In recent decades, there has been a rise in public consciousness of the adverse effects of expanded skin contact with sunlight, particularly the ultraviolet (UV) spectrum. UV radiation causes serious ...health problems like skin cancer, early aging, erythema, pigmentation, etc., due to contact with the skin. Therefore, the highly efficient UV-protection materials were manufactured using polypropylene and TiO2 (PPTO) through cost-effective and easy methods. The designated 7.5 PPTO and 15 PPTO were prepared, varying the amount of TiO2, as well as without using TiO2 (PPNF), which was also manufactured as a control material. All the as-synthesized nonwoven fibers were carefully characterized employing a variety of microscopic and spectroscopic methods, such as X-ray diffraction, Fourier transform infrared spectroscopy, thermogravimetric analysis, field-emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, ultraviolet–visible diffuse reflectance spectroscopy, and contact angle measurements. In conclusion, 15 PPTO showed the highest UV-protection ability (87.5%) compared to 7.5 PPTO and PPNF. In addition, 15 PPTO exhibited 1.76 and 1.32 times higher protection than 7.5 PPTO and PPNF, respectively, when exposed to UB-B radiation. The enhanced activity may be due to the amount of TiO2 because TiO2 increased the product’s absorption and reflection capability. Overall, the PPTO nonwoven fibers can be applied to block harmful UV radiation.
The cellulose fabrics made from 100 % cotton with antibacterial and UV protective properties were successfully created by loading of Ag/TiO
2
nanocomposite during and after dyeing with yellow, red ...and blue reactive dye. Blank dyeing (dyeing with all chemicals except dye) was performed to show that reactive dyes have an ability to increase the adsorption and adhesion of Ag/TiO
2
nanocomposite on cotton fabrics. The colour of the samples before and after washing and exposure to artificial light was measured by reflectance spectroscopy. The presence of nanocomposite on samples was confirmed by scanning electron microscope. The increased adsorption capacity of cotton towards Ag/TiO
2
nanocomposite due to the presence of reactive dyes was confirmed by measuring the quantity of silver using inductively coupled plasma mass spectroscopy. The same samples showed excellent UV protective properties with UV protection factor (UPF 50+), and excellent antibacterial properties against
E. coli
and
S. aureus
. Due to a good adhesion of nanocomposite on samples where loading of nanocomposite and dyeing with reactive dye was performed simultaneously, the samples retained their excellent protective properties after repetitive washing cycles.
UV protection and coatings for plastics are important in many applications. The cladding of low microwave (MW) absorption composite coatings on high MW transparent plastic substrates is a challenge ...due to their disparate dielectric properties. Moreover, an uneven heat energy conversion within the composite creates an additional hurdle in producing a coating with good surface integrity. In this study, a protocol was developed to overcome these difficulties based on a hybrid approach. The adverse effect of temperature mismatch between the coating and substrate was reduced through a two-way susceptor-aided heating mechanism. Low MW absorbing sol–gel derived composite coatings consisting of silicon dioxide (SiO
2
) and titanium dioxide (TiO
2
) were successfully cladded on the surface of MW and visual light transparent polycarbonate to produce a clear protective coating with UV-resistance. Nanoindentation tests were conducted to assess the effectiveness of the proposed protocol. Significant enhancement in the surface elastic modulus and hardness were achieved.
Schematic of hybrid MW cladding of sol–gel derived SiO
2
/TiO
2
coating on polycarbonate. The heat energy transferred to the sample is a combination of (1) the heat generated through MW coupling of the SiO
2
/TiO
2
coating and (2) the heat transfer by conduction, convection, and radiation from the heated. This process promotes hydrolysis and condensation reactions, leading to fast densification of the coating. Moreover, the difficulty of processing low microwave absorbing and microwave transparent materials simultaneously has been overcome. As a result, a crack-free SiO
2
/TiO
2
coating with enhanced surface mechanical properties can be produced within a minute.
Highlights
A hybrid microwave cladding process has been developed for the fabrication of composite coating systems with disparate dielectric properties.
