Effect of Shape and Interfacial Morphology of n-Octadecane Phase Change Material In situ Shape-Stabilized in Alginate/PVA Blend on Efficiency of Latent Heat

In order to investigate the effect of shape and interfacial morphology of n-octadecane phase change material in situ shape-stabilized in alginate/poly(vinyl alcohol) (PVA) blends on efficiency of latent heat, the in situ shape-sta-bilization films (ISSFs) were prepared from the hybrid solution of alginate/PVA blend and n-octadecane emulsion. It was found that the shape of n-octadecane domain in the polymer blend film was changed from disk to spherulite with increas-ing of polymer concentration in the hybrid solutions. At 18 wt% of alginate/PVA, the aspect ratio of n-octadecane in ISSFs was reached to almost 1. With decreasing of aspect ratio, the specific interfacial area decreased resulting in higher efficiency of latent heat. Moreover, it was notable that the interfacial morphology between n-octadecane and polymeric matrix of ISSFs affects significantly on the efficiency by showing that the efficiency of ISSFs decreased when alginate/PVA were chemically modified due to increase of micro-roughness in the interface.