טכניון מכון טכנולוגי לישראל
הטכניון מכון טכנולוגי לישראל - בית הספר ללימודי מוסמכים  
M.Sc Thesis
M.Sc StudentNormatov Jenny
SubjectPorous Nanocomposites Synthesized within High Internal Phase
Emulsions
DepartmentDepartment of Materials Science and Engineering
Supervisor Professor Michael Silverstein
Full Thesis textFull thesis text - English Version


Abstract

A high internal phase emulsion (HIPE) is defined as an emulsion in which the dispersed phase occupies more than 74% of the volume. PolyHIPE are crosslinked porous polymers synthesized by polymerizing monomer in the continuous phase of a HIPE. PolyHIPE have unusual porous structures, low bulk densities, and high permeability. Porous nanocomposites would be a novel class of materials with unique properties that would be attractive for the advanced technology applications. The objectives of this research were to synthesize nanocomposite polyHIPE based on an elastomeric polymer using several different approaches, investigate the influences of the nanoscale reinforcements on the structure and properties of the polyHIPE, and compare the nanocomposite polyHIPE synthesized using the different approaches. Four types of nanocomposites were synthesized: (1) copolymers of 2-ethylhexyl acrylate (EHA), divinylbenzene (DVB), and a polyhedral oligomeric silsesquioxane (POSS) bearing a vinyl group; (2) EHA crosslinked with poly(vinyl silsesquioxane) (VSQ); (3) EHA/DVB with reactive VSQ or non-reactive poly(methyl silsesquioxane) (MSQ); (4) Organic/inorganic hybrid interpenetrating networks of EHA/DVB and a Si-O network from tetraethylorthosilicate (TEOS) hydrolysis and condensation. The porous structures, mechanical properties, and thermal properties of the nanocomposite polyHIPE were characterized. Incorporation of Si-O moieties increased the tan δ peak temperature, modulus, and stress plateau. Pyrolysis of the POSS- and VSQ-based nanocomposite polyHIPE yielded porous inorganic monoliths consisting of Si-O networks.