INTRODUCTION
Chemically and thermodynamically foam is an unstable, dispersed system of entrapment of gaseous molecules in solid or liquid matter. Instability of foam is caused generally due to coalescence, liquid drainage and disproportion of bubbles. Foam being aqueous system can be produced using surfactants available commercially. The types of surfactants used in preparation of aqueous foam influence the foam properties (Eisner et al., 2007; Bhakta and Ruckenstein, 1995). Successful foam requires the formation, growth and stabilization of the gas bubbles in the reacting medium. The bubbles in foam can be more or less homogeneous and vary in size. The shape of bubble of the foam may be almost spherical to irregular polyhedral, based on the way in which the foam is generated and the excipients used (Nikolai et al., 2009). Other parameters include the nature and concentration of the foaming agent, viscosity of the liquid phase, …show more content…
As there is no particular common procedure to determine and characterize foam stability, it is important to analyze the methods used in characterization of foam. There have been much common parameters such as half-life, foam decay, Foamability, bubble size to determine foam stability but the recent foam research has produced various other parameters and techniques to determine stability of foaming solutions (Curschellas et al., 2012). Chunxiu et al., have reported the use of bipolar headed surfactants along with magnesium to produce ultra-stable foam. Molecular dynamic simulation can be used to determine and compare the molecular array behavior of surfactant molecules and molecular interaction affecting foam stability. Foam lamella thinning behavior was studied by a modified apparatus. The wide orientation distribution of surfactant tail and smaller tilt angle of head group ensures the stability of foam by enhancing the viscosity and elasticity of foam film (Li et al.,
Chemically and thermodynamically foam is an unstable, dispersed system of entrapment of gaseous molecules in solid or liquid matter. Instability of foam is caused generally due to coalescence, liquid drainage and disproportion of bubbles. Foam being aqueous system can be produced using surfactants available commercially. The types of surfactants used in preparation of aqueous foam influence the foam properties (Eisner et al., 2007; Bhakta and Ruckenstein, 1995). Successful foam requires the formation, growth and stabilization of the gas bubbles in the reacting medium. The bubbles in foam can be more or less homogeneous and vary in size. The shape of bubble of the foam may be almost spherical to irregular polyhedral, based on the way in which the foam is generated and the excipients used (Nikolai et al., 2009). Other parameters include the nature and concentration of the foaming agent, viscosity of the liquid phase, …show more content…
As there is no particular common procedure to determine and characterize foam stability, it is important to analyze the methods used in characterization of foam. There have been much common parameters such as half-life, foam decay, Foamability, bubble size to determine foam stability but the recent foam research has produced various other parameters and techniques to determine stability of foaming solutions (Curschellas et al., 2012). Chunxiu et al., have reported the use of bipolar headed surfactants along with magnesium to produce ultra-stable foam. Molecular dynamic simulation can be used to determine and compare the molecular array behavior of surfactant molecules and molecular interaction affecting foam stability. Foam lamella thinning behavior was studied by a modified apparatus. The wide orientation distribution of surfactant tail and smaller tilt angle of head group ensures the stability of foam by enhancing the viscosity and elasticity of foam film (Li et al.,