DC electrorheological response of polyethylene/organically modified layered silicate nanocomposites

Abstract

The present work reports the electrorheological (ER) response of high-density polyethylene (HDPE)/organically modified silicate layers nanocomposites based on four commercially available HDPE matrices. Two single-site catalyzed bimodal resins, one single-site catalyzed unimodal resin and one Ziegler-Natta catalyzed unimodal resin are studied. It is revealed that the distinct separation of the two modes of the bimodal HDPE resins significantly enhances the ER response. It is proposed that the slower structural relaxation modes introduced by higher molecular weight species in the bimodal HDPE matrices enhance the ER response of the nanocomposites. This is ascribed to the longer induction time for leaking current density, which is an indicator of mobility and release of immobilized cationic surfactants at the silicate layers surface induced by field exposure. It is found that the screening effect of prematurely released cationic surfactants leads to a weaker ER response in nanocomposites whose matrices have faster relaxation modes.

Preparation of Cellulose/Laponite Composite Particles and Their Enhanced Electrorheological Responses

“…In this study, we introduce Laponite, a synthetic clay type with 2-dimentional disk shape (thickness: 1 nm; diameter: 25 nm), into cellulose particles by the dissolution–regeneration process of cellulose. In a previous study, Laponite as well as many other kinds of clays were used as ER materials separately or blended with polymers [ 31 , 32 , 33 ]. The special layered structures of clays played significant roles in preparing composite particles with intercalated, exfoliated, and even core–shell structures [ 34 , 35 , 36 ].…”