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This document is a collection of three JRC Technical Reports that together form the “NanoDefine Methods Manual”, which has been developed within the NanoDefine project ‘Development of an integrated approach based on validated and standardized methods to support the implementation of the EC recommendation for a definition of nanomaterial’, funded by the European Union’s 7th Framework Programme, under grant agreement 604347. The overall goal of the NanoDefine project was to support the implementation of the European Commission Recommendation on the definition of nanomaterial (2011/696/EU). The project has developed an integrated empirical approach, which allows identifying a material as a nano- or not a nanomaterial according to the EC Recommendation. The NanoDefine Methods Manual consists of three parts: Part 1: The NanoDefiner Framework and Tools, which covers the NanoDefiner framework, general information on measurement methods and performance criteria, and tools developed by NanoDefine such as a materials categorisation system, a decision support flow scheme and an e-tool. Part 2: Evaluation of Methods, which discusses the outcome of the evaluation of the nanomaterials characterisation methods for measuring size. Part 3: Standard Operating Procedures (SOPs), which presents the 23 Standard Operating Procedures developed within the NanoDefine project. In this combined document, these three parts are included as stand-alone reports, each having its own abstract, table of contents, page, table and figure numbering, and references.
The present series of reports, the NanoDefine Methods Manual, has been developed within the NanoDefine project 'Development of an integrated approach based on validated and standardized methods to support the implementation of the EC recommendation for a definition of nanomaterial'1 funded by the European Union's 7th Framework Programme, under grant agreement 604347.
In 2011 the European Commission (EC) published the recommendation (2011/696/EU) for a definition of the term 'nanomaterial'1, the EC NM Definition, as a reference to determine whether an unknown material can be considered as a 'nanomaterial' for regulatory purposes. One challenge is the development of methods that reliably identify, characterize and quantify nanomaterials (NM) both as substances and in various products and matrices.
The overall goal of NanoDefine was to support the implementation of the EC NM Definition. It can also support the implementation of any NM definition based on particle size. The project has developed an integrated approach, which allows identifying any material as a nano or non-nano material according to the EC NM Definition. NanoDefine explicitly supported the governance challenges associated with the implementation of legislation concerning nanomaterials by:
- addressing the issues on availability of suitable measuring techniques, reference materials, validated methods, acceptable to all - developing an integrated and interdisciplinary approach and a close international co-operation and networking with academia, commercial firms and standardization bodies.
Thus, the NanoDefine Methods Manual provides guidance on practical implementation of the EC NM Definition throughout the nanomaterial characterization process, and on the characterization techniques employed as well as their application range and limits. It assists the user in choosing the most appropriate measurement method(s) to identify any substance or mixture for a specific purpose, according to the EC NM Definition of a nanomaterial. The NanoDefine project also explored how to assess a material against the criteria of the definition through proxy solutions, i.e. by applying measurement techniques that indirectly determine the D50. Those findings were developed through empirically based scientific work and are included in Part 1 of this Manual. As they go beyond the text of the EC NM Definition, they may be used as practical approach to indicate whether a material is a nanomaterial or not, but keeping in mind that they should not be taken as recommendation for the implementation of the EC NM Definition in a regulatory context.
The NanoDefine Methods Manual consists of the following three parts:
Part 1: The NanoDefiner Framework and Tools
Part 2: Evaluation of Methods
Part 3: Standard Operating Procedures (SOPs)
Part 1 covers the NanoDefiner framework, general information on measurement methods and performance criteria and tools developed by NanoDefine such as a materials categorisation system, a decision support flow scheme and an e-tool.
Part 2 discusses the outcome of the evaluation of the nanomaterials characterisation methods for measuring size.
Part 3 presents the 23 Standard Operating Procedures developed within the NanoDefine project. The current document is part 3.
