Papers by Keyword: Membrane Modification

Abstract: Membrane-based separation technology has grown significantly due to its cost-effectiveness, energy efficiency, easy system operations, and scale-up. The versatility of membrane application is also a significant factor in their widespread use in many separation processes. Their applications span water treatment, gas purification, energy production, and biomedicine. While promising, membrane technology still requires improvements in membrane features and performance, such as pore structure, fouling resistance, chemical stability, and concurrent enhancement of permeability and selectivity. Atomic Layer Deposition (ALD) has emerged as a powerful tool for enhancing membrane properties and performance through surface modification with atomic-scale precision, enabling conformal coatings, functional surface modification, and precise control over pore size. The ability of ALD to deposit uniform and conformal films on membrane substrates makes it a favourable modification technique. This review offers a concise yet informative discussion on the fundamentals of ALD, its integration with membrane modification, recent advancements in ALD-modified membranes, emerging trends in membrane modification via ALD, and challenges of ALD application in membrane modification.

Abstract: Membrane modification is an important technology to improve the membrane performance. Ceramic membranes modified with nanometal oxide coating are prepared by homogeneous precipitation or in-situ hydrolysis method. TEM images show that the nanocoating distributes in the surface of the membrane pores. The nanocoating has no the separation function but just changes the surface characters of ceramic membrane. The permeate flux of the modified membrane increase above 20% than the unmodified membrane while treating the stable o/w emulsion with the concentration of 4g/L.

Abstract: The fouling problem has to be solved because fouling significantly reduces the performance of porous polymeric membranes. This paper presents methods to prepare low fouling membranes or to modify commercial/existing membranes to be low fouling membranes. At first, the principle of membrane separation as well as fouling phenomenon is presented. Important low fouling characters are also outlined. Thereafter, modification of membrane polymers to obtain low fouling character, principle as well as recent development in preparation of low fouling polymeric membranes and membrane modification of commercial/existing membrane are discussed.

Abstract: Membrane surface modification is the important method to decrease membrane fouling. The hydrophilic modification of ceramic membrane with nano-sized inorganic coating is prepared by the wet chemical methods. The thin nano coating is not a separating top layer but distributes uniformly on the surface of the membrane pore wall. The coating does not change the structure of the membrane pores. Therefore, water flows on not the pore wall but the nano coating surface. The results show that the water flux of the modified membrane is higher than that of the unmodified membrane despite that the mean pore size of the modified membrane decreases. The “boundary slip” is used to explain this special phenomenon. What generates the slippage The slippage is relative with the molecular layer adhered tightly on the hydrophilic pore wall, the roughness and the surface charge of the nano coating, the interaction between the ions in water and the nano coating, et al.

Abstract: Membrane surface modification is the important method to decrease membrane fouling. Recent efforts have been made to develop the hydrophilic modified ceramic membrane with nano-sized inorganic coating in our research group. In the modified membrane, the nano coating does not form a separating layer, just distributes uniformly on the surface of the membrane pore wall. It results in that: (1) if the feed is water, the water flux of the modified membrane is higher than that of the unmodified one despite the fact that the mean membrane pore size decreases after the modification; (2) if the feed is oily emulsion, the steady flux is obtained in a short time and keeps in the following time. The flux is far higher than that of the unmodified one because the hydrophilic nano coating prevents the cake from forming on the membrane surface. The nano-sized metal oxide modification application in the membrane technology not only expands the newly research area of the membrane technology but also makes the modified ceramic membrane have a good perspective application in the industry. This paper will introduce the development of the modified membrane with nano inorganic coating and give a clear future research direction.