How to create a temperature-dependent thermophysical function when using the PDE toolbox？

Dear all:

I want to use the PDE toolbox to create a thermal model of PCM materials, so I want to create a temperature-dependent thermophysical function . I encountered a lot of difficulties in the process of creating functions, and I also read many questions but found that they could not be solved well, can you help me see? Code attached，Thanks in advance.