Towards the standardization of biochar analysis: the COST action TD1107 interlaboratory comparison
(2016)
Biochar produced by pyrolysis of organic residues is increasingly used for soil amendment and many other applications. However, analytical methods for its physical and chemical characterization are yet far from being specifically adapted, optimized, and standardized. Therefore, COST Action TD1107 conducted an interlaboratory comparison in which 22 laboratories from 12 countries analyzed three different types of biochar for 38 physical–chemical parameters (macro- and microelements, heavy metals, polycyclic aromatic hydrocarbons, pH, electrical conductivity, and specific surface area) with their preferential methods. The data were evaluated in detail using professional interlaboratory testing software. Whereas intralaboratory repeatability was generally good or at least acceptable, interlaboratory reproducibility was mostly not (20% < mean reproducibility standard deviation < 460%). This paper contributes to better comparability of biochar data published already and provides recommendations to improve and harmonize specific methods for biochar analysis in the future.
This paper presents investigations on the tribological behaviour of PTFE composites against steel at cryogenic temperatures. The results showed that the friction coefficient decreases with temperature down to 77 K, but did not follow a linear evolution further down to extreme low temperatures. It can be stated that the cryogenic environment has a significant influence on the tribological performance of the polymer composites. The effect of low temperatures was more clearly detected at low sliding speed, where friction heat is reduced. A change in wear mechanism from adhesive to abrasive was observed in this case. SEM and AFM analyses showed that the PTFE matrix composites investigated under these experimental conditions have transferred material onto the disc down to very low temperatures. Chemical analyses indicate the presence of iron fluorides.
Tribologisches Verhalten der Werkstoffpaarung Polymerverbundwerkstoff/Stahl bei tiefen Temperaturen
(2003)
Effects of Heat Treatment on the Structure of Thermal Plasma Synthesized SiCN Composite Nanopowders
(2003)
SiCN composite nanopowders with different chemical composition and characteristics were synthesized by the RF induction plasma at atmospheric pressure. Frequently the as-produced powders exhibit a high degree of chemical disorder or structural defects. Because the composition and the microstructure of starting powders have a great influence on the properties of composite ceramics, the changes of chemical composition, crystallization, and morphology of the as-produced powders during heat treatment up to 1500 °C were investigated in detail.
Die Produktion von neuen effektiven und 'grünen' Weichmachern für Polyvinylchlorid (PVC) stellt eine der großen Herausforderungen in der chemischen Industrie dar. In diesem Beitrag wird über Ergebnisse von Untersuchungen berichtet, in denen symmetrische Ester einer Reihe von Fettsäuren und Triethylenglykol (TEG) gewonnen wurden und die als effektive Plastifizierungskomponenten verwendet wurden. Die Veresterung wurde unter Zugabe von Titandioxid Degussa P-25 in Nanopartikelgröße als umweltverträgliche Technologie durchgeführt. Eine gute Verträglichkeit und eine niedrige Flüchtigkeit der Ester auf Biobasis in den PVC-Rezepturen werden gezeigt und es konnten bessere physiko-mechanische Eigenschaften der PVC-Komposite eingestellt werden. Die Ester können als effektive und umweltfreundliche PVC-Weichmacher und als Ersatz für herkömmliche Phtalate empfohlen werden.
We report on a new series of isoreticular frameworks based on zinc and 2-substituted imidazolate-4-amide-5-imidate (IFP-1–4, IFP=imidazolate framework Potsdam) that form one-dimensional, microporous hexagonal channels. Varying R in the 2-substitued linker (R=Me (IFP-1), Cl (IFP-2), Br (IFP-3), Et (IFP-4)) allowed the channel diameter (4.0–1.7 Å), the polarisability and functionality of the channel walls to be tuned. Frameworks IFP-2, IFP-3 and IFP-4 are isostructural to previously reported IFP-1. The structures of IFP-2 and IFP-3 were solved by X-ray crystallographic analyses. The structure of IFP-4 was determined by a combination of PXRD and structure modelling and was confirmed by IR spectroscopy and 1H MAS and 13C CP-MAS NMR spectroscopy. All IFPs showed high thermal stability (345–400°C); IFP-1 and IFP-4 were stable in boiling water for 7 d. A detailed porosity analysis was performed on the basis of adsorption measurements by using various gases. The potential of the materials to undergo specific interactions with CO2 was investigated by measuring the isosteric heats of adsorption. The capacity to adsorb CH4 (at 298 K), CO2 (at 298 K) and H2 (at 77 K) at high pressure were also investigated. In situ IR spectroscopy showed that CO2 is physisorbed on IFP-1–4 under dry conditions and that both CO2 and H2O are physisorbed on IFP-1 under moist conditions.
