These two maxima are linked to the different spherulite
growth rates of the a and a' crystal modifications, the one at higher temperature is associated to growth of a spherulites
, the one at lower temperature is linked to a' crystals [56, 57], The addition of PPC does not affect the position of the two maxima, but produces a sizeable increase of the rate of crystal growth of both crystal modifications, with some slightly more pronounced effect for the a crystals.
In semi-crystalline polyolefins, crystallites form aggregates, resulting in structures such as spherulites
In order to lead active ingredients directly to the melanocyte, the heart of the targeted zone, these ingredients have been encapsulated in Spherulites
In thin section these large ash layers consist of calcitic plant ash with embedded reed and grass phytoliths associated with occasional animal dung spherulites
(Canti 1999), suggesting the presence of dung fuel (Figure 3f).
Both images show that big spherulites
grow due to the isothermal conditions but especially in the interface between surrounding powder and molten areas both materials are significantly different.
A similar porosity effect occurs when stretching film that contains hard spherulites
or "beta-formation crystals" that form during annealing.
The lamellae are typically organized into spherulites
with the proper thermal history.
For example, it has been firmly verified by WAXD that [beta]-iPP are primarily unoriented during the major growth process , What's more, in many cases, [beta] spherulites
could be detected in neat iPP without crystalline or lamellar orientation under weak shear field [38, 53-57], Therefore, it can be concluded that oriented [alpha]-row nuclei are not necessary to induce [beta]-iPP.
The growth rates and morphology of the sample spherulites
were determined by a polarized optical microscope (LV100 POL, Nikon) equipped with a hot stage.
Calcareous dung spherulites
form on the intestinal tracks of animals and an association of their presence with intensive animal activity has been established at historic and archaeological sites (Courty et al.
Nucleators and clarifiers induce formation of smaller spherulites
that scatter less light.
The radial growth rate of spherulites
is often used to measure crystallization rate.