title: Measuring contact angles inside of capillary tubes with a tensiometer.
abstract: We describe a new tensiometry method that allows for determination of wetting inside small diameter tubes or hollow fibers, where the maximum force from the ultimate rise height of liquid is used to estimate advancing contact angles. The technique was first validated with transparent tubes of glass, poly(carbonate) (PC) and poly(tetrafluoroethylene) (PTFE) using four liquids: isopropanol, silicone oil, ethylene glycol and water. Advancing contact angles measured with the tensiometer agreed well with those estimated from final rise height. As this tensiometry technique does not require a view of the liquid, it can be used to measure the wettability inside opaque tubes. We demonstrated this with poly(ether ether ketone) (PEEK) tubes.
authors.affiliation: Entegris, Inc., 101 Peavey Road, Chaska, MN 55318, United States. Electronic address: chuck.extrand@colder.com.
authors.forename: C W
authors.initials: CW
authors.lastname: Extrand
authors.affiliation: Entegris, Inc., 101 Peavey Road, Chaska, MN 55318, United States.
authors.forename: Sung In
authors.initials: SI
authors.lastname: Moon
keywords: Capillary tubes; Contact angles; Hollow fibers; Wetting