Effect of electric field strength and exposure time on epoxy and high density polyethylene measured by positron annihilation lifetime

1996 ◽  
Vol 211 (1) ◽  
pp. 77-83 ◽  
Author(s):  
Ehsan A. H. Gomaa ◽  
H. Schut ◽  
A. Van Veen ◽  
M. Mohsen ◽  
U. Fromm ◽  
...  
2008 ◽  
Vol 607 ◽  
pp. 88-90
Author(s):  
Hong Mei Wang ◽  
Zhe Chen ◽  
Peng Fei Wang ◽  
Shao Jie Wang

Two types of composites-high density polyethylene/polystyrene (HDPE/PS) with clay, and high density polyethylene grafted with acrylic acid/PS (PEAA/PS) with clay-were prepared via melt compounding. X-ray diffraction (XRD) results revealed that the dispersion of clay in compatibilized blends was better than immiscible blends. Positron annihilation lifetime spectroscopy (PALS) has been utilized to investigate the microstructure of two types of composites. The ortho-positronium (o-Ps) intensity for PEAA/PS was lower than that for HDPE/PS. The results provided evidence that the chain segments with carboxyl group would be easier to intercalate the gallery of silicates.


2012 ◽  
Vol 733 ◽  
pp. 143-146
Author(s):  
Jerzy Kansy ◽  
Magdalena Ziąbka

The positron irradiation effect in high density polyethylene at ambient temperature is studied by positron annihilation lifetime method. The positron spectra are analyzed with a model which takes into account positron trapping and so called delayed formation of positronium (DFP). A good relationship is noticed between the rate of positron trapping and the rate of DFP.


2016 ◽  
Vol 136 (10) ◽  
pp. 1420-1421
Author(s):  
Yusuke Tanaka ◽  
Yuji Nagaoka ◽  
Hyeon-Gu Jeon ◽  
Masaharu Fujii ◽  
Haruo Ihori

2021 ◽  
Vol 87 (2) ◽  
Author(s):  
Swati Baruah ◽  
U. Sarma ◽  
R. Ganesh

Lane formation dynamics in externally driven pair-ion plasma (PIP) particles is studied in the presence of external magnetic field using Langevin dynamics (LD) simulation. The phase diagram obtained distinguishing the no-lane and lane states is systematically determined from a study of various Coulomb coupling parameter values. A peculiar lane formation-disintegration parameter space is identified; lane formation area extended to a wide range of Coulomb coupling parameter values is observed before disappearing to a mixed phase. The different phases are identified by calculating the order parameter. This and the critical parameters are calculated directly from LD simulation. The critical electric field strength value above which the lanes are formed distinctly is obtained, and it is observed that in the presence of the external magnetic field, the PIP system requires a higher value of the electric field strength to enter into the lane formation state than that in the absence of the magnetic field. We further find out the critical value of electric field frequency beyond which the system exhibits a transition back to the disordered state and this critical frequency is found as an increasing function of the electric field strength in the presence of an external magnetic field. The movement of the lanes is also observed in a direction perpendicular to that of the applied electric and magnetic field directions, which reveals the existence of the electric field drift in the system under study. We also use an oblique force field as the external driving force, both in the presence and absence of the external magnetic field. The application of this oblique force changes the orientation of the lane structures for different applied oblique angle values.


Sign in / Sign up

Export Citation Format

Share Document