RESUMO
Here we show the effect of the ionic liquid nature, its content and monomer/crosslinker ratio on the copolymerization of N-vinylpyrrolidone (NVP) with triethylene glycol dimethacrylate (TEGDMA) induced by UV or heat irradiation. For the first time, kinetics curves of photopolymerization NVP with TEGDMA in the presence of ionic liquids are obtained. The ionic liquids EmimBF4, BmimBF4, OmimBF4 and EmimTFSI with different cation and anion structures and lengths of the alkyl radical were varied in photopolymer compositions. To understand the influence of ionic liquids on the polymerization kinetics, photo-DSC, dynamic DSC, and FTIR were performed. Parameters obtained from photo-DSC curves allowed to develop the methodology for the stereolithography of ionogels. The presented data constitutes the complete dataset useful for 3D-printing of ionogels with high accuracy, which is reported in the main article.
RESUMO
Inspired by natural muscle, a key challenge in soft robotics is to develop self-contained electrically driven soft actuators with high strain density. Various characteristics of existing technologies, such as the high voltages required to trigger electroactive polymers ( > 1KV), low strain ( < 10%) of shape memory alloys and the need for external compressors and pressure-regulating components for hydraulic or pneumatic fluidicelastomer actuators, limit their practicality for untethered applications. Here we show a single self-contained soft robust composite material that combines the elastic properties of a polymeric matrix and the extreme volume change accompanying liquid-vapor transition. The material combines a high strain (up to 900%) and correspondingly high stress (up to 1.3 MPa) with low density (0.84 g cm-3). Along with its extremely low cost (about 3 cent per gram), simplicity of fabrication and environment-friendliness, these properties could enable new kinds of electrically driven entirely soft robots.The development of self-contained electrically driven soft actuators with high strain density is difficult. Here the authors show a single self-contained soft robust composite material that combines the elastic properties of a polymeric matrix and the extreme volume change accompanying liquid vapour transition.
RESUMO
A combination of the high damage tolerance of TRIP-steel and the extremely low thermal conductivity of partially stabilized zirconia (PSZ) can provide controlled thermal-mechanical properties to sandwich-shaped composite specimens comprising these materials. Sintering the (TRIP-steel-PSZ)/PSZ sandwich in a single step is very difficult due to differences in the sintering temperature and densification kinetics of the composite and the ceramic powders. In the present study, we successfully applied a two-step approach involving separate SPS consolidation of pure (3Y)-TZP and composites containing 20 vol % TRIP-steel, 40 vol % Al2O3 and 40 vol % (3Y)-TZP ceramic phase, and subsequent diffusion joining of both sintered components in an SPS apparatus. The microstructure and properties of the sintered and bonded specimens were characterized. No defects at the interface between the TZP and the composite after joining in the 1050-1150 °C temperature range were observed. Only limited grain growth occurred during joining, while crystallite size, hardness, shear strength and the fraction of the monoclinic phase in the TZP ceramic virtually did not change. The slight increase of the TZP layer's fracture toughness with the joining temperature was attributed to the effect of grain size on transformation toughening.