Short Twaron aramid fiber reinforced thermoplastic polyurethane

Mechanical, dynamic mechanical, and rheological behaviors of a short p‐aramid fiber reinforced thermoplastic polyurethane (TPU) have been studied in the range of 0–30 wt% of fibers. The tensile strength of the composite is improved slightly at higher fiber content with a minimum at around 10 wt% of fibers. The addition of fibers markedly reduces elongation at break and entails a steady increase in the elastic modulus, but decreases the wear resistance of the matrix. Storage modulus (E′) is increased and the shapes of loss tangent (tan δ) peaks point to a possible fiber–matrix interaction. Rheological studies show a power law behavior for all composites and increased viscosity with fiber loading. Study of the tensile and cryogenic fracture surfaces by scanning electron microscopy (SEM) indicates good correlation between the modes of failure and strength of the composites. The micrographs reveal good interfacial adhesion and extensive peeling and fibrillation of the fibers in the compounded and fractured composites. Theoretical models have been used to fit the experimental modulus data. Copyright © 2008 John Wiley & Sons, Ltd.     

Development of a novel electrochemical biosensor based on catalytic properties of adenosine deaminase immobilized on graphene oxide/carboxymethyl chitosan/multi-wall carbon nanotube platform

A new type of biosensor was designed based on Adenosine deaminase (ADA) immobilized on graphene oxide (GO)/carboxymethyl chitosan (CMC)/multi-wall carbon nanotube (MWCNT) platform nanostructure, fabricated and successfully applied (utilized) in Adenosine detection. Square wave voltammetry was used to study the biosensor catalytic activity. Morphological analysis of the nanostructure was performed by AFM and SEM methods. The results provided here proved that utilizing GO/CMC/MWCNT leads to effective immobilization of ADA which was confirmed by the long term stability of the biosensor during examined intervals. The immobilized ADA activity was examined and the kinetic parameters (K _m and V _max) were found to be 47.5 μM and 5.8 μM min^?1, respectively. Furthermore, benznidazole was introduced as a potent ADA inhibitor using virtual screening. Outstanding inhibition characteristics of benznidazole was observed against ADA. ADA inhibition by benznidazole was non-competitive with the inhibition constant of 0.42 μM. Such an interesting template with an easy preparation process with low cost can provide a novel matrix for developing biosensors and biocatalysts based on enzyme immobilization.     

Estimation of mechanical properties of LDPE/LLDPE/SEBS nanocomposite reinforced with calcium carbonate nanoparticles by Ch mathematical model

Journal of Thermal Analysis and Calorimetry - Doing experiments in order to determine mechanical properties of nanocomposites costs a lot. Therefore, finding the ways by which the properties of the...