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An Optical Sensor for Measuring Fluorescence Anisotropy of Oriented Polymers



S C. Roth, Anthony J. Bur


An optical sensor containing polarizing optical components has been constructed for the purpose of measuring fluorescence anisotropy of fluorescent dyes. The measurement involves the detection of vertical and horizontal components of fluorescent light. Using a Glan-Taylor calcite polarizer, both vertical and horizontal components are collected by separate optical fibers and measured simultaneously using a two channel photon counter. The primary application of this sensor is the measurement of molecular orientation during polymer processing. The sensor head is designed to operate at elevated temperatures of polymer processing, up to 300 [degrees] C. To carry out process monitoring, a fluorescent dye is mixed with a polymer resin at approximately 10 ppm by weight concentration. Dyes which have geometrical asymmetry in their molecular structure or are covalently bonded to the polymer molecule are usually used. The anisotropy measurement yields information about the orientation of the dye molecule in an oriented medium. Two applications of the sensor are described, extrusion of polyethylene through a slit die (shear flow), and extension of crosslinked polybutadiene (extension stress).
Conference Dates
May 1, 1998
Conference Location
Conference Title
Society of Plastics Engineers. Technical Meeting


extension stress, fluorescence anisotropy, molecular orientation, optical sensor, polybutadiene, polyethylene, polymer extrusion, shear stress, slit die rheometer


Roth, S. and Bur, A. (2008), An Optical Sensor for Measuring Fluorescence Anisotropy of Oriented Polymers, Society of Plastics Engineers. Technical Meeting, Undefined (Accessed April 18, 2024)
Created October 16, 2008