Conformal coating of polymer fibers on nonwoven substrates
AssigneesPathogen Removal and Diagnostic Technologies, Inc., North Carolina State University
InventorsYong Zheng, Samana Roy Chowdhury, Patrick Vasconcelos Gurgel, Haiyan Liu, Ruben G. Carbonell
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Abstract
The present invention describes a novel process for the conformal coating of polymer fibers of nonwoven substrates. This process is based on modification of polymer fiber surfaces by controlling the degree of etching and oxidation to improve adhesion of initiators to the surface and to facilitate subsequent conformal polymer grafting. The modified fiber surfaces render new functionalities to the surface, such as increased hydrophilicity, attached ligands or changed surface energy. The invention includes the modified polymer fibers produced by the process described herein.
Claims14
A process to modify a fiber surface of a polymer nonwoven substrate to obtain a conformal coating, comprising:
- 1) increasing roughness of a fiber surface and increasing the hydroxyl, carbonyl and any other oxygen containing group through exposure to UV in air at a wavelength between 150-300 nm, wherein said exposure to UV in air generates ozone;
- 2) soaking the substrate with a solution containing both a monomer and an initiator;
- 3) sandwiching the soaked substrate obtained from step 2 between two glasses;
- 4) exposing the substrate to UV or heat for grafting to form the conformal coating;
- and
- 5) washing and drying the substrate.
A process to modify a fiber surface of a polymer nonwoven substrate to obtain a conformal coating, comprising:
- 1) increasing roughness of a fiber surface and increasing the hydroxyl, carbonyl and any other oxygen containing group through exposure to UV in air at a wavelength between 150-300 nm, wherein said exposure to UV in air generates ozone;
- 2) soaking the substrate with a solution containing both a monomer and an initiator;
- 3) sandwiching the soaked substrate obtained from step 2 between two glasses, wherein said sandwiching promotes, during subsequent grafting, formation of a saturated vapor phase near the surface of the substrate;
- 4) exposing the substrate to UV or heat for grafting to form the conformal coating;
- and
- 5) washing and drying the substrate.
Dependencies are inferred from the claim text.