Fabricators and processors alike demand consistently high quality for their intermediate and final products. The properties of these goods usually also have to meet specific requirements. Particularly the surfaces of workpieces or mouldings are expected to exhibit several different functions at one and the same time, depending on the industry. Robustness, unchanging appearance, mar resistance, impact resistance or UV stability may be required, for instance. The INM – Leibniz Institute for New Materials uses nanoparticles as design element for such multifunctional coatings. These nanoparticles are specifically adapted to the particular application by Small Molecule Surface Modification (SMSM). How this approach can be used to produce custom-tailored coatings will be demonstrated at the TechConnect World trade fair on 15 and 16 June in Washington DC, USA, where the INM will be presenting this and other results. Working in cooperation with the VDI Association of German Engineers it will be showcasing its latest developments at Stand 301 in the German Area. Depending on which property is desired, the nanoparticles used can be surface modified with organic moieties. Small Molecule Surface Modification (SMSM) bestows specific combinations of desired properties, for example hydrophilic, hydrophobic, adhesive, anti-adhesive, acidic, basic, inert or polymerizable. Nanoparticles thus modified are used to develop nanocomposites: they combine the physical solid-state properties of e.g. ceramics or semiconductors with classic polymer-processing technology. Titanium dioxide, barium titanate, indium-tin oxide or zirconium dioxide, for instance, are used as nanoparticles. In addition to the chemical intrinsic composition of the nanoparticles and their SMSM surface treatment, the properties that are attainable for the desired coatings also vary with the size and dispersal mode of the nanoparticles. INM’s composite systems are produced via wet-chemical processes. The modified nanoparticles and additives combine with a polymer matrix (an epoxy resin, an acrylate, a polyimide for example) or a hybrid matrix (organic-inorganic) to produce a coatable Nanomer® composite system. “The modular principle makes it possible to achieve a number of properties at one and the same time in one material,” explains Carsten Becker-Willinger, head of the program division Nanomers, “it helps us to respond in a highly systematic way to the different needs of industry,” the chemist summarizes the potential of nanocomposite technology.
read more "Surface-modified nanoparticles endow coatings with combined properties"
New composite protects from corrosion at high mechanical stress
Material researchers at the INM – Leibniz Institute for New Materials will be presenting a composite material which prevents metal corrosion in an environmentally friendly way, even under extreme conditions. It can be used wherever metals are exposed to severe weather conditions, aggressive gases, media containing salt, heavy wear or high pressures. The INM from Saarbrücken will be one of the few German research institutions at the TechConnect World trade fair on 15 and 16 June in Washington DC, USA, where it will be presenting this and other results. Working in cooperation with the VDI Association of German Engineers it will be showcasing its latest developments at Stand 301 in the German Area. 
New composite protects from corrosion at high mechanical stress. “This patented composite exhibits its action by spray application”, explains Carsten Becker-Willinger, Head of the Nanomers Program Division. “The key is the structuring of this layer - the protective particles arrange themselves like roof tiles. As in a wall, several layers of particles are placed on top of each other in an offset arrangement; the result is a self-organized, highly structured barrier”, says the chemical nanotechnology expert. The protective layer is just a few micrometers thick and prevents penetration by gases and electrolytes. It provides protection against corrosion caused by aggressive aqueous solutions, including for example salt solutions such as salt spray on roads and seawater, or aqueous acids such as acid rain. The protective layer is an effective barrier, even against corrosive gases or under pressure. After thermal curing, the composite adheres to the metal substrate, is abrasion-stable and impact-resistant. As a result, it can withstand high mechanical stress. The coating passes the falling ball test with a steel hemispherical ball weighing 1.5 kg from a height of one meter without chipping or breaking and exhibits only slight deformation, which means that the new material can be used even in the presence of sand or mineral dust without wear and tear. The composite can be applied by spraying or other commonly used wet chemistry processes and cures at 150-200°C. It is suitable for steels, metal alloys and metals such as aluminum, magnesium and copper, and can be used to coat any shape of plates, pipes, gear wheels, tools or machine parts. The specially formulated mixture contains a solvent, a binder and nanoscale and platelet-like particles; it does not contain chromium VI or other heavy metals. INM conducts research and development to create new materials – for today, tomorrow and beyond. Chemists, physicists, biologists, materials scientists and engineers team up to focus on these essential questions: Which material properties are new, how can they be investigated and how can they be tailored for industrial applications in the future? Four research thrusts determine the current developments at INM: New materials for energy application, new concepts for medical surfaces, new surface materials for tribological systems and nano safety and nano bio. Research at INM is performed in three fields: Nanocomposite Technology, Interface Materials, and Bio Interfaces.
