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    Preparation and characterisation of diopside-based glass-ceramic foams

    , Article Ceramics International ; Volume 38, Issue 3 , 2012 , Pages 2005-2010 ; 02728842 (ISSN) Hasheminia, S ; Nemati, A ; Eftekhari Yekta, B ; Alizadeh, P ; Sharif University of Technology
    2012
    Abstract
    Foaming and crystallisation behaviours of compacted glass powders based on a diopside glass-ceramic composition were investigated using the sintering route. The foaming agent was 2 wt.% SiC particles. The effect of PbO on the foaming ability of glasses was investigated. The results showed that the addition of PbO not only improved the foaming ability, by improving the wettability of the glass-SiC particles but also increased the crystallisation temperature and widened the temperature interval between the dilatometric softening point and the onset of crystallisation. The glass-SiC wetting angle was decreased from 85°for the lead-free glass, to 55°for the glass that contains 15 wt.% PbO  

    Interdiffusion versus crystallization at semicrystalline interfaces of sintered porous materials

    , Article Polymer ; Volume 156 , 2018 , Pages 54-65 ; 00323861 (ISSN) Salari, M ; Pircheraghi, G ; Sharif University of Technology
    Elsevier Ltd  2018
    Abstract
    Sintering process at temperature intervals close to the melting point of polymers is greatly important due to its role in synthesizing porous materials. During sintering, particles of polymeric materials coalesce throughout a process called interdiffusion. On the contrary, crystallization strongly affects the interdiffusion process at temperature intervals below and close to the melting point. Apparently, the outcome of the contention between these two factors would determine the interfacial width. Therefore, the current study presents a model, which takes both crystallization and interdiffusion into account, to predict sintering kinetic. Consequently, interfacial strength was assessed with... 

    Dielectric properties of nematic liquid crystal doped with Fe3O4 nanoparticles

    , Article Phase Transitions ; 2016 , Pages 1-9 ; 01411594 (ISSN) Maleki, A ; Majles Ara, M. H ; Saboohi, F ; Sharif University of Technology
    Taylor and Francis Ltd 
    Abstract
    The influence of Fe3O4 nanoparticles (NPs) on dielectric properties of planar and homeotropic oriented nematic liquid crystals (NLCs) were studied during the temperature interval of 298–322 °K. It was found that the dielectric permittivity was considerably increased by adding NPs mass percentages. The structural characterization of the synthesized NPs with the scale 14–18 nm has been analyzed by the X-ray diffraction and field-emission scanning electron microscopy results. The obtained dielectric anisotropy ((Formula presented.)) and mean dielectric ((Formula presented.)) have shown an immense increment in the value of 1% and 10% wt. NPs doped NLCs, respectively. These results were assigned... 

    Dielectric properties of nematic liquid crystal doped with Fe3O4 nanoparticles

    , Article Phase Transitions ; Volume 90, Issue 4 , 2017 , Pages 371-379 ; 01411594 (ISSN) Maleki, A ; Majles Ara, M. H ; Saboohi, F ; Sharif University of Technology
    Taylor and Francis Ltd  2017
    Abstract
    The influence of Fe3O4 nanoparticles (NPs) on dielectric properties of planar and homeotropic oriented nematic liquid crystals (NLCs) were studied during the temperature interval of 298–322 °K. It was found that the dielectric permittivity was considerably increased by adding NPs mass percentages. The structural characterization of the synthesized NPs with the scale 14–18 nm has been analyzed by the X-ray diffraction and field-emission scanning electron microscopy results. The obtained dielectric anisotropy (Δε) and mean dielectric (Formula presented.) have shown an immense increment in the value of 1% and 10% wt. NPs doped NLCs, respectively. These results were assigned to the strong...