PEBAX® with PEG functionalized POSS as nanocomposite membranes for CO2 separation

Abstract

Nanocomposite membranes were prepared by incorporation of commercial poly(ethylene glycol) functionalized polyoctahedral oligomeric silsesquioxanes (PEG-POSS) in two grades of poly(ether-block-amide) namely PEBAX ® MH 1657 and PEBAX ® 2533. Single gas permeabilities of N 2 , O 2 , CH 4 , H 2 , and CO 2 were measured using the time-lag method. CO 2 permeability increased two fold after incorporation of 30 wt% PEG-POSS in PEBAX ® MH 1657, while the selectivity was not significantly affected at 30 °C. Simultaneous enhancement in permeability and selectivity was observed up to 30 wt% loading of PEG-POSS in PEBAX ® 2533 at 30 °C. The effect of temperature upon CO 2 permeability and CO 2 selectivity over N 2 , O 2 , CH 4 and H 2 was studied between 30 ºC to 70 °C. Substantial influence upon the thermal transition of the polyether domain of both polymers was observed due to incorporation of PEG-POSS by differential scanning calorimetry (DSC). Atomic force microscopy was used to evaluate the impact of 30 wt% PEG-POSS loading upon the surface topography of both investigated grades of PEBAX ®. Scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) were used to study the membrane morphology and the distribution of the nanofillers (PEG-POSS) in PEBAX ® membranes.

The effect of amine substituent chain length on POSS/Polysulfone mixed matrix membrane

“…The formation of these ellipsoidal inclusions or oval shaped holes were located all over the cross sections of the AMPOSS-b/PSf MMMs. Similar findings have been reported and the cause was identified to be the poor miscibility between the fillers with the polymer matrix [24]. Furthermore, the empty voids visible in Figure 4 were perhaps the result of filler aggregates that have been detached from the polymer matrix during the breakage of sample for SEM analysis [36].…”

“…Moreover, its ability to be functionalised into different variations has sparked an interest to develop MMMs with improved properties [22]. Most importantly, its separated, non-aggregated, well-defined size and structure induces good dispersion in various polymers [20,[23][24][25] The incorporation of POSS in polymeric matrixes can be done via two approaches which are chemical cross-linking and physical blending. In chemical cross-linking, the formation of covalent bonds between POSS and polymer matrices are encouraged whilst in physical blending, POSS particles are embedded into the polymer matrices via melt mixing or solvent casting methods.…”

Polyhedral oligomeric silsesquioxane/polyamide bio-nanocomposite membranes: structure-gas transport properties

“…In the present study, the incorporation of POSS, which creates 22 roughness on the surface, is helpful for adsorption whereas it restricts diffusion. Similar results were obtained by Rahman et al 14 From Table 1, it is clear that the incorporation of 20 wt.% POSS seemed to have increased the surface roughness of the polymer matrix.…”

“…11,12 Therefore, polyhedral oligomeric silsesquioxane (POSS) is of particular interest, mainly, in the preparation of membranes for gas separation operations. 9,[13][14][15][16][17][18][19][20][21][22][23][24] Unlike the common nanoparticles, POSS is very small (1-3 nm) and the chemistry of POSS is quite flexible. 25 POSS molecules embody a truly hybrid inorganic core/organic shell architecture that are naturally compatible with organic hosts, such as renewable resources 26,27 and natural biomaterials.…”

Stability of blended polymeric materials for CO2 separation

“…[25] Poly(ethylene glycol) functionalized POSS [26] and PDMS [23] give very promising gas transport property change to Pebax ® when blended with it. Here we report on results of the blend stability.…”