Properties of core–shell structured nanopowders of molecular crystals fabricated by dry grinding

Kunihiro Ichimura,*^ab Ken'ichi Aoki,^ab Haruhisa Akiyama,^c Shin Horiuchi,^c Shusaku Nagano^d and Shinji Horie^e

* Corresponding authors

^a Faculty of Science, Toho University, 2-2-1 Miyama, Funabashi, Chiba, Japan
E-mail: k-ichimura@sci.toho-u.ac.jp
Fax: +81-47-472-1331
Tel: +81-47-472-1331

^b Research Centre for Materials with Integrated Properties, Toho University, 2-2-1 Miyama, Funabashi, Chiba, Japan

^c Nanotechnology Research Institute, National Institute of Advanced Industrial Science and Technology, 1-1-1 Higashi, Tsukuba, Ibaraki, Japan

^d Department of Molecular Design and Engineering, Graduate School of Engineering, Nagoya Universiy, Furo-cho, Chikusa, Nagoya, Japan
E-mail: snagano@apchem.nagoya-u.ac.jp.

^e R&D Center, Toda Kogyo Corporation, Otake, Hiroshima, Japan

Abstract

A generic way to prepare nano-sized molecular crystals in large scale is described. The dry mechanical grinding of a mixture of molecular crystals with surface-modified Stöber silica nanoparticles gave voluminous hybridised powders with core–shell nanostructures, which were revealed by TEM and EFTEM measurements. Fluorescence spectra of the hybrids of emissive crystals suggested that crystal structures of the bulk are preserved even after the milling. Calorimetric measurements disclosed that melting points of crystals are lowered as a result of the nanohybridisation and that the depression of melting point and heat of fusion are reversibly proportional to shell thickness.

Article information

https://doi.org/10.1039/B925120K

Article type

Paper

Submitted

01 Dec 2009

Accepted

04 Mar 2010

First published

14 Apr 2010

Download Citation

J. Mater. Chem., 2010,20, 4312-4320

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