title: Large increase in the heat transfer through monolayers detected by beam deflection.
abstract: We report the application of photothermal beam deflection for studying heat transfer across the liquid/ gas interface covered with surfactant monolayers. Laser-induced Marangoni convection was generated on the surface of an absorbing aqueous solution with and without a monolayer. The change in heat transfer to the air was monitored by the deflection of a probe beam propagating close to the solution surface. A large increase in the deflection as well as in the air temperature for monolayer-covered surfaces was observed. A film-balance study showed that the magnitude of deflection increases as a function of monolayer compression.
authors.affiliation: Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, Av. Prof. Lineu Prestes 748, cep 05508-000, São Paulo, Brasil. marcosgugliotti@hotmail.com
authors.forename: Marcos
authors.initials: M
authors.lastname: Gugliotti
authors.forename: Tiago S
authors.initials: TS
authors.lastname: Rodrigues
authors.forename: Mauricio S
authors.initials: MS
authors.lastname: Baptista
authors.forename: Mario J
authors.initials: MJ
authors.lastname: Politi
mesh_terms: D004735:Energy Transfer; D006358:Hot Temperature; D007834:Lasers; D008027:Light; D008567:Membranes, Artificial; D010777:Photochemistry; D012542:Scattering, Radiation; D012996:Solutions; D013499:Surface Properties / Q000528:radiation effects; D013501:Surface-Active Agents / Q000737:chemistry / Q000528:radiation effects*; D013816:Thermodynamics; D013997:Time Factors
chemical_list: D008567:Membranes, Artificial; D012996:Solutions; D013501:Surface-Active Agents