Optically monitored dip coating as a contactless viscometry method for liquid films.
Real-time interferometric monitoring of the dip coating process is applied to the study of properties of flowing liquids. Nonvolatile Newtonian oils are considered, allowing validity of a simple model after the steady state is reached where film physical thickness depends on time as t(-1/2). Measurement of two distinct mineral oil standards, under several withdrawing speeds, resulted in kinematic viscosities of 1.17+/-0.03 and 9.9+/-0.2 S (1S = 1 cm2/s). Agreement of these results with nominal values from the manufacturer suggests that interferometric monitoring of dip coating may become a valuable method for accurate, contactless viscometry of liquid films. Advantages and present limitations are discussed.
Michels
Alexandre F
AF
Universidade Federal do Rio Grande do Sul, Campus do Vale CP15051, Porto Alegre, Rio Grande do Sul 91501-970, Brasil. michels@if.ufrgs.br
Menegotto
Thiago
T
Horowitz
Flavio
F