Post-doctoral researcher, Citrus Research and Education Center, University of Florida, Lake Alfred, FL
Professor, Virginia Polytechnic Institute and State University, Blacksburg, VA
Pages: 13 Published: Jan 1998
The study was conducted to investigate the physico-chemical properties and the spread pattern on velvetleaf (Abutilon theophrasti Medikus) foliage of several organosilicones, oil concentrates, nonionic adjuvants, and adjuvant mixtures. A dynamic contact angle analyzer, surface tensiometer, and goniometer were used to measure the static surface tension, dynamic surface tension, and contact angle, respectively, of solutions made with these adjuvants. The progress of droplet spread of different adjuvant solutions containing fluorescent dye on leaves of velvetleaf was recorded by image analyzer. Organosilicones were superior wetting agents and showed excellent spreading patterns on velvetleaf foliage. In addition, organosilicones not only exhibited extremely low static surface tension, but also showed superior performance in lowering dynamic surface tension. A logistic dose response relationship existed between adjuvant concentration and contact angle on parafilm. However, across a wide range of concentrations, there was no clear relationship between surface tension and contact angle even in a homogeneous adjuvant solution; although, at normal use rates, the lower the surface tension, the lower the contact angle should be on target surfaces.
static surface tension, dynamic surface tension, contact angle, crop oil concentrate, nonionic surfactants
Paper ID: STP14171S