Free-standing graphene films embedded in epoxy resin with enhanced thermal properties

The poor thermal conductivity of polymer composites has long been a deterrent to their increased use in high-end aerospace or defence applications. This study describes a new approach for the incorporation of graphene in an epoxy resin, through the addition of graphene as free-standing film in the polymeric matrix. The electrical and thermal conductivity of composites embedding two different free-standing graphene films was compared to composites with embedded carbon nanotube buckypapers (CNT-BP). Considerably higher thermal conductivity values than those achieved with conventional dispersing methods of graphene or CNTs in epoxy resins were obtained. The characterisation was complemented with a study of the structure at the microscale by cross-sectional scanning electron microscopy (SEM) images and a thermogravimetric analysis (TGA). The films are preconditioned in order to incorporate them into the composites, and the complete manufacturing process proposed allows the production and processing of these materials in large batches. The high thermal conductivity obtained for the composites opens the way for their use in demanding thermal management applications, such as electronic enclosures or platforms facing critical temperature loads.European Defence Agency tender No 17.ESI.OP.066. Study on the Impact of Graphene on Defence Application

Tailored Mobility in a Zeolite Imidazolate Framework (ZIF) Antibody Conjugate*.

Zeolitic imidazolate framework (ZIF) hybrid fluorescent nanoparticles and ZIF antibody conjugates have been synthesized, characterized, and employed in lateral-flow immunoassay (LFIA). The bright fluorescence of the conjugates and the possibility to tailor their mobility gives a huge potential for diagnostic assays. An enzyme-linked immunosorbent assay (ELISA) with horseradish peroxidase (HRP) as label, proved the integrity, stability, and dispersibility of the antibody conjugates, LC-MS/MS provided evidence that a covalent link was established between these metal-organic frameworks and lysine residues in IgG antibodies

Application of standardization for the design and construction of carbon nanotube-based product pilot lines in compliance with EU regulation on machinery

The "PLATFORM" manufacturing ecosystem for pilot production of pre-commercial CNT-based nano-enabled products, consists of three pilot lines (PPLs) for the manufacture of buckypapers, doped prepregs and doped veils. The PPLs have been constructed with the ultimate goal to commercialize these products in the European market in 2020/2022.This goal requires having the PPLs in compliance with the applicable product safety regulation by that date (CE marking). The main EU regulation for new machinery (as the PPLs) is the Directive 2006/42/EC on Machinery (MD). This Directive sets out the general mandatory Essential Health and Safety Requirements (EHSRs) related to the design and construction of machinery, while particular technical specifications for fulfilling them are provided in European harmonized standards. Application of harmonized standards is voluntary but confers a presumption of conformity with the EHSRs they cover. The PPLs are unique machines for own use and must comply with the MD before they are put into service, in 2020/2022. But the MD does not provide specific EHSRs for nanosafety and no harmonized standards are available in this field for the safe design of the PPLs. In this context, this paper shows the standardization strategy followed by the project PLATFORM (GA 646307) to design the PPLs in compliance with the EHSR referred to the risks to health resulting from hazardous substances emitted by machinery (MD, Annex I, EHSR 1.5.13). In the absence of nanosafety harmonized standards to satisfy the aforementioned EHSR, the design and design verification of the PPLs were carried out through A & B - type harmonized standards (e.g. EN ISO 12100, EN ISO 14123-1/2), and other European and international standards.The projects PLATFORM and OASIS have received funding from the European Union’s Horizon 2020 research and innovation programme, under grant agreements Nº 646307 and Nº 814581, respectively. This paper reflects only the authors’ views, and the Commission is not responsible for any use that may be made of the information contained therein

PLATFORM: Study of the integration of materials manufactured with CNTs in current processes of manufacture by infusion in aeronautics

