Spatially-controlled modified porous membrane
View Patent ↗This invention relates to a general method to surface modify porous membranes with a free radical polymerized polymer coating in a layer which is less than the thickness of the membrane. Another object of this invention relates to a general method to surface modify porous membranes with a free radical polymerized polymer coating to a predetermined and controlled depth from a first facial surface. Another object of this invention is to provide a general method to surface modify porous membranes with a free radical polymerized polymer coating into a pattern on one or both facial surfaces, the pattern maintaining its form to a controlled depth into the membrane. Membrane modification is spatially controlled through the use of a polymerization preventing agent (PPA), which prevents modification from occurring in defined spatially volumes of the membrane. The invention relates to porous membranes surface modified by the methods described.
1. A coated porous membrane having a first porous surface, a second porous surface, and a continuous porous structure that extends throughout the membrane from the first to the second surface defining a thickness, said membrane having a patterned free radical polymerized crosslinked hydrophobic polymer coating that covers portions of said first porous surface and said second porous surface and extends to a predetermined and controlled depth from said first porous surface into said continuous porous structure, said depth extending through a depth ranging from 8-80% of the membrane thickness, wherein a portion of the membrane is contacted with an agent which prevents the polymer coating from polymerizing.
2. The membrane of claim 1 , wherein the porous membrane comprises a hydrophilic polymer material.
3. The membrane of claim 2 , wherein the porous hydrophilic membrane polymer material is polyvinylidene difluoride.
4. The membrane of claim 1 , wherein said hydrophobic polymer coating material is polyacrylates.
5. The membrane of claim 1 , wherein the agent which prevents the polymer from polymerizing contacts the second surface.
6. The membrane of claim 1 , wherein the agent which prevents the polymer from polymerizing is oxygen.
7. The membrane of claim 1 , wherein the agent which prevents the polymer from polymerizing is 2,2,diphenyl-1-picrylhydrazyl.
8. A coated porous hydrophilic membrane suitable for use in enzyme assays having a first porous surface, a second porous surface, and a continuous porous structure that extends throughout the hydrophilic membrane from the first to the second surface, said hydrophilic membrane having a free radical polymerized crosslinked hydrophobic polymer coating that;
i) extends to a predetermined and controlled depth from said first porous surface into said continuous porous structure, said depth extending through a depth ranging from 8-80% of the membrane thickness; and
ii) covers a portion of the first porous surface as a patterned coating;
wherein a portion of the membrane is contacted with an agent which prevents the hydrophobic polymer coating from polymerizing.
9. The membrane of claim 8 , wherein the hydrophilic porous membrane is selected form the group consisting of a microporous hydrophilic polymer membranes and ultrafiltration hydrophilic polymer membranes.
10. The membrane of claim 9 , wherein the hydrophilic porous membrane material is polyvinylidene difluoride.
11. The membrane of claim 8 , wherein said hydrophobic polymer coating material is polyacrylates.
12. The membrane of claim 8 , wherein the patterned hydrophobic polymer coating that covers portions of the first surface and the second surface is a different pattern on each surface.
13. The membrane of claim 8 , wherein the hydrophobic polymer coating does not wet with a liquid having a surface tension greater than about 21 mN/m.
14. A coated porous membrane having a first porous surface, a second porous surface, and a continuous porous structure that extends throughout the membrane from the first to the second surface defining a thickness, said membrane having a patterned free radical polymerized crosslinked hydrophobic polymer coating that covers said first porous surface and said first porous surface and extends about halfway through the depth of the membrane, wherein a portion of the membrane is contacted with an agent which prevents the polymer coating from polymerizing.
15. The membrane of claim 14 , wherein the porous membrane comprises a hydrophilic polymer material.
16. The membrane of claim 15 , wherein the porous hydrophilic membrane polymer material is polyvinylidene difluoride.
17. The membrane of claim 14 , wherein said hydrophobic polymer coating material is polyacrylates.
18. The membrane of claim 14 , wherein the hydrophilic porous membrane is selected form the group consisting of a microporous hydrophilic polymer membranes and ultrafiltration hydrophilic polymer membranes.
19. The membrane of claim 15 , wherein the porous hydrophilic membrane polymer material is polyvinylidene difluoride.
20. The membrane of claim 14 , wherein the patterned hydrophobic polymer coating that covers portions of the first surface and the second surface is a different pattern on each surface.
21. The membrane of claim 14 , wherein the hydrophobic polymer coating does not wet with a liquid having a surface tension greater than about 21 mN/m.