Abstract: For an insoluble surfactant-laden droplet spreading on corrugated topography,a disjoining pressure model induced by concentration of surfactant was established. Non-model stability theory was carried out to investigate stability of spreading. It indicates that compared with droplet spreading without disjoining pressure,under disjoining pressure advancing front height of droplet reduce apparently and spreading rate increases which improves stability of spreading. Long perturbation wave is conducive to enhance stability of droplet evolution and stability is enhanced with increasing wave number. However,spreading stability trends to deteriorate and even transit to unstable with increasing wave number of short perturbation waves. Reducing attraction strength coefficient α₁ and increasing repulsion strength coefficient α₂ promote spreading stability at small wave number(k=3). In addition,droplet displays more stable spreading with increasing α₁ and decreasing α₂ at large wave number(k=30).

Key words: surfactant-laden droplet, topography surface, disjoining pressure, non-model stability