Interaction and UV-Stability of Various Organic Capping Agents on the Surface of Anatase Nanoparticles

Anatase nanoparticles synthesized by the sol-gel method were surface-functionalized with long alkyl chain coupling agents as compatibilizers for a nonpolar environment, containing different anchor groups for surface interaction namely phosphonate (dodecyl phosphonate), carboxylate (dodecanoic acid), sulfate (sodium dodecyl sulphate), and amine (dodecyl amine). It was shown that the surface of the nanoparticles can be functionalized with the various surface groups applying similar reaction conditions. The kind of surface interaction was analyzed applying FTIR spectroscopy. The phosphonate and the carboxylate groups interact with the surface via quite strong covalent or coordinative interactions, respectively. The sulfate and amine based coupling agents on the other hand exhibit electrostatic interactions. UV stability studies of the surface bound groups revealed different degradation mechanisms for the various functionalities and moreover showed that phosphonates are the most stable among the investigated surface capping groups

Enhanced Lightweight Design : First Results of the FP7 Project ENLIGHT

© 2016 The Authors. Published by Elsevier B.V. The European Green Vehicle project ENLIGHT aims to advance highly innovative lightweight material technologies for application in structural vehicle parts of future volume produced Electric Vehicles (EVs) along four axes: performance, manufacturability, cost effectiveness and lifecycle footprint. The main target is to develop viable and sustainable solutions for medium production volume up to 50.000 EVs destined to reach the market in the next 8-12 years. The specific objectives of the ENLIGHT project are on holistic and integrated conceptual design and manufacturing concerning how the technologies and materials addressed can be combined into a representative medium-volume EV. The solutions will be demonstrated in five modules: a front module and central floor module, a front door, a sub-frame and suspension system as well as a cross-car beam. In this paper, a summary of the major results obtained up to the 3rd project year will be presented. ispartof: pages:1031-1040 ispartof: Transportation Research Procedia vol:14 pages:1031-1040 ispartof: 6th Transport Research Arena TRA2016 location:Warsaw, Poland date:18 Apr - 21 Apr 2016 status: publishe

Click reactions of spherosilicates and polyhedral oligomeric silsesquioxanes. : a novel strategy towards hybrid materials

In the last decade inorganic-organic hybrid materials have attracted much attention due to their improved properties arising from the synergetic junction of the two components. For instance optimizing mechanical, thermal or optical properties as well as hydrophobicity, permeability, catalytic properties and many more can provide new materials with user-defined features1-3. Aim of this work was to find a simple and effective pathway for a covalent connection between the inorganic and organic component in such materials. While several methods were used for the covalent connection of the components previously, such as hydrosilation reaction4-7, copolymerization of functional macromonomers8,9 or the use of macroinitiators10,11, this work will study the click chemistry bond formation between inorganic building blocks based on spherosilicates and silsesquioxanes or on mixtures of spherosilicates and polymers. For this purpose full eight corner azide and alkyne modified silica cages were prepared. Azide end-modified poly(methyl methacrylate) and polydimethylsiloxane with alkyne end-groups were used as polymeric matrices. The two components were covalently connected by Huisgen 1,3-dipolar cycloaddition reaction to give a hybrid material.7

Commercial textile reinforcements – performance in green cement and surface treatment

The present report addresses the Deliverables 2.1 and 2.2 of the project ‘Green cement based on blast-furnace slag’. Deliverable 2.1 aims at the evaluation of the mechanical and thermal performance of commercial reinforcements. Deliverable 2.2 describes the modification of those commercial reinforcements and evaluation.Two different commercial textile reinforcement grids for concrete were evaluated: (i) a basalt-fibre grid from US Basalt impregnated with epoxy resin and (ii) a carbon fibre grid from V. Fraas that is impregnated with Styrene-butadiene rubber (SBR). The grids were exposed to plasma oxidation to increase their hydrophilicity and create functional groups that can react with the uncured cement. The adhesion to the green cement matrix was then measured of both, the untreated and the plasma treated grids by pull-out testing of fibre bundles.Deliverables 2.1 &amp; 2.2 of the project ’Green cement based on blast furnace slag’ funded by Vinnova under their programme ‘Innovationer för ett hållbart samhälle’ (Diarienummer 2016-03367).</p

