Percolation phenomena in the polymer composites with conducting polymer fillers

The electrical properties of polymer nanocomposites based on dielectric polymer matrices of different types and electrically conductive polymer fillers – polyortotoluidine, polyorthoanisidine and polyaniline have been studied. It is shown that the concentration dependence of the specific conductivity on the content of fillers has a percolation character with a low “percolation threshold”, which depends on the nature of the polymer matrix and polyaminoarene and is 1.7-10.0 vol.%. The calculated critical parameters of electroconductivity are characteristic of the formation of an infinite 3-dimensional cluster of conductivity and indicate a significant influence of the nature of the components and morphology of the material on the charge transfer processes in such systems.

Study on Critical Density of Percolation in Crowds in Public Areas

The percolation model is an effective tool to solve the problem of fluid flow in the pores; the situation of outsiders crossing the crowd is similar. This paper verifies the obvious percolation phenomenon in the randomly distributed crowd by [Formula: see text] simulation and reveals several characteristics and laws of the crowd percolation phenomena. Studies have shown that sites with different spatial dimensions have different densities of crowd percolation: when the actual density of the crowd is greater than the critical density of the crowd percolation, the outsider is difficult to pass through the crowd; otherwise, the outsider can pass through the crowd easily. Therefore, the critical density of crowd percolation can be one of the indicators of crowd management in public areas, which will provide important guidance for the design of public areas, site selection of public activities and crowd management.

A Percolation-Like Process of Within-Organization Collective Corruption: A Computational Approach

This study investigates how collective corruption appears, using a computational method. Specifically, acknowledging that the characteristics of collective corruption process are analogous to percolation phenomena, we illuminate that collective corruption is formed by ongoing social interactions in an organizational boundary. By formulating a percolation-based system dynamics model, we consider the behavioral characteristics of collective corruption in terms of individuals’ corruption preferences governed by personal attributes on corruption. We also propose and examine scenarios regarding the formation of collective corruption.

Switch between critical percolation modes in city traffic dynamics

Percolation transition is widely observed in networks ranging from biology to engineering. While much attention has been paid to network topologies, studies rarely focus on critical percolation phenomena driven by network dynamics. Using extensive real data, we study the critical percolation properties in city traffic dynamics. Our results suggest that two modes of different critical percolation behaviors are switching in the same network topology under different traffic dynamics. One mode of city traffic (during nonrush hours or days off) has similar critical percolation characteristics as small world networks, while the other mode (during rush hours on working days) tends to behave as a 2D lattice. This switching behavior can be understood by the fact that the high-speed urban roads during nonrush hours or days off (that are congested during rush hours) represent effective long-range connections, like in small world networks. Our results might be useful for understanding and improving traffic resilience.

Polystyrene adsorbed multi-walled carbon nanotubes incorporated polymethylmethacrylate composites with modified percolation phenomena

ABSTRACTExtensive work has been done on the modification of multi-walled carbon nanotubes (MWCNTs) to improve their characteristics. Here, polystyrene (PS) was adsorbed on the surface of MWCNTs by dispersion process, using toluene as medium. PS modified MWCNTs (PS-MWCNTs) have been dispersed in polymethylmethacrylate (PMMA) matrix to prepare composite, PS-MWCNTs/PMMA. It is expected that PS adsorbed at the surface of the MWCNTs will help in improving the interaction between MWCNTs and PMMA which results uniform and homogeneous dispersion of the former in later. Thus, synthesized composites were characterized by UV-Vis and FTIR spectroscopy to monitor the functionality of developed product. Electrical parameters including conductivity and dielectric properties were measured with the help of LCR meter. Electrical characters of the composites were explored by investigating the effect of contents of PS-MWCNTs on conductivity and dielectric properties. Percolation behaviour was examined and calculated value of percolation threshold was 0.1wt%.