“…For example, instead of flocculation and sedimentation in the bulk solvent, the stable clusters and various macro structures appear at the surface, which is attributed to the colloid-colloid attraction. Recent experimental studies of Ruiz-Garcia et al [1,2], and Ghezzi and Earnshaw [3,4] revealed spontaneous formation of loosely bounded ordered structure in colloidal mono-layer trapped at the air-water interface. These include clusters that consist of several colloidal particles, a fragment of two-dimensional crystals, large voids within an extended two-dimensional structure which resembles foams, etc.…”