Pore properties of hierarchically porous carbon monoliths with high surface area obtained from bridged polysilsesquioxanes

Hierarchically porous carbon monoliths with high specific surface area have been prepared via a nano-phase extraction technique from carbon/silica composites which had been prepared from arylene-bridged polysilsesquioxanes. The nano-sized silica phase developed in the composite has been removed to increase micropores, resulting in a similar effect to thermal activation of carbons. The resultant carbons are expected to possess homogeneously distributed micropores. Here we report the changes of the pore characteristics through the synthesis process by the nitrogen adsorption–desorption method and mercury porosimetry. In particular, the growth of silica phase in carbon/silica composites at different temperatures has been characterized by the micropore analysis using the Horváth-Kawazoe method

Highly porous melamine-formaldehyde monoliths with controlled hierarchical porosity toward application as a metal scavenger

We report a new synthetic strategy for melamine-formaldehyde (MF) monoliths with controlled hierarchical porosity toward metal-ion scavengers. The obtained MF monoliths possessed micro-, meso- and macroporosity, which allowed efficient adsorption performance of precious metal ions in water. Applications such as recovery/removal of metal ions are expected

Sol–gel based structural designs of macropores and material shapes of metal–organic framework gels

We have developed a general synthetic strategy to control macroporous structures and material shapes of metal–organic framework (MOF) gels via a sol–gel based structural control process. A series of 1, 3, 5-benzene tricarboxylic acid (BTC) based MOF gels, Cr-BTC and Zr-BTC, have been chosen as a proof of concept

Layered Double Hydroxide (LDH)-based Monolith with Interconnected Hierarchical Channels: Enhanced Sorption Affinity for Anionic Species

Monolithic layered double hydroxides (LDHs) with interconnected channels have been expected to enhance sorption rate as well as increase accumulation of anions. Although powder molding can form easy-handled LDH compacts, interconnected channel formation therein has not been achieved. Herein, we demonstrate cm-scale monolithic LDH-based composites with interconnected hierarchical channels via a spontaneous sol−gel reaction. The synthesis was performed on Mg−Al hydrotalcite-type LDHs starting from metal chlorides aqueous/ethanolic solution with poly(ethylene oxide) incorporated. Addition of propylene oxide triggers sol−gel reaction to form monolithic xerogels with a formula of [Mg0.66Al0.33(OH)2Cl0.33·2.92H2O]·3.1Al(OH)3. LDH crystals together with aluminum hydroxide crystals homogeneously build up gel skeletons with well-defined hierarchical channels. The interconnected channels in μm range (macrochannel) are formed as a phase-separated structure, whereas the channels in nm range (nanochannel) are as interstices of primary particles. The channel architectures are preserved in the course of rehydration process, affording enhanced sorption affinity for anion species in the process. Both of macro and mesochannels as well as high charge density of the obtained LDHs (Mg/Al=2.0) contribute enhanced anion sorption in the monolithic xerogels. The materials obtained here opens up applications of high performance adsorbent and ion-storage free from diffusion limitation.The present work is partially supported by Grant-in-Aid for Scientific Research (B) (No. 22360276), and Grant-in-Aid for Young Scientists (B) (No. 24750206) from the Ministry of Education, Culture, Sports, Science and Technology (MEXT), administrated by Japan Society for the Promotion of Science (JSPS). Y. T. is also partially supported financially by a research grant from The Murata Scientific Foundation

Layered double hydroxide composite monoliths with three-dimensional hierarchical channels: structural control and adsorption behavior

Hierarchically porous layered double hydroxide (LDH) materials have potential in anion-exchange, adsorption and catalysis applications, because of their large surface areas and liquid transportation capabilities. The preparation of monolithic LDH-Al(OH)3 composites with hierarchical µm/nm-scale channels and their adsorption behavior is reported. Monolithic gels were synthesized via sol-gel processing, from metal salt precursor solutions. m-scale macrochannels spontaneously formed by inducing phase separation during sol-gel transition. nm-scale mesochannels were accommodated as interstices between primary/secondary particles. In this study, these hierarchical channel sizes were controlled. The macrochannel size was controlled by tuning the degree of phase separation. The mesochannel size was controlled independently, by tuning the crystallite size of LDH under different solvothermal conditions. The relationship between pore characteristics and adsorption behavior of tailored hierarchically porous LDH-Al(OH)3 monolithic gels were investigated by using dye molecules as adsorbates. Monolithic gels with larger macrochannels and mesochannels exhibit faster adsorption rate and higher affinity, respectively. LDH-Al(OH)3 monolithic gels with hierarchical channels may have potential in some applications such as biosensing, water purification and catalysis.The study was supported by a Grant-in-Aid for Scientific Research (B) (No. 22360276) and a Grant-in-Aid for Young Scientists (B) (No. 24750206), from the Ministry of Education, Culture, Sports, Science and Technology (MEXT), Japan Society for the Promotion of Science (JSPS)

Fabrication of hierarchically porous monolithic layered double hydroxide composites with tunable microcages for effective oxyanion adsorption

