Membrane Technology and Chemistry

Prospects of Polymeric Nanocomposite Membranes for Water Purification and Scalability and their Health and Environmental Impacts: A Review

“…Despite the fact that this classification aids in visualising the configuration of membrane layers, it is deemed unsuitable for describing the structure–function relationship of PNCs because all separation properties of porous membranes are dependent on the “active layer”, which would be defined as the layer with the littlest pore size distribution constituting the membrane structure, and as a result, the porous substrate must be understood to explain the separation properties. An asymmetric polymeric membrane, for example, is defined as porous polymeric support covered on its surface by a thin film with a pore-size distribution less than the support’s pore-size distribution; as a result, all retention characterisations in this type of membrane are largely decided by the thin film comprising the active layer, as the porous polymeric support’s function is to enhance the mechanical characteristics of the multi-layered system [ 120 ]. In the cases of “nanomaterial thin-film PNC” (symmetric membrane|nanomaterial), “thin-film PNC with nanocomposite substrate” (nanocomposite support|active layer), and “surface-coated PNC” (support|activelayer|nanomaterial), the previous classification describes multilayer membranes rather than PNCs.…”

“…The examination of separation processes is essential for a complete comprehension of PNCs. In general, two mechanisms can be identified for membrane separation processes: (i) separation by size-based exclusion and (ii) separation by dissolution–diffusion [ 120 ]. In the first case, particles that are larger than the pore in the membrane are retained, while those that are smaller are allowed to pass through.…”

“…The input stream’s liquid phase might be homogeneous (e.g., aqueous dissolution for macromolecule removal) or heterogeneous (e.g., aqueous dispersion for the removal of suspended solids). In some settings (e.g., air filtration), it may be seen as a gaseous fluid containing suspended particulates [ 120 , 215 ]. During the second step, known as separation by dissolution–diffusion, the substance that penetrates the membrane is first dissolved inside the membrane (during the stage referred to as the dissolution stage), and then it diffuses across the membrane (i.e., diffusion stage).…”

Evaluation of poly(ethylene-co-vinylacetate) as polymeric adsorbent of polychlorinated biphenyls in water.

“…where L1 is the permeability calculated for GF without impregnation and L2 is the permeability for passive sample (i.e., GF-EVA-M1 and GF-EVA-M2). In addition, the average percentage change in pore radius (Δrp) was evaluated using the membrane-equivalent concept based on the Hagen-Poiseuille model [21]; thus, the Equation 3 is stablished, being:…”

Nanostructured polymer composites with potential applications into the storage of blood and hemoderivates.

“…AgNPs were synthesized by two methodologies based on chemical reduction of silver atoms which have been previously described [16][17]. First one, 100 mL of 1.0 mmolL -1 AgNO3 solution was heated to boiling under reflux and constant stirring, after, slowly 1.0 mL of 1.0 mg/100 mL of sodium citrate solution and 1.0 mL of 400 mmolL -1 of NMDG solutions were added drop to drop and in that order; reaction time was one hour.…”