The purpose of SURFANICOL project is to study the structure and dynamics of anisotropic particles at interfaces and in particular the manifestation of the coupling between the rotational and translational degrees of freedom on the motion of individual particles and on the phase behavior of concentrate systems. The project involves a team of physicists and physical chemists of Montpellier and a team of physicists from Hong Kong. Both teams share expertise in hydrodynamics and each is distinguished by expertise in nanotechnology for Hong Kong and in optics and physical chemistry for Montpellier. Many industrial processes are based on the trapping of solid particles at fluid interfaces: including stabilization of emulsions in food and pharmaceutical, flotation applied to wastewater treatments and separation of minerals industries. The optimization of these processes is based on a better understanding of individual and collective behavior of the particles, but so far, academic interest has focused on spherical particles. The first part of the project will be devoted to the study of individual particle. We expect an enhancement of the translation-rotation coupling when the particles are trapped at interfaces and will pay a particular attention to the passage of the particle from solution to the interface, when solid friction of the triple line add gradually to viscous forces. The use of active colloids, i.e. propelled through a surface catalyzed reaction, will offer a new way to control this coupling, since the power supplied by the reaction depends on the orientation of the particle, which is subject to thermal fluctuations. In the second part of the project we will study the role of translation- rotation coupling in the structure and dynamics of two-dimensional concentrated phases as nematic, hexatic, and glass. To moderate capillary interaction we will design low surface tension interfaces, playing on the proximity of the critical point of immiscible blends. The use of active colloids will also allow to overcome the kinetic barriers induced by capillary forces. The project consists of several tasks the first of which will be the preparation of particles and interfaces suitable for the proposed studies. In the second task holographic detection coupled with multi-traps optical tweezers, which will be developed in the Montpellier, will allow to reveal the dynamical approach of particles to the interfaces, until trapping. These measurements will be combined with force measurements on single particles developed in Hong Kong from an atomic force microscope. Finally, phase transitions in two dimensions will be observed by video microscopy, with image processing at single-particle resolution to get a unique knowledge of these systems. The expertise exchange will be facilitated by the exchange of two jointly supervised PhD students co-funded by ANR and RGC.