Tribologisches Verhalten der Werkstoffpaarung Polymerverbundwerkstoff/Stahl bei tiefen Temperaturen
(2005)
Thermal shock cycle experiments between room and cryogenic temperatures on polymer composites
(2002)
This study deals with the development of PEEK (polyehteretherketone) and PTFE (polytetrafluoroethylene) based composites, optimized for low friction and low wear performance under extreme environments. It is demonstrated that the incorporation of a harder polymer component into PTFE (such as PEEK particles), a short fiber reinforcement (e.g. carbon fibers CF), and internal lubricants (e.g. PTFE particles), helps to reduce the friction and to improve the wear resistance over a very wide temperature range.
An experimental cold-gas study of the response of a choked convergent–divergent nozzle to swirl perturbations is presented. The perturbations were obtained by means of upstream unsteady tangential injections into initially steady flows with different values of steady background swirl. The swirl perturbations induced changes in the axial mass-flow rate, due to either their ingestion or evacuation by the nozzle. This in turn caused a downstream acoustic response. For low-intensity background swirl the responses were found to be similar to those obtained without steady background swirl. Perturbations of a high-intensity background swirl led to different effects. For long injection times, the negative mass-flow rate modulation occurred in two stages. The first stage was similar to that of the background-swirl free case. The second stage occurred after a short time delay, and induced a much stronger negative acoustic response. This unexpected behavior suggests that a significant part of the tangentially injected fluid flows upstream inducing an accumulation of swirl, which is – after tangential injection is ceased – suddenly cleared out through the nozzle. A scaling rule for the amplitudes of these acoustic responses is reported. Furthermore, quasi-steady models, based on steady-state measurements are proposed. These models predict the downstream acoustic response amplitude within a factor two. Additionally, preliminary empirical evidence of the effect of swirl on the downstream acoustic response due to the interaction of entropy patches with a choked nozzle is reported. This was obtained by comparison of sound produced by abrupt radial or tangential sonic injection, upstream from the choked nozzle, of air from a reservoir at room temperature to that from a reservoir with a higher stagnation temperature. Because the mass flow through the nozzle does not increase instantaneously, the injected higher-enthalpy air accumulates upstream of the injection-port position in the main flow. This eventually induces a large downstream acoustic pulse when tangential injection is interrupted. The magnitude of the resulting sound pulse can reach that of a quasi-steady response of the nozzle to a large air patch with a uniform stagnation temperature equal to that of the upstream-injected heated air. This hypothesis is consistent with the fact that the initial indirect-sound pulse is identical to one obtained with unheated air injection. The authors posit that – given all of the insight gleaned from them in this case – acoustic measurements of indirect sound appear to be a potentially useful diagnostic tool.
Thin metal-filled polyterafluoroethylene films with various metal concentration were produced by co-deposition in vacuum. Metal nanocluster size increased with metal concentration. Films were heated up to 300 degrees C, their optical spectra were recorded during heating. The changes in plasmon band shape and wavelength of the nanocluster ensemble during heating are not linearly related with metal concentration and heating temperature. This is caused by different thermal behavior of the complex processes, which are taking place in each of the two materials present in the film. The metal cluster size and optical properties of the whole ensemble can be purposefully formed by varying metal nature, its concentration and annealing temperature of the film. Nano- and micro-domains with properties different from original film were generated by focused excimer laser or electron beam. Gold-filled PTFE nano-structured films were used as substrate for surface enhanced Raman scattering measurements of ultrathin film of Rhodamine 6G dye.
