Hierarchical composites from carbon fibres electrosprayed with carbon nanotubes

 This research developed a novel method for coating carbon nanotubes onto carbon fibre surfaces. It provided valuable guidance for producing various CNT morphologies on fibre surfaces. More importantly, the produced hybrid structures improved interfacial bonding in composites significantly, and this research will explore more potential applications of new generation composites

A sustainable approach to the low-cost recycling of waste glass fibres composites towards circular economy

For practical applications, both environmental and economic aspects are highly required to consider in the development of recycling of fibre reinforced polymers (FRPs) encountering their end-of-life. Here, a sustainable, low cost, and efficient approach for the recycling of the glass fibre (GF) from GF reinforced epoxy polymer (GFRP) waste is introduced, based on a microwave-assisted chemical oxidation method. It was found that in a one-step process using microwave irradiation, a mixture of hydrogen peroxide (H2O2) as a green oxidiser and tartaric acid (TA) as a natural organic acid could be used to decompose the epoxy matrix of a waste GFRP up to 90% yield. The recycled GFs with ~92.7% tensile strength, ~99.0% Young\u27s modulus, and ~96.2% strain-to-failure retentions were obtained when compared to virgin GFs (VGFs). This short microwave irradiation time using these green and sustainable recycling solvents makes this a significantly low energy consumption approach for the recycling of end-of-life GFRPs

Hydrophilic PAN based carbon nanofibres with improved graphitic structure and enhanced mechanical performance using ethylenediamine functionalized graphene

Polyacrylonitrile (PAN) reinforced with nano-carbons such as graphene (Gr) and carbon nanotubes (CNTs) provides great opportunity for the development of low-cost and high-performance carbon materials. However, the poor dispersion and weak interaction between the carbon nanofillers and the surrounding PAN matrix prevent the final carbonized materials from reaching their full potential. Herein, we demonstrate a chemical approach using ethylenediamine (EDA) acting as a linker between graphene nanoplatelets and PAN for improved mechanical performance. The as-prepared CNFs exhibit a higher carbon yield and tensile modulus as well as improved graphitic structure compared to pristine PAN and PAN/Gr nanofibres. Furthermore, EDA can act as a N source for N-doping during the carbonization, enabling CNFs with hydrophilicity performance

Multifunctional PA6 composites using waste glass fiber and green metal organic framework/graphene hybrids

Glass fiber-polyamide 6 (PA6) composites are widely used for various automotive applications, yet the ability to exhibit multifunctional properties and the cost of it remains challenging. Herein this work introduces a cost-effective approach for utilization of waste glass fiber (GF), green aluminium metal organic framework (Al-MOF), and industry-grade graphene nanoplatelets (GNPs) for the fabrication of multifunctional PA6 thermoplastic composites with enhanced mechanical performance and fire retardancy. The results demonstrate that hybrid filler of Al-MOF and GNPs have a synergistic effect in improving the mechanical properties and fire retardancy of GF reinforced PA6 composites. Compared to the neat PA6, the PA6 composite containing 20 wt% GFs, 5 wt% GNPs, and 5 wt% Al-MOF exhibited ~97% and ~93% improvements in tensile and flexural strength, respectively. Also, compared to the neat PA6, 27 and 55°C increases were observed in glass transition temperature (Tg) and heat deflection temperature, respectively. Thermal stability and fire retardancy of the GFs/PA6 composites were significantly improved when hybridized with GNPs and Al-MOF

A Nanoparticle Approach towards Morphology Controlled Organic Photovoltaics (OPV)

polymer

Capsular polypyrrole hollow nanofibers: an efficient recyclable adsorbent for hexavalent chromium removal

