The preparation process and optimization condition for synthesize polyamide microparticles directly onto cellulosic surface carried out by interfacial polymerization were investigated by a design screening method. The influences of organic solvent choice, the impregnation time, the monomer amount as well as the temperature bath and the reaction time were studied. Based on the encapsulation yield percentage (polymerization yield), the optimum conditions for microparticles preparation were (i) the use of cyclohexane, (ii) impregnation time = 30 min, (iii) released time = 5 min, (iv) terephtaloyl chloride/ethylene diamine mole ration about 1/10, and (v and vi) reaction time = 19 h at 20 degrees C. The formation of these microparticles was predicted by the analysis of the spreading coefficient in the system; and characterized Fourier transform infrared spectroscopy (FT-IR) and thermogravimetric (TGA) experiments. These analyses revealed the formation of the polyamide microparticles shell and the presence of diamine and water in the core. Based on the experimental results, the process was also applied on a cotton fabric for a potential use for textile purpose with a polymerization yield about 80%. (C) 2012 Elsevier B.V. All rights reserved.