The mini‐emulsion polymerization of polystyrene–titanium dioxide (PS/TiO2) hybrid antibacterial material was carried out. Triethylene glycol dimethacrylate (TEGDMA) was used, as a crosslinking agent, to enhance the stability, the encapsulation efficiency of TiO2, the self‐organized structure of the nanoparticles and photocatalytic behavior. The particle size and morphology as well as the photocatalytic properties of the polymer hybrids were characterized by dynamic light scattering, field emission SEM and UV–visible spectroscopy. The results showed that the average particle size of PS/TiO2 hybrids was in the range 98–242 nm with a narrow size distribution. The results of field emission SEM demonstrated the raspberry‐like self‐organized hexagonal structure of the polymer hybrids in the presence of TEGDMA. The morphology and structure of the PS/TiO2 hybrid were observed using high resolution TEM. The results show that the PS and PS/TiO2 hybrids have a well‐defined structure. Energy‐dispersive X‐ray spectroscopy was used to confirm that PS/TiO2 hybrid contains elemental titanium. It was noticed that the elemental analysis of Ti and O was 8.03 wt% (2.9 at%) and 7.97 wt% (6.5 at%), respectively. It should be emphasized that the results of high resolution TEM and energy‐dispersive X‐ray spectroscopy are considered excellent proof for the formation of PS/TiO2 hybrid. The thermal properties of PS and the hybrids with TiO2 were explored by DSC. It was found that the presence of TEGDMA in the system may reduce the glass transition temperature (Tg) of the polymer hybrids. XRD confirmed the formation of PS/TiO2 hybrids and the antibacterial activity was also investigated. An escalation of intensity in the XRD pattern of the TiO2 signals in the PS/TiO2 hybrids was observed. The antibacterial activity study noted that the PS/TiO2 hybrid demonstrated excellent antifungal and antibacterial properties against a broad range of both Gram‐positive (Staphylococcus aureus) and Gram‐negative (Klebsiella pneumoniae) bacteria. The photocatalytic efficiency of PS/TiO2 was assessed by monitoring the discoloration of an organic dye (methylene blue) under UVA irradiation. It indicated that the photocatalysis of PS/TiO2 in the presence of TEGDMA was increased due to the association of TEGDMA in the self‐organization structure of the hybrid system. © 2021 Society of Industrial Chemistry.