Nanoporous organosilica membrane for water desalination

Abstract

Nanoporous organosilica membranes are successfully coated on porous alumina tubes and tested for desalination via membrane distillation. The membranes produced pure water (up to 13 kg m(-2) h(-1)) across an extreme range of salt concentrations (10-150 g L(-1) NaCl) at moderate temperatures (≤60 °C) without exhibiting the characteristic flux decay of competing materials.

Mesoporous TiO 2 based membranes for water desalination and brine processing

“…As shown in Table 1, all these microporous inorganic membranes generally deliver high salt rejection at improved water fluxes of values up 11.5 kg m -2 h -1 depending upon the testing conditions. Recently, Chua and co-workers reported the preparation of ordered mesoporous silica membranes delivering reasonable water fluxes and high salt rejection [12]. A more recent work from Diniz da Costa's group [14] has shown that interlayer free carbonised template silica membranes formed mesoporous carbon moieties within the silica matrix, thus conferring improved water fluxes of up to [17,18] and ultrafiltration [19] processes only.…”

Mesoporous organosilica membranes: Effects of pore geometry and calcination conditions on the membrane distillation performance for desalination

“…3, are in agreement with the XRD data with all samples exhibiting long range order. For samples PMO-2-300A and PMO-2-350N this took the form of cage-like cubic pores, whereas the PMO-1-300A and PMO-1-350N samples exhibited a distorted orthogonal pore structure derived from body-centred cubic geometry [9]. This is reasonable as F127 has a longer EO chain that favours aggregation into globular structures which result in larger cage-like pores [31,32].…”

“…pore wetting) must improve to be commercially competitive with RO has seen a new range of membrane materials emerge including ceramics [4,5] and carbon nanotubes [6], as well as different morphologies [7,8]. Of these, ordered organosilica membranes have shown considerable promise [9].…”

“…PMO materials demonstrate some variability in hydrophobicity [24], which is a function of surface roughness (relatively unexplored in the PMO literature) and surface chemistry (dependent on the organic functional groups) [25], among others. Previously, we showed that a PMO membrane synthesized from 1, 2-bis(triethoxysilyl) ethane (BTESE) and the non-ionic triblock copolymer surfactant Pluronic F68 gave excellent fluxes of up to 13 L m −2 h −1 across an extreme range of salt concentrations (10-150 g L −1 NaCl) at moderate temperatures (b 60°C) [9]. In contrast to other MD work with inorganic materials [26,27], no discernible concentration polarisation was evident as salt concentration increased, rather temperature polarisation provided the most significant boundary layer resistance [28].…”

Carbon molecular sieve membranes for desalination

“…If the water flux is sufficiently fast, the surface concentration experienced by the 0.3 and 3.5% NaCl solutions would be comparable and the real difference in vapour pressure (at the membrane surface) would be much smaller than the apparent difference (when considering the bulk liquid). A recent study into ordered mesoporous hybrid silica membranes for desalination also noted that the flux of their membranes was essentially independent of the salt feed concentration (up to 15 wt% NaCl) (Chua, Lin et al 2013). …”