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Instrumentation
Published in Suresh C. Ameta, Rakshit Ameta, Garima Ameta, Sonochemistry, 2018
There are many materials, both natural and man-made, that exhibit a range of piezoelectric effects. Some of the naturally occurring piezoelectric materials are:Berlinite (structurally identical to quartz)QuartzCane sugarRochelle saltTopazTourmalineBoneSilkWood due to piezoelectric texture.
Dielectric Polarization
Published in Sivaji Chakravorti, Electric Field Analysis, 2017
Piezoelectric materials could be natural or synthetic. The most commonly used natural piezoelectric material is quartz (SiO2). But synthetic piezoelectric materials, for example, ceramics and polymers, are more efficient. The piezoelectric materials used in practice are berlinite (AlPO4), gallium orthophosphate (GaPO4), barium titanate (BaTiO3), lead zirconate titanate (PZT: PbZr1−xTixO3), aluminium nitride (AlN) and polyvinylidene fluoride to name a few. In recent years, piezoceramics and piezopolymers are widely used in smart structures. Very recently, breakthrough in single crystal growth technique has enabled the development of high strain and high electric breakdown piezoceramics.
Piezoelectrical Materials for Biomedical Applications
Published in Jince Thomas, Sabu Thomas, Nandakumar Kalarikkal, Jiya Jose, Nanoparticles in Polymer Systems for Biomedical Applications, 2019
M. S. Neelakandan, V. K. Yadu Nath, Bilahari Aryat, K. A. Vishnu, Jiya Jose, Nandakumar Kalarikkal, Sabu Thomas
There are many materials, both natural and man-made, that exhibit a range of piezoelectric effects. Some naturally piezoelectric occurring materials include berlinite (structurally identical to quartz), cane sugar, quartz, Rochelle salt, topaz, tourmaline, and bone (dry bone exhibits some piezoelectric properties due to the apatite crystals, and the piezoelectric effect is generally thought to act as a biological force sensor). An example of man-made piezoelectric materials includes barium titanate (BT) and lead zirconate titanate.
Adsorption behaviours and mechanisms of heavy metal ions’ impact on municipal waste composts with different degree of maturity
Published in Environmental Technology, 2019
Ling Liu, Xiaoping Guo, Chengliang Zhang, Chao Luo, Chaoqun Xiao, Ruoyu Li
The XRD spectra (Figure 5) showed composts and metals-loaded composts by single- or quaternary-metal system, and the figure illustrates the presence of a significant amount of amorphous material due to HA in the sample. The diffraction peaks of the compost before and after adsorbing heavy metals will change. Compost components were well recognized according to the Powder Diffraction File (PDF) and Standards analysis, such as graphite [C; PDF n. 41-1487], quartz [SiO2; PDF n. 43-0596], berlinite [AlPO4; PDF n. 10-0423] and calcite [CaCO3; PDF n. 05-0586]. The changes of patterns were observed at 2θ = 27.7° and 29.2° compared with original composts sample; however, the patterns at 2θ = 32.1° decreased when the composts were loaded with metals, which can be attributed to CaSiO3. Multi-charged ions (Si4+ and Al3+) can be replaced by other low valence metal ion to make the compost particles negatively charged, thus the composts have the ability to adsorb cations. Heavy metal ions could react with aluminium silicate minerals in composts to form MSiO3. The formation of MAl2(SiO4)2 can be attributable to surface complexes between metal ions and the kaolinite mineral [37]. The mechanism between HA/FA, kaolinite mineral and metal ions can be expressed as follows:
On structure and oxidation behaviour of non-stoichiometric amorphous aluminium phosphate coating
Published in Surface Engineering, 2019
Aluminium phosphate with chemical composition of AlPO4 is a well-known ceramic material with low density (2.56 g cm−3 for berlinite), high melting temperature (1800°C), and high hardness (6.5 Mohs) [1]. It is also chemically compatible with most widely used ceramic materials including silicon carbide, alumina, mullite, and silica over a moderate range of temperatures [2]. However, stoichiometric aluminium phosphate is isostructural with silica and undergoes similar polymorphic transformations (quartz-type, tridymite, and cristobalite). In fact, its use as a high temperature ‘engineering ceramic’ material is limited primarily because of the phase transformations which involve large molar volume changes [3]. Therefore, synthesis of non-stoichiometric and amorphous aluminium phosphate with no allotropic volume changes which is stable at the elevated temperatures appears advantageous as it skips the aforementioned drawbacks and provides unique properties arising from the amorphous structure such as superior corrosion and oxidation resistance [4].