How to Improve Properties of Paraffin Wax Phase Change Material
To improve the phase change properties of paraffin wax, there are two methods: physical blending method and microencapsulation technology. Now Let’s come to know their pros and cons respectively.
Physical Blending Method
The physical blending method uses physical interaction to immobilize the solid-liquid phase change material on the support, including adsorption (intermolecular force or hydrogen bonding force) or encapsulation technology (mesh structure).
This type of material undergoes solid-liquid phase changes in nature and maintains a stable solid shape macroscopically, which is often referred to as shaped phase change material (PCM).
The shaped phase change material usually consists of a phase change material and a support material. When the phase transition temperature of the phase change material is exceeded, the composite phase change material can maintain its solid form macroscopically, and the solid-liquid phase occurs microscopically.
Therefore, it does not require encapsulation and is no detachment from the container wall during heating and heat release. Because the physical force is relatively small, when the material is used multiple times, the phase change material and the support body are prone to separate.
Microencapsulation technology is a method of dispersing a solid-liquid phase change material such as paraffin or an inorganic hydrated salt into a solid or liquid spherical microparticle, and then encapsulating a stable polymer film on the surface to obtain a microencapsulated phase change material.
At present, the main problem is that the phase change volume of the solid-liquid phase change material is as high as 15% or more, and the repeated absorption and expansion affect the service life of the material,therefore, the polymer encapsulation layer is required to have sufficient thickness.
Another disadvantage is that the thermal conductivity of such materials is low, and thermal conductivity additives are required in many cases, which also increases the cost and reduces the heat storage capacity and temperature control capability.
Paraffin wax is a good phase change material, of which the related research is going on. Ffaith, paraffin wax manufacturers, has high quality paraffin wax and special wax.