Highly conductive and stretchable conductors fabricated from bacterial cellulose

Abstract

Advanced materials that can remain electrically conductive under substantial elastic stretch and bending have attracted extensive interest recently owing to their broad application potentials, particularly for flexible electronics. Here, we have developed a simple and inexpensive method to fabricate highly conductive and stretchable composites using bacterial cellulose (BC) pellicles as starting materials, which can be produced in large amounts on an industrial scale via a microbial fermentation process. The prepared pyrolyzed BC (p-BC)/polydimethylsiloxane (PDMS) composites exhibit a high electrical conductivity of 0.20-0.41 S cm À1 , which is much higher than conventional carbon nanotubes and graphene-based composites. More importantly, the p-BC/PDMS composites that combine high stretchability with high conductivity show great electromechanical stability. Even after 1000 stretching cycles at the maximum strain of 80%, the resistance of the composites increased by only B10%. The resistance increased slightly (B4%) after 5000 bending cycles with a maximum bending radius of 1.0 mm.

Ultralight nanofibre-assembled cellular aerogels with superelasticity and multifunctionality

“…This large energy dissipation resulted from the viscoelasticity of the organic nanofibrous networks. After 10 cycles, a nearly constant energy loss coefficient of B0.4 was calculated, which was higher than that for typical carbon or metal foams 16,40 . Further dynamic compressive viscoelastic measurements revealed that the Young's modulus (E 0 ) and loss modulus (E 00 ) were nearly stable and were independent of the angular frequency (o) over the three decades of accessible o from 1.8 to 628 rad s À 1 (Fig.…”

“…Inspired by this idea, creating three-dimensional (3D) nanofibrous aerogels (NFAs) with high continuity and an open-cell cellular structure could be another strategy for achieving promising performance for widespread applications. Several cellulosic materials, including bacterial cellulose fibrils, cellulose nanocrystals and lignocellulose, have recently been used as building blocks and assembled into NFAs [16][17][18] . However, the inherent limits on the diversity of bulk materials, combined with the lack of precise control of the physicochemical and mechanical properties, present major challenges in the synthesis of NFAs that must be addressed before their extensive practical applications.…”

Biological Water Dynamics and Entropy: A Biophysical Origin of Cancer and Other Diseases

“…Other models for electron capture in water-for example, electrons in p-orbital-like water cavities-have been proposed and verified experimentally [127]. Electrical current which depends on the presence of water has been detected in association with cellulose [128], proteins [129,130], microtubules [131], and DNA [132,133]. In 1987, Careri et al demonstrated direct current (DC) protonic conductivity of powders of lysozyme for varied levels of hydration [134,135] and suggested that hydration-induced protonic conduction and enzymatic activity corresponds to the formation of a percolation network of absorbed water molecules on the surface of the macromolecule.…”

Mo2C nanoparticles embedded within bacterial cellulose-derived 3D N-doped carbon nanofiber networks for efficient hydrogen evolution

“…8,9,[16][17][18][19] Bacterial cellulose (BC), a low-cost and environmentally friendly biomass, can be produced on an industrial scale via the microbial fermentation process. 20 Our recent studies demonstrated that BC was an excellent precursor for producing heteroatom-doped carbon nanofiber (CNF) aerogels for energy storage and conversion. [21][22][23] In this work, using BC as 3D nanostructured carbon source, we report a facile method for synthesizing a non-noble-metal HER electrocatalyst consisting of ultrafine Mo 2 C nanoparticles embedded within 3D N-doped carbon nanofiber networks (Mo 2 C@N-CNFs) via a solidstate reaction between (NH 4 ) 6 Mo 7 O 24 and BC.…”