The need to improve non-intrinsic properties of composite materials is a fact that leads to studies such as the one carried out in this project, where the possibility of integrating new materials development into common materials is analyzed to provide them with an improved properties: mechanical or electric. The main objective of the project is to analyze the possibility of introducing the new materials into the current manufacturing processes, improving the properties of the raw material (dry carbon fiber fabric infused with monocomponent epoxy resin), under aeronautical requirements. Two material developments are made with carbon nanotubes in two different formats: buckypapers and thermoplastic doped veils. The implementation of each materials has been studied in current infusion processes, more concretely manufacturing processes by RTM (Resin Transfer Molding). The studied possibilities are: buckypapers incorporated in dry preforms, for their subsequent infusion and doped veils embedded in dry preforms, for their subsequent infusion. The obtained results at this moment (2nd year of the project) are satisfactory, although it´s necessary to optimize the materials to improve the automation of the manufacturing process and achieve a greater improvement of properties

PLATFORM: Study of the integration of new nanomaterials in a current processes of manufacture with prepreg materials in aeronautics

PLATFORM appear for the need to improve non-intrinsic properties of composite materials, principally its mechanical and electrical properties. The main objective of the project is to analyze the possibility of introducing three new materials in development into the current manufacturing processes, improving the properties of the raw material, more concrectly prepreg unidirectional carbon fibre with epoxy resin. Several material developments are made with carbon nanotubes in three different formats: buckypapers, thermoplastic doped veils and CTN treated prepreg. The implementation of each materials has been studied in current infusion processes, more concretely manufacturing with prepregs and cure in an autoclave. The studied possibilities are: buckypapers incorporated and doped veils embedded in prepreg laminates or full manufacturing with treated prepreg. The obtained results at the 2nd year of the project are satisfactory, but it´s necessary to optimize the materials to automate the manufacturing and improve the final properties

Synergy effect in the addition of nanoreinforcements in matrix and onto the continouos fiber for composite structural health monitoring

The aim of the research is focused on the manufacture of multiscale reinforced composites with self-monitoring capabilities. In order to achieve it, reference material based on epoxy resin and glass fiber fabric has been modified by the addition of carbon nanotubes which allow the creation of a nanoreinforcement electrically conductive percolation network. The registration of electrical resistance variations due to strain or damage can be used to monitorize these effects caused by the mechanical loads. The research also studies the modification of the electrical properties (electrical conductivity measured in both transverse and longitudinal directions) and interlaminar mechanical properties caused by the use of nanoreinforced resins or surface modified fabrics. Multiscale reinforced composites manufactured allow the detection and partial location of damage caused during the interlaminar strength test. Moreover, differences in sensitivity due to manufacturing method and nanoreinforcement used have been clarified

Using an embedded Buckypaper to monitor mode I crack growth in bonded joints

Structural Health Monitoring (SHM) systems are commonly integrated in bonded joints for different applications in order to detect and predict potential fatigue and damages caused by internal and external agents they are subjected to during their operation life. However, each of the current SHM systems presents some drawbacks, as the reduction of structural properties or the difficulty in its implementation. This work deals with the use of a Carbon Nanotube film (Bukypaper) as a sensor in double cantilever beam (DCB) bonded joint specimens for crack growth monitoring purposes. Buckypaper (BP) sheets were manufactured and integrated in adhesive film layers and its integration quality was studied by Scanning Electron Microscopy (SEM). The effect of the integration of different thickness BPs in the mechanical performance of the bonded joints was also assessed performing DCB fracture tests. Also, electro-mechanical tests were conducted using the BP as the sensor, monitoring the output in the electrical resistance during the crack propagation. It was observed the capability of BP to detect and locate the damage during the test with a linear dependence between the electrical resistance measured in the BP and the deduced crack growth, proving the potential of the BP to monitor self-sensing bonded joints.Basque Government (Ekonomiaren Garapen eta Lehiakortasun Saila, Eusko Jaurlaritza) in the frame of ELKARTEK programme to ACTIMAT project – Materiales Inteligentes Para Productos y Procesos de Fabricación Avanzada [KK-2018/00099]