Transmitted Light Intensity Measurement
The crystallization induction time and the crystallization behavior of
MKF without and with the application of HIU were characterized using a
light intensity measurement probe (PASCO airlink) connected with a light
sensor. Light intensity is normally regarded as secondary tools to study
crystallization, because the data analysis is not straightforward (Tiang
and Dealy, 2012). However, it is a simple technique to use and is more
useful for probing early kinetics than well-established techniques such
as dilatometry, differential scanning calorimetry (DSC), x-ray
scattering, optical microscopy and pulsed-nuclear magnetic resonance
(Fritsch et al., 2006; Wright et al., 2000). A laser pointer was
used as a light source. It was positioned so that the light went through
the sample inside the glass cell and was received on the opposite side
of the sample by the light detector. Changes in the transmitted light
intensity signal during crystallization were monitored by the software
SPARKvue (Roseville, CA 95747 USA) that was linked to the light
detector. As the sample began to crystallize, less light could go
through the sample, resulting in the drop in the transmitted intensity.
The recorded light intensity was normalized so that the maximum
intensity for each sample was set to be 1 and the minimum intensity was
set to be 0.