Eur. Phys. J. E (2004) 13: 391-400
https://doi.org/10.1140/epje/i2003-10085-7

Inter-lamellar interactions modulated by addition of guest components

¹ Department of Physics, Faculty of Science, Ochanomizu University, 2-1-1 Otsuka, Bunkyo, 112-0012, Tokyo, Japan
² Department of Chemistry, Faculty of Science, Tokyo Metropolitan University, 1-1 Minami-Osawa, Hachioji, 192-0397, Tokyo, Japan

^* e-mail: imai@phys.ocha.ac.jp

Abstract

We have investigated the effects of a guest component (polymer or spherical colloidal particle) confined between flexible lamellar slits on the inter-lamellar interaction by means of a small-angle X-ray scattering technique and a neutron spin echo technique. The dominant interaction between flexible lamellar membranes without guest components is the Helfrich mechanism. The addition of a neutral polymer into the lamellar phase induces an attractive inter-lamellar interaction and finally destabilizes the lamellar phase. On the other hand, spherical colloidal particles confined between flexible lamellar membranes reduce the undulational fluctuations of lamellae and bring a repulsive inter-lamellar interaction. The behavior of the layer compression modulus of the lamellar membrane containing colloidal particles is well described by the entropical repulsive inter-lamellar interaction driven by steric hindrance.