1
Wolfgang J Wrasidlo: Asymmetric membranes. Brunswick Corporation, James S Waldron, December 16, 1986: US04629563 (290 worldwide citation)

Improved ultraporous and microporous membranes are provided with an entirely reticulated structure free of large finger voids. The reticulated support structure has gradually increasing pore size which reaches a maximum of from about 10 to about 20,000 times the diameter of the skin pores at the opp ...


2
Wolfgang J Wrasidlo: Dispersing casting of integral skinned highly asymmetric polymer membranes. Brunswick Corporation, James S Waldron, September 27, 1988: US04774039 (111 worldwide citation)

There is disclosed, in one aspect, an improved highly asymmetric membrane comprising a skin and a porous asymmetric support. The skin contains pores which have an mean pore diameter of from about 0.005 to about 3.0 microns and the asymmetric support comprises a reticulated structure which contains p ...


3
Wolfgang J Wrasidlo: Composite semipermeable membranes made from polyethylenimine. Universal Oil Products Company, Fitch Even Tabin & Luedeka, April 20, 1976: US03951815 (83 worldwide citation)

Composite semipermeable membranes are made by reacting a film-forming polymer with a cross-linking monomer to form a polymeric ultrathin film having semipermeable properties. During the formation, a grafting reaction is carried out at reactive sites so there are few remaining active sites where oxid ...


4
Wolfgang J Wrasidlo: Semipermeable membranes and the method for the preparation thereof. The United States of America represented by the Secretary of the Interior, William S Brown, Donald R Fraser, January 25, 1977: US04005012 (75 worldwide citation)

Semipermeable membranes which are useful in reverse osmosis processes are prepared by forming a polymeric ultra-thin film which possesses semipermeable properties on a microporous support. An example of the composite semipermeable membrane comprising an ultra-thin film formed by contacting an amine ...


5
Wolfgang J Wrasidlo, Frieder K Hofmann, Dirk M deWinter: Membrane bioreactor system. Brunswick Corporation, Waldron & Associates, June 26, 1990: US04937196 (43 worldwide citation)

A bioreactor is disclosed in which cells are confined to a compartment formed by porous hydrophyllic sheet membranes through which a nutrient solution diffuses in and exocellular products and metabolic waste diffuse out. Adjacent gas compartments allow the flow of free oxygen into the cell compartme ...


6
Wolfgang J Wrasidlo, Karol J Mysels: Hydrophilic surfaces and process for making the same. Brunswick Corporation, Edward D O Brian, K H Boswell, November 1, 1983: US04413074 (37 worldwide citation)

A hydrophilic surface can be provided on a hydrophobic polymer surface by contacting the hydrophobic surface with a solution of a hydroxyalkyl cellulose and a perfluorocarbon surfactant in water or a mixture of water and one or more aliphatic alcohols so as to form a layer of the solution on the hyd ...


7
Wolfgang J Wrasidlo, Karol J Mysels: Semi-permeable membranes and processes for making the same. Brunswick Corporation, Edward D O Brian, K H Boswell, February 21, 1984: US04432875 (36 worldwide citation)

Semi-permeable, porous membranes useful as filtration and reverse osmosis membranes can have or can consist of a porous layer of a hydrophobic polymer rendered hydrophilic at its surface by the presence of a surfactant containing both hydrophobic and hydrophilic groups, the surfactant being bonded t ...


8
Wolfgang J Wrasidlo: Ultrafiltration thin film membranes. Memtec North America Corporation, Waldron & Associates, March 21, 1989: US04814082 (34 worldwide citation)

Mono-layer thin film membranes are provided which are ultraporous. Such mono-layers are formed having a thickness on the order of about 1.2 to 150 nanometers, by a variety of polymerization, cross-linking, and film treatment processes to achieve the development of controlled pore sizes in the ultrap ...


9
Wolfgang J Wrasidlo: Ultrapous thin-film membranes. Memtec America Corporation, Waldron & Associates, December 3, 1991: US05069945 (32 worldwide citation)

Mono-layer thin film membranes are provided which are ultraporous. Such mono-layers are formed having a thickness on the order of about 1.2 to 150 nanometers, by a variety of polymerization, cross-linking, and film treatment processes to achieve the development of controlled pore sizes in the ultrap ...


10
Wolfgang J Wrasidlo, Frieder K Hofmann, Karol J Mysels: Polytetrafluoroethylene coating of polymer surfaces. Memtec North America, Waldron & Associates, August 8, 1989: US04855162 (29 worldwide citation)

Adherent, PTFE coatings on polymer surfaces can be produced at temperatures well below the sintering temperature of PTFE, by contacting the surface with a dilute dispersion of PTFE particles and heating the surface to its softening point (in the vicinity of its glass transition temperature) to dry i ...