Coating of a hydrophobic polymer substrate with a nonstoichiometric polyelectrolyte complex

A method of coating surfaces of fibers of which a fibrous web is comprised, which fibers are composed of a hydrophobic polymer, the method comprising:

• providing a solution of a first polyelectrolyte having a first molecular weight and ionizable groups with a first latent charge;
• providing a solution of a second polyelectrolyte having a second molecular weight and ionizable groups with a second latent charge;
• mixing the solution of the first polyelectrolyte and the solution of the second polyelectrolyte in amounts which are selected to give a ratio of the number of ionizable groups in the first polyelectrolyte to the number of ionizable groups in the second polyelectrolyte of at least about 2, and under conditions adapted to result in the formation of a nonstoichiometric polyelectrolyte complex;
• and
• contacting the surfaces of the fibers with a solution of the nonstoichiometric polyelectrolyte complex under conditions sufficient to result in the coating of the surfaces of the fibers with the nonstoichiometric polyelectrolyte complex;
• wherein:
• the second latent charge is opposite the first latent charge;
• and
• the first molecular weight is at least about 40,000 daltons and at least about 2 times the second molecular weight.

A coated substrate comprising:

• a substrate comprised of a hydrophobic polymer;
• and
• a substantially uniform coating of a nonstoichiometric polyelectrolyte complex on a surface of the substrate;
• wherein:
• the polyelectrolyte complex is comprised of a first polyelectrolyte having a first molecular weight and ionizable groups with a first latent charge, and a second polyelectrolyte having a second molecular weight and ionizable groups with a second latent charge;
• the second latent charge is opposite the first latent charge;
• the ratio of the number of ionizable groups in the first polyelectrolyte to the number of ionizable groups in the second polyelectrolyte is at least about 2;
• and
• the first molecular weight is at least about 40,000 daltons and at least about 2 times the second molecular weight.

A fibrous web comprising:

• fibers composed of a hydrophobic polymer;
• and
• a substantially uniform coating of a nonstoichiometric polyelectrolyte complex on the surfaces of the fibers;
• wherein:
• the polyelectrolyte complex is comprised of a first polyelectrolyte having a first molecular weight and ionizable groups with a first latent charge, and a second polyelectrolyte having a second molecular weight and ionizable groups with a second latent charge;
• the second latent charge is opposite the first latent charge;
• the ratio of the number of ionizable groups in the first polyelectrolyte to the number of ionizable groups in the second polyelectrolyte is at least about 2;
• and
• the first molecular weight is at least about 40,000 daltons and at least about 2 times the second molecular weight.