Synthesis and gas permeability of highly elastic poly(dimethylsiloxane)/graphene oxide composite elastomers using telechelic polymers

Gas permeation and selectivity of poly(dimethylsiloxane)/graphene oxide composite elastomer membranes

“…Highly elastic telechelic PDMS/GO elastomers were synthesized as described elsewhere [7]. Briefly, a known amount of telechelic PDMS was dissolved in THF while stirring to ensure complete dissolution of the polymer.…”

“…In order to form a solid crosslinked elastomer, the sol precursor was heated to 160 °C in a vacuum oven for 24 hours and cooled slowly to room temperature before use. Neat PDMS elastomer was also synthesized as a reference material and the detailed synthesis procedure is described elsewhere [7].…”

“…Detailed information on the mechanism of the reaction that occurs during thermal annealing, accompanied with evidence of crosslinking from multiple analytical methods are described in detail elsewhere [7]. Briefly, amine functional groups on the ends of a telechelic PDMS precursor (a viscous liquid) undergo crosslinking reactions with epoxy groups on the surface of GO during simple thermal annealing to form a solid elastomer.…”

“…For instance, all of the gases studied in this work showed more than 99.9% reduction in gas permeability by incorporating 3.55 vol % GO. It is postulated that the general processing approach and chemical network formed during the cross-linking reaction between the primary amine ends and epoxy groups on the surface of the GO platelets (corresponding ATR-FTIR data in Figure S4) promoted the efficient dispersion of impermeable fillers throughout the matrix; homogeneous filler dispersion is one of the most important factors in reducing gas permeabilities [7]. Another possibility for the exceptional barrier properties in the present study could be related to the use of a higher aspect ratio filler, which would be expected to increase the diffusion length and the tortuosity for gas transport.…”

“…Graphene has been a common target due to its intrinsic strength and impermeability to gases, such that transport can only occur through major defects or in-between GO sheets. Previously, our group developed a simple method to synthesize highly elastic telechelic poly(dimethylsiloxane) (PDMS)/graphene oxide (GO) elastomers using affordable amineterminated telechelic PDMS and graphite [7]. The formation of ethanolamine covalent bonds was proposed based on the heating-induced reaction of primary amine end groups on the polymer with the highly reactive epoxy groups on the surface of GO.…”