A method for inactivating a pathogen is described, comprising the steps of: providing, in a solution: (1) a charged polymer comprising charged monomers and counterions to the charged monomers; increasing a pH of the solution with a base, the step of increasing the pH further comprising the step of: introducing salt ions into the solution; (2) removing at least ten percent of the salt ions from the solution; (3) decreasing the pH of the solution; (4) contacting the pathogen with the charged polymer; and (5) inactivating at least fifty percent of the pathogens within thirty minutes of the step of contacting, where a conductivity of the solution is in a range of 0.1 to 10 mS/cm and/or a total cationic charge of the solution is in a range of 0.4 to 15 C/cm.sup.3.

A method for inactivating a pathogen is described, comprising the steps of: providing, in a solution: (1) a charged polymer comprising charged monomers and counterions to the charged monomers; increasing a pH of the solution with a base, the step of increasing the pH further comprising the step of: introducing salt ions into the solution; (2) removing at least ten percent of the salt ions from the solution; (3) decreasing the pH of the solution; (4) contacting the pathogen with the charged polymer; and (5) inactivating at least fifty percent of the pathogens within thirty minutes of the step of contacting, where a conductivity of the solution is in a range of 0.1 to 10 mS/cm and/or a total cationic charge of the solution is in a range of 0.4 to 15 C/cm.sup.3.

A method for inactivating pathogens is described, comprising the steps of: (1) preparing a copolymer comprising repeating units, the repeating units comprising at least two of: first monomers comprising a NH.sub.2.sup.+CH.sub.2CH.sub.2 group; second monomers comprising a NHCH.sub.2CH.sub.2 group; and third monomers comprising an acyl group, C(O)R, attached to a nitrogen in a polymer backbone group of the copolymer comprising NCH.sub.2CH.sub.2, wherein R comprises a hydrocarbon chain, the repeating units arranged in any order in the copolymer; (2) preparing a formulation, the formulation comprising the copolymer and a total cationic charge in a range of 0.2 to 10 C/cm.sup.3, the total cationic charge at least 95% offset by counteranions in the formulation; and (3) inactivating at least ninety percent of the pathogen within a time period of less than ninety minutes from contact of the pathogen with the copolymer.

A method for inactivating pathogens is described, comprising the steps of: (1) preparing a copolymer comprising repeating units, the repeating units comprising at least two of: first monomers comprising a NH.sub.2.sup.+CH.sub.2CH.sub.2 group; second monomers comprising a NHCH.sub.2CH.sub.2 group; and third monomers comprising an acyl group, C(O)R, attached to a nitrogen in a polymer backbone group of the copolymer comprising NCH.sub.2CH.sub.2, wherein R comprises a hydrocarbon chain, the repeating units arranged in any order in the copolymer; (2) preparing a formulation, the formulation comprising the copolymer and a total cationic charge in a range of 0.2 to 10 C/cm.sup.3, the total cationic charge at least 95% offset by counteranions in the formulation; and (3) inactivating at least ninety percent of the pathogen within a time period of less than ninety minutes from contact of the pathogen with the copolymer.

A method for inactivating pathogens, comprising the steps of: (1) partially protonating polyethylenimine to yield a first copolymer, the first copolymer comprising: first monomers, the first monomers comprising a NH.sub.2.sup.+CH.sub.2CH.sub.2 group; and second monomers, the second monomers comprising a NHCH.sub.2CH.sub.2 group, the first monomers and the second monomers arranged in any order in the copolymer; (2) preparing a formulation, the formulation comprising the first copolymer and a total cationic charge in a range of 0.2 to 10 C/cm.sup.3, the total cationic charge at least 95% offset by counteranions in the formulation; (3) contacting the pathogens with the formulation; and (4) inactivating at least ninety percent of the pathogens within ninety minutes of the step of contacting.

A method for inactivating pathogens, comprising the steps of: (1) partially protonating polyethylenimine to yield a first copolymer, the first copolymer comprising: first monomers, the first monomers comprising a NH.sub.2.sup.+CH.sub.2CH.sub.2 group; and second monomers, the second monomers comprising a NHCH.sub.2CH.sub.2 group, the first monomers and the second monomers arranged in any order in the copolymer; (2) preparing a formulation, the formulation comprising the first copolymer and a total cationic charge in a range of 0.2 to 10 C/cm.sup.3, the total cationic charge at least 95% offset by counteranions in the formulation; (3) contacting the pathogens with the formulation; and (4) inactivating at least ninety percent of the pathogens within ninety minutes of the step of contacting.

A method for inactivating pathogens is described, comprising the steps of: partially deacylating a poly(2-alkyl-2-oxazoline) to yield a copolymer, an alkyl in the poly(2-alkyl-2-oxazoline) comprising a hydrocarbon chain, the copolymer comprising: first monomers, the first monomers comprising a NH.sub.2.sup.+CH.sub.2CH.sub.2 group; and second monomers, the second monomers comprising an acyl group, C(O)R, attached to a nitrogen in a polymer backbone group comprising NCH.sub.2CH.sub.2, wherein R comprises the hydrocarbon chain, the first monomers and the second monomers arranged in any order in the copolymer; preparing a formulation, the formulation comprising the copolymer and a total cationic charge in a range of 0.2 to 10 C/cm.sup.3, the total cationic charge at least 95% offset by counteranions in the formulation; contacting the pathogens with the formulation; and inactivating at least ninety percent of the pathogens within ninety minutes of the step of contacting.

A method for inactivating pathogens is described, comprising the steps of: partially deacylating a poly(2-alkyl-2-oxazoline) to yield a copolymer, an alkyl in the poly(2-alkyl-2-oxazoline) comprising a hydrocarbon chain, the copolymer comprising: first monomers, the first monomers comprising a NH.sub.2.sup.+CH.sub.2CH.sub.2 group; and second monomers, the second monomers comprising an acyl group, C(O)R, attached to a nitrogen in a polymer backbone group comprising NCH.sub.2CH.sub.2, wherein R comprises the hydrocarbon chain, the first monomers and the second monomers arranged in any order in the copolymer; preparing a formulation, the formulation comprising the copolymer and a total cationic charge in a range of 0.2 to 10 C/cm.sup.3, the total cationic charge at least 95% offset by counteranions in the formulation; contacting the pathogens with the formulation; and inactivating at least ninety percent of the pathogens within ninety minutes of the step of contacting.

A method for treating a pathogen is described, comprising the steps of: (1) spraying a formulation onto a substrate, the formulation comprising: a charged polymer comprising charged monomers, counterions to the charged monomers; and, an adhesion promoter; (2) drying the formulation to yield a film comprising a critical load of adhesion in a range of 10 to 600 N; (3) contacting the pathogen with the film; and (4) inactivating, with the film, at least fifty percent of the pathogen within thirty minutes of the step of contacting, where the adhesion promoter is optionally an antipathogen, such as a polydiallyldimethylammonium salt.

A hydrophilic copolymer comprising a constituent unit (a) represented by formula (1) and a constituent unit (b) represented by formula (2) is used to impart a coating film excelling in hydrophilicity, antifogging, and water resistance.

##STR00001##

(In formula (1), R.sup.1 represents a hydrogen atom or methyl group, each R.sup.2 independently represents a hydrogen atom or C1-6 alkyl group, and X.sup.1 represents a divalent linking group. In formula (2), R.sup.3 represents a hydrogen atom or methyl group, R.sup.4 and R.sup.5 each independently represent a C1-10 alkyl group or C6-10 aryl group, X.sup.2 represents a bivalent linking group, n represents an integer from 1 to 3, and the asterisk (*) represents a bond to an adjacent constituent unit.)