A review on electrospun magnetic nanomaterials:methods, properties and applications

Magnetic materials display attractive properties for a wide range of applications. More recently, interest has turned to significantly enhancing their behaviour for advanced technologies, by exploiting the remarkable advantages that nanoscale materials offer over their bulk counterparts. Electrospinning is a high-throughput method that can continuously produce nanoscale fibres, providing a versatile way to prepare novel magnetic nanomaterials. This article reviews 20 years of magnetic nanomaterials fabricated via electrospinning and introduces their two primary production methods: electrospinning polymer-based magnetic fibres directly from solution and electrospinning fibrous templates for post-treatment. Continual advances in electrospinning have enabled access to a variety of morphologies, which has led to magnetic materials having desirable flexibility, anisotropy and high specific surface area. Post-treatment methods, such as surface deposition, carbonization and calcination, further improve or even create unique magnetic properties in the materials. This renders them useful in broad ranging applications, including electromagnetic interference shielding (EMS), magnetic separation, tissue engineering scaffolding, hyperthermia treatment, drug delivery, nanogenerators and data storage. The processing methods of electrospun magnetic nanofibres, their properties and related applications are discussed throughout this review. Key areas for future research have been highlighted with the aim of stimulating advances in the development of electrospun magnetic nanomaterials for a wide range of applications

Thermally triggerable, anchoring block copolymers for use in aqueous inkjet printing

Towards the goal of shifting from toxic organic solvents to aqueous-based formulations in commercial inkjet printing, a series of well-defined poly[(2-hydroxyethyl acrylate-stat-N-hydroxymethyl acrylamide)-block-propyl methacrylate], P[(HEA-st-HMAA)-b-PMA], amphiphilic block copolymers with varying degrees of polymerization and comonomer compositions were synthesized via reversible addition–fragmentation chain transfer (RAFT) polymerization. Optimized RAFT polymerization conditions were found to allow larger batch synthesis (>20 g scale) without compromise over molecular design control (molecular mass, hydrophobic/hydrophilic balance, dispersity, etc.). The copolymers were subsequently investigated for their crosslinking and adhesive properties, as well as jetting performance, to determine their suitability for use in aqueous ink formulations. Crosslinking was found to occur much faster for copolymers containing more of the crosslinkable HMAA monomer units and at higher molecular masses, allowing control over the required post-deposition processing time. The amphiphilic block copolymers synthesized herein demonstrate enhanced adhesive properties compared to a selection of commercial inks whilst also achieving high print quality and performance for use in aqueous continuous inkjet (CIJ) printing, which is a key step towards greener processes in the packaging industries, where printing onto hydrophobic substrates is needed

A brief guide to polymer characterization: structure (IUPAC technical report)

To bolster the series of Brief Guides released by International Union of Pure and Applied Chemistry (IUPAC), here we introduce the first Brief Guide to Polymer Characterization. This article provides a concise overview of characterization methods for teachers, students, non-specialists, and newcomers to polymer science as well as being a useful manual for researchers and technicians. Unlike pure low molar mass chemical substances, polymers are not composed of identical molecules. The macromolecules which comprise a single polymer sample vary from one another, primarily in terms of size and shape, but often also in the arrangement or positioning of atoms within macromolecules (e.g., chain branching, isomerism, etc.). Polymer properties are often drastically different from those of other substances and their characterization relies on specialist equipment and/or common equipment used in a specialized way (e.g., particular sample preparation or data analysis). This Brief Guide focuses uniquely on the structural characterization (i.e., analyzing the molecular and multi-molecular aspects) of polymers. The complex nature of the structural variables possible in macromolecular materials often presents a challenge with regard to the detailed structural characterization of polymers. This Brief Guide provides a useful starting point to direct the reader to the most commonly used and useful techniques to characterize these structural variables