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RESEARCH PROFILE

Professor Dr. Makoto Ogawa

School of Energy Science and Engineering (ESE)
Department of Chemical and Biomolecular Engineering
Tel. +66-33-014-255
Email makoto.ogawa@vistec.ac.th
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Polymer-clay nanocomposites

 

Research Overview

Polymer-clay nanocomposites have been attracted in both academic and industrial interest because the intercalated polymer has the possibility to take an unusual ordered conformation to improve their structural and functional properties of clay-based nanocomposites. Our group has experienced in these fields so far, and here, we show the reports of previous studies on the interactions of polymers and nanosheets to give guideline to for the further development in the area of polymer-clay nanocomposites.

Smectite clay

Smectites are phyllosilicate minerals characterized by a 2 : 1 layer structure in which two tetrahedrally coordinated silica and a length or breadth from a few tens of nm up to 1 mm. Negative charges of the sheet generated by the isomorphous substitution of the layer are counterbalanced by cationic species placed in the galleries. These cations in the gallery can be easily exchanged with organic ions, such as ammonium and phosphonium, to give organically modified materials.


Fig.1 Crystal structure of a dioctahedral smectite nanosheet.

Polymer-clay nanocomposites

The polymer–clay nanocomposites where the polymer chains are intercalated into the interlayer galleries of clay exhibit useful properties such as mechanical strength, thermal stability, gas barrier and flame retardancy even at very low clay contents as a few mass %. Our research group has been studying the incorporation of polymers, both water soluble and insoluble polymers, into smectites clay. That can lead many useful applications as seen in the following

Adsorbent/absorbent

Some layered clay minerals are known to accommodate various organic substances in their interlayer spaces to form intercalation compounds. Montmorillonite, which is one of typical swelling clay minerals, has been widely used as a host material. In this work, montmorillonite-acrylamide intercalation compounds were prepared by treating sodium montmorillonite with acrylamide aqueous solution. The intercalated acrylamide was polymerized to form montmorillonite-polyacrylamide intercalation compounds. These compounds absorbed more water than raw sodium montmorillonite that can use as water absorbents.

Bio-sorbent

Bionanocomposite materials, a group of organic-inorganic hybrid materials involving naturally occurring polymers and inorganic solids that show at least one dimension at nanometer scale, can exhibit improved structural and functional properties together with biocompatible and biodegradable character associated with the biopolymer. Sacran, an anionic megamolecular polysaccharide extracted from the cyanobacterium. Aphanothece sacran, is an interesting biopolymer for developing functional clay-based bionanocomposites due to its colloidal and metal complexing properties. This work introduces novel bionanocomposites based on the assembly of sacran to sepiolite, a fibrous hydrated magnesium silicate. The prepared sacran–sepiolite bionanocomposites could be of great interest as biosorbents for the selective recovery of neodymium ions from aqueous solutions.

Fig. 2 Possible arrangement of the sacran chains in liquid crystal domains in sacran-sapiolite samples favouring the Nd3+ ion uptake.

UV light durability and controlled refractive index

A layered titanate-epoxy nanocomposite was synthesized by the reaction of a layered titanate modified with glycidyl and octadecyl groups and an epoxy resin followed by curing. The nanocomposite exhibited durability toward UV light compared with the pristine epoxy resin.

Fig. 3 Hybridization of a layered titanate with epoxy resin was possible by the modification of the titanate with alkyl and glycidyl groups.

Stabilization of dyes using PVP/clay system

Tris(2,2’-bipyridine) ruthenium(II) complex [Ru(bpy)3]2+ is one of the molecules studied most extensively for photo/ electrochemistry because of its unique combination of chemical stability and luminescence. In order to avoid aggregation of the complex, a water soluble polymer poly(vinylpyrrolidone) (PVP) was intercalated. [Ru(bpy)3]2+- fluortetrasilicic mica (TSM)-PVP intercalation compounds were prepared by cation exchange after the adsorption of PVP. The cointercalated PVP prevented self-aggregation of [Ru(bpy)3]2+ by surrounding [Ru(bpy)3]2+ in close contact in the sterically limited interlayer spaces.


Fig. 4 PVP suppress the segregation of [Ru(bpy)3]2+ on clays.

PVP was intercalated into the two dimensional interlayer space of a synthetic saponite which adsorbed rhodamine 6G (R6G) by ion exchange. The expansion of the interlayer space depended on the composition. R6G degradation upon sunlight irradiation was suppressed in the presence of PVP.


Fig. 5 Rhodamine 6G was stabilized in PVP-saponite.

Recent award:

The 1st FIT-ME Symposium-Chemistry and Applications of Inorganic Layered Materials
Date: May 16, 2016
Venue: Fukuoka Institute of Technology, Japan
Website: http://www.fit.ac.jp/~miyamoto/1stFITMEsympo/
 

Excellent Poster Award from the Forum on Low-dimensional Photo-functional Materials of Chemical Society of Japan:

Aranee TEEPAKAKORN (Vidyasirimedhi Institute of Science and Technology)
"Interactions of smectites with poly (vinyl pyrrolidone)"

 
 

Selected Publications

  1. Alcântara A. C. S., Darder M., Aranda P., Tateyama S., Okajima K. M., Kaneko T., Ogawa M. and Ruiz-Hitzky E. J. Mater. Chem. A, 2, 1391-1399 (2014).
  2. Nakamura T. and Ogawa M. Appl. Clay Sci., 83-84, 469-473 (2013).
  3. Sohmiya M. Omata S. and Ogawa M. Polym. Chem., 3, 1069-1074 (2012).
  4. Nakade M., Kameyama K. and Ogawa M. J. Mater. Sci., 39, 4131-4137 (2004).
  5. Isoda K., Kuroda K. and Ogawa M. Chem. Mater.,12, 1702-1707 (2000).
  6. Ogawa M., Tsujimura M. and Kuroda K. Langmuir, 16, 4202-4206 (2000).
  7. Ogawa M., Inagaki M., Kodama N., Kuroda K. and Kato C. J. Phys. Chem., 97, 3819-3823 (1993).
  8. Ogawa M., Inagaki M., Kodama H., Kuroda K. and Kato C. Mol. Cryst. Liq. Cryst., 216, 141-144 (1992).
  9. Ogawa M., Kuroda K. and Kato C. Clay Sci., 7, 243-251 (1989).
 

Research Group Members:

Dr. Makoto Ogawa (Professor)
Dr. Sareeya Bureekaew (Lecturer)
Dr. Surakerk Onsuratoom (Postdoctoral Research Fellow)
Dr. Tetsuo Yamaguchi (Postdoctoral Research Fellow)
Dr. Hojoon Shin (Postdoctoral Research Fellow)
Dr. Sebastian Bosch (Postdoctoral Research Fellow)
Ms. Thipwipa Sirinakorn
Mr. Kasimanat Vibulyaseak
Mr. Natthawut Homhuan
Ms. Kamonnart Imwiset
Ms. Aranee Teepakakorn
Mr. Wichayut Reanthonglert
Ms. Soontaree Intasa-ard