Polyglycerol (PG) coated polypropylene (PP) films were synthesized in a two-step approach that involved plasma bromination and subsequently grafting hyperbranched polyglycerols with very few amino functionalities. The influence of different molecular weights and density of reactive linkers were investigated for the grafted PGs. Longer bromination times and higher amounts of linkers on the surface afforded long-term stability. The protein adsorption and bacteria attachment of the PP-PG films were studied. Their extremely low amine content proved to be beneficial for preventing bacteria attachment.
Identifying nanomaterials (NMs) according to European Union Legislation is challenging, as there is an enormous variety of materials, with different physico-chemical properties. The NanoDefiner Framework and its Decision Support Flow Scheme (DSFS) allow choosing the optimal method to measure the particle size distribution by matching the material properties and the performance of the particular measurement techniques. The DSFS leads to a reliable and economic decision whether a material is an NM or not based on scientific criteria and respecting regulatory requirements. The DSFS starts beyond regulatory requirements by identifying non-NMs by a proxy Approach based on their volume-specific surface area. In a second step, it identifies NMs. The DSFS is tested on real-world materials and is implemented in an e-tool. The DSFS is compared with a decision flowchart of the European Commission’s (EC) Joint Research Centre (JRC), which rigorously follows the explicit criteria of the EC NM definition with the focus on identifying NMs, and non-NMs are identified by exclusion. The two approaches build on the same scientific basis and measurement methods, but start from opposite ends: the JRC Flowchart starts by identifying NMs, whereas the NanoDefiner Framework first identifies non-NMs.
The present series of reports, the NanoDefine Methods Manual, has been developed within the NanoDefine project 'Development of an integrated approach based on validated and standardized methods to support the implementation of the EC recommendation for a definition of nanomaterial', funded by the European Union's 7th Framework Programme, under grant agreement 604347.
In 2011 the European Commission (EC) published a recommendation for a definition of the term 'nanomaterial', the EC NM Definition, as a reference to determine whether an unknown material can be considered as a 'nanomaterial' for regulatory purposes1. One challenge is the development of methods that reliably identify, characterize and quantify nanomaterials (NM) both as substances and in various products and matrices.
The overall goal of NanoDefine was to support the implementation of the EC NM Definition. It can also support the implementation of any NM definition based on particle size. The project has developed an integrated approach, which allows identifying any material as a nano- or not a nanomaterial according to the EC NM Definition. NanoDefine explicitly supported the governance challenges associated with the implementation of legislation concerning nanomaterials by:
- addressing the issues on availability of suitable measuring techniques, reference materials, validated methods, acceptable to all stakeholders (authorities, policy makers, commercial firms),
- developing an integrated and interdisciplinary approach and a close international co-operation and networking with academia, commercial firms and standardization bodies.
Thus, the NanoDefine Methods Manual provides guidance on practical implementation of the EC NM Definition throughout the nanomaterial characterization process, and on the characterization techniques employed as well as their application range and limits. It assists the user in choosing the most appropriate measurement method(s) to identify any substance or mixture for a specific purpose, according to the EC NM Definition of a nanomaterial. The NanoDefine project also explored how to assess a material against the criteria of the definition through proxy solutions, i.e. by applying measurement techniques that indirectly determine the x50. Those findings were developed through empirically based scientific work and are included in Part 1 of this Manual. As they go beyond the text of the EC NM Definition, they may be used as practical approach to indicate whether a material is a nanomaterial or not, but keeping in mind that they should not be taken as recommendation for the implementation of the EC NM Definition in a regulatory context.
The NanoDefine Methods Manual consists of the following three parts:
Part 1: The NanoDefiner Framework and Tools
Part 2: Evaluation of Methods
Part 3: Standard Operating Procedures (SOPs)
Part 1 covers the NanoDefiner framework, general information on measurement methods and performance criteria and tools developed by NanoDefine such as a materials categorisation system, a decision support flow scheme and an e-tool.
Part 2 discusses the outcome of the evaluation of the nanomaterials characterisation methods for measuring size.
