The Fabrication And Properties Of The Superhydrophobic/Anti-UV Fabric Based On TiO₂

In recent years,with the continuous improvement of people's living standards and the development of science / technology,people paid much more attention to the multifunctional fabrics such as the self-cleaning and the UV protecting fabrics.In this thesis,a durable superhydrophobic and UV protection coating was fabricated onto the polyethylene terephthalate(PET)fabric via a conventional solution immersion process by using the hydrophobized Ti O2(h Ti O2)nano-particles(NPs)and polydimethylsiloxane(PDMS).The fabrication process contained two steps.Firstly,the Ti O2 NPs were hydrophobized with hexadecyltrimethoxysilane(HDTMS);then,the so-obtained h Ti O2 NPs were deposited onto the PET fabric via a conventional solution immersion process.The fabrication process was simple and operated under mild conditions.The main research and results were as follows.(1)The hydrophobization of Ti O2 NPs.Taking advantage of the condensation between the hydroxyl groups of the hydrolyzed HDTMS(Si-OH)and the hydroxyl groups on the surface of Ti O2(Ti-OH),the pristine Ti O2 NPs were hydrophobized by HDTMS.X-ray photoelectron spectra(the emergence of Si 2p)and Fourier transform infrared spectra(the emergence of C-H stretching vibration)demonstrated that such a modification was successful.After modification,Ti O2 NPs became hydrophobic with the CA of 132.7 ±2°.(2)Surface wettability and durability of superhydrophobicity.The PET superhydrophobic fabric(SF)was fabricated by immersing the pristine PET fabric into the dispersion of h Ti O2 NPs and polydimethylsiloxane(PDMS)in tetrahydrofuran.Scanning electron microscopic analyses showed that the h Ti O2 NPs were attached to the fibers and the surface became rougher.The PET fabric after treating became superhydrophobic with contact angle of 163.6 ± 2° and sliding angle of 3.4 ± 1°.The durability of the soobtained SF was assessed by different methods.Specifically,the SF was immersed into different aqueous solutions with different p H values(such as the dilute HCl aqueous solution with the p H of 1,the Na Cl aqueous solution with the p H of 7,and the Na OH aqueous solution with the p H of 14)for 7 days,or immersed into the ultrapure water and ultrasonicated for 24 h,or washed acceleratedly in water according to the standard of temperature 40 °C,accelerated washing time 45 min for 5 cycles(1 cycle is equal to 5cycles of commercial or home laundering),or slid against 1200 mesh abrasive paper under the load of 10 ± 10%N with the distance of 208 ± 3 mm for 20 cycles.After that,the contact angle was measured to be higher than 150° for all tests.(3)UV resistance and its durability.The UV protection ability for the fabric before and after finishing was tested.Results showed that the UV protection coefficient(UPF)for the pristine PET fabric and the SF was 16.11 and 107.35,respectively.The obvious increase in UPF was due to the high UV adsorption ability of the Ti O2 NPs.After washed acceleratedly in water according to the standard of temperature 40 °C,accelerated washing time 45 min for 5 cycles(1 cycle is equal to 5 cycles of commercial or home laundering),or slid against 1200 mesh abrasive paper under the load of 10 ± 10% N with the distance of 208±3 mm for 20 cycles,the UPF was still as high as 88.67 or 45.66,respectively.These results showed that the so-obtained SF possessed excellent UV protection ability with UPF higher than 50,which still maintained in a high level after washing or sliding.