Capsular polypyrrole hollow nanofibers (PPy-HNFs) were fabricated via in situ polymerization of pyrrole on an organic-inorganic template, followed by acid etching. Their application in removing hexavalent chromium (Cr(vi)) from aqueous solution was then investigated. The morphologies of the capsular PPy-HNFs were studied by both scanning electron microscopy (SEM) and transmission electron microscopy (TEM), which showed that the PPy-HNFs had a capsular structure in the walls of hollow nanofibers. Fourier transform infrared (FTIR) spectroscopy and X-ray photoelectron spectroscopy (XPS) data confirmed the adsorption of Cr on capsular PPy-HNFs. The adsorption capacity increased with reduced pH of the initial solution and the adsorption process can be described using the pseudo-second-order model. These capsular PPy-HNFs showed a high Cr(vi) adsorption capacity up to 839.3 mg g-1. This adsorption capacity was largely retained even after five adsorption/desorption cycles. Electrostatic attraction between Cr and PPy-HNFs was studied using a proposed adsorption mechanism. The capsular PPy-HNFs formed a flexible membrane, which allowed easy handling during application. This study has demonstrated the possibilities of using this capsular PPy-HNF membrane for heavy metal removal from aqueous solution

Investigation of chitosan adsorption onto cotton fabric with atmospheric helium/oxygen plasma pre-treatment

In this study, the effects of helium or a helium/oxygen mixture atmospheric pressure plasma treatment on the adsorption of chitosan onto the cotton fabric were investigated. Fabrics were treated with plasma prior to a chitosan finishing process, whereby fabrics were surface coated using a pad/dry/cure method. Fourier transform infrared spectroscopy, scanning electron microscopy, X-ray photoelectron spectroscopy, surface energy analyser and contact angle measurements were used to investigate the changes on the cotton surface. Furthermore, antimicrobial activity of the cotton fabric was evaluated. The results showed that plasma pre-treatment enhanced the chitosan adsorption to the cotton surface through physical bonding and there was weak evidence of chemical bonding interactions. A combination of plasma and chitosan treatment did not show any significant differences on the antimicrobial properties compared to chitosan only treated fabric. Plasma treatment changed the fibres physically and enhanced the surface energy and thickness of chitosan distributed on the fibres

Nano-magnetite decorated carbon fibre for enhanced interfacial shear strength

The modification of carbon fibres surface has been achieved by high temperature (1000 °C) growth of Fe3O4 magnetic nanoparticles (MNPs) on the surface of carbon fibres using ammonium iron (II) sulphate as a single precursor of the nanoparticles. As a consequence, the formation of MNPs on the surface of unsized carbon fibres increased the interfacial shear strength by 84.3%, as measured by single fibre fragmentation test. Further investigation on interfacial reinforcing mechanism confirmed an increase in average total surface energy of carbon fibres from 58.81 for unmodified carbon fibre to 64.31 mJ/m2 for MNPs decorated fibres. Fundamental analysis revealed a 12.44% increase in average dispersive and no significant reduction in average specific surface energy of carbon fibre after MNPs surface decoration. This led to an increase in interlaminar shear strength from 46.9 to 63.3 MPa due to the strong mechanical interlocking at the MNPs decorated-carbon fibre/epoxy interface which can be described by improve in the dispersive component of the surface energy

Electrospun tin oxide nanofibers with different precursor solution

In this paper, electrospinning method was adopted to prepare tin oxide nanofibers membrane with three kinds of novel precursor solution PVP/C12H24O4Sn, PVP/ C4H10OSn and PVP/SnCl4. The morphology, surface element, thermal analysis and crystal structure of the fibers membrane were investigated by SEM, EDS, TG-DTA and XRD. The results showed that the organic/inorganic hybrid nanofibers with an average diameter of 300～700 nm can be obtained by electrospinning. But after calcined at 600&deg;C, the loose and porous tin oxide nanofibers membrane with an average diameter of 100～250 nm can be obtained only by using PVP/SnCl4 as preceusor solution, moreover, it showed good fiber forming property. From XRD spectra, it was found that the rutile structure tin oxide finally obtained without other crystalline forms.</jats:p