increasing diffusion coefficients and/or leading to liquid phase sintering. Consequently, the dielectric properties in microwave frequencies can be reduced. This work focused on the utilization of high energy ball-milling as a method of reducing initial particle size and further improving sintering of ZTS.The powders obtained were characterized by X-ray diffraction as a function of milling time, as well as by a light scattering particle size analyzer.


2020 ◽  
Vol 8 (6) ◽  
pp. 3749-3755

In the present study Cu2MnSnS4 /Se4 nanostructured material is synthesized using mechanical alloying. The elemental powders were alloyed in a high-energy ball mill under the following conditions: milling time 25 hours, ball-to-powder mass ratio (BPR) 10:1 and a rotation speed of 300 rpm. Detailed investigation of the microstructure of the synthesized alloy was carried out. The starting elemental powders size and morphology were characterized using Apreo field emission gun scanning electron microscope (FEGSEM). Elemental mapping of the synthesized alloy was characterized using energy dispersive spectroscopy (EDS) attached to FEGSEM system. Analysis of microstructure was performed using EDAX-TEAM advanced software. A dynamic laser light scattering was used for particle size analysis. The results showed that Cu2MnSnS4 /Se4 nanostructured is successfully synthesized by ball milling. The Z-average size distribution of the particle reveals that ball milling results in a considerable refining in the particle size from 44 micron down to 923.5 nm. Further, it was observed that 94.4% showed an average size of 725.8±233 nm. Microstructural analysis confirmed the formation of a homogenous structure of Cu2MnSnS4 /Se4 alloy in the powder and green samples. The elemental mapping confirmed the formation of solid solution of the processed alloy with homogenous distribution of all elements in the examined region. Quantitative analysis performed by EDAX-TEAM software confirmed the chemical composition and homogeneity of the processed material.


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