What's New!

2018/10/1
HW and Prof. Kubo (Tohoku Univ.), Dr. Onodera (Hitachi), Dr. Bai (Kyocera) organize "Tribology simulation" symposium, and many JAST & STLE young researchers organize "JAST & STLE young tribologist symposium", ITC2019 (International Tribology Conference), September 17-21, 2019, Sendai International Center.
2018/2/5
HW and Prof. Hedong Zhang (Nagoya Univ) organize "Advanced Simulation in Science and Engineering" session at 2018 JSME-IIP/ASME-ISPS(MIPE 2018) Joint Conference on Micromechatronics for Information and Precision Equipment , August 29-30, 2018, Hilton San Francisco Financial District, San Francisco, California, USA.
2017/12/25
We organize Special session of Tribology and Interface at MMM2018 which will be held in Oct. 2018 at Osaka Japan. Please join us!
2017/5/22
We made 2 presentations at the STLE 2017 annual meeting at Atlanta U.S.
2017/5/22
Prof. Washizu will join 10th Liquid Matter Conference, Ljubljana, Slovenia (17 July), The 8th Advanced Forum on Tribology 2017, Zhenjiang, China (14 Sep.), World Tribology Congrress 2017, Peking, China (17 Sep.).
2017/4/17
Mr. Maeda (MS student) won a " 2016 Student Award" from the Japanese Society of Tribologists.
2017/3/20
Prof. Washizu made a presentation at 4th International Tribology Symposium of IFToMM (International Federation for the Promotion of Mechanism and Machine Science) (ITS-IFToMM 2017) / 1st K-Tribology International Symposium (K-TIS 2017), Jeju, Korea.
2017/1/25
We made 3 presentations at the Symposium on Surface Science & Nanotechnology -25th Anniversary of SSSJ Kansai- (SSSN-Kansai).
2016/11/1
Dr. Le Van Sang joined our Lab as Research Lecturer.
2016/10/1
Dr. Natsuko Sugimura joined our Lab.
2016/10/1
T. Maeda and Prof. Washizu will join The 4th International Conference on Molecular Simulation in 2016/10/23.
2016/5/14
Prof. Washizu will join 4th Malaysia-Japan Tribology Symposium in 2016/8/25 as an invited speaker.
2016/4/10
We won an award of Tribology Online 2015.
2016/1/7
A Happy new year! Prof. Washizu will join CECAM workshop on Interactions and Transport of Charged Species in Bulk and at Interfaces in 2016/7/4.
2015/10/1
Prof. Washizu will join Pacifichem2015 in 2015/12/20
2015/10/1
The web site is open!
2015/10/1
Prof. Washizu started the lab.

Welcome to Washizu Lab!

Our Materials Simulation Laboratory is located in the Computational Science Center Building on the Kobe Campus for Information Science, University of Hyogo. If you are interested in one of our research projects, please contact us.


MMM2018

We organized special session of Tribology and Interface the 9th Multiscale Materials Modeling (MMM). Thank you for your kind collaboration.

2018 JSME-IIP/ASME-ISPS(MIPE 2018) Joint Conference on Micromechatronics for Information and Precision Equipment

HW and Prof. Hedong Zhang (Nagoya Univ) organized "Advanced Simulation in Science and Engineering" session at this conference. August 29-30, 2018, Hilton San Francisco Financial District, San Francisco, California, USA. Thank you for your kind collaboration.

2 Master Course Students won award at 6th World Tribology Congress (WTC2017).

In 19 Sep, H. Akiyama (M2) and M. Konishi (M2) made presentation and won the "Best Poster Award" in 6th World Tribology Congress (WTC2017) at Beijing, China. This conference is the largest conference in Tribology field, held every 4 years, like the Olympic game. Congratulations!

Invited Talk

This summer we made invited talks at The 8th Advanced Forum on Tribology 2017, Zhenjiang . The title was "Tribological Simulations for Carbon Based Materials". We will also make 3 presentations at 6th World Tribology Congress 2017 , Beijing.

Master Course Student won award at MJTS2017, Kuala Lumpur, Malaysia.

In 29 Aug, M. Konishi (M2) made presentation and won the "Best Poster Award" in 5th Malaysia-Japan Tribology Symposium (MJTS2017). Congratulations!

Master Course Students joined STLE2017 at Atlanta, GA, USA.

In 22 May, H. Akiyama (M2) and M. Konishi (M2) made presentations in STLE 2017 annual meeting. Thank you for kind discussions.

Student award

Mr. Maeda (MS student) won a " 2016 Student Award" from the Japanese Society of Tribologists. The title of the paper is "Mechanism of ultra-low friction of multilayer graphene studied by all atom molecular dynamics". Congratulation!

Invited Talk

This summer we made invited talks at CECAM workshop on Interactions and Transport of Charged Species in Bulk and at Interfaces (Vienna) and 4th Malaysia-Japan Tribology Symposium (Kuala Lumpur).

