in this research, process asymmetric polyetherimide hollow fiber membranes using ethanol (0, 2 and 4 wt%) as non-solvent additive in the polymer dope via phase inversion method were fabricated. aqueous solution of 1-methyl-2-pyrrolidine (nmp) (90%) was applied as a bore fluid to avoid inner skin layer formation and water was used as the external coagulant. the morphology of fabricated membranes...

carbon molecular sieve membranes (cmsms) have been considered as very promising candidates for gas separation, in terms of separation properties as well as thermal and chemical stability. due to the numerous advantages and wide applications of carbon membranes, their application for gas separation is of special importance. because of the importance of carbon membranes and a large number of stud...

in this work, novel thin film composite membranes (tfcs) of poly (ether-6-block amide) (pebax-1657) on a polyvinyl chloride (pvc) ultrafiltration membrane as support were prepared using inclined coating method for co2 separation. investigating the effects of top selective layer thickness formed by controlling the coating angle (15-60°) and polymer solution concentration (5-10 wt.%), and also, t...

results the mean kt/v was 1.27 ± 0.28 in high-flux and 1.10 ± 0.32 in low-flux membrane which, these differences were statistically significant (p = 0.017). the mean of urr was 0.65 ± 0.09 in high-flux and 0.61 ± 0.14 in low-flux membrane, which these differences were not statistically significant (p = 0.221). patients and methods forty hemodialysis patients participated in this cross-over clin...

heterogeneous proton exchange membranes (pem) are synthesized using the dry phase inversion technique. the casting solutions are prepared by dispersing a finely ground cation exchange resin particle in n,n-dimethylacetamide (dmac) solution of polyvinyl-chloride (pvc). results show that ion exchange capacity is increased with the addition of 1 %-wt nanosilica (from 0.14 to 0.27 meq/g) while it i...

in this work a new resistance model has been presented based on that of henis-tripodi which can be used for interpretation of gas permeation data in composite and asymmetric membranes. in contrast to the previous works, in this model the fraction of the support layer surface that includes the pores filled with coating material has been taken into account. the influences of the filled pores on s...

Zeolite Y and its ultra-stabilized hierarchical derivative (USY) are the most widely used zeolite-based heterogeneous catalysts in oil refining, petrochemisty, other chemicals manufacturing. After almost 60 years of academic industrial research, their resilience is unique as no catalyst displaced them from key processes such FCC hydrocracking. The present study highlights difference leading to ...

The weathering of a specimen kaolinite clay was studied over the course of 369 d via solid-state 29Si magic angle spinning (MAS) nuclear magnetic resonance (NMR) spectroscopy and high-field 27Al MAS NMR. The chosen baseline solution conditions (0.05 mol kg-1 of Al, 2 mol kg-1 of Na+, 1 mol kg-1 of NO3-, 1 mol kg-1 of OH-, and pH approximately 13.8) approximate those of solutions leaking from wa...