Amelioration of Hydrogen Uptake and Release Features of Magnesium Adding a Polymer Polyvinylidene Fluoride via Milling in Hydrogen in a Planetary Ball Mill

2020 ◽  
Vol 20 (11) ◽  
pp. 7105-7113
Author(s):  
Young Jun Kwak ◽  
Myoung Youp Song

In the present study, a polymer polyvinylidene fluoride (PVDF) was chosen as an adding material to ameliorate hydrogen uptake and release features of Mg. Samples with a composition of 95 wt.% Mg+5 wt.% PVDF (called 95Mg + 5PVDF) were made via milling in hydrogen atmosphere in a planetary ball mill (reactive planetary ball milling). The hydrogen release reaction of magnesium hydride formed in the as-prepared 95Mg+5PVDF during reactive planetary ball milling started at 681 K. In the third cycle (CN = 3), the amount of hydrogen absorbed for 60 min, A (60 min), was 3.44 wt.% hydrogen at 573 K in 12 bar hydrogen. The PVDF is believed to have melted during reactive planetary ball milling, and the sliding or lubrication between Mg particles and hardened steel balls was avoided, leading to a good contact between them and a highly effective milling. The milling in hydrogen atmosphere in a planetary ball mill of Mg with PVDF is believed to have generated defects and cracks. The Mg2C3 produced from PVDF during hydrogen uptake-release cycling is believed to have been spread among particles and to have kept particles from coalescing. To the best of our knowledge, this is the first study to use a polymer PVDF as an additive material for the amelioration of hydrogen uptake and release features of Mg.

RSC Advances ◽  
2016 ◽  
Vol 6 (84) ◽  
pp. 81219-81230 ◽  
Author(s):  
Amir Rahmani ◽  
Alireza Khataee ◽  
Baris Kaymak ◽  
Behrouz Vahid ◽  
Mehrangiz Fathinia ◽  
...  

Natural martite microparticles (NMMs) were prepared with a high energy planetary ball mill to form a nanocatalyst for a Fenton-like process.


2016 ◽  
Vol 821 ◽  
pp. 399-404 ◽  
Author(s):  
Monika Vilémová ◽  
Barbara Nevrlá ◽  
Zdenek Pala ◽  
Lenka Kocmanová ◽  
Marek Janata ◽  
...  

Tungsten is currently considered as the most suitable plasma facing material for the first wall of a nuclear fusion reactor. First wall will be subjected to harsh conditions that will gradually deteriorate properties of the wall material. Some studies point out that fine-grained tungsten could be more resistant to the structure and property changes than coarse-grained tungsten. However, tailoring of tungsten microstructure is very laborious. Due to its high melting point, tungsten is very often processed mechanically and subsequently sintered into a compact body. In this study, preparation of ultrafine-grained tungsten by mechanical processing in a planetary ball mill was examined. Three types of tungsten samples were compared. One was made from coarse grained tungsten powder consolidated by SPS (spark plasma sintering). Other two samples were prepared from the powder processed in a planetary ball mill with and without addition of Y2O3. After ball milling, the powders were consolidated by SPS, i.e. fast sintering process that allows preserving fine-grained structure of the powder material. Properties of the samples such as hardness and thermal conductivity were examined and correlated with the processing history and microstructure.


2017 ◽  
Vol 10 (04) ◽  
pp. 1750047 ◽  
Author(s):  
Babak Alinejad ◽  
Korosh Mahmoodi

Natural graphite is a soft material that conventional milling methods fail to grind into nanoparticles. We found that adding NaCl into graphite during milling allows obtaining graphene nanoflakes of about 50[Formula: see text][Formula: see text][Formula: see text]200[Formula: see text]nm2 as evidenced by Transmission Electron Microscope (TEM). NaCl particles are substantially brittle and harder than graphite, serving as milling agents by both helping to chop graphite into smaller pieces and preventing graphite particles from agglomeration. After milling, NaCl can be easily washed away by water. Probable mechanism for exfoliation of graphene during the modified ball milling may be explained by NaCl and graphene slipping or sliding against and over each other, exfoliating the graphene particles into thin layers.


2013 ◽  
Vol 795 ◽  
pp. 711-715 ◽  
Author(s):  
N.Z.F. Mukhtar ◽  
M.Z. Borhan ◽  
Mohamad Rusop ◽  
Saifollah Abdullah

Ball milling is a top down approach and a method to reduce size of particle while Zeolite is a valuable inorganic materials having wide variety of applications. In this paper, ball milling of commercial synthetic Zeolite powder was studied with their time varied. Wet ball milling was selected as a potential means to decrease the particle size of Zeolite over dry grinding. The parameters that included in this study were rotational speed, balls to powder ratio, water to powder ratio and milling time. These nanozeolite were characterized via Zeta-sizer nanoseries of particle sizer, FESEM, and also FTIR. Results showed that commercial synthetic Zeolite powder with particle size larger than 45 μm may be reduced into the size range between 0.2 0.3 μm by planetary ball mill.


2011 ◽  
Vol 264-265 ◽  
pp. 496-501
Author(s):  
Hong Fei Sun ◽  
Wa Fang ◽  
Zhen Xing Yu ◽  
Wen Bin Fang

Nanocrystallite Mg-3Al-Zn alloy was synthesized by ball milling of elemental powders of Mg, Al and Zn under hydrogen atmosphere. The powders of Mg, Al and Zn were mechanical alloying and disproportionated by ball milling under hydrogen and desorption-recombination was then performed. The structural changes due to both the milling in hydrogen and the subsequent desorption-recombination treatment were characterized by X-ray diffraction (XRD). The desorption–recombination behavior of the hydrogenation alloy was investigated by differential scanning calorimetry (DSC). The morphology and microstructure of the final alloy powders subject to desorption–recombination treatment were observed by TEM and HRTEM, respectively. The results showed that, by milling in hydrogen for 60 h, the Mg-3Al-Zn alloy was disproportionated into nano-structured with average size of about 60-70 nm, and a subsequent desorption–recombination treatment at 320°C for 30 min alloy didn’t vary the average crystallite size of powders.


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