Open AccessCharge trapped mechanism for semi‐crystalline polymer electrets: quasi‐dipole model
Author(s) -
Chen Gangjin,
Zhang Jianfeng,
Shi Xiaoyan,
Peng Huili,
Chen Xi
Publication year - 2020
Publication title -
iet nanodielectrics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.23
H-Index - 9
ISSN - 2514-3255
DOI - 10.1049/iet-nde.2020.0003
Subject(s) - electret , crystallite , materials science , dipole , chemical physics , polymer , charge (physics) , amorphous solid , composite material , crystallography , chemistry , organic chemistry , physics , quantum mechanics , metallurgy
Polymer electrets are increasingly getting application in a very wide range. However, its charge trapped mechanism is still poorly understood. It is always challenging how to improve its charge trapped ability and to enhance its performance stability. In this study, a charge trapped mechanism, quasi‐dipole model, is proposed for semi‐crystalline polymer electrets. Every grain of crystallite is viewed as a dipole based on the polarisation effect between crystalline and amorphous region when charged. The energy level of the charge trap has a dependence on the crystallite structure. The more regular the crystallite grain structure the better charge stability is. The melt‐blown polypropylene (MBPP) electret fabrics with α or mesomorphic crystallite are used as the model material to verify the rationality of the mechanism. The experiment results from thermally stimulating discharge and X‐ray diffraction proved that the charge‐trapped stability could be improved by means of transformation from meso‐crystalline to α crystalline structure. The MBPP fabric containing α‐crystallite shows much better charge trapped performance than one containing mesomorphic‐crystallite because of more regular structure in α crystallite. The findings not only present new insight into charge‐trapped phenomena in polymer electrets, but also provide innovation for the processing technology of polymer electret materials.