Abstract:

Objective Car seats are the most frequently touched parts by the human body during the use of the car, and human sweat and dirt can easily adhere to the car seat fabric. The interaction of the sweat and dirt can produce low fatty acids and some volatile compounds, which would emit foul odor, causing concerns to quality of life and human health. Therefore, it is necessary to develop antimicrobial car seat fabrics to improve the interior environment of automobiles.

Method With tetrabutyl titanate as titanium source, boric acid and urea as dopants, and polyester knitted fabric as substrate, polyester knitted fabric loaded with boron-nitrogen co-doped nano-titanium dioxide (B-N-TiO₂) antibacterial agent was prepared by rapid sol-gel method. The antibacterial properties of B-N-TiO₂/polyester knitted fabric specimens were analyzed by oscillation tests under solar light illumination using Escherichia coli and Staphylococcus aureus as the target strains. X-ray diffraction and UV-Vis diffuse reflection absorption spectroscopy were used to analyze the spectral properties of antibacterial agents. The breaking strength, the wear resistance, the water repellency, the color fastness against rubbing, and the pH value of polyester knitted fabric specimens before and after antibacterial finishing were tested.

Results By measuring the bacteriostatic rate of B-N-TiO₂ photocatalytic antibacterial agents with different boron doped amounts on E. coli, the optimal molar ratio of boric acid and tetrabutyl titanate was found to be 0.75∶1. The optimal impregnation loading process for B-N-TiO₂/polyester knitted fabrics was selected by orthogonal test optimization process under the conditions of 5 min impregnation loading time, baking temperature 120 ℃, and baking time 15 min. The antibacterial inhibition rates of B-N-TiO₂/polyester knitted fabric specimens prepared by the optimal process against Escherichia coli and Staphylococcus aureus were 98.4% and 94.4%, respectively, and the antibacterial rates after 20 washes were 91.8% and 91.3%, respectively. The microscopic morphology of the fabric before and after the loading of photocatalytic antibacterial agent was analyzed, and it was found that after finishing with antibacterial agent, a layer of smooth membrane was tightly coated on the surface of polyester fiber, and that after 20 washes, a large proportion of membrane was still tightly wrapped on the fiber surface. After loading the antibacterial agent, the breaking strength of the fabric was increased, the wear resistance was increased, and the water repellency level of the fabric was enhanced. The color fastness against rubbing was not changed. The pH value of the water extract of the antibacterial fabric was reduced, and the key properties were found in line with the requirements of relevant standards.

Conclusion B-N-TiO₂ photocatalytic antibacterial agents have excellent loading effect on polyester fabrics. After 20 times of washing, a very small part of the antibacterial agent membrane on the surface of fiber in the antibacterial fabric cracks and falls off under the impact of water flow and steel ball rubbing, but a large quantity of antibacterial agent membrane wrapped on the fiber surface, which further indicates that the antibacterial fabric has excellent durability and antibacterial properties. The result confirms that the durable antibacterial performance of the B-N-TiO₂/polyester knitted fabric exceeds AA level.

Key words: boron-nitrogen co-doped nano-titanium dioxide, textile for automotive interior, polyester knitted fabric, antibacterial finishing, functional textile