Electrically conductive composites comprising polymers and graphene are extremely versatile and have a wide range of potential applications. The conductivity of these composites depends on the choice of polymer matrix, the type of graphene filler, the processing methodology, and any post-production treatments. In this review, we discuss the progress in graphene-polymer composites for electrical applications. Graphene filler types are reviewed, the progress in modelling these composites is outlined, the current optimal composites are presented, and the example of strain sensors is used to demonstrate their application.

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Electrical percolation in graphene-polymer composites

Textile wastewater heavy metal pollution has become a severe environmental problem worldwide. Metal ion inclusion in a dye molecule exhibits a bathochromic shift producing deeper but duller shades, which provides excellent colouration. The ejection of a massive volume of wastewater containing heavy metal ions such as Cr (VI), Pb (II), Cd (II) and Zn (II) and metal-containing dyes are an unavoidable consequence because the textile industry consumes large quantities of water and all these chemicals cannot be combined entirely with fibres during the dyeing process. These high concentrations of chemicals in effluents interfere with the natural water resources, cause severe toxicological implications on the environment with a dramatic impact on human health. This article reviewed the various metal-containing dye types and their heavy metal ions pollution from entryway to the wastewater, which then briefly explored the effects on human health and the environment. Graphene-based absorbers, specially graphene oxide (GO) benefits from an ordered structured, high specific surface area, and flexible surface functionalization options, which are indispensable to realize a high performance of heavy metal ion removal. These exceptional adsorption properties of graphene-based materials support a position of ubiquity in our everyday lives. The collective representation of the textile wastewater's effective remediation methods is discussed and focused on the GO-based adsorption methods. Understanding the critical impact regarding the GO-based materials established adsorption portfolio for heavy metal ions removal are also discussed. Various heavy-metal ions and their pollutant effect, ways to remove such heavy metal ions and role of graphene-based adsorbent including their demand, perspective, limitation, and relative scopes are discussed elaborately in the review.

https://onlinelibrary.wiley.com/doi/pdf/10.1002/tcr.202000153

A Review on Heavy Metal Ions and Containing Dyes Removal Through Graphene Oxide-Based Adsorption Strategies for Textile Wastewater Treatment

Flexible, superhydrophobic and highly conductive composite based on non-woven polypropylene fabric for electromagnetic interference shielding

Nanoparticle (NP)/polymer nanocomposites received considerable attention because of their important applications including catalysis. Metal and metal oxide NPs may impart catalytic properties to polymer nanocomposites, while polymers with a different structure, functionality, and architecture control the NP formation (size, shape, location, composition, etc.) and in this way, govern catalytic properties of nanocomposites. In this review we will discuss the influence of the polymer nanostructure (thin or grafted layers, polymer ordering, polymer nanopores), architecture (branched vs linear), functional groups (coordinating or ionic), specific properties (reducing, stimuli responsive, conductive), etc. on the formation of metal or metal oxide NPs and the catalytic behavior of the nanocomposites. The development of novel and efficient catalysts is crucial for progress in chemical sciences, and this explains a huge number of publications in this area in recent years. Taking into consideration previous review articles on NP/polymer catalysts, we limited this review to a discussion of a narrow temporal scope (2017-April 2019), while embracing a broad subject scope, i.e., considering any polymers and NPs which form catalytic nanocomposites. This gives us a unique view of the field of catalytic polymer nanocomposites and allows understanding of where the field is going.

Role of Polymer Structures in Catalysis by Transition Metal and Metal Oxide Nanoparticle Composites.

Advanced drug and gene delivery systems based on functional biodegradable polycarbonates and copolymers

Polypyrrole nanowire/silver nanoparticle composites (PPy/Ag) are obtained in aqueous media through a one-pot method without any external stimulus. PPy nanowires were assembled on the reactive self-degraded template of the complex of AgNO3 and methyl orange (MO). During the synthesis process in the dark surrounding, Ag nanoparticles could be uniformly decorated onto the surface of PPy nanowires in situ by the redox reaction of pyrrole and AgNO3. Neither additional reducing agents for the growth of silver nanoparticles nor oxidizing agents for the polymerization of pyrrole are utilized. The formation mechanism, morphologies, structural characteristics, and conductivity of the obtained PPy/Ag nanocomposites are reported. The as-prepared PPy/Ag nanocomposites exhibit well-defined response to the electrochemical reduction of hydrogen peroxide. Moreover, the preliminary antibacterial assays indicate that the PPy/Ag nanocomposites also possess antibacterial abilities against Escherichia coli.

Synthesis of polypyrrole nanocomposites decorated with silver nanoparticles with electrocatalysis and antibacterial property

Facile synthesis of nitrogen-doped graphene aerogels for electrochemical detection of dopamine

Facile Assembly of Polyaniline/Graphene Oxide Composite Hydrogels as Adsorbent for Cr(VI) Removal

Silver nanoparticles/polydopamine coated polyvinyl alcohol sponge as an effective and recyclable catalyst for reduction of 4-nitrophenol

The alginate/reduced graphene oxide composite hydrogels with hierarchical network structures were synthesized through the hydrothermal treatment of graphene oxide and alginate in an aqueous solution followed by ionically cross-linking of metal ions. The network of reduced graphene oxide was prepared via self-assembly of graphene nanosheets in the presence of alginate during the hydrothermal process; then, the polymer network of alginate was obtained by ionically cross-linking, forming the composite hydrogel. The effect of metal ions on the physical properties of the composite hydrogels was investigated. The prepared alginate/reduced graphene oxide composite hydrogel cross-linked by Fe3+ ions showed higher compression strength and lower swelling ratio. Moreover, due to the synergetic interaction between graphene and alginate, the composite hydrogels exhibited the improved dye adsorption performance, especially for cationic dyes. Even after ten adsorption/desorption cycles, the composite hydrogels can retain more than 90% dye adsorption capacity. The results indicated that the composite hydrogel with good stability, adsorption and regeneration ability could be a promising candidate for dye removal from waste aqueous solutions.

Zhang Qiao

Papers

Synthesis of polypyrrole nanocomposites decorated with silver nanoparticles with electrocatalysis and antibacterial property

Facile synthesis of nitrogen-doped graphene aerogels for electrochemical detection of dopamine

Facile Assembly of Polyaniline/Graphene Oxide Composite Hydrogels as Adsorbent for Cr(VI) Removal

Silver nanoparticles/polydopamine coated polyvinyl alcohol sponge as an effective and recyclable catalyst for reduction of 4-nitrophenol

Strong alginate/reduced graphene oxide composite hydrogels with enhanced dye adsorption performance