Electroconductive cellulose nanocrystals - Synthesis, properties and applications: A review.

There is a growing interest in the synthesis of electrically conductive cellulose nanocrystal (CNC) for advanced applications, such as supercapacitor, batteries, sensor, and printed electronics. CNC is recognized as an attractive template for the fabrication of functional nanomaterials. Since CNC possesses many attractive properties, it is a sustainable template to prepare conductive nanomaterials, by either coating it with a conductive material or transforming it into carbon nanorods. This review summarizes the utilization of a sustainable and low-cost CNC to produce conductive nanocomposites via an environmentally friendly process. Electroconductive CNCs with enhanced electrical properties, lower electrical percolation threshold, and better mechanical properties can be produced and are attractive systems for many new applications.

Interfacial Control of the Synthesis of Cellulose Nanocrystal Gold Nanoshells.

Cellulose nanocrystal (CNC) gold nanoshell was prepared using a polymer-coated CNC as a template. A seed-mediated shell growth approach (ex situ) was employed, gold nanoparticles (AuNPs) of two sizes were prepared, and the effect of the size of AuNP on the shell quality (smoothness, evenness, and continuity) was elucidated. Additionally, a novel one-pot synthesis approach (in situ) was evaluated for the preparation of the gold nanoshell, where polymer-coated CNCs with adsorbed ascorbic acid were used to reduce Au ions to form a metallic gold shell on CNC. The surface coverage was manipulated by adding different amounts of plating solutions. The formation and morphology of gold nanoshells were evaluated by zeta potential measurements, dynamic light scattering, UV-vis spectroscopy, and transmission electron microscopy (TEM). The catalytic performance of the CNC-gold nanostructures for the reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) was governed by the surface area of gold shells.

Facile thermochemical conversion of FeOOH nanorods to ZnFe2O4 nanorods for high-rate lithium storage.

We successfully prepared ZnFe2O4 nanorods (ZFO-NRs) by a simple thermochemical reaction of FeOOH nanorods with Zn(NO3)2 to use as an anode material in lithium-ion batteries. The FeOOH nanorod shape was well maintained after conversion into ZFO-NR with the formation of porous structures. The nanorod structure and porous morphology facilitate Li+ transport, improve the reaction rates owing to the larger contact area with the electrolyte, and reduce the mechanical stress during lithiation/delithiation. The ZFO-NR electrode exhibited a reversible capacity of 725 mA h g-1 at 1 A g-1 and maintained a capacity of 668 mA h g-1 at 2 A g-1; these capacities are much higher and more stable than those of ZFO nanoparticles prepared by a hydrothermal method (ZFO-HT) (216 and 117 mA h g-1 at 1 and 2 A g-1, respectively). Although ZFO-NRs exhibited high, stable capacities at moderate current densities for charging and discharging, the capacity rapidly decreased under fast charging/discharging conditions (>4 A g-1). However, carbonized ZFO-NR (C/ZFO-NR) exhibited an improved reversible capacity and rate capability resulting from an increased conductivity compared with ZFO-NRs. The specific capacity of C/ZFO-NRs at 1 A g-1 was 765 mA h g-1; notably, a capacity of 680 mA h g-1 was maintained at 6 A g-1.

Nanoparticles of conjugated polymers prepared from phase-separated films of phospholipids and polymers for biomedical applications.

Phase separation in films of phospholipids and conjugated polymers results in nanoassemblies because of a difference in the physicochemical properties between the hydrophobic polymers and the polar lipid heads, together with the comparable polymer side-chain lengths to lipid tail lengths, thus producing nanoparticles of conjugated polymers upon disassembly in aqueous media by the penetration of water into polar regions of the lipid heads.