Polymerized high internal phase emulsions containing a porogen: Specific surface area and sorption

Abstract

ABSTRACT:Highly porous, open-cell polymers [poly-(HIPE)] were prepared by polymerizing the monomers in the continuous phase (ϳ 10%) of high internal phase emulsions (HIPE). This paper discusses using poly(HIPE) to remove bromoform from an aqueous solution through sorption, a combination of adsorption and absorption. The crosslinked polystyrene (xPS) and crosslinked poly(ethylhexyl acrylate) (xPEHA) had cell diameters from 1.5 to 15 m, intercellular pore diameters from 0.3 to 1.5 m, and densities of about 0.10 g/cc. The specific surface area of the glassy xPS increased from 7.9 to 28.8 m 2 /g on extraction in methanol, most likely due to crazing. The use of a toluene porogen in the xPS (xPS-T) reduced the density to 0.05 g/cc and yielded a rough surface with nanoscale porosity and a specific surface area of 132 m 2 /g. xPS and xPEHA, with very different molecular structures but with similar specific surface areas, exhibited similar sorption behavior. Extraction produced increases in the xPS and xPS-T sorption plateaus and sorption capacities. For larger specific surface areas, the sorption at low concentrations was relatively independent of concentration, indicating a case of adsorption with the sites occupied. For all the other cases, absorption seems to dominate and sorption is more strongly dependent upon concentration.

PolyHIPE: IPNs, hybrids, nanoscale porosity, silica monoliths and ICP-based sensors

“…The density of S-bCT (0.05 g/cm 3 , for 55(67S/33DVB):45T) reflects the mass fraction of monomer in the HIPE (0.06). The addition of a porogen also yielded a significant increase in surface area, from 29 m 2 /g for S-a to 132 m 2 /g for S-bCT [10]. The addition of a porogen to the HIPE containing VS enhanced the yield producing polyHIPE whose composition more closely resembled the monomer composition in the HIPE.…”

“…The use of polymers as absorbents for the removal of contaminants from water is being investigated [4,5]. PolyHIPE, with their porous structure, have demonstrated advantageous structural properties and absorbency for use as absorbents [6][7][8][9][10]. PolyHIPE have also been used in ion exchange systems [11,12] and as heat resistant structural foams [13][14][15][16].…”

“…The polyHIPE synthesis has been described in detail elsewhere [9,10,23,29]. Briefly, the comonomers and emulsifier were stirred in a beaker for 5 min with a magnetic stirrer.…”

Synthesis and properties of polystyrene-based polyHIPEs reinforced with quadruple hydrogen bond functionality

“…These hierarchically porous materials, known as polyHIPEs, have huge amount of voids and windows (or throats, the small pores connecting the neighbor voids) by removal of the internal phase. PolyHIPEs have advantages such as high permeability, easy preparation, facile control of voids and windows size, etc., which are being considered for myriad applications such as in filtration media for separation [4][5][6][7][8], support for catalyst [9][10][11], scaffold for tissue engineering [12][13][14][15][16][17][18], adsorbent for scavenging [19][20][21][22][23][24][25][26] and storage for hydrogen [27,28].…”

Graphene Oxide Nanoparticles and Their Influence on Chromatographic Separation Using Polymeric High Internal Phase Emulsions

“…Attempts to increase the surface area of these materials have consisted mainly of introducing different additional porogens, which can leave the materials with low mechanical rigidity [15,16]. This decreased rigidity would compromise the material's ability to function as a high pressure stationary phase.…”