Theory and measurements for 0-3 BaTiO3/PVDF composites

This work extended the range of material properties by fabricating the BaTiO3 /PVDF composite. In order to obtain the 0-3 composite without the interconnectivity of the ceramic powders, a low volume fractionof 0.3 of barium titanate (BaTiO3) was filled in a matrix of polyvinylidene fluoride (PVDF) and the mixture was homogeneously stirred. The composite was shaped into a sheet form by a tape casting method. Themicrostructure of the composite was observed using scanning electron microscopy (SEM) which revealed that the connectivity of the composite was mainly 0-3. Subsequently, theoretical models and equations wereapplied to the composite for comparisons with measurements. The density and heat capacity of the composites were experimentally obtained to be 3.21103 kg/m3 and 3021.7 J/kg oC, respectively. The compositewas corona poled before the test of dielectric response. Its 1 kHz-dielectric constant and dielectric loss at room temperature were 11.5 and 0.21, respectively. The good dielectric combined with the flexibility of thematerial implies that the composite is attractive for electronic applications where a light, environmentally friendly, ease to fabricate and low-cost device is required

Durable slippery lubricant-infused multiscale-textured surfaces for repelling highly adhesive liquids

Surfaces that can repel various types of liquid and retain surface properties over acceptably long periods of time are in great demand. Here, we presented a simple but effective technique to fabricate slippery, lubricant-infused surfaces with excellent liquid-repellent properties and resistance to hydrodynamic damage, evaporation, and high static pressure. Chemically-functionalized multiscale-textured surfaces were impregnated by highly-viscous and vacuum-grade lubricants that fully wetted the nanoscale roughness while conformed to the microscale textures. This generated slippery rough surfaces with improved liquid-resistant properties evaluated by water and highly-adhesive latex. The respective contact angles of water and latex droplets were above 130.1 ± 0.8° and 105.7 ± 1.1°, while water and latex sliding angles were less than 5.8 ± 0.7° and 8.7 ± 0.7°, respectively. More importantly, the slippery roughness reduced liquid-lubricant contact areas, and protected the lubricating layer from flow-induced erosion. The particular lubricant-infused surfaces can withstand an impact of a water jet speed up to 2.6 ms ^−1 for at least 10 min. Furthermore, the viscous lubricant layer was unaffected by evaporation at 65 °C for at least 11 weeks, and stable under hydrostatic pressure of 150 kPa for 20 min