Patent ID: 8104624
Filing Date: 2012-01-31
Classification: B01D,C02F,C08L,D01D,D01F

Abstract:
1. A method for making a multi-polymeric solution having a known cloud point for production of a hollow-fiber membrane, comprising: determining a cloud point for a sample system comprising water and, in known amount ratios, polyethersulfone (PES), a polar solvent, a first polyvinylpyrrolidone (PVP), and a second PVP by conducting a series of trials comprising successively increasing water concentration in the sample system until the cloud point in the sample system is reached, wherein the trial immediately prior to the achievement of the cloud point defines a water amount at near-cloud point conditions in the sample system; preparing a multipolymeric solution comprising a volume of water, a volume of polar solvent, PES, the first PVP, and the second PVP, all present in the same percentage of ingredients at which the sample system reached near-cloud point conditions, comprising mixing a portion of the volume of polar solvent and the entire volume of water;