Yazdimamaghani M.,Oklahoma State University |
Yazdimamaghani M.,Iranian Institute of Research and Development in Chemical Industries ACECR |
Pourvala T.,Iranian Institute of Research and Development in Chemical Industries ACECR |
Motamedi E.,Tarbiat Modares University |
And 3 more authors.
Materials | Year: 2013
Nanocomposites of encapsulated silica nanoparticles were prepared by in situ emulsion polymerization of acrylate monomers. The synthesized material showed good uniformity and dispersion of the inorganic components in the base polymer, which enhances the properties of the nanocomposite material. A nonionic surfactant with lower critical solution temperature (LCST) was used to encapsulate the silica nanoparticles in the acrylic copolymer matrix. This in situ method combined the surface modification and the encapsulation in a single pot, which greatly simplified the process compared with other conventional methods requiring separate processing steps. The morphology of the encapsulated nanosilica particles was investigated by dynamic light scattering (DLS) and transmission electron microscopy (TEM), which confirmed the uniform distribution of the nanoparticles without any agglomerations. A neat copolymer was also prepared as a control sample. Both the neat copolymer and the prepared nanocomposite were characterized by Fourier transform infrared spectroscopy (FTIR), thermal gravimetric analyses (TGA), dynamic mechanical thermal analysis (DMTA) and the flame resistance test. Due to the uniform dispersion of the non-agglomerated nanoparticles in the matrix of the polymer, TGA and flame resistance test results showed remarkably improved thermal stability. Furthermore, DMTA results demonstrated an enhanced storage modulus of the nanocomposite samples compared with that of the neat copolymer, indicating its superior mechanical properties. © 2013 by the authors.
Zamen M.,Iranian Institute of Research and Development in Chemical Industries ACECR |
Zamen M.,K. N. Toosi University of Technology |
Soufari S.M.,Iranian Institute of Research and Development in Chemical Industries ACECR |
Vahdat S.A.,Iranian Institute of Research and Development in Chemical Industries ACECR |
And 4 more authors.
Desalination | Year: 2014
This paper experimentally evaluates a two-stage technique to improve the humidification-dehumidification process in fresh water production from brackish water. According to modeling results of multi-stage process and on the basis of construction cost estimation, using a two-stage process is the most suitable choice that can improve important parameters such as specific energy consumption, productivity and daily production per solar collector area and thus, investment cost. A pilot plant was designed and constructed in an arid area with 80m2 solar collector area to evaluate the two-stage process. This unit was tested on cold and hot days. The effect of main parameters on fresh water production of the unit is studied. Experimental results show that two-stage HD desalination unit can increase heat recovery in condensers and hence, reduce thermal energy consumption and investment cost of the unit. Moreover, productivity can be increased by 20% compared with the single-stage unit. © 2013 Elsevier B.V.