Growing ZnO nanowires on aramid fabric for improving the ultraviolet aging property

Abstract

Aramid fiber is commonly used for ballistic vests because of its excellent mechanical properties. However, it has a drawback in that the fiber force deteriorates under ultraviolet (UV) irradiation. It is proposed in this paper to grow ZnO nanowires on aramid fabric through the hydrothermal method for improving its UV aging properties. Fourier transform infrared spectroscopy analyses illustrate that there is some damage to the N-H and C-N chemical bonds for bare aramid fabric after UV irradiation, although no significant damage is shown by scanning electron microscopy observation. For fabrics subject to 120 h UV irradiation, the warp and weft tensile force of bare fabric decrease by 38.44% and 18.15%, respectively. However, the warp and weft tensile force of fabric with ZnO nanowires increase by 275.52% and 164.84%, respectively, and remain at 241.67% and 197.13% after UV irradiation, respectively. In addition, the burst force of bare fabric decreases over by 50% due to the UV irradiation. Nevertheless, with ZnO nanowires, the burst force of aramid fabric increases dramatically and the increase percentage is over 200%. Even after the UV irradiation, the burst force of fabric with nanowires still retains almost 30% over the bare fabric.

Layer-by-Layer Self-Assembly Approach in the Uv Protective Modification of Aramid-Based Materials

“…The FTIR spectra show specific amide-related peaks at certain wavenumbers: 3308 cm -1 (amide A), 1642 cm -1 (amide I), 1537 cm -1 (amide II), 1298 cm -1 and 1223 cm -1 (amide III), and 721 cm -1 (amide IV) [11,27,[46][47][48][49]. Additionally, bands at 817 cm -1 indicate out-of-plane C-H vibrations of two adjacent hydrogens in an aromatic ring, while 521 cm -1 , 720 cm -1 , and 805 cm -1 bands suggest out-of-plane N-H deformation modes, indicating para disubstitution in the aromatic ring [50,51]. The absorption bands at 1510 cm -1 , 1014 cm -1 , and 817 cm -1 are attributed to the C-H deformation of the aromatic ring [52], and the band at 1605 cm -1 is related to the C=C tensile vibration of the benzene ring [12,50,53].…”

Protect aramid materials from UV‐induced damage by ANF and ANF/light stabilizer composites

“…The amide bonds in the aramid fiber can be cleaved by the energy generated by UV irradiation (297.2-594.8 kJ mol À1 ). 5 UV irradiation will cause bond cleavage, chain scission, and oxidation of terminal groups of the polymer. 6 Thus, the aramid fiber will be gradually damaged, from the outer skin to the interior core.…”

“…Aramid materials have to endure harsh environmental conditions in many of the above‐mentioned applications. The amide bonds in the aramid fiber can be cleaved by the energy generated by UV irradiation (297.2–594.8 kJ mol −1 ) 5 . UV irradiation will cause bond cleavage, chain scission, and oxidation of terminal groups of the polymer 6 .…”