Journal article
Direct piezoelectric effect in geopolymeric mortars
Materials & design, Vol.107, pp.57-64
10/05/2016
DOI: 10.1016/j.matdes.2016.05.108
Abstract
In this paper the occurrence of a direct piezoelectric effect has been discovered for the first time in a metakaolin based geopolymeric mortar. Unlike any other known piezoelectric material (quartz single-crystal, PZT, PVDF), wherein the formation of local electric dipoles is due to the elastic deformation of the non-centrosymmetric crystalline structures, a new and different piezoelectric mechanism was observed in geopolymers. It is due to a complex interplay that involves not-framework cations, framework and water contained in the material pores. In particular, the model proposed by authors attributes the piezoelectric effect to the charge imbalance and local dipoles generated under compressive stress by the migration, within the network of interconnected pores of geopolymer, of the hydrated Na+ cations, coordinated in a charge balancing arrangement with the aluminium tetrahedra. The absence of a charge generation in dehydrated samples and the inexistence of a converse piezoelectric response confirmed that quartz impurities present inside the material don't contribute to the direct piezoelectric effect, thus due only to ionic mobility. Furthermore, an anisotropic behavior of the effect was observed and the measured charge coefficient in the predominant direction was found to lie in the range (4÷40) pC/N, depending on the water content in geopolymers.
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•The occurrence of a direct piezoelectric effect has been discovered for the first time in a metakaolin geopolymeric mortar•Unlike any other known piezoelectric material, the effect is related to ionic mobility•A physical-chemical model is proposed•An anisotropic behavior of the effect was observed•The charge coefficient in the predominant direction lies in the range (4÷40) pC/N, depending on the water content
Details
- Title: Subtitle
- Direct piezoelectric effect in geopolymeric mortars
- Creators
- Caterina Lamuta - University of Calabria, Department of Mechanical, Energy and Management Engineering – DIMEG, Ponte P. Bucci, cubo 44C, 87030 Arcavacata di Rende, CS, ItalySebastiano Candamano - University of Calabria, Department of Environmental and Chemical Engineering – DIATIC, Ponte P. Bucci, cubo 44A, 87030 Arcavacata di Rende, CS, ItalyFortunato Crea - University of Calabria, Department of Environmental and Chemical Engineering – DIATIC, Ponte P. Bucci, cubo 44A, 87030 Arcavacata di Rende, CS, ItalyLeonardo Pagnotta - University of Calabria, Department of Mechanical, Energy and Management Engineering – DIMEG, Ponte P. Bucci, cubo 44C, 87030 Arcavacata di Rende, CS, Italy
- Resource Type
- Journal article
- Publication Details
- Materials & design, Vol.107, pp.57-64
- DOI
- 10.1016/j.matdes.2016.05.108
- ISSN
- 0264-1275
- eISSN
- 1873-4197
- Publisher
- Elsevier Ltd
- Grant note
- name: PON MaTeRiA, award: PONa3_00370
- Language
- English
- Date published
- 10/05/2016
- Academic Unit
- Mechanical Engineering
- Record Identifier
- 9984064200602771
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