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Title: Thermal casting process for the preparation of anisotropic membranes and the resultant membrane

Abstract

A method for providing anisotropic polymer membranes from a binary polymer/solvent solution using a thermal inversion process. A homogeneous binary solution is cast onto a support and cooled in such a way as to provide a differential in cooling rate across the thickness of the resulting membrane sheet. Isotropic or anisotropic structures of selected porosities can be produced, depending on the initial concentration of polymer in the selected solvent and on the extent of the differential in cooling rate. This differential results in a corresponding gradation in pore size. The method may be modified to provide a working skin by applying a rapid, high-temperature pulse to redissolve a predetermined thickness of the membrane at one of its faces and then freezing the entire structure.

Inventors:
 [1];  [1]
  1. Albany, CA
Issue Date:
Research Org.:
Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)
OSTI Identifier:
866222
Patent Number(s):
4659470
Assignee:
United States of America as represented by United States (Washington, DC)
Patent Classifications (CPCs):
B - PERFORMING OPERATIONS B01 - PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL B01D - SEPARATION
B - PERFORMING OPERATIONS B29 - WORKING OF PLASTICS B29C - SHAPING OR JOINING OF PLASTICS
DOE Contract Number:  
AP03-84SF15389
Resource Type:
Patent
Country of Publication:
United States
Language:
English
Subject:
thermal; casting; process; preparation; anisotropic; membranes; resultant; membrane; method; providing; polymer; binary; solvent; solution; inversion; homogeneous; cast; support; cooled; provide; differential; cooling; rate; thickness; resulting; sheet; isotropic; structures; selected; porosities; produced; depending; initial; concentration; extent; results; corresponding; gradation; pore; size; modified; applying; rapid; high-temperature; pulse; redissolve; predetermined; freezing; entire; structure; predetermined thickness; cooling rate; pore size; casting process; resulting membrane; binary poly; polymer membrane; polymer membranes; solvent solution; resultant membrane; entire structure; initial concentration; anisotropic membranes; binary solution; inversion process; /210/264/521/

Citation Formats

Caneba, Gerard T. M., and Soong, David S. Thermal casting process for the preparation of anisotropic membranes and the resultant membrane. United States: N. p., 1987. Web.
Caneba, Gerard T. M., & Soong, David S. Thermal casting process for the preparation of anisotropic membranes and the resultant membrane. United States.
Caneba, Gerard T. M., and Soong, David S. Thu . "Thermal casting process for the preparation of anisotropic membranes and the resultant membrane". United States. https://www.osti.gov/servlets/purl/866222.
@article{osti_866222,
title = {Thermal casting process for the preparation of anisotropic membranes and the resultant membrane},
author = {Caneba, Gerard T. M. and Soong, David S},
abstractNote = {A method for providing anisotropic polymer membranes from a binary polymer/solvent solution using a thermal inversion process. A homogeneous binary solution is cast onto a support and cooled in such a way as to provide a differential in cooling rate across the thickness of the resulting membrane sheet. Isotropic or anisotropic structures of selected porosities can be produced, depending on the initial concentration of polymer in the selected solvent and on the extent of the differential in cooling rate. This differential results in a corresponding gradation in pore size. The method may be modified to provide a working skin by applying a rapid, high-temperature pulse to redissolve a predetermined thickness of the membrane at one of its faces and then freezing the entire structure.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {1987},
month = {1}
}