Semipermeable encapsulated membranes with improved acid and base

Details Semipermeable encapsulated membranes with improved acid and base Semipermeable encapsulated membranes with improved acid and base

1998-06-10

2000-07-11

Dudash, Diana

Liquid purification or separation

Filter

Material

21050027, 21050034, 21050041, 210506, 21050035, 21050037, 21050042, 427244, 427245, 427341, 427352, 427353, B01D 3900, B01D 3914, B01D 7100, B05D 138

Patent

active

060867647

ABSTRACT:
A process for the preparation of semipermeable membranes with improved acid and base stability including: (a) coating a base and acid stable ultrafiltration (UF) membrane support polymer, with a high molecular weight amphoteric polyelectrolyte coating polymer optionally in solution, the amphoteric polyelectrolyte containing both cationic and anionic groups and in addition primary and secondary amine groups, the solution optionally containing a latent internal crosslinker compound that is a polyfunctional compound that crosslinks the coating polymer only during a curing step at elevated temperatures and basic pH; (b) draining or washing the coated support; and (c) reacting the coating with a solution of an external crosslinking compound that is a polyfuntional compound, not overly reactive so as not to be hydrolyzed prematurely in solution, the time of exposure to the external crosslinking compound being sufficient to ensure its diffusion into the bulk of the coating, so that the crosslinking is effected not only on the solution-polymer coating interface, but throughout the bulk of the coating as well. The sequence (a)-(c) may optionally be repeated a number of times to give multiple crosslinked layers; draining or washing the coated UF support; and curing the coated membrane by heating at an elevated temperature and basic pH to complete crosslinking by the external crosslinking molecule and if present, also effect crosslinking by the latent internal crosslinker, that is primarily activated only at the elevated temperature conditions.

REFERENCES:
patent: 4360434 (1982-11-01), Kawaguchi et al.
patent: 4618533 (1986-10-01), Steuck
patent: 4659474 (1987-04-01), Perry et al.
patent: 4690766 (1987-09-01), Linder et al.
patent: 4767645 (1988-08-01), Linder et al.
patent: 4778596 (1988-10-01), Linder et al.
patent: 4839203 (1989-06-01), Davis et al.
patent: 5024765 (1991-06-01), Linder et al.
patent: 5039421 (1991-08-01), Linder et al.
patent: 5348652 (1994-09-01), Creusen et al.
patent: 5616246 (1997-04-01), Gagnon et al.
patent: 5766473 (1998-06-01), Strobel et al.

Affiliated with

Also associated with

Rating

Semipermeable encapsulated membranes with improved acid and base does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Semipermeable encapsulated membranes with improved acid and base, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Semipermeable encapsulated membranes with improved acid and base will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-538470