Design features topology to control the spread of the liquid has been extensively studied. Micropillar structure, for example, can maintain a steady trickle at the end of the pathway inhibits the contact of solid progress more sharp edges.
The behavior of droplets pinned on the pillars are not circular, however, has received little attention. In this study, we analyzed the retention of microdroplets with a high surface tension and low on axisymmetric and asymmetric porous micropillar structure. the structure of the circle, square, and triangle made on a silicon substrate that is used to characterize the dynamic behavior of the droplets before and after it exploded. Condition critical clamping pressure based on the visualization and measurement of droplet.
A theoretical model was developed based on the free energy analysis to predict the change in pressure due to the advancement of the working fluid in the micropillar. For high surface tension liquid (eg, water), the maximum pressure occurs when the contact line is pinned along the edges of the pores inside. For low surface tension liquid (eg, isopropanol and Novec 7500), the maximum pressure occurs when the contact line is pinned along the outer edges of the structure. The results of theoretical and experimental shows how droplets embedded on a micropillar triangles show the smallest critical volume during the burst.
When using IPA solution (γ = 23 mN / m) and Novec 7500 (γ = 16 mN / m) as the working fluid, changes the shape micropillar of the circle of the triangle, respectively, resulting in 83% and 76% in volume exploded critical. Meanwhile, the increased pressure to explode 172-300 and 127-216 Pa Pa to IPA and Novec 7500, respectively. These findings provide new insight into the rational design of surface micro / nanoengineered structure for tuning the surface wetting characteristics in scientific and engineering applications.
Evolution of Microdroplet Morphology Confined on Asymmetric Micropillar Structures.
Measurement and Correlation of Thermal Conductivity 1,1,1,2,2,4,5,5,5-Nonafluoro-4- (trifluoromethyl) -3-pentanone.
New experimental data on the thermal conductivity of 1,1,1,2,2,4,5,5,5-nonafluoro-4- (trifluoromethyl) -3-pentanone (Novec 649) reported for vapor, liquid and supercritical state. This new experimental data obtained by the hot-wire apparatus while over the temperature range from 183 K to 501 K and at a pressure of 0.02 MPa to 69 MPa. This data is used to develop a wide-range correlation to the thermal conductivity of the vapor, liquid and supercritical fluids.
The experimental data reported here has the uncertainty of 1% for liquid and supercritical region (density> 600 kg m-3), 1.5% for steam and supercritical region (≥ 1 MPa pressure and density of <200 kg m-3), 3% for supercritical state (200 kg m-3 ≤ density ≤ 600 kg m-3), and 3% for steam and supercritical state (pressure <1 MPa). Thermal-conductivity correlations developed in this study is estimated to have expanded relative uncertainty, at a confidence level of 95%, from about 1% to 4% depending on the temperature and pressure, with greater uncertainty in critical areas.
In this study, we have proposed a new solvent-based method uses a particular concentration of 3M ™ Novec ™ HFE-72DE and 7200 solvent for duct tape outlines of a porous article with minimal impact on the quality of latent fingerprints deposited on the surface of duct tape sticky-side.
A series of experiments determined that a mixture of 30% HFE-72DE: 7200 (v / v) was found to be the most effective to separate the various brand duct tape of various types of porous surfaces, including copy paper office, paper, cardboard and tissue cloth, which had been stored for 30 days before untangling.
