Nanoencapsulation of n-Octadecane Phase Change Material in Self-Assembled Polyelectrolyte by Soft Solution Technique

Abstract

Nanoencapsulation of n-octadecane phase change material was performed by facile soft solution technique. An emulsion of n-octadecane and sodium dodecyl sulfate was prepared by high intensity sonication and then mixed with 1–6 mM of poly(diallyldimethylammonium chloride) (PDDA) solution. The capsules with globular core-shell structure were obtained via self-assembly of PDDA molecules coated on the primary emulsion droplets, described as PDDA encapsulated n-octadecane (PDDA-en-Oc). Average particle size and ζ-potential of PDDA-en-Oc increased with increasing of PDDA concentration due to the different PDDA conformation and thickness of capsules' shell. The smaller diameter of PDDA-en-Oc, the faster heat releasing and absorption were obtained. However, the increasing of PDDA concentration could improve the encapsulation efficiency, resulting in an increment of latent heat quantity. The PDDA-en-Oc capsules prepared from 4 mM PDDA with ∼166 nm in size possessed the maximum latent heat and encapsulation efficiency (i.e., 124.4 J/g and 58%, respectively).

Keywords:

• Green chemistry
• nanoencapsulation
• phase change materials
• polyelectrolytes
• self-assembly

Notes

^a The values were calculated using formula in Eq. 1.