posted on 2017-09-27, 00:00authored byZijie Qiu, Eric K. K. Chu, Meijuan Jiang, Chen Gui, Ni Xie, Wei Qin, Parvej Alam, Ryan T. K. Kwok, Jacky W. Y. Lam, Ben Zhong Tang
The glass transition
temperature (Tg) is an important physical
parameter and signifies the reversible
transition process between the glassy state and the rubbery state
in polymeric materials. Herein, a simple yet reliable method, denoted
as ADEtect, utilizing aggregation-induced emission luminogens (AIEgens)
for Tg measurement was developed. The
fluorescent images of AIEgen-doped polymer films taken at different
temperatures were monitored by a camera under the same settings. By
using a MATLAB program, the grayscale of the selected area in each
image was calculated. This value decreased steadily with increasing
the temperature, and a significant change was observed at Tg. By plotting a graph of the second derivative
of relative grayscale against temperature, the Tg of a polymer can be unambiguously determined from the lowest
point. The present method shows performance comparable to that of
conventional DSC measurement in terms of sensitivity and reliability.
Besides, it can measure multiple samples in parallel, suggesting that
ADEtect is a versatile technique with high commercial value and promising
for high-throughput Tg measurement.