Search

Conducting polymer hydrogels (CPHs) are an attractive class of materials that synergize the electrical properties of organic semiconductors with the physical properties of hydrogels. Of particular interest is the implementation of CPHs as electrode materials for electrochemical energy storage by taking advantage of redox-tunable conjugated backbones and the large electroactive surface area. Herein, the use of 2D electrolytes as an effective post-polymerization additive to enhance the pseudocapacitive performance of CPHs, is demonstrated. By using the self-doped conjugated polyelectrolyte CPE-K hydrogel as a model system, improvements in cycling stability, specific capacitance and working voltage window upon addition of the 2D electrolytes, are shown. Furthermore, positively charged 2D electrolytes to be more effective than their negatively charged counterparts are revealed. Rheology measurements and SEM imaging indicate that the 2D electrolytes serve as non-covalent cross-linkers that help in forming a mechanically more robust and highly percolated conducting network. These results provide a new and simple to execute post-polymerization strategy to optimize the electrochemical performance of CPH-based pseudocapacitors. National Research Foundation (NRF) This work was supported by the National University of Singapore start up grant R143-000-A97-133 and the Medium-Sized Centre (MSC) grant from the National Research Foundation (NRF) of Singapore, Prime Minister's Office. G.Q. acknowledges funding from the President's Graduate Fellowship (PGF) under the National University of Singapore.

A class of compounds sharing the properties of 2D materials and electrolytes, namely 2D electrolytes is described theoretically and demonstrated experimentally. 2D electrolytes dissociate in different solvents, such as water, and become electrically charged. The chemical and physical properties of these compounds can be controlled by external factors, such as pH, temperature, electric permittivity of the medium, and ionic concentration. 2D electrolytes, in analogy with polyelectrolytes, present reversible morphological transitions from 2D to 1D, as a function of pH, due to the interplay of the elastic and Coulomb energies. Since these materials show stimuli-responsive behavior to the environmental conditions, 2D electrolytes can be considered as a novel class of smart materials that expand the functionalities of 2D materials and are promising for applications that require stimuli-responsive demeanor, such as drug delivery, artificial muscles, and energy storage.

This article describes the application of ionic liquid 1-decyl-3-methylimidazolium tetrafluoroborate in the preparation of polypropylene-silica composites. The sol-gel technology was used to prepare xerogel silica-ionic liquid hybrid S1, which was obtained as a free flowing powder of aggregated spherical particles. Ionic liquid free silica S2 was obtained by extraction and calcination of S1. Melt blending of isotactic polypropylene with S1 and S2 afforded the composites C1 (with ionic liquid) and C2 (without ionic liquid), respectively. The presence of ionic liquid on the S1 silica surface promoted significantly improved silica dispersion in the polymer matrix and prevented compression of the silica particles. Furthermore, the crystallization temperature of composite C1 was significantly higher, which indicated that silica-ionic liquid filler S1 acted as nucleating agent. The resistance to thermal decomposition of both composites was increased, but this was higher in the presence of ionic liquid. These results show that liquid salts can function as coupling agents and compatibalizers for the preparation of polymeric composites with differentiated properties. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010

The Sonogashira cross-coupling reaction of vinylic and heteroaromatic tellurium dichlorides has been explored, yielding the corresponding enynes and 2-alkynyl substituted heteroaromatic compounds. The reaction was carried out with PdCl2/CuI as catalysts and triethylamine as base, using methanol as solvent. The reaction proceeded under mild conditions and the cross-coupled products were obtained in good yields and in a stereoconservative manner.