read more "New composite protects from corrosion at high mechanical stress"
New composite protects from corrosion at high mechanical stress. “This patented composite exhibits its action by spray application”, explains Carsten Becker-Willinger, Head of the Nanomers Program Division. “The key is the structuring of this layer - the protective particles arrange themselves like roof tiles. As in a wall, several layers of particles are placed on top of each other in an offset arrangement; the result is a self-organized, highly structured barrier”, says the chemical nanotechnology expert. The protective layer is just a few micrometers thick and prevents penetration by gases and electrolytes. It provides protection against corrosion caused by aggressive aqueous solutions, including for example salt solutions such as salt spray on roads and seawater, or aqueous acids such as acid rain. The protective layer is an effective barrier, even against corrosive gases or under pressure. After thermal curing, the composite adheres to the metal substrate, is abrasion-stable and impact-resistant. As a result, it can withstand high mechanical stress. The coating passes the falling ball test with a steel hemispherical ball weighing 1.5 kg from a height of one meter without chipping or breaking and exhibits only slight deformation, which means that the new material can be used even in the presence of sand or mineral dust without wear and tear. The composite can be applied by spraying or other commonly used wet chemistry processes and cures at 150-200°C. It is suitable for steels, metal alloys and metals such as aluminum, magnesium and copper, and can be used to coat any shape of plates, pipes, gear wheels, tools or machine parts. The specially formulated mixture contains a solvent, a binder and nanoscale and platelet-like particles; it does not contain chromium VI or other heavy metals. INM conducts research and development to create new materials – for today, tomorrow and beyond. Chemists, physicists, biologists, materials scientists and engineers team up to focus on these essential questions: Which material properties are new, how can they be investigated and how can they be tailored for industrial applications in the future? Four research thrusts determine the current developments at INM: New materials for energy application, new concepts for medical surfaces, new surface materials for tribological systems and nano safety and nano bio. Research at INM is performed in three fields: Nanocomposite Technology, Interface Materials, and Bio Interfaces.
Transient melting of a nanocrystal: seeing is believing
Jesse Clark, working as a postdoc in the LCN group of Ian Robinson, has discovered a spectacular transient melting phenomenon in nanocrystals. Coherent X-ray diffraction experiments, carried out at the LCLS X-ray free electron laser facility at Stanford, have allowed snapshot imaging of a single 300 nm gold nanocrystal in the picosecond time interval after the particle was excited with a laser. The crystal was found to expand uniformly following the excitation and to reach the melting point about 50 ps later ("Imaging transient melting of a nanocrystal using an X-ray laser"). What is striking about the result, shown in the figure, is that the crystal melts from the outside and then re-solidifies in synchrony with the induced acoustic vibrations. 
Imaging transient melting of a nanocrystal using an x-ray laser. Snapshot projection images of a gold nanocrystal, 300nm across, before and after excitation with a femtosecond laser. The second image, 50 picoseconds after excitation, displays a low density skin that returns to the original density at later times This result has significant implications beyond our basic understanding of the melting process. A reproducible molten state of a metal such as platinum could have useful catalytic properties, while preserving the integrity and large surface area of the particle. Ian Robinson, coordinator of the project said "Bragg Coherent Diffraction Imaging is an emerging X-ray technique with great potential for probing the dynamics of matter. The dynamic imaging of the melting transition, visualised in this work, anticipates a whole new field of materials science in the time domain. I would expect there will be surprise discoveries in the transition regions between classical thermodynamic phases, with the possibility of entirely new transient phases of matter." The work was supported by a European Research Council Advanced grant entitled "nanosculpture".
read more "Transient melting of a nanocrystal: seeing is believing"
Imaging transient melting of a nanocrystal using an x-ray laser. Snapshot projection images of a gold nanocrystal, 300nm across, before and after excitation with a femtosecond laser. The second image, 50 picoseconds after excitation, displays a low density skin that returns to the original density at later times This result has significant implications beyond our basic understanding of the melting process. A reproducible molten state of a metal such as platinum could have useful catalytic properties, while preserving the integrity and large surface area of the particle. Ian Robinson, coordinator of the project said "Bragg Coherent Diffraction Imaging is an emerging X-ray technique with great potential for probing the dynamics of matter. The dynamic imaging of the melting transition, visualised in this work, anticipates a whole new field of materials science in the time domain. I would expect there will be surprise discoveries in the transition regions between classical thermodynamic phases, with the possibility of entirely new transient phases of matter." The work was supported by a European Research Council Advanced grant entitled "nanosculpture".
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