Graphene stimulates the nucleation and growth rate of NaCl crystals from hypersaline solution via membrane crystallization

Abstract

Advanced graphene engineered membranes designed for sustainable crystallization of high-quality crystals from hypersaline water.

A few-layer graphene for advanced composite PVDF membranes dedicated to water desalination: a comparative study

“…This behaviour is in agreement with what recently observed for GPNs (UW) 35 and suggested there was no inertia of graphene towards water vapour but rather a supporting action in the diffusion process. This experimental evidence is unquestionably corroborated by the literature, which refers to a certain aptitude of graphene to interact with water molecules [42][43][44][45]72 with indications from the adsorption of water vapour on exfoliated GPNs of up to 249 cm 3 g À1 at 20 C, 42 the adsorption of water on the edge of graphene through the dissociation of H 2 O to an H atom and OH group, 71 the increased work adhesion between water and the membrane surface modied with GPNs. 45 Herein, Raman spectroscopy gave an indication of the presence of defects due to the edges of the WJM akes (Fig.…”

“…Considering that the membranes exhibited a more or less comparable porosity and thickness but a smaller mean pore size for the FLG-WJM(0.65) membrane, it is reasonable to suppose an involvement of the nanoller in the mass transfer through the membranes. 35,45,71 Table 2 shows the MD transport coefficients (B) calculated for the two FLG-WJM membranes. In both cases, the trend uctuated independently of the difference in the partial pressure applied across the membranes.…”

“…[28][29][30][31][32][33] Recently, graphene platelets (GNPs), graphene oxide (GO) and reduced graphene oxide (rGO), have been regarded as interesting materials to increase the productivity of membranes [34][35][36][37][38][39][40][41] for water desalination purposes. Defective graphene and derivatives have been oen proposed for membrane distillation operations due to their attractive hydrophobic and anti-wetting nature, anti-fouling properties and selective sorption of water vapours [34][35][36][37][38][39][40][41][42][43][44][45][46][47] . However, a lot of attention has been paid to identify a suitable polymer-nanoller ratio for achieving good performance; whilst the morphological and chemical features of the nano-ller have been hardly considered in the nal outcome of the process.…”

Performance of PVDF Based Membranes with 2D Materials for Membrane Assisted-Crystallization Process

“…Moreover, the presence of fillers in PVDF-based membranes reduced the time for detection of the first clearly visible crystals in comparison with PVDF-pristine membrane, from 285 min to 140 min in the case of PVDF/BT (0.5%) (Figure 6). The obtained experimental results agree with the findings of Perrotta et al [7,17], where it was suggested that well-established interactions at the graphene-solution interface stimulate water sequestration from ion-water clusters and promote ion-ion aggregation. As a consequence, reduced nucleation time and increased growth rate of the crystals can be detected in the PVDF/G (0.5%) with respect to the pristine PVDF membrane (sample 1, Table 3).…”

Operation of Three-Stage Process of Lithium Recovery from Geothermal Brine: Simulation

“…In the 2010s, a new method called membrane-assisted crystallization was proposed for simultaneous water production using membrane technology and recovery of dissolved compounds in the solid form by its crystallization from saturated solutions [ 32 ]. This approach is compelling because of its compactness, lesser metal consumption, and greater flexibility in the process operation, and it was already utilized for crystallization of inorganic salts [ 33 , 34 ] and organic compounds [ 35 ] using pressure-driven processes of solution concentration (reverse osmosis, nanofiltration) as well as evaporation processes (pervaporation, membrane distillation). The membrane distillation (MD) can be considered one of the effective approaches for the concentration of different kinds of brines with moderate or high salinity [ 36 ].…”