Page 20 - Solutions for Plastic Evaluation

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Product Evaluation
Local Structure
Thermal Analysis

Evaluation of Plastic Materials Measurement of Water Melting in a Polymer Electrolyte Fuel Cell Membrane Using a DSC
The figure below shows the results from measuring the melting process of water in a solid polymer membrane at various water content
levels. At a 6.7% water content, a melting peak for water was not observed. The -23.8°C peak for a water content of 8.5% is presumably
due to the melting of water clusters in the solid polymer membrane. The two-stage peak in water content levels at 12.6% and higher is
presumably due to peaks for melting free water and water clusters. It shows that as the water content increases, the temperature peak
increases. In other words, the amount of free water increases. The temperature and area of the peak for water from clusters melting is
probably related to the size of the clusters.
Evaluation of Raw Materials

Product Evaluation

Product Information Melting of Water in Polymer Electrolyte Fuel Cell Membrane

Measurement of Water Melting in Silica Gel Pores Using a DSC

The figure below shows the results from hydrating silica gels A, B, and C with water weighing roughly the same as their
respective dry gel weights and then using a differential scanning calorimeter to cool the gels to about -40°C before heating.
In each sample, two melting peaks were measured. These presumably correspond to the water in pores melting at a lower
temperature and water outside the pores (on the surface) melting at a higher temperature. The peak temperature of pore
water melting appears at successively higher temperatures for silica gels A, B, and C. That is probably due to the melting point
decreasing as the pore diameter decreases.

Melting of Water in Silica Gel Pores

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