| Summary: | Increasing antibiotic resistance of several pathogenic microorganisms calls for alternative approaches to prevent spreading of bacterial diseases. We propose to employ for this purpose coatings obtained from positively charged latex dispersions. In this contribution we characterize aqueous mixed dispersions containing TiO<sub>2</sub> or CaCO<sub>3</sub> and methyl methacrylate-ethyl acrylate or styrene-ethyl acrylate copolymers synthesized using a cationic surfactant, cetyltrimethylammonium bromide as an emulsifier. Particle size, electrokinetic (ζ) potential of the mixed dispersions and the resulting thin films, as well as antimicrobial properties of the latter are described. The TiO<sub>2</sub> and CaCO<sub>3</sub> dispersions were stabilised with polyethyleneimine (PEI) and optimum pH for the mixed dispersions were chosen on the basis of ζ-potential measurements. For TiO<sub>2</sub>, the maximum ζ = +35 mV was found at pH 7.5, and for CaCO<sub>3</sub>, pH was set at 8.2 (ζ = +38 mV), to prevent its dissolution. In most 1:1 mixtures of TiO<sub>2</sub> or CaCO<sub>3</sub> with the cetyltrimethylammonium bromide (CTAB)-stabilised latex dispersions, two distinct particles populations were observed, corresponding to the bare latex and bare TiO<sub>2</sub> or CaCO<sub>3</sub> fractions. Films made of the mixed dispersions remained positively charged and showed antimicrobial activity similar or reduced with respect to the bare polymer films.
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