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Manufacturing and Investigating of Polypropylene/Silica Nanocomposites via in-situ Polymerization and Using Bi-supported Ziegler-Natta Catalyst
, M.Sc. Thesis Sharif University of Technology ; Ramezani Saadat, Ahmad (Supervisor)
Abstract
The main object of this thesis is production and investigation of polypropylene-fumed silica nanocomposites by using bi-supported Ziegler-natta catalytic system and in-situ polymerization. Magnesium ethoxide and fumed silica were used as supports of catalyst. TiCl4 was accompanied by triisobutyl aluminum(TiBA) and diisobutyl phthalate(DIBP) as electron doner constituting Ziegler-Natta catalytic system. Preparation of catalyst and polymerization were taken place in slurry phase under the argon atmosphere. At the beginning of the polymerization experiment, several type of nanocomposites were made under various conditions(such as different Al/Ti molar ratio) to find optimum condition to...
Comparison between electron-beam and chemical crosslinking of silicone rubber
, Article Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms ; Volume 243, Issue 2 , 2006 , Pages 354-358 ; 0168583X (ISSN) ; Dadbin, S ; Panahinia, F ; Sharif University of Technology
2006
Abstract
Silicone rubber (SR) was irradiated by electron beam over a dose range of 50-300 kGy in the absence of chemical reagents. Molecular weight between crosslinks (Mc) in the network of SB was determined by two methods of solvent swelling and modulus of elasticity. The network structure of the elastomer crosslinked by electron beam irradiation and chemical vulcanization was compared. Mechanical tests were performed to determine shore hardness, tensile elongation, strength and modulus of the samples. It was found that SR is effectively crosslinked by electron beam irradiation. The tensile strength, hardness, modulus and elongation of irradiated SR were higher than peroxide-crosslinked SR. The...
Monitoring of microscopic behavior of nano-enhanced colloidal gas aphron in fractured and un-fractured non-uniform porous medium
, Article Journal of Petroleum Science and Engineering ; Volume 210 , 2022 ; 09204105 (ISSN) ; Ghazanfari, M. H ; Sharif University of Technology
Elsevier B.V
2022
Abstract
The present article aimed to examine the pore-scale examination of a fluid capability to block pores and fractures deduced by return permeability and the blocking ability of a novel lightweight Colloidal Gas Aphron Nano-Fluid (CGANF) in heterogeneous fractured/un-fractured porous medium. Silica (S) and fumed silica (FS) nanoparticles, Sodium Dodecyl Sulfate (SDS) anionic surfactant, and Xanthan Gum (XG) bio-polymer were employed for following up CGANF bubbles' movements in incongruous micro-models’ inclusive crack. The transparent nature of the glass micro-model provides an intuition into the lenticular behavior of CGANF bubbles in the heterogeneous porous media. Differential pressure...
Pore-scale analysis of filtration loss control by colloidal gas aphron nano-fluids (CGANF) in heterogeneous porous media
, Article Experimental Thermal and Fluid Science ; Volume 77 , 2016 , Pages 327-336 ; 08941777 (ISSN) ; Ghazanfari, M. H ; Sharif University of Technology
Elsevier Inc
2016
Abstract
This study concerns micro-scale analysis of filtration loss control induced by blockage ability of a new colloidal gas fluid, Colloidal Gas Aphron Nano-Fluid (CGANF) in fractured porous media. Fumed silica nanoparticles and a novel environmentally friendly bio surfactant, Olea Europaea, were used for monitoring CGANF displacements in heterogeneous micromodels including single fracture. Analysis of pressure drop along the micromodel during tests showed an increasing resistance to flow of CGANF dispersion through porous media as more CGANF was injected. When lamella division occurs, more small bubbles are formed and then pressure drop through porous media increases. Small bubbles play an...
Production and characterization of UHMWPE/fumed silica nanocomposites
, Article Polymer Composites ; Volume 33, Issue 10 , 2012 , Pages 1858-1864 ; 02728397 (ISSN) ; Saremi, M. G ; Amoli, B. N ; Izadi, H ; Sharif University of Technology
Wiley
2012
Abstract
Ultrahigh-molecular-weight polyethylene (UHMWPE)/fumed silica nanocomposites were prepared via in situ polymerization using a bi-supported Ziegler-Natta catalytic system. Nanocomposites with different nanoparticle weight fractions were produced in order to investigate the effect of fumed silica on thermal and mechanical properties of UHMWPE/fumed silica nanocomposites. The viscosity average molecular weight (M) of all samples including pure UHMWPE as the reference sample and nanocomposites were measured. Scanning electron microscope (SEM) images showed the homogenous dispersion of nanoparticles throughout the UHMWPE matrix while no nanoparticle cluster has been formed. Crystallization...