Activated carbon

An active carbon cloth material including a surface coating of polytetrafluoroethylene substantially only a single particle in thickness, said surface coating rendering said active carbon cloth substantially waterproof and allowing gas to permeate there-through, said particles of polytetrafluoroethylene being held onto said active carbon cloth material only by surface forces developed between said active carbon cloth material and said particles of polytetrafluoroethylene, said particles of polytetrafluoroethylene having a particle size in a range from one to one hundredth of a micron and being present in a range from 5 to 10% by weight of the active carbon cloth material.

A waterproof cloth comprising a cloth of active carbon material having a coating of discrete solid particles of a particulate hydrophobic material deposited on its surface, said particulate hydrophobic material being present in an amount sufficient to render said active carbon material substantially waterproof, and in an amount whereby said surface coating is permeable by a gas, which surface coating of hydrophobic material is a layer substantially only a single particle in thickness held onto said active carbon material only by surface forces developed between said active carbon and said particles of hydrophobic material.

A method of waterproofing a fabric of active carbon material comprising depositing discrete solid particles of a particulate hydrophobic material onto the surface of said active carbon material in an amount in a range between 5% to 10% by weight of said active carbon material to render said active carbon material substantially waterproof, and whereby said surface coating is permeable by a gas.