**8. Conclusion**

Most of the basic theories of the nucleation have been summarized in this chapter. The objective of this chapter is to introduce more about the primary, secondary, homogeneous, heterogeneous, ice growth and the kinetics of the nucleation. Even though the homogeneous and heterogeneous nucleation can be called as part of the primary nucleation, both of it has different characteristic as both processes happen at different situation and time. Basically, homogeneous always nucleate new crystals while heterogeneous only focus on the growth of the crystals. Both nucleations can be analyzed through the kinetics of the nucleation and the ice growth of the crystals or bubbles.

### **Acknowledgements**

The authors would like to acknowledge Centre for Biofuel and Biochemical Research (CBBR) and also Chemical Engineering Department, Universiti Teknologi PETRONAS for the support.

### **Conflict of interest**

The authors declare no conflict of interest.

*Synthesis Methods and Crystallization*
