There is provided a surface-active material that comprises fibres which have been modified so as to impart surface-active properties onto said fibres and giving it a contact angle between 60.degree. and 120.degree., wherein the fibres have an aspect ratio of more than 10 to 1,000. The surface-active material can be used for foam and emulsion formation and stabilisation, coatings, encapsulation and drug delivery. It can for example be used in the following industries: foods, home and personal care, oilfield, agriculture, textile, construction, emulsion polymerisation, leather, plastic, pulp, paper and pharma.