The 290th MANA Seminar
Prof. Naoya Yoshida & Prof. Kaili Lin
| Date | October 12, Friday |
| Time | 15:30-17:00 |
| Place | Auditorium, 1F, WPI - MANA Bldg., NAMIKI Site, NIMS |
Download PDF file for seminar info.
15:30-16:15
Control of wettability on solid surfaces, and scope for its applications
Wettability is practically important property in many fields, such as adhesion, cleaning, coating, and so on. Nowadays, we can easily prepare surfaces of hydrophobic or hydrophilic (tunable from superhydrophobic to superhydrophilic). Wettability, which generally means static contact angle, is controlled by two factors, surface energy and surface roughness. On the other hand, it is still difficult to understand and control dynamic wettability (spreading or moving of a droplet). Our group has focused on this point, and studied detail of it on surfaces of organic polymers, self-assembled monolayers, and ceramics. In this presentation, I will show you several results and applications of wettability control.
Speaker
Prof. Naoya Yoshida, Department of Environmental and Energy Chemistry, Kogakuin University, Japan
Chair
Dr. Jun Nakanishi, MANA Independent Scientist, MANA, NIMS
16:15-17:00
Hydroxyapatite and Silicate Bioceramics: from Morphology and Composition Control to Applications
Most of chemical energy production technologies such as fossil fuel combustion and fuel cell are relying upon platinum group metal (PGM) catalysts for cleaning toxic exhaust gas and/or promoting electrochemical reactions. While, in turn deposit of PGMs is localized and limited, so that the development of PGM-free catalysts are urgent mission of material science. Herein we report that single crystals of nanometer thickness can, when rationally organized, realize improved catalytic activities, selectivities and durability. We synthesized nanometer-thin single crystals of copper(II) oxide (CuO) with extremely developed {001} surfaces through a ligand-assisted hydrothermal reaction. The CuO crystals spontaneously intersected one another to form a highly porous micro-assembly, maximizing the effective {001} surfaces for the purification of nitrogen monoxide (NO). The conformation of the CuO micro-assembly not only permitted the smooth access of reactants to the {001} surfaces but also strongly suppressed thermal agglomeration of the catalytic center. Consequently, the CuO micro-assembly outperformed different CuO materials in durability and even rivaled an equivalent weight of PGM nanoparticles in the purification of NO. Our results indicate that adequate organization of nanometer-thin single crystals is a powerful approach toward high-performance catalysts without using precious-group metal elements.
Speaker
Prof. Kaili Lin, Shanghai Institute of Ceramics, Chinese Academy of Sciences, China
Chair
Dr. Guoping Chen, MANA PI, MANA, NIMS