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The multifunctionality of carbon fiber (CF) is being extensively explored. Herein, polyimide covalent organic frameworks (PI‐COFs) are grafted bound to CF to enhance their mechanical and electrochemical properties. Here, a range of COF scaffolds are grafted to the surface of CFs via a two‐step functionalization. First, melamine is tethered to the fiber surface to provide an anchoring point for the COFs followed by a "graft from" approach to grow three different sized PI‐COFs utilizing three differently sized dianhydride, PMDA to form MA‐PMDA, NTCDA to form MA‐NTCDA, and PTCDA to form MA‐PTCDA COFs. These COFs increase the capacitance of CF by a maximum of 2.9 F g−1 (480% increase) for the MA‐PTCDA, this coincides with an increase in interfacial shear strength by 67.5% and 52% for MA‐NTCDA and MA‐PTCDA, respectively. This data represents that the first‐time CF has been modified with PI‐COFs and allows access to COF properties including their porosity and CO2 capture ability while being attached to a substrate. This may lead to additional high‐value recyclability and second‐life applications for CFs. [ABSTRACT FROM AUTHOR]

Carbon fibres are multifunctional materials considered for the realisation of structural battery electrodes. Processing conditions affect the carbonaceous microstructure of carbon fibres. The microstructure dictates the fibre's mechanical properties, i. e. modulus and strength, as well as its electrochemical capacity. Here, carbon fibre processing conditions are investigated to identify the effect of carbonisation temperature on carbon fibre multifunctionality. Different thermal conditions during carbonisation are considered, while keeping the precursor material, applied tension, and oxidation temperature constant. The carbonaceous microstructure of fibres is investigated via wide‐angle x‐ray scattering (WAXS) and transmission electron microscopy (TEM) analyses to determine the effect of the carbonisation temperature. Mechanical and electrochemical tests are performed to characterise carbon fibre multifunctionality with respect to mechanical and electrochemical performance. A moderate trade‐off between mechanical and electrochemical performance is demonstrated, where the elastic modulus and strength decrease and the electrochemical capacity increase with reduced carbonisation temperature. Here, for the studied temperature interval, the elastic modulus and strength is found to drop up to 7 % with a 15 % increase in capacity. Thus, fibres customised for targeted multifunctionality within a limited design space can be realised by careful selection of the processing conditions in conventional carbon fibre manufacture. [ABSTRACT FROM AUTHOR]

Silk fibroin interactions with metallic surfaces can provide utility for medical materials and devices. Toward this goal, titanium alloy (Ti6Al4 V) was covalently grafted with polyacrylamide via electrochemically reducing 4‐nitrobenzene diazonium salt in the presence of acrylamide. Analysis of the modified surfaces with FT‐IR spectra, SEM and AFM were consistent with surface grafting. Functionalised titanium samples with a silk fibroin membrane, with and without impregnated therapeutics, were used to assess cytocompatibility and drug delivery. Initial cytocompatibility experiments using fibroblasts showed that the functionalised samples, both with and without silk fibroin coatings, supported significant increases between 72–136 % in cell metabolism, compared to the controls after 7 days. A 7‐days release profiling showed consistent bacterial inhibition through gentamicin release with average inhibition zones of 239 mm2. Over a 5‐week period, silk fibroin coated samples, both with and without growth factors, supported better human mesenchymal stem cell metabolism with increases reaching 1031 % and 388 %, respectively, compared to samples without the silk fibroin coating with. [ABSTRACT FROM AUTHOR]

Solvate ionic liquids (SILs), equimolar amounts of lithium salts and polyether glymes, are well studied highly customisable "designer solvents". Herein the physical, thermal and ion mobility properties of SILs with increased LiTFSI (LiTFSA) concentration, with ligand 1 : >1 LiTFSI stoichiometric ratios, are presented. It was found that between 60–80 °C, the lithium cation diffuses up to 4 times faster than the corresponding anion or ligand (glyme). These systems varied from viscous liquids to self-supporting gels, though were found to thin exponentially when heated to mild temperatures (50–60 °C). They were also found to be thermally stable, up to 200 °C, well in excess of normal operating temperatures. Ion mobility, assessed under an electric potential via ionic conductivity, showed the benefit of SIL optimisation for attaining greater concentrations of Li+ cations to store charge during supercapacitor charging and discharging. Molecular dynamics simulations interrogate the mechanism of enhanced diffusion at high temperatures, revealing a lithium hopping mechanism that implicates the glyme in bridging two lithiums through changes in the denticity. [ABSTRACT FROM AUTHOR]

A silver catalysed radical decarboxylation process was used to graft a copolymer (4 : 1; methylacrylate/acrylic acid) onto short carbon fibres. Surface grafting was confirmed by XPS, SEM and TGA, suggesting that the polymer accounted for 10% of the modified materials mass. Incorporation of these surface enhanced carbon fibres into an epoxy resin gave composites demonstrating an increase in ductility and a clear change in failure mode from adhesive, at the fibre–matrix interface, to cohesive, within the matrix polymer itself. [ABSTRACT FROM AUTHOR]

Bonding dissimilar materials has been a persistent challenge for decades. This paper presents a method to modify a stainless steel surface (316 L), routinely used in medical applications to enable the significant adhesion of a biopolymer (silk fibroin). The metallic surface was first covalently grafting with polyacrylamide, to enable a hydrogen bonding compatible surface. The polymerisation was initiated via the irreversible electrochemical reduction of a 4‐nitrobenzene diazonium salt (20 mM), in the presence of an acrylamide monomer (1 M) at progressively faster scan rates (0.01 V/s to 1 V/s). Examination of the modified samples by FT‐IR was consistent with successful surface modification, via observations of the acrylamide carbonyl (1600–1650 cm−1) was observed, with more intense peaks correlating to slower scan rates. Similar observations were made with respect to increasing surface polarity, assessed by water contact angle. Reductions of >60° were observed for the grafted surfaces, relative to the unmodified control materials, indicating a surface able to undergo significant hydrogen bonding. The adhesion of silk to the metallic surface was quantified using a lap shear test, effectively using silk fibroin as an adhesive. Adhesion improvements of 5–7‐fold, from 4.1 MPa to 29.3 MPa per gram of silk fibroin, were observed for the treated samples, highlighting the beneficial effect of this surface treatment. The methods developed in this work can be transferred to any metallic (or conductive) surface and can be tailored to complement any desired interface. [ABSTRACT FROM AUTHOR]

This article, titled "Influence of Carbonisation Temperatures on Multifunctional Properties of Carbon Fibres for Structural Battery Applications," discusses the reaction of a tailor-made carbon fiber with lithium atoms when exposed to the ambient atmosphere. The lithium atoms rapidly react with oxygen and moisture, resulting in the growth of lithium oxide dendrites. The article includes an SEM image that resembles a bonfire lit at night in the woods. The research article provides more detailed information on this topic. [Extracted from the article]