Crystallization Measurement by Optical Observation DSC using a

Crystallization Measurement by Optical Observation DSC
using a Polarizing Filter
Yuichi Kasai1, Masayuki Iwasa1, Kenichi Shibata2 and Brian Goolsby3
(1Hitachi High-Tech Science Corporation, 2Hitachi High-Technologies Science America Inc., 3Hitachi High-Technologies America Inc.)
Introduction
Configuration
Hitachi thermal analysis systems can observe the sample during measurement and pinpoint
when visible changes occur. It is possible to simultaneously obtain optical images and collect
thermal data, such as DSC and TG, and to link the data together.
As a result, we can more thoroughly understand the phenomena during thermal analysis.
USB camera
Image data
To enhance the sample observation information collected using a DSC,
a polarizing filter was installed, and images of the spherocrystals
in polyvinylidene fluoride (PVDF) were successfully collected.
Polarizing filter
The configuration and the results from this new optical
observation system design are presented, along with
discussion of the measurement results.
Lens barrel
Polarizing filter
Differential scanning calorimeter DSC7000X
with Real View System
Half mirror
Sample
Light source
Surface observation of PVDF cast film by SPM
PVDF cast film
Topography
Silicon wafer
Objective lens
Cross section profile
DSC signal
500
Furnace
2 .0
DSC / mW
Height / nm
Sample
0 .0
- 2 .0
- 4 .0
0
0
10mm
4 .0
50 .0
110
15 0.0
Temp. / ºC
25 0.0
distance / m
 Melting of PVDF is a reversible phenomenon. It can be done repeatedly and reversibly.
 Sample was cut to about 3mm in order to fit into the sample pan
Results
★Cooling rate dependence of crystal size
★An example of optical observation DSC data using a polarizing filter
0.0
Cooling rate
2 ºC/min
Melting
Heating
150 ººC
-100.0
145 ºC
C
DSC / W
-50.0
5 ºC/min
10 ºC/min
10 m
← Layered →
crystal
Spherocrystal ↑
Crystallization
-200.0
100.0
120.0
140.0
Cooling
160.0
Scan rate
: 20 ºC/min
Sample weight :3mg
(PVDF cast film :0.008
:0 008 mg)
Pan
: Aluminum open
180.0
200.0
140 ºC
C
-150.0
Each point on the DSC curve represents where one image was collected.
Most of the 3mg sample weight was silicon wafer. However the melting and
crystallization peak of PVDF were clearly detected even though its weight
contribution was extremely small.
135 ºC
C
These image data show the crystallization process of melted PVDF. It is found
that the spherocrystal size is affected by the cooling rate. The spherocrystal
becomes large as cooling rate becomes low. However the physical location of
crystallization is the same.
130 ºC
Temperature / ºC
Conclusions
Acknowledgment
 Hitachi has demonstrated thermal analysis combined with sample observation
using a polarizing filter. Furthermore, this DSC system has the capability of detecting a peak
even if sample
l weight
i ht is
i extremely
t
l small.
ll
 The measurement results show that the size of spherocrystal depends on the cooling rate
after melting.
The presenters are indebted to Mr. Hiroji Kunitoshi of Nitto Analytical
Techno-Center Co. Ltd. for his helpful advice and the provision of sample.
43rd Annual Conference of NATAS, Montreal, Quebec, Canada, August 10-13, 2015, McGill University
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