Paper award

We won an award of Tribology Online 2015. S. Kajita, M. Tohyama, H. Washizu, S. Ohmori, K. Watanabe, S Shikata, "Friction modification by shifting of phonon energy dissipation in solid atom", Tribology Online 10, (2) 156-161 (2015). https://www.jstage.jst.go.jp/article/trol/10/2/10_156/_pdf

Guide for Application for the graduate students on Master and Ph.D. Program in 2019.

We are looking for Master and PhD students to join the next generation of outstanding researchers in molecular simulation. The candidate must pass the entrance exam and the Japanese-Language Proficiency Test N2. Though the research advisor can teach in English, the candidate need to understand Japanese to study the usual lectures in the curriculum.

Recent Publications

Le Van Sang*, A. Yano, A. Isohashi, N. Sugimura, H. Washizu*, "Smoothed particle hydrodynamics study of friction of the coarse-grained a-Al2O3/a-Al2O3 and a-Fe2O3/a-Fe2O3 contacts in behavior of the spring interfacial potential", Trib. Intl., DOI: 10.1016/j.triboint.2019.03.015 (2019). pdf, pdf (arxiv), Free in 50 days
The paper investigates sliding friction of the a-Al2O3/a-Al2O3 and a-Fe2O3/a-Fe2O3 contacts by using the spring interfacial potential. It is found that at micronscale the friction properties of the oxides are almost independent of the coarse-graining and are the same in the different sliding directions. Even the hardness contacts friction coefficient shows a decrease with increasing intensity of the normal component of the interfacial interaction force. This result is as an implementation for the previous observations of sliding friction of various materials that showed that a drop of friction coefficient with increasing externally applied normal load has originated from deformation of interfaces or occurrence of debris at contact, indicating an unsteady contact.

M. Konishi, H. Washizu, "Understanding the effect of the base oil on the physical adsorption process of organic additives using molecular dynamics", Trib. Intl., DOI: 10.1016/j.triboint.2019.01.027 (2019). pdf, pdf (arxiv)
Organic friction modifiers (OFMs) are widely added to oil to reduce the boundary friction in many kinds of lubricants such as vehicle engine oils. At the contact area in machine elements, the OFMs form a self-assembled organic monolayer. Although the friction properties of the monolayer are widely studied on a molecular level, the formation process is not well-known. In this study, the initial adsorbing process of additive molecules in explicit base oil molecules are calculated using molecular dynamics. The adsorption time depends on the structure of the base oils. Another effect of the base oil other than "chain matching" is found.

K. Nishikawa, H. Akiyama, K. Yagishita, H. Washizu, "Molecular dynamics analysis of adsorption process of anti-copper-corrosion additives to the copper surface", Jurnal Tribologi (accepted, Malaysian Tribology Society). pdf (arxiv)
As a model system of the adsorption process of anti-corrosion additives on a metal surface, molecular dynamics simulations of benzotriazole (BTA) molecules with copper slabs were completed. As a force field, ReaxFF was used to simulate both adsorption dynamics and the charge transfer on the solid surface. Two simulations are presented. In order to investigate the physical adsorption on the surface, the simulation was done for the adsorption process of BTA molecules on the copper (II) oxide slab. BTA molecules formed on adsorbed layer in parallel to the surface, and aggregation of the molecules due to the surface diffusion was found. In order to investigate the selective and chemical adsorption on the surface, a hybrid slab, which has both a copper (Cu) area and a copper (I) oxide (Cu2O) area, was used. A selective adsorption phenomenon was found. The number of BTA molecules adsorbed on the Cu area is 5 times greater than that on the Cu2O area. Detailed dynamics focused on charge transfer showed a surface diffusion and enhancement of polarization due to charge transfer from the metal surface caused the selective adsorption. In a real phenomenon, the reason why a few anti-corrosion additives are able to protect a metal surface is postulated to be due to this selective nature of adsorption onto a newly formed metal surface.

Le Van Sang, A. Yano, S. Fujii, N. Sugimura,H. Washizu, "Coarse-grained model for spring friction study of micron-scale iron by smoothed particle hydrodynamics", EPL (Europhys. Lett.) 122, 2 (2018) 26004. pdf, pdf (arxiv)
This is the first paper of the colaboration with Dr. Le Van Sang, Mitsubishi Heavy Industry, and us. We propose numerical model to simulate micron-scale friction phenomena by bottom up simulation method from atomistic scale. We found the importance of surface force in perpendicular direction to the interface to the origin of friction.

T. Kinjo, H. Yoshida, H. Washizu, "Coarse-grained simulations of polyelectrolyte brushes using a hybrid model", Colloid Polym. Sci., 296(3), 441-449 (2018). pdf.
Polyelectrolyte brush are widely used for low friction system, binders for batteries. Studies on high charge fractions, however, are relatively rare dute to the complexity involving counterion condensation. We studied the structure of polyelectrolyte brushes using new simulation method based on DPD.


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