New approach to impart antibacterial effect and improve ink jet printing properties with modified SiO2 sols containing cationic biocides

The modified SiO2 sols were synthesized by tetraethoxysilane (TEOS), γ-glycidoxypropyltrimethoxysilane (GPTMS) and cetyltrimethyl ammonium bromide (CTAB) via sol–gel process. Particle size analysis, Fourier transformed infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) were used to characterize the sols. The sols were treated on cotton knitted samples by impregnation. The antibacterial activities of the samples were assessed against S. aureus bacteria and E. coli bacteria according to the AATCC 100-2004 standard method. The samples treated by sols exhibited the satisfactory antibacterial activity. The inhibitory rate for S. aureus and E. coli were both more than 95% when the concentration of CTAB was at 0.10 mol, which could be due to the high antibacterial activity of CTAB. The outline sharpness, color depth and hand feeling of ink jet printing samples treated by sols were analyzed. The outline sharpness and color depth of treated samples were improved more considerably than those of untreated samples, which were both attributed to the existence of modified sols on the treated sample surfaces. But the hand feeling of treated samples declined slightly because of the films generated on the treated sample surfaces.