Enhancement of Biodegradable Poly(Ethylene Oxide) Ionic–Polymer Metallic Composite Actuators with Nanocrystalline Cellulose Fillers

Biodegradable ionic polymer metallic composite (IPMC) electroactive polymers (EAPs) were fabricated using poly(ethylene oxide) (PEO) with various concentrations of lithium perchlorate. Nanocrystalline cellulose (NCC) rods created from a sulfuric acid hydrolysis process were added at various concentrations to increase the EAPs’ elastic modulus and improve their electromechanical properties. The electromechanical actuation was studied. PEONCC composites were created from combining a 35-mg/mL aqueous NCC suspension with an aqueous, PEO solution at varying vol.%. Due to an imparted space charge from the hydrolysis process, composites with an added 1.5 vol.% of NCC suspension exhibited an electromechanical tip displacement, strain, and elastic modulus that was 40.7%, 33.4% and 20.1% higher, respectively, than those for PEO IPMCs without NCC. This performance represented an increase of 300% in the energy density of these samples. However, the electromechanical response decreased when the NCC content was high. NCC without the space charge were also tested to verify the analysis. Additionally, the development of new relationships for modeling and evaluating the time-dependent instantaneous tip angular velocity and acceleration was discussed and applied to these IPMCs.

Recent Progress on Cellulose-Based Electro-Active Paper, Its Hybrid Nanocomposites and Applications

We report on the recent progress and development of research into cellulose-based electro-active paper for bending actuators, bioelectronics devices, and electromechanical transducers. The cellulose electro-active paper is characterized in terms of its biodegradability, chirality, ample chemically modifying capacity, light weight, actuation capability, and ability to form hybrid nanocomposites. The mechanical, electrical, and chemical characterizations of the cellulose-based electro-active paper and its hybrid composites such as blends or coatings with synthetic polymers, biopolymers, carbon nanotubes, chitosan, and metal oxides, are explained. In addition, the integration of cellulose electro-active paper is highlighted to form various functional devices including but not limited to bending actuators, flexible speaker, strain sensors, energy harvesting transducers, biosensors, chemical sensors and transistors for electronic applications. The frontiers in cellulose paper devices are reviewed together with the strategies and perspectives of cellulose electro-active paper and cellulose nanocomposite research and applications.

Hybrid nanocomposite based on cellulose and tin oxide: growth, structure, tensile and electrical characteristics

A highly flexible nanocomposite was developed by coating a regenerated cellulose film with a thin layer of tin oxide (SnO₂) by liquid-phase deposition. Tin oxide was crystallized in solution and formed nanocrystal coatings on regenerated cellulose. The nanocrystalline layers did not exfoliate from cellulose. Transmission electron microscopy and energy dispersive x-ray spectroscopy suggest that SnO₂ was not only deposited over the cellulose surface, but also nucleated and grew inside the cellulose film. Current-voltage characteristics of the nanocomposite revealed that its electrical resistivity decreases with deposition time, with the lowest value obtained for 24 h of deposition. The cellulose-SnO₂ hybrid nanocomposite can be used for biodegradable and disposable chemical, humidity and biosensors.