Light Conversion and Scattering in UV Protective Textiles

Abstract

The primary cause of skin cancer is believed to be a long exposure to solar ultraviolet radiation (UV-R) crossed with the amount of skin pigmentation in the population. It is believed that in childhood and adolescence 80% of UV-R gets absorbed, whilst in the remaining 20% gets absorbed later in the lifetime. This suggests that proper and early photoprotection may reduce the risk of subsequent occurrence of skin cancer. Textile and clothing are the most suitable interface between environment and human body. It can show UV protection, but in most cases it does not provide full sun screening properties. UV protection ability highly depends on large number of factors such as type of fibre, fabric surface and construction, type and concentration of dyestuff, fluorescent whitening agent (FWA), UV-B protective agents, as well as nanoparticles, if applied. Based on electronically excited state by energy of UV-R (usually 340-370 nm), the molecules of FWAs show the phenomenon of fluorescence giving to white textiles high whiteness of outstanding brightness by reemitting the energy at the blue region (typically 420-470 nm) of the spectrum. By absorbing UV-A radiation, optical brightened fabrics transform this radiation into blue fluorescence, which leads to better UV protection. Natural zeolites are rock-forming, microporous silicate minerals. Applied as nanoparticles to textile surface, it scatters the UV-R resulting in lower UV-A and UV-B transmission. If applied with other UV absorbing agents, e.g. FWAs, synergistic effect occurs. Silicones are inert, synthetic compounds with a variety of forms and uses. It provides a unique soft touch, is very resistant to washing and improves the property of fabric to protect against UV radiation. Therefore, the UV protective properties of cotton fabric achieved by light conversion and scattering was researched in this paper. For that purpose, the stilbene-derived FWAs were applied on cotton fabric in wide concentration range without/with the addition of natural zeolite or silicone- polydimethylsiloxane. UV protection was determined in vitro through ultraviolet protection factor. Additionally, the influence to fabric whiteness and hand was researched

Durable antibacterial and UV protective properties of cellulose fabric functionalized with Ag/TiO2 nanocomposite during dyeing with reactive dyes

“…The dramatic increase of UPF is noticed on dyed and Ag/TiO 2 NC loaded samples, boosting the UPF values from 51.62 up to 328.90 (Table 6). The TiO 2 particles have absorption capacity in the UV region, reflecting visible and UV rays, thuds their incorporation in textile materials improves the UV blocking capacity of the fibres (Grancarić et al 2014). Higher UPF's were calculated for cotton fabrics dyed with higher concentration of reactive dye and for samples where Ag/TiO 2 NC was loaded during dyeing (Table 6).…”

Skin Cancer and UV Protection

“…Good skin protection thereby can be achieved by the textile itself, if the fabric is sufficiently dense. Introducing the nanoparticles in textile finishing, led to UV protection by coating the surface of textiles and clothing with nanoparticles of TiO 2 titanium, and zinc oxide [28][29][30], and nowadays, of natural zeolite clinoptilolite [22,32,33].…”

The influence of FWA chemical constitution to the whiteness and UV protection of cotton and cotton/polyester blend

“…It should be noted that FWA treatment also results in better UV protection due to the absorption of ultraviolet radiation. (UV-R) [5][6][7][8][9][10][11][12][13][14]. Long exposure to solar ultraviolet radiation, along with the amount of skin pigmentation, is the primary cause of skin cancer [6,15,16].…”

“…This can be achieved by reducing the time of exposure time to sunlight, using sunscreen and protective textiles. Since good UV protection with textiles depends on a large number of factors [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20], such as, the type of fiber, fabric surface and construction, porosity, density, moisture content, presence of nanoparticles, as well as type and concentration of applied dyestuff, FWAs or UV-B protective agents, designing and engineering of UV protective fabrics always FWAs' were used in wide concentration range: 0.5, 1, 2 and 5% owf by batch wise method having LR 1:30 at 100 °C for 30 min in stainless-steel bowls (Linitest, Original Hanau). After the treatment, the fabrics were airdried.…”