The presentation shortly shows the research that I did during my Ph.D. at the Eindhoven University of Technology. The aim is the microencapsulation of salt hydrates for their use in heat storage applications. The central question of the research is: "How to use Pickering emulsions efficiently for microencapsulation?"
2. Aim: Encapsulation of salt hydrates
Salt hydrates can store large amounts of thermal energy by undergoing a
solid-liquid phase change (phase change materials, PCMs).
Encapsulation allows the incorporation
of salt hydrates in construction materials.
10. Colloidal cages
Formation of colloidosomes
- Disperse particles in C7
- Add H2O
- Shear for 10 s at 10.000 rpm (20.000 s-1) with Ultraturrax®
- Heat to 35 C° (sintering)
11. Colloidal cages
Dp = 1.8 µm Dp = 5.0 µm
Increasing particle size
Particle density capsules is incomplete for small particles.
Possible cause: attraction among the particles.
Soft Matter 2011, 7 pp 2033 – 2041 & Physical review E 2012, 85, 061404
12. Colloidal cages
Particle density decreases with the particle diameter.
Rp[mm] Density [-]
5.0 0.98
3.3 0.89
2.7 0.84
1.9 0.75
1.8 0.74
Soft Matter 2011, 7 pp 2033 – 2041 & Physical review E 2012, 85, 061404
13. Colloidal cages
- Attraction leads to aggregation.
- Smaller particles exhibit more irregular aggregates, than
large particles.
24. Micro-encapsulation of CaCl2 6H2O
Properties clearly show effect of micro-encapsulation.
Confined crystallization (DSC) Deliquescence (gravimetry)
25. Conclusion
• Encapsulation of salt hydrates is successful.
• Study revealed important parameters for a successful &
efficient micro-encapsulation from Pickering emulsions.
• Wetting & colloidal stability are fundamentally related in the
case of Pickering stabilization.
26. Acknowledgements
• Prof. dr. ir. L. Klumperman
• Prof. dr. J. Meuldijk
• Prof. dr. A. van Herk
• Ing. Herman Reezigt
Questions?
jorissalari@gmail.com