Hybrid Supramolecular and Colloidal Hydrogels that Bridge Multiple Length Scales

Angew Chem Weinheim Bergstr Ger. 2015 Apr 27;127(18):5473-5478. doi: 10.1002/ange.201410570. Epub 2015 Mar 13.

Abstract

Hybrid nanocomposites were constructed based on colloidal nanofibrillar hydrogels with interpenetrating supramolecular hydrogels, displaying enhanced rheological yield strain and a synergistic improvement in storage modulus. The supramolecular hydrogel consists of naphthyl-functionalized hydroxyethyl cellulose and a cationic polystyrene derivative decorated with methylviologen moieties, physically cross-linked with cucurbit[8]uril macrocyclic hosts. Fast exchange kinetics within the supramolecular system are enabled by reversible cross-linking through the binding of the naphthyl and viologen guests. The colloidal hydrogel consists of nanofibrillated cellulose that combines a mechanically strong nanofiber skeleton with a lateral fibrillar diameter of a few nanometers. The two networks interact through hydroxyethyl cellulose adsorption to the nanofibrillated cellulose surfaces. This work shows methods to bridge the length scales of molecular and colloidal hybrid hydrogels, resulting in synergy between reinforcement and dynamics.

Die Kombination eines kolloidalen Hydrogels aus nanofibrillärer Zellulose mit einem supramolekularen Hydroxyethylzellulose‐Hydrogel führt zu einem Verbundhydrogel. Die beiden Netzwerke wechselwirken durch Adsorption der Hydroxyethylzellulose an der Oberfläche der fibrillären Zellulose, was in einer erhöhten rheologischen Streckdehnung und einem gesteigerten Speichermodul resultiert.WILEY-VCH.

Keywords: Hydrogele; Nanoverbundstoffe; Nanozellulose; Supramolekulare Chemie.