ISSN:
1435-1536
Keywords:
Dielectric property
;
interfacial polarization
;
microcapsule
;
poly(methylmethacrylate)
;
polystyrene
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
,
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Abstract The dielectric behavior of poly(methyl methacrylate) (PMMA) microcapsules was analyzed theoretically by taking account of the frequency dependence of the relative permittivityɛ s and the electrical conductivityχ s of the capsule wall. For comparison, similar analysis was applied to polystyrene (PS) microcapsules which have frequency-independentɛ s andχ s . The behavior ofɛ s andχ s of the PMMA microcapsules was assumed to be represented by a dielectric relaxation of them-th power type on the basis of dielectric data on underwater PMMA films. By means of a theory of the interfacial polarization, some consideration was carried out regarding the effect of the frequency dependence ofɛ s andχ s on the dielectric behavior of the PMMA microcapsules. The consideration led to predictions that the frequency dependence ofɛ s andχ s causes (i) the variation in the relaxation intensity with the change in the conductivity of suspending medium, (ii) the frequency dependence of the permittivity at low frequencies and (iii) the frequency dependence of the conductivity at high frequencies. The theoretical prediction (i) was verified by observed data, (ii) and (iii) remaining unverified owing to the experimental difficulty.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01410859
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