Polypyrrole Polyethylene Composite for Controllable Linear Actuators in Different Organic Electrolytes

Controllable linear actuation of polypyrrole (PPy) is the envisaged goal where only one ion dominates direction (here anions) in reversible redox cycles. PPy with polyethylene oxide (PEO) doped with dodecylbenzenesulfonate forms PPy-PEO/DBS films (PPy-PEO), which are applied in propylene carbonate (PC) solvent with electrolytes such as 1-ethyl-2,3-dimethylimidazolium trifluoromethanesulfonate (EDMICF3SO3), sodium perchlorate (NaClO4) and tetrabutylammonium hexafluorophosphate (TBAPF6) and compared in their linear actuation properties with pristine PPy/DBS samples. PPy-PEO showed for all applied electrolytes that only expansion at oxidation appeared in cyclic voltammetric studies, while pristine PPy/DBS had mixed-ion actuation in all electrolytes. The electrolyte TBAPF6-PC revealed for PPy-PEO best results with 18% strain (PPy/DBS had 8.5% strain), 2 times better strain rates, 1.8 times higher electronic conductivity, 1.4 times higher charge densities and 1.5 times higher diffusion coefficients in comparison to PPy/DBS. Long-term measurements up to 1000 cycles at 0.1 Hz revealed strain over 4% for PPy-PEO linear actuators, showing that combination of PPy/DBS with PEO gives excellent material for artificial muscle-like applications envisaged for smart textiles and soft robotics. FTIR and Raman spectroscopy confirmed PEO content in PPy. Electrochemical impedance spectroscopy (EIS) of PPy samples revealed 1.3 times higher ion conductivity of PPy-PEO films in PC solvent. Scanning electron microscopy (SEM) was used to investigate morphologies of PPy samples, and EDX spectroscopy was conducted to determine ion contents of oxidized/reduced films.

in vitro Cytotoxicity examination of the seashell and fish scale substances embedded with high degree of compactness in polyethylene composite

The organic response of polymer composites is facilitated by adding natural filler materials. Several new composite formulations claim to reduce the environmental impact. The present study assessed the cytotoxic responses of seashell and fish scale filled composite materials. The Polyethylene high-density (PEHD), 30 wt. % of the seashell and 30 wt. % of a seashell and fish scale combinations blended with the polymer matrix composites with 10:3 proportion (PEHD 100 g:Reinforcements 30 g), and are then fabricated by the plastic injection molding machine. To better imitator the microstructure and the mineral component of natural bone, novel hydroxyapatite / polymer composite scaffolds are allowed to interact 10, 20, 30, 40 and 50 μl of standard fresh cell culture medium for 24 hours. Morphology of cell, cell viability, and the effect of Cytotoxicity on polyethylene based composite samples were examined through ISO 10993:5, and 10993:12 test standards. The percentage of cell viability and the level of toxicity were compared.

Mesoscale modeling and biocompatibility of nano-hydroxyapatite reinforced ultra-high molecular weight polyethylene composite

This work aims to implement an efficient and accurate computational model to predict elastoplastic properties of UHMWPE/nano-HA bio-composite. Mean-field (MF) homogenization and finite element (FE) techniques are implemented to predict the elastoplastic behavior of composite. The predicted results obtained by MF and FE were compared and validated experimentally by fabricating the specimen using microwave-assisted compression molding. The axial and transverse moduli were increased by 49% at a 20% weight fraction of nano-HA. The hardening modulus was also found to be increased by 67%. Further, Degree of crystallinity (Xc) of fabricated composite specimens was determined using differential scanning calorimetry analysis. It was found that the Xc increased 34% with the addition of 20% weight fraction of nano-HA. In vitro, direct contact cytotoxicity and antibacterial test were performed to determine cell adhesion and bacterial behavior of the composite.