Removal of toxic substances from industrial wastes is an urgent issue for realizing a sustainable society. Layered double hydroxides (LDHs) are expected to be an effective adsorbent for toxic anions, especially oxyanions, because of their high anion adsorption capacity and reusability. Monolithic LDH materials with rational meso- and macropores are expected to show high adsorption capacity/rate towards targeted toxic substances owing to their large specific surface area and liquid transport property. Besides fabricating hierarchical pores, size control of microcages in LDH crystals is required to achieve selective removal of oxyanions. Herein, we prepared hierarchically porous monolithic LDH composites with tunable microcages by changing the combination of cationic species in the LDH crystal. Monolithic Mg-, Mn-, Fe-, Co- and Ni-Al type LDH composites with hierarchical pores were successfully prepared via an epoxide-mediated sol-gel reaction accompanying with phase separation. The monolithic Co-Al type LDH composite with hierarchical pores exhibited the highest CrO42− adsorption capacity because its microcage size well fits the CrO42− size. Also Co-Al type LDH composite adsorbed different oxyanions, depending on their affinity with the LDH, in SO42−, CrO42−, MoO42− and HVO42− co-existing solution. The pore size controllability in discrete length-scales of micrometers, nanometers, and picometers offers LDHs with tailored surface chemistries and physical properties desirable for effective and selective oxyanion adsorption.The study was supported by JSPS KAKENHI (No. 26288108, 26630322).This work is partially supported by the Kazuchika Okura Memorial Foundation and the Hosokawa Powder Technology Foundation

A Study of Life History on the Professional Development of Teaching: Part 4: Focusing on teaching in physical education of an elementary school teacher C

This study aims to clarify the experiences that helped Elementary School Teacher C hold his belief of teaching in physical education as an elementary school teacher for 19 years. The following points summarizes the findings. First, after starting on the new post of an elementary school physical education specialist at K University Attached Elementary School in April 1998, Mr. C formed a view on physical education that the aim of physical education was the acquisition of exercise skill, not the competitive advantage which the acquisition of exercise skill provided. At the same time, Mr. C, following his views on physical education teaching, devised teaching materials and guided his students to achieve the targets he set for them. Second, Mr. C was affected by exercise instruction and the views of Mr. Motohiro Yamauchi on pupil, which transformed his views on physical education. Mr. C started providing students time for basic movement as warm-up exercise and gave them chances to push themselves. This transformation resulted with him noticing that the role of the classroom teacher included understanding the sensitive side of students and thinking of ways to observe and understand the exercise by classroom children through an understanding of exercise by his own children, in addition to the interchange through lesson study with Mr. Motohiro Yamauchi

A study of life history on the professional development of teaching: part 5: Focusing on teaching style in physical education of an elementary school teacher C

This study aims to clarify the process of formation and transformation of ‘teaching style’ in physical education of Elementary School Teacher C as the second study of a life history on the professional development of Teacher C’s teaching. The results are summarized as following points. 1. Teacher C formed his teaching style into mastery leaning for the accomplishment of the exercise skill through utilizing formative assessment. 2. Teacher C transformed his teaching style into supporting pupils’ learning for the accomplishment of the exercise skill through continuous cultivation of their motor sensation

Research into Pupils' Movement Skills on Gymnastics Apparatus: Focusing on the Relationship Between Sub-Teaching Material and Supra-Teaching Material <Practical Research>

運動学習を効果的に進めるためには，下位教材の運動技能と上位教材の運動技能がどのように関係しているかを明らかにする必要がある。本研究は，「はねとび」「はねおき」のための教材として，下位教材に「アンテナブリッジ」，上位教材に「前転ブリッジ」を設定して，教材間の運動技能の関係を明らかにすることを目的とした。 そこで，児童の学習実態から「アンテナブリッジ」と「前転ブリッジ」の運動技能の関係について分析を行ったところ，「アンテナブリッジ」の達成が，「前転ブリッジ」の達成と関係しており，「アンテナブリッジ」と「前転ブリッジ」の関係を考慮した指導を行う必要があると示唆された。 また，下位教材の「アンテナブリッジ」を未達成であっても，学習の中で，補助によって動きの感覚がわかったり，「はね動作」が安定したりすることで上位教材の「前転ブリッジ」ができるようになった例もみられた。The purpose of this research is to identify relationship between movement skills teaching materials through the teaching of a neckspring by setting an "antenna bridge" as the sub-teaching material and "forward roll and antenna bridge" as the supra-teaching material. This would help to identify how sub-teaching and supra-teaching materials are related to the effective teaching of Physical Education. The research on the relationship between the "antenna bridge" and the "forward roll and antenna bridge" indicated that the achievement of the "antenna bridge" may be followed by the achievement of the "forward roll and antenna bridge." This indicates that the teaching materials should be correlated when the "antenna bridge" and "forward roll and antenna bridge" are taught. Some pupils' performance implied that even students who had not achieved the "antenna bridge" may become able to do the "forward roll and antenna bridge," the supra-teaching material, by learning how to spring with the teacher's assistance