Spectroscopic Study of UV Transparency of Some Materials

Abstract

Elevated exposure to Ultra-Violet Radiation (UVR) from the sun has led to adverse effects on human skin and foods, and therefore, the need for materials that offer resistance to Ultra-Violet (UV) penetration for protection. Some building window and non-window-materials, car-glasses, Linear Low Density Polyethylene (LLDPE) and Polyethylene Terephthalate (PET) rubber and plastic materials have been investigated to determine their transparencies and suitability for use as shields against UVR. These were studied by directly measuring scattered solar radiation through the optical window of a spectrometer and then measuring the scattered light when the window was completely covered with the material to be examined. Wavelengths of light that were not absorbed when sunlight was incident on the samples and the transmitted intensity of sunlight at each wavelength through each sample as compared to the transmitted intensity through air were determined in the UVB and UVA spectral regions. The results showed that the building window-glasses were opaque to UVB but transparent to UVA while the non-window-glasses exhibited transparency in the UVB and UVA spectral regions. The car-glass (laminated), used as windscreen, was opaque to UVB and UVA while the side-glass (non-laminated) was opaque to UVB but transparent to UVA. Perspex, sometimes used as an alternative to windscreen and side-glass in cars, exhibited transparency in UVB and UVA spectral regions. The LLDPE materials used for food storage were transparent to UVB and UVA while the PET plastic materials used for water, fruit juice and beverage storage was opaque to UVB but transparent to UVA.

Vitamin D deficiency causes rickets in an urban informal settlement in Kenya and is associated with malnutrition

“…Public health strategies to improve vitamin D levels may provide benefit beyond prevention and treatment of rickets, but should be tested in rigorous controlled trials. Solar bottle bulbs (which involve the incorporation of water‐filled plastic drink containers into the roof of a settlement) represent an innovative approach to increasing indoor sunlight exposure in urban informal settlements (http://www.literoflight.org), however the use of common polyethylene terephthalate plastic bottles means that the UVB wavelengths important for vitamin D production are filtered out (Sackey et al, ). Adaptation of this approach may be feasible and could provide a cheap and durable solution.…”

“…represent an innovative approach to increasing indoor sunlight exposure in urban informal settlements (www.literoflight.org), however the use of common polyethylene terephthalate plastic bottles means that the UVB wavelengths important for vitamin D production are filtered out (Sackey et al, 2015). Adaptation of this approach may be feasible and could provide a cheap and durable solution.…”

Fluoropolymer coated alanine films treated by atmospheric pressure plasmas − In comparison with gamma irradiation

“…Since increase in temperature by the treatment was moderate as shown in Figure , the bulk modification in the present study is probably caused by high energy photo‐emission of the plasmas such as ultraviolet (UV) rays. Penetration depth of UV rays into polymeric materials depends on the materials themselves and the wavelength of UV . Fluoropolymers are known to be substantially UV transparent even at short wavelengths, while alanine absorbs a broad range of UV .…”

“…Penetration depth of UV rays into polymeric materials depends on the materials themselves and the wavelength of UV. [43] Fluoropolymers are known to be substantially UV transparent even at short wavelengths, [44] while alanine absorbs a broad range of UV. [45] It is therefore likely that UV rays emitted from the plasma can pass through the fluoropolymer layer and easily be absorbed by alanine.…”

Polythiophene coated poly(methyl methacrylate) sheet as a new candidate for flexible organic electrode applications

“…As said, poly(methylmethacrylate) (PMMA), a solutioncast low-temperature processed material, is a transparent amorphous polymer with a relatively high glass-transition temperature (T g = 105 °C) [33]. Due to its low cost, PMMA can be integrated in building components such as windows and floating tiles while it bears a conductive polymer coating such as polythiophene, polyaniline or polypyrrole [34]. A review of scientific literature reveals that PET films and sheets are overwhelmingly used as substrate for conductive polymeric coatings.…”