A Facile Synthesis of Poly(aniline-<Emphasis Type="Italic">co</Emphasis>-3-trifluoromethyl aniline) Doped Silver Nanoparticles in Micellar Solution: Its Humidity Sensor Application

Copolymerization of aniline and 3-trifluoromethyl aniline was carried out by in-situ chemical oxidative technique using slow dispersion of silver nanoparticles. The prepared copolymer was characterized by UV–Vis and FTIR spectroscopy, SEM, XRD, electrical conductivity and humidity sensing techniques. UV–Vis spectrum shows absorption bands around 320 and 620 nm respectively corresponding to π–π* and n–π* transitions. Band gap value of the polymers confirms its semiconducting nature. SEM analysis shows highly agglomerated spherical morphology and the particle size ranges from 100 to 200 nm. The XRD pattern shows amorphous nature of nanocomposite. The electrical conductivity of this nanocomposite changes from 1.86 × 10^–9 to 2.86 × 10^–11 S/cm due to the steric effect of trifluoromethyl group. The relative humidity sensing was studied based on the resistance variations due to the absorption of water molecules in the polymer matrices. It was observed from the fabricated sensors that the resistance decreases from 400 to 230 MΩ when the relative humidity (% RH) changes from 17 to 47%.     

Surface modification and grafting of carbon fibers: A route to better interface

This review is an audit of various Carbon fibers (CF) surface modification techniques that have been attempted and which produced results with an enhancement in the interfacial characteristics of CFRP systems. An introduction to the CF surface morphology, various techniques of modifications, their results and challenges are discussed here. CFs are emerging as the most promising materials for designing many technologically significant materials for current and future generations. In order to extract all the physic-mechanical properties of CF, it is essential to modulate a suitable environment through which good interfacial relation is achieved between the CF and the matrix. The interface has the utmost significance in composites and hybrid materials since tension at the interface can result in a deterioration of the fundamental properties. This review is aimed to provide a detailed understanding of the CF structure, its possible ways of modification, and the influence of interfacial compatibility in physic-mechanical and tribological properties. Both physical and chemical modifications are illustrated with specific examples, in addition to the characterization methods. Overall, this article provides key information about the CF based composite fabrication and their many applications in aerospace and electronics- where light weight and excellent mechanical strength are required.     

White graphene reinforced polypyrrole and poly(vinyl alcohol) blend nanocomposites as chemiresistive sensors for room temperature detection of liquid petroleum gases

Microchimica Acta - The authors describe the preparation of PVA/WPPy/hBNNP nanocomposite films by solution casting method from poly(vinyl alcohol) (PVA), water soluble polypyrrole (WPPy), and using...