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porous-polymers
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Preparation of Hydrogen Adsorbent Nanoporous Polymer for Fuel Cell Applications
, M.Sc. Thesis Sharif University of Technology ; Frounchi, Masoud (Supervisor) ; Mousavi, Abbas (Supervisor)
Abstract
Application of fuel cells as one of the new and clean energy generators at recent years is many interesting for governments. In many cases hydrogen gas is fuel of these cells. One of the problems at this field is issue of hydrogen storage with a safety and ecconemical way. Usually storage of hydrogen be done with several different ways : Composite tank, Liquid hydrogen, Metal hydride , Chemical hydride, carbon nanotube and etc. Use of polymers that have ability of adsorption is one of topics that is attended at these years , because of their low density and easy process ability and low explosion risk and economical aspect . So at this research we try to identify polymers that have...
Development of Polymerization Method to Produce Spherical Polymer Particles with Nanoscale Porosity in Packed Beds
, M.Sc. Thesis Sharif University of Technology ; Shojaei, Akbar (Supervisor) ; Abd Khodaei, Mohammad Jafar (Supervisor) ; Nematollah Zadeh, Ali (Co-Advisor)
Abstract
Porous polymeric particles have the extensive application in various sciences and various methods have been introduced for production of these particles. Depending on method of production, porous polymeric beads can be produced in diverse shapes, pore size, pores interconectivity, surface morphology and chemical properties. In common methods for production of porous polymeric particles, tuning the size and porosity is difficult or even impossible. Porous polymeric beads with the vast surface area and good functionality have been applied for adsorption of various materials. The purpose of this study is therefore to investigate a new procedure for the production of porous polymeric...
Study of the Evolution of Three-dimensional Pore Structure during Sintering of High Density Polyethylene Powders with Different Particle Size and Melt Flow Index
, M.Sc. Thesis Sharif University of Technology ; Pircheraghi, Gholamreza (Supervisor)
Abstract
Recently, macroporous polymers have gained wide acceptance for applications such as filters, membranes, biodegradable scaffolds, retention media, sound mufflers and etc. In this research, by keeping in mind the importance of the pore structure in the functionality of the porous part, three dimensional images of the pore structure during sintering was obtained using an optimized manual serial sectioning technique. Then, using the Euler number as a property of the topology of the pore surface, evolution of the three dimensional pore structure was scrutinized for two types of powders, powder A with a mean particle size of 200 micron and melt flow index of 0.2 (g/10 min) and powder B with a mean...
Fabrication and characterization of a starch-based nanocomposite scaffold with highly porous and gradient structure for bone tissue engineering
, Article Biomedical Physics and Engineering Express ; Volume 4, Issue 5 , 2018 ; 20571976 (ISSN) ; Eslamian, M ; Bagheri, R ; Sharif University of Technology
Institute of Physics Publishing
2018
Abstract
Starch based scaffolds are considered as promising biomaterials for bone tissue engineering. In this study, a highly porous starch/polyvinyl alcohol (PVA) based nanocomposite scaffold with a gradient pore structure was made by incorporating different bio-additives, including citric acid, cellulose nanofibers, and hydroxyapatite (HA) nanoparticles. The scaffold was prepared by employing unidirectional and cryogenic freeze-casting and subsequently freeze-drying methods. Fourier transform infrared (FTIR) spectroscopy confirmed the cross-linking of starch and PVA molecules through multiple esterification phenomenon in the presence of citric acid as a cross-linking agent. Field emission scanning...
Supported deep eutectic liquid membranes with highly selective interaction sites for efficient CO2 separation
, Article Journal of Molecular Liquids ; Volume 342 , 2021 ; 01677322 (ISSN) ; Khan, A. L ; Gilani, M. A ; Bilad, M. R ; Khan, A. U ; Sharif University of Technology
Elsevier B.V
2021
Abstract
This study demonstrates a new strategy in which deep eutectic solvents (DES), a new class of sustainable organic solvents, were impregnated into micro porous polymer support for separation of CO2 from CH4. Three different types of DESs were prepared by mixing and subsequent heating of betaine as hydrogen bond acceptor (HBA) in combination with either glycerol (G), ethylene glycol (EG) or urea (U) as hydrogen bond donors (HBD) in 1:3 stoichiometric mole ratio. The Fourier transform infrared (FTIR) spectroscopy was performed to confirm the formation of DESs. The gas permeation results showed that permeability of CO2 increased from 31.23 to 35.67 Barrer on substitution of HBD from glycerol to...
Novel nano-porous hydrogel as a carrier matrix for oral delivery of tetracycline hydrochloride
, Article Colloids and Surfaces A: Physicochemical and Engineering Aspects ; Volume 392, Issue 1 , December , 2011 , Pages 16-24 ; 09277757 (ISSN) ; Pourjavadi, A ; Soleyman, R ; Sharif University of Technology
Abstract
A novel nano-porous hydrogel (NPH) was synthesized via graft copolymerization of sodium acrylate (Na-AA) and acrylamide (AAm) onto salep backbones and its application as a carrier matrix for oral delivery of tetracycline hydrochloride (TH) was investigated. The Taguchi method as a strong experimental design tool was used for synthesis optimization. The swelling behavior of optimum hydrogel was measured in various media. The hydrogel formation was confirmed by Fourier transform infrared spectroscopy (FT-IR) and thermogravimetrical analysis (TGA). The study of the surface morphology of the hydrogels using SEM and AFM showed a nanoporous (average pore size: 180. nm) structure for the sample...
Extraction of hydroxyapatite nanostructures from marine wastes for the fabrication of biopolymer-based porous scaffolds
, Article Marine Drugs ; Volume 18, Issue 1 , 2020 ; Mohandes, F ; Mazaheri, M ; Dolatyar, B ; Askari, M ; Simchi, A ; Sharif University of Technology
MDPI AG
2020
Abstract
Three-dimensional porous nanocomposites consisting of gelatin-carboxymethylcellulose (CMC) cross-linked by carboxylic acids biopolymers and monophasic hydroxyapatite (HA) nanostructures were fabricated by lyophilization, for soft-bone-tissue engineering. The bioactive ceramic nanostructures were prepared by a novel wet-chemical and low-temperature procedure from marine wastes containing calcium carbonates. The effect of surface-active molecules, including sodium dodecyl sulfate (SDS) and hexadecyltrimethylammonium bromide (CTAB), on the morphology of HA nanostructures is shown. It is demonstrated that highly bioactive and monophasic HA nanorods with an aspect ratio > 10 can be synthesized in...