Interaction and UV-Stability of Various Organic Capping Agents on the Surface of Anatase Nanoparticles

Anatase nanoparticles synthesized by the sol-gel method were surface-functionalized with long alkyl chain coupling agents as compatibilizers for a nonpolar environment, containing different anchor groups for surface interaction namely phosphonate (dodecyl phosphonate), carboxylate (dodecanoic acid), sulfate (sodium dodecyl sulphate), and amine (dodecyl amine). It was shown that the surface of the nanoparticles can be functionalized with the various surface groups applying similar reaction conditions. The kind of surface interaction was analyzed applying FTIR spectroscopy. The phosphonate and the carboxylate groups interact with the surface via quite strong covalent or coordinative interactions, respectively. The sulfate and amine based coupling agents on the other hand exhibit electrostatic interactions. UV stability studies of the surface bound groups revealed different degradation mechanisms for the various functionalities and moreover showed that phosphonates are the most stable among the investigated surface capping groups

Development of textile reinforcements with improved adhesion and thermal stability for green cement

The present report addresses the Deliverable 2.3 of the project ‘Green cement based on blast-furnace slag’. Deliverable 2.3 aims at the development of new textile reinforcements with improved adhesion and thermal stability for green cements.Two different approaches for impregnation of textile reinforcements with materials that exhibit good adhesion to cementitious matrices as well as good thermal stability were studied: (i) impregnation with cementitious materials, (ii) impregnation with molecular precursors. Moreover, a nano-CSH impregnation system developed at Chalmers was characterized and compared to the systems developed at RISE.Deliverable 2.3 of the project ’Green cement based on blast furnace slag’ funded by Vinnova under their programme ‘Innovationer för ett hållbart samhälle’ (Diarienummer 2016-03367).</p

Materials with variable stiffness

In this study different concepts to attain a material that can reduce its stiffness upon external stimulation areevaluated. All concepts rely on resistive heating of a carbon fibre reinforcement upon application of electric current through the fibres. The stiffness reduction relies on a phase transformation due to heating of the material.During the European project ENLIGHT, four different stiffness-modifiable materials were investigated. The materials differ in their thermal, mechanical and processing properties as well as the achievable stiffness reduction. The materials have many potential applications, but are of special interest for road safety. Within ENLIGHT, the material was considered for application in a softening car hood. Requirements for such an application were defined with regards to the mechanical and thermal performance, as well as the activation time. It is crucial for active safety systems in cars to be activated within a short time. According to investigations performed at Honda, the time interval between impact at the front of the car and head impact on the hood is 60 ms for children (more for adults). Therefore, upon activation at front impact, the hood stiffness needs to be reduced within 60 ms in order to soften the impact with the hood. Longer activation time can be allowed if the stiffness-reduction is activated by a collision warning system. Such a solution would make sense in situations where the time between alert and collision is not sufficient to stop the vehicle (stopping time is e.g. ≥1 s at 40 km/h and ≥2.5 s at 70 km/h). Calculations performed at Swerea SICOMP revealed that activation times in the range of 500 ms – 1 s can be achieved with the power sources already available in electric vehicles. However, anactivation time of 60 ms cannot be achieved for the amount of material required for efficient stiffness-reduction in a hood. Hence, the technology needs to be combined with a collision warning system. The ability of the material to reduce its stiffness was verified by dynamic mechanical analysis (DMTA), in-plane shear tests (IPS) at different temperatures and 3-point-bending tests. Verification of the possibility to achieve stiffness reduction upon application of current within the required time was performed using a 3-point-bending set-up where specimens were heated with short voltage pulses while monitoring stiffness.To date stiffness-reductions between 50% and 90% have been demonstrated for the different materials