Smart and robust electrospun fabrics of piezoelectric polymer nanocomposite for self-powering electronic textiles

The present work designs a piezoelectric nanogenerator (PENG) based on the electrospun nanofibers of the piezoelectric polymer, polyvinylidene fluoride hexafluoropropylene (PVDF-HFP), by uniformly drawing the spun membranes containing cellulose nanocrystals (CNC, 2 wt%) and the Fe-doped nano ZnO (2 wt%). The hybrid nanocomposite fibers were made in double layers, with CNC/PVDF-HFP composite on one side and the Fe-doped ZnO/PVDF-HFP on the other side. This ferroelectric polymer composite exhibited maximum peak-to-peak output voltage of 12 V with a current density, 1.9 ?Acm?2, which are respectively higher by 60 and 2.3 times compared to the neat polymer fibers. The PENG is tested for its energy harvesting ability by exposing it to different environments such as ultrasound vibrations and human body movements during hand tapping, elbow movements and by attaching with the textile fabrics. While the finger tapping generated peak-to-peak output voltage of 6.5 V, elbow movements resulted in 5.5 V generation. In all sorts of movements, the nanogenerator shows good output performance indicating its compatibility with textile materials. The mechanical properties, breakdown strength and dielectric properties of the material are also in accordance with its possible applications in wearable electronic textiles. - 2019 The AuthorsThis publication is made possible by NPRP grant 6-282-2-119 from the Qatar National Research Fund (a member of Qatar Foundation). The statements made herein are solely the responsibility of the authors.Scopu

Mechanical, morphological and thermal properties of LDPE/glass, MDPE/glass and HDPE/glass fibre reinforced composites

Three types of polyethylenes (low density: LDPE, medium density: MDPE, and high density: HDPE) were used to investigate the effect of chain branching on the dispersion and adhesion in glass fibre (GF) reinforced polymer composites. The compounding of LDPE/GF, MDPE/GF and HDPE/GF was carried out in a Brabender twin screw extruder. In each composite system, glass fibre was 20% weight and the main matrix was 80%. The mixtures were fed into hopper of the extruder, extruded, cooled and granulated. The compounded samples were prepared as test specimens by a PE 5 injection molding machine. Mechanical, morphological and thermal methods were used as the characterization techniques to study the interaction between the glass fibre and the polyethylene. Addition of glass fibres to the matrix enhanced the mechanical properties for all composite systems. The degree of enhancement, however, depended on the branching and crystallinity of each polymer. The long chain branching (LCB) in LDPE resulted in higher increase in modulus both in the melt and in the solid state. The higher crystallinity of HDPE was responsible for higher increase in tensile strength and less fibre pull-out upon addition of glass fibres. Scanning electron microscopy of LDPE/glass fibre reinforced composites showed more fibre pull out from the matrix. The addition of glass fibres also resulted in improved thermal stability of the various polyethylene samples. The main aim of this study was to understand the effect of the branching of polyethylene on adhesion of GF to the polymer chain and the results on mechanical, thermal properties of glass fibre reinforced composites.</jats:p

Flexible oil sensors based on multiwalled carbon nanotube-filled isoprene elastomer composites

Oil Spills Due To Either Accidents Or Deliberate Oily Discharges Cause Severe Pollution And Can Be Thwarted If Proper Detection Facilities Are Applied. This Article Reports New Flexible Oil Sensor Capabilities Of Three Different Elastomer (natural Rubber, Butyl Rubber, And Styrene-isoprene-styrene Copolymer) Composites Of Multiwalled Carbon Nanotubes (MWCNTs). We Highlight The Sensor Manufacturing By Simple Means Of Solution Mixing, And The Uniform Dispersion Of MWCNTs In The Elastomers Is Substantiated With The Help Of Morphology And Structural Analyses. Electrical Percolation And Semiconductor Characteristics Were Also Examined For Composites. The Developed Materials Show Better Oil Sensing Above The Percolation Level, And The Filler-polymer Interfacial Interaction Is The Main Factor Regulating The Oil-detecting Capability. The Efficiency Of The Sensors Was Also Tested After Many Instances Of Bending. 2016, Rubber Division of The American Chemical Society. All Rights Reserved.Scopu

Plastics recycling: Insights into life cycle impact assessment methods

The increased consumption of plastics in day to day life has a significant impact on the environment. Life cycle assessment (LCA) is widely used to select a sustainable alternative in plastic waste management. The LCA studies on mechanical recycling and energy recovery scenarios showed that recycling resulted in lower emissions and provided benefits to the environment. These results are valid only if the performance of the recycled plastic is equivalent to those of the virgin materials. Many LCA studies have been focused on individual impact categories rather than aggregated single score. The decision making process becomes complex if individual impact categories are used. This research is focused on the comparison of LCA results between individual and aggregated impacts and integration of performance of recycled plastics in LCA. The results indicated that recycling was the preferred option if it could replace a minimum of 70-80% of virgin plastics. © Institute of Materials, Minerals and Mining 2013

A review on composite materials based on recycled thermoplastics and glass fibres

Mechanical properties The purpose of this paper is to review recent work on composite materials based on recycled thermoplastics and glass fibres (GFs). The high collection and separation cost of plastics waste, and the legislative push to increase recycling rates, require the inclusion of increasing proportions of low-quality plastic waste into recycled products. A robust method for upgrading mixed plastics recyclates is the incorporation of fillers and reinforcements. In particular, addition of chopped GF can lead to material systems with more favourable and consistent sets of mechanical properties. Provided a good interfacial adhesion is achieved, the key structural properties of the composite (stiffness and strength) are mainly dictated by the reinforcement. Therefore, a wide range of polymers, including blends, are accessible for recycling into semistructural products. Glass fibres are one of the most cost-effective ways of reinforcing recycled polymers, as testified by several patents and commercial products which appeared in the last decade.Scopu