Part 3 presents the 23 Standard Operating Procedures developed within the NanoDefine project.
The current document is part 2.
This chapter deals with the development of polyetheretherketone (PEEK) and polytetrafluoroethylene (PTFE)-based composites, optimized for low friction and low wear performance under extreme environments. It is demonstrated that the incorporation of a harder polymer component into PTFE (such as PEEK particles), a short fiber reinforcement (e.g. carbon fibers (CFs)) and internal lubricants (e.g. PTFE particles) helps to reduce the friction and to improve the wear resistance over a very wide temperature range.
Im Jahr 2011 hat der Bundestag in Deutschland den Ausstieg aus der Kernenergie beschlossen. Der angefallene Abfall wird mehr als hunderttausend Jahre eine derartig hohe Aktivität besitzen, dass er eine erhebliche Gefahr für nachfolgende Generationen darstellen kann. Dieser radioaktive Abfall soll in tiefen geologischen Formationen (z.B. Salz, Ton oder Kristallin) sicher endgelagert werden. Die Endlager werden mittels sogenannter geotechnischer Abdichtbauwerke (Schachtbzw. Streckenverschlüsse) verschlossen, wofür u.a. Zement- oder Sorel-basierte Baustoffe (Betone) in Frage kommen. Die Beschreibung des Dichtvermögens dieser Bauwerke ist unabdingbar. In der Forschungsphase werden verschiedene Werkstoffe untersucht und Methoden für die zerstörungsfreie Untersuchung der Bauwerke als Mittel der Qualitätsprüfung entwickelt. Hierbei ist der Nachweis der Rissfreiheit bzw. die Detektion möglicher Risse ein vorrangiges Thema. In den letzten Jahren konnten bereits umfangreiche Erfahrungen mit der Untersuchung von in-situ-Versuchsobjekten in Realmaßstab gesammelt werden. Die Messungen wurden im Endlager für radioaktive Abfälle Morsleben am in-situ-Versuch “Abdichtbauwerk im Steinsalz” und in der Grube Teutschenthal am Großversuch GV2 durchgeführt. Es ist gelungen mit einem neu entwickelten Ultraschall-Messsystem Eindringtiefen bis ca. 9,0 m zu realisieren. Die Messungen mit dem Large Aperture Ultrasonic System in Kombination mit der Rekonstruktion-Methode Synthetic Aperture Focusing Technique zeigen, dass die zerstörungsfreie Prüfung von Abdichtbauwerken möglich und die Nutzung des Messsystems zur Qualitätssicherung bei der Erstellung der Verschlussbauwerke vielversprechend ist.
The electrospray ionization (ESI) method was used for deposition of thin films of poly(acrylic acid) (PAA) onto ZSM-5, Cu/ZSM-5 and Ag-Cu/ZSM-5 zeolites. This method allowed the formation of uniform polymer films of controlled thickness on conductive substrates.
The zeolites were prepared home-made. The effect of incorporation of Cu (5 wt.%) and Ag-Cu (1+4 wt.%) onto ZSM-5 on its particle size, unit cell parameters and crystallinity was investigated.
The deposited PAA layer acts as a common dispersing agent with its ionic COOH (COO-) groups. The antibacterial activity towards the bacterial strains such as Staphylococcus pneumonia (S. Pneumonia), Bacillus subtilis (B. subtilis), Escherichia coli (E. coli) and Pseudomonas aeruginosa (P. aeruginosa) as Gram positive and Gram negative bacteria, respectively, and Aspergillus fumigatus (A. fumigatus), Candida albicans (C. albicans) as Fungi was evaluated. The chemical and physical modifications of ZSM-5, Cu/ZSM-5 and Ag-Cu/ZSM-5 surfaces were characterized by X-ray photoelectron spectroscopy, Fourier-transform infrared spectroscopy, atomic force microscopy and X-ray diffraction.
