MECHANICS OF INTERFACES - THE STABILITY OF A SPHERICAL SHAPE

Conditions are considered for the loss of stability of a spherical interface. An arbitrary interface is characterized by the force factors, such as surface tension, first and second moments, moduli of elasticity and cutting forces. In a deformed state the conditions of internal interface equilibrium are assumed to be satisfied. General expressions are obtained for the stability criterion which relate the system parameters and the pressure drop between homogeneous phases separated by the interface. Particular cases are considered of a non-expansible membrane and an interface with a small expansion modulus of elasticity.