![]() However, the addition of 0.4% CB induces the percolation threshold if the CB particles are localized only at the interface between PE and PS. When CB particles are selectively localized only in PE phase and the CB/PE/PS forms a co-continuous structure, the percolation threshold is obtained with an addition of 3% CB. For example, with polyethylene (PE)/polystyrene (PS) 45/55 blend, the composite shows a remarkable reduction in the percolation threshold depending on where the CB is localized in the system. Specifically, if CB is densely dispersed in one phase or at the interface of the blend and it eventually shows a co-continuous structure, the composite can form a double-percolated structure, giving rise to an increase in the electrical conductivity, even with a lower particle concentration compared to those of typical binary composites. When CB is incorporated into immiscible phases, it becomes localized in one specific phase or at the interface between the phases according to the balance of the spreading coefficient of the particles between the phases. This is realized based on selective localization of CB particles in a multi-phase system due to a thermodynamic reason. The composites often show a significant reduction in the percolation threshold when manipulating the particle distribution in an immiscible blend system. The percolation of CB in a polymer depends significantly on the surface properties of CB, as well as on the interaction between the CB particles and the polymer matrix. The particle percolation of such a high order structure is attributed to high storage modulus (G′), high Young’s modulus, high dielectric loss (ε″), and negative–positive switching of dielectric constant at high frequency (of 103 Hz) of composite.Īmong the diverse conductive particles, carbon black (CB) has been widely used to induce electrical performance due to its low cost and good dispersibility. The reduced size of the secondary phase under a mixing condition with high shear force prior to the addition of CB provides a larger interfacial area for CB to diffuse into the PCL phase during the subsequent mixing step, resulting in a further expansion of CB aggregation throughout the composite. Meanwhile, the two-step mixing process causes the CB aggregates to expand and create a higher structure (aggregate perimeter~aggregate size 0.8). Under the single-step mixing protocol, the ternary composite shows a structure with greater CB aggregation in the form of a high aspect ratio and large aggregates (aggregate perimeter~aggregate size 0.7). To further control the percolation structure, the composite fabrication is controlled by splitting a typical single-step mixing process into two steps, focusing on the dispersion of the secondary PCL phase and the CB particles separately. ![]() Furthermore, when the drop size of the PCL phase becomes smaller, the ternary composite forms a percolation of high order structure, resulting in a remarkable enhancement of the electrical conductivity (~4 × 10 −2 S/m with 4 wt.% CB). Thus efficiency of air preparation units may be increased as it is possible to fill more material into the container without additional energy usage compared to normal gravitational deposition.A ternary composite of poly(lactic acid) (PLA), poly(caprolactone) (PCL), and carbon black (CB) shows the PCL-induced CB self-aggregation and percolation formation when the amount of the PCL phase as the secondary phase is as small as the amount of CB. A conical hopper and under this multiple cylindrical rods were used to reach uniform deposition and high value of particle packing density. ![]() Main idea of this research was the usage of the so called “snowstorm” filling technique. ![]() According to this in our present paper the gravitational deposition of particulate materials was investigated from viewpoint of porosity. To avoid unnecessary energy consumption it is recommended to examine the possibility of filling more particles into the canister without outer excitation. However, applying outer excitation decreases the efficiency of filling procedure because of the high energy consumption of the vibratory device. In order to achieve this, mechanical excitation (ensured by a vibration platform) is commonly used. Practically this means decreasing porosity of the filler media. It is necessary to increase the mass of particulate material filled into the dryer for improving its efficiency. In various fields ranging from manufacturing or pharmaceutical industry to agriculture or automotive industry air filters and -dryers filled with porous desiccant media are used for industrial air preparation. ![]()
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