This volume contains the proceedings of the IXth annual meeting of the European Colloid and Interface Society (ECIS) which took place in Barcelona, Spain, in September 1995. The contributions cover a broad range of fields in modern colloid science, as well as their technical, experimental and theoretical aspects. Specific emphasis is given to: - Surfactant aggregates, micelles, vesicles and liquid crystals; - Colloidal particles: interaction, structure and aggregation; - Emulsions and concentrated systems; - Microemulsions; - Mixed colloidal systems; - Rheology; - Biocolloids; - Membranes, films and interfaces.Formation and structure of reverse vesicles.- Phase diagram of the 1-dodecyl pyridinium bromide-dodecane-water surfactant system.- Characterization of structural transitions in the SLS/n-alcohol/water system.- Surfactant self-diffusion and networks of wormlike micelles in concentrated solutions of nonionic surfactants.- Thermodynamic theory and experimental studies on mixed short-chain lecithin micelles.- Phase behavior in sodium cholate/calcium chloride mixtures.- The effect of sub-solubilizing concentrations of sodium deoxycholate on the order of acyl chains in dipalmitoylphosphatidylcholine (DPPC). Study of the fluorescence anistropy of 1,6-diphenyl-1,3,5-hexatriene (DPH).- Multifractality of lyotropic liquid crystal formation.- Surfactant aggregation and response of ion-selective electrode.- 3-Deoxy-s-alkyl-d-glucose derivative micelle formation, CMC and thermodynamics.- Computer simulation studies of surfactant systems.- Equation of state of a colloidal crystal: An USAXS and osmotic pressure study.- Interaction behaviour in a binary mixture of polymer particles.- Electric light scattering from polytetrafluorethylene suspensions. II. Influence of dialysis.- Two photon rayleigh scattering in micellar and microemulsion systems.- Dynamic scaling in colloidal fractal aggregation: Influence of particleló‡