Lamellae surface energy

Nevertheless, it has subsequently been suggested that, for polyethylene, there could be a phase inversion at small lamellar thickness which could make the hexagonal the precursor of orthorhombic crystallization from the melt even at atmospheric pressure [4]. The basis of this proposal will now be outlined and the conclusion reached that it is inapplicable, in part because the effective fold surface energy during growth of hexagonal lamellae is not sufficiently low. 

A surfactant film is adsorbed on the surfaces of the foam lamella and, depending on concentration, micelles may be present. If the foam lamella is stretched in the direction of the arrows, for instance by an external force, the surface film is depleted and the coverage is incomplete in this zone. This causes an increase of the surface energy in this zone and... 

Particulate dewatering An example of a particulate dewatering defoamer is one containing hydrophobic silica particles. The silica particles are coated with insoluble silicone films, resulting in particles that have such a low surface energy that they exert a dewatering action on the foam lamella. 

For a simple pol3mier crystal, the lamellae dominate the growth and the two surfaces that contain the folded chains dominate the total surface energy term. It can be assumed that there is a free energy term that is independent of this fold surface and represents the interaction between the al -trans linear chains, stems, and has the form... 

The superstructure of HEPP is a manifestation of bulk-microfibril composites. The elastic force at room temperature consists of three parts entropic elasticity ( 20%), surface energy ( 50%) and deformation of lamellae ( 30%). 

Attention in more recent models has been given to the free surface energy change of the polymers with strain [6-9]. Furthermore, the focus has changed from the lamellae to the microfibrils. 

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