Takashi Kato

In the 21st century, soft materials will become more important as functional materials because of their dynamic nature. Although soft materials are not as highly durable as hard materials, such as metals, ceramics, and engineering plastics, they can respond well to stimuli and the environment. The introduction of order into soft materials induces new dynamic functions. Liquid crystals are ordered soft materials consisting of self-organized molecules and can potentially be used as new functional

Additional functionality can be incorporated into liquid crystalline materials by using phase segregation and self-assembly. Intermolecular interactions such as hydrogen bonding and ionic interactions play key roles in the formation of these complex structures. One-, two-, and three-dimensional phase-segregated structures on various scales of length are formed by self-assembly of a variety of partially incompatible molecules. Such structures can enhance anisotropic properties such as ionic condu

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTA new approach to mesophase stabilization through hydrogen bonding molecular interactions in binary mixturesTakashi Kato and Jean M. J. FrechetCite this: J. Am. Chem. Soc. 1989, 111, 22, 8533–8534Publication Date (Print):October 1, 1989Publication History Published online1 May 2002Published inissue 1 October 1989https://pubs.acs.org/doi/10.1021/ja00204a044https://doi.org/10.1021/ja00204a044research-articleACS PublicationsRequest reuse permissionsArticl

Since the discovery of the liquid-crystalline state in 1888, liquid crystal science has made great advances through fusion with various technologies and disciplines. Recently, new molecular design strategies and new self-assembled structures have been developed as a result of the progress made in synthetic procedures and characterization techniques. Since these liquid crystals exhibit new functions and properties derived from their nanostructures and alignment, a variety of new functions for liq

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTStabilization of a liquid-crystalline phase through noncovalent interaction with a polymer side chainTakashi Kato and Jean M. J. FrechetCite this: Macromolecules 1989, 22, 9, 3818–3819Publication Date (Print):September 1, 1989Publication History Published online1 May 2002Published inissue 1 September 1989https://pubs.acs.org/doi/10.1021/ma00199a060https://doi.org/10.1021/ma00199a060research-articleACS PublicationsRequest reuse permissionsArticle Views1

This article focuses on the synthetic approach to the preparation of calcium carbonate–organic hybrid materials, which are obtained by self-organization processes under mild conditions. In these processes, organic molecules such as functionalized polymers and aligned amphiphilic molecules on the surface play key roles in the crystallization of calcium carbonate, which results in the formation of hybrid materials. As well as being environmentally benign, the hybrid materials have controlled morph

Liquid-crystalline (LC) physical gels are a new class of dynamically functional materials consisting of liquid crystals and fibrous aggregates of molecules that are called "gelators". Liquid-crystalline physical gels, which are macroscopically soft solids, exhibit induced or enhanced electro-optical, photochemical, electronic properties due to the combination of two components that form phase-separated structures. In this tutorial review, we describe the materials design and structure-property r

Columnar liquid crystals have recently been developed as dynamically functional anisotropic materials. In this feature article, some recent examples of the materials design and functionalisation of columnar liquid crystals are described. Not only disklike molecules but also molecules with unconventional shapes can form columnar liquid-crystalline assemblies with nanosegregated structures. Moreover use of non-covalent interactions such as hydrogen bonding, ionic and electron donor-acceptor intera

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTHydrogen-bonded liquid crystals. Novel mesogens incorporating nonmesogenic bipyridyl compounds through complexation between hydrogen-bond donor and acceptor moietiesTakashi Kato, Jean M. J. Frechet, Paul G. Wilson, Takeshi Saito, Toshiyuki Uryu, Akira Fujishima, Chihiro Jin, and Fumiko KaneuchiCite this: Chem. Mater. 1993, 5, 8, 1094–1100Publication Date (Print):August 1, 1993Publication History Published online1 May 2002Published inissue 1 August 1993

Formation of the nacre of a shell is mimicked here to synthesize layered polymer/calcium carbonate composites such as that shown in the Figure. The combination of insoluble chitin or chitosan solid matrices with soluble acidic macromolecules such as poly(acrylic acid) is used to induce thin-film crystallization of CaCO3 on the solid matrices. The polymorph formed can also be controlled employing this method.

Liquid crystals are molecular materials that combine anisotropy with dynamic nature. Recently, the use of hydrogen bonding for the design of functional liquid crystalline materials has been shown to be a versatile approach toward the control of simple molecularly assembled structures and the induction of dynamic function. A variety of hydrogen-bonded liquid crystals has been prepared by molecular self-assembly processes via hydrogen bond formation. Rod-like and disk-like low-molecular weight com

Liquid-Crystalline behavior over a wide temperature range and reversible phase transitions are observed for the polymer network 1, which is held together by hydrogen bonds between benzoic acid and pyridyl units

Abstract The stability of a hydrogen-bonded complex built through inter-molecular hydrogen bonding between carboxylic acid and pyridine fragments has been examined using infrared spectroscopy. Infrared spectra as a function of temperature have been recorded for the 1:1 complex of 4-hexyloxybenzoic acid and trans-4-propoxy-4′-stilbazole from the crystalline state to the isotropic state. A dependence of the stability of the hydrogen bond on molecular orientation is observed clearly in the infrared

Abstract Dynamische weiche Materialien werden im 21. Jahrhundert an Bedeutung gewinnen. Zwar sind diese Funktionsmaterialien nicht so beständig wie Metalle, Keramiken oder Plastik, dafür reagieren sie aber gut auf externe Reize. Geordnete weiche Materialien können dynamische Funktionen erfüllen. Flüssigkristalle aus selbstorganisierten Molekülen sind ein Beispiel hierfür: Sie eignen sich möglicherweise zum Elektronen‐, Ionen‐ oder Stofftransport sowie als sensorisch, katalytisch, optisch oder bi