A three-dimensional Monte Carlo model for electrically conductive polymer matrix composites filled with curved fibers

Polymer ◽  
2008 ◽  
Vol 49 (19) ◽  
pp. 4230-4238 ◽  
Author(s):  
H.M. Ma ◽  
X.-L. Gao
2018 ◽  
Vol 765 ◽  
pp. 60-64
Author(s):  
Seung Pyo Woo ◽  
Sung Min Park ◽  
Gyung Mok Nam ◽  
Young Choi ◽  
Sang Heon Park ◽  
...  

The GnF/SU-8 composites are new polymer matrix composites (PMCs) composed of graphite nanoflakes (GnFs) bound together by SU-8 photoresist. The PMCs therefore have excellent ultraviolet (UV) photopatternability and high electrical properties. In spite of the unique material properties of GnF/SU-8 composites, much still remains uncertain about their controllability in both UV photopatternability and electrical properties. Here, we investigate 7 kinds of GnF/SU-8 composites having different GnF concentrations of 5.0 to 25.0 wt.% to characterize the changes in the UV photopatternability (i.e., polymerized thickness and photopattern quality) and electrical conductivity of GnF/SU-8 composites caused by a variation in GnF concentration. The polymerized thickness of GnF/SU-8 composites is measured to be in the range of 4.06 to 23.99 μm, which is inversely proportional to GnF concentration and also directly proportional to UV dose (i.e., 345 to 3,450 mJ/cm2) because of the screening effect of GnF existed in the composites; the photopattern quality at the edge is in inverse proportion to GnF concentration. An increase in GnF concentration leads to a significant change in the electrical conductivity of GnF/SU-8 composites in a proportional way (up to 25.34 S/m). The GnF/SU-8 composites are expected to be widely used as UV photopatternable and electrically conductive PMCs for diverse engineering applications.


Nano Letters ◽  
2021 ◽  
Vol 21 (3) ◽  
pp. 1493-1499
Author(s):  
Kai Zhou ◽  
Wei Li ◽  
Bijal Bankim Patel ◽  
Ran Tao ◽  
Yilong Chang ◽  
...  

2020 ◽  
pp. 132-138
Author(s):  
E. M. Lenchenko ◽  
N. P. Sachivkina

Yeast-like fungi of the genus Candida are causative agents of the infectious pathology of the mucous membrane of the gastrointestinal, respiratory, urogenital tracts and skin of mammals, sepsis, and disseminated infection in birds. The search and testing of multilevel algorithms for biofilm identification when exposed to chemotherapeutic and disinfectant drugs for blocking the synthesis or destruction of the intercellular matrix in the development of superficial, deep and systemic candidiasis of animals are relevant for developing and improving diagnostic and antiepidemic measures. It was established that the formation of biofilm heterogeneous structure comprises multiple stages implementing the processes of intercellular communication due to the synthesis of a polymer matrix composites. Optical microscopy revealed a three-dimensional structure of biofilms in the form of a dense network consisting of yeast cells, hyphal and pseudohyphalic forms surrounded by an intercellular polymer matrix. Candida spp. pathogenicity factors contribute to infection of susceptible species due to adhesion, invasion, secretion of hydrolases, dimorphism. Formation of mono-species or poly-species biofilms of microorganisms, including Candida spp., causes the development of superficial, deep and systemic candidiasis. Detection of a large amount of yeast and micellar phases in C. albicans and C. africana isolates was a differential sign of a significant degree of colonization of the mucous membranes of the larynx, pharynx, and tonsils in case of local and systemic pathologies in pigs. The results of studies of the biofilm heterogeneous structure and phenotypic signs of yeast-like fungi can be used in a comparative study of biological characteristics and the identification of common patterns and differential signs of microorganisms, optimization of mycological diagnostics, and also in the development of antimycotic drugs.


Author(s):  
Jun Han ◽  
Lingyu Sun ◽  
Lijun Li ◽  
Bincheng Huang ◽  
Xudong Yang ◽  
...  

As a kind of functional materials, conductive polymer matrix composites filled with carbon nanotube (CNT) has potential application in structural health monitoring. A good formula should have a low percolation threshold and high piezoresistive strain sensitivity, which are always being sought by costly and time-consuming experimental method. Up to date, there is still a lack of numerical models to predict the sharp transition moment in electrical conductivity and mechanical resistance characteristics. This paper aims to establish a three-dimensional (3D) numerical model to observe the conductive network formation, predict the percolation threshold and investigate the piezoresistive characteristics of CNT-filled polymer matrix composites. Additionally, the influence of filler size, filler shape and filler volume fraction on the percolation threshold and piezoresistive characteristics would be investigated. The modeling and numerical simulation method can not only provide theoretical guidance for such a functional composite material, but also could be used in the future study on design and preparation of other conductive composites with two fillers added to improve the piezoresistive strain sensitivity and to decrease the percolation threshold.


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