The Cu/ZSM-5 and Ag-Cu/ZSM-5 nanocomposites coated with a 10 nm thick PAA layer exhibit significant antibacterial activity. The carboxyl (¬-COOH) or the corresponding carboxylate groups (¬-COO-) interact with Cu2+ and Ag+ ions by formation of ionic bonds (¬-COO-Ag+ or 2 ¬-COO->Cu2+). Moreover, short exposure to light and temperature has reduced Cu2+ and Ag+ to Cu0 and Ag0.
Indirect combustion noise due to the interaction of flow inhomogeneities with a choked combustion-chamber exit is an important cause of combustion instability in solid rocket motors.
Moreover, it is believed to be an issue in electrical-power generation turbines and aero-engines. If these flow inhomogeneities are essentially characterized by the fluid having a locally appreciablydifferent thermodynamic state, the acoustic response engendered by its interaction with the combustion-chamber exit is commonly referred to as entropy noise. In this paper, dedicated numerical-simulation results of entropy-patch choked-nozzle interactions are presented. Two types of entropy patches were considered: rectangular slugs and circular spots. Moreover, analytical-model-based analysis, of said simulation results, is presented. Based on said analysis, the authors posit the existence of three modeling regimes: the quasi-steady-modeling regime, the blended-physical-effects regime, and the inertial-modeling regime.
In this work we present the preparation of conductive polyethylene/carbon nanotube composites based on the segregated network concept. Attention has been focused on the effect of decreasing the amount of filler necessary to achieve low resistivity. Using high- and low-grade single-walled carbon nanotube materials we obtained conductive composites with a low percolation threshold of 0.5 wt.% for high-grade nanotubes, about 1 wt% for commercial nanotubes and 1.5 wt% for low-grade material. The higher percolation threshold for low-grade material is related to low effectiveness of other carbon fractions in the network formation. The electrical conductivity was measured as a function of the single-walled carbon nanotubes content in the polymer matrix and as a function of temperature. It was also found that processing parameters significantly influenced the electrical conductivity of the composites. Raman spectroscopy was applied to study single wall nanotubes in the conductive composites.
Polytetrafluoroethylene (PTFE) films have been deposited onto polycarbonate (PC) substrates from the products of PTFE evaporation, activated by a cloud of accelerated electrons. A 40.68 MHz glow discharge was used during the deposition process. The polymer films have been characterised by XPS, FTIR and AFM. The use of the low power plasma during film growth led to the formation of PTFE films with modified structure. Films are amorphous and contain more cross-links, but in general, the structure of their macromolecules is still linear. An increase of RF-power leads to the formation of films with large amount of double bonds and enhanced internal stresses.
Deposition of PTFE on PC without plasma treatment led to the formation of PTFE clusters up to 50 nm in diameter. The RMS roughness of the films, deposited without plasma, was about 4 nm, while the films deposited with plasma treatment had a roughness of 1.5 nm. The use of plasma has an additional effect if a PTFE coating is deposited on the PC substrate with submicrometer-sized steps. Without plasma the steps retain a rectangular shape. Deposited with the RF-discharge the PTFE layers resemble plasma-polymerised films. Under certain conditions the deposited films can fill trenches in the substrate like a wetting liquid, while under other conditions they avoid trenches and grow in between them.
Substrate-induced self-assembly of donor-acceptor type compounds with terminal thiocarbonyl groups
(2013)
Two types of conjugated thiocarbonyl-terminated compounds have been synthesized and their ability to be adsorbed on surfaces of the different nature, namely, glass, polytetrafluoroethylene (PTFE), and gold has been studied. Different morphology of the films prepared by thermal vacuum evaporation and drop-casting from solutions has been observed depending on the surface used. It has been found that gold surface has a unique property to influence self-assembly of both monolayer and larger aggregates or crystals of the compounds, in contrast to glass and PTFE substrates. It was found that thiocarbonyl group is able to be chemisorbed to the gold surface. However, it was concluded that in spite of the fact that the thiocarbonyl groups are important for the chemical interaction with the gold surface, physical adsorption on the substrate surface, compoundcompound and compound–solvent (when using solution) interactions are of great significance to drive self-assembly of the final film.