The difficulty of processing low microwave absorbing and microwave transparent materials has been overcome.
Fabrication of crack-free silicon dioxide (SiO
2
)/titanium dioxide (TiO
2
) composite coatings on polycarbonate substrates with enhanced surface mechanical properties has been demonstrated.
This process greatly reduces the processing time from hours to less than a minute when compared to conventional methods.
Premordanting of jute fabric was carried out following single mordanting by biomordants (myrobolan and pomegranate) and ecofriendly chemical mordants (ferrous sulphate and potash alum) and double ...mordanting by sequential treatment of biomordant and ecofriendly chemical mordant. Extraction condition of natural dyes from manjistha, annatto, ratanjot and babool was standardised and applied on premordanted jute fabric. There is a substantial improvement of colour yield, levelness of dyeing and wash fastness properties of natural dyed jute fabric after double premordanting using bio and chemical mordant. Light fastness ratings are moderate to good while rubbing fastness are very good to excellent for all the natural dyed jute fabric. Very good ultraviolet (UV) protection ratings are achieved in case of dyeing of jute fabric using natural dyes extracted from manjistha, annatto, ratanjot and babool after premordanting with sequential treatment of biomordant and chemical mordant. UV protection properties of natural dyed jute fabric follows the order babool > annatto > manjistha > ratanjot.
In this research, cotton fabrics were treated with carboxylated chitosan, loaded by the pad-dry-cure method for
investigating the absorption of heavy metals and the Ultraviolet (UV) protection ...properties of fabric samples. For this
purpose, chitosan-treated cotton fabrics were soaked in CuSO4 solution to investigate the rate of heavy metal
absorption. The surface morphology of cotton fabrics was investigated using Scanning electron microscopy (SEM)
analysis. Inductively coupled Plasma Spectroscopy (ICP) analysis was employed to examine the amount of heavy
metals' absorption upon chitosan-treated cotton fabrics. Besides, reflection and transmission spectrophotometry
analyses were used to examine the optical properties of cotton fabrics. The results show a noticeable increase in copper
absorption by increasing the amount of chitosan. The maximum absorption of Cu belongs to the %6 chitosan-treated
sample by 7357.6 PPM, equal to %7.35. The more concentration of chitosan in the fibre causes a higher rate of UV
protection. Therefore, the chitosan-treated cotton fabrics examined in this work can be used for various water filtration
purposes, notably to eliminate toxic metals. Also, It can be used as a wearable textile for protecting against harmful UV
rays.
Zinc oxide (ZnO) nanoparticles were loaded over non-thermal plasma (P1) and citric acid (P2)-functionalized cotton fabrics using a room temperature sonification process. The cotton samples were ...pretreated with dielectric barrier discharge (DBD) plasma and citric acid to introduce some reactive moieties on the fabric to enhance the adhesion power of ZnO nanoparticles with an average particle size of 41 nm. The nanoparticles were dispersed homogeneously on the surface of the P1 sample, which enhanced the antibacterial, UV protection and photocatalytic self-cleaning characteristics of ZnO-loaded fabric. The self-cleaning efficiency of P1 and P2 samples was measured to be about 77% and 63%, respectively. The inhibition zones of 5.5 mm and 5.4 mm were produced by sample P1 against E. coli and S. aureusbacteria, respectively, which were slightly higher than the inhibition zones produced by sample P2. The inhibition zone of the samples roughly decreased by 17% after performing 10 wash cycles. The unloaded cotton fabric had a UPF value of 70.02 units and blocking percentage of 70.92% and 76.54% for UVA and UVB radiations, respectively. The UVA-blocking capacity of samples P1 and P2 was 95.27% and 91.22, respectively. Similarly, the UVB blocking capacity was 94.11% and 92.65%, respectively. The pre-coating plasma treatment was found to be helpful in improving the UV-blocking ability of ZnO-loaded cotton fabric.
Abstract : Cosmetic standard poly methyl methacrylate (PMMA) UV evaluation plates, i.e., roughened PMMA plates, are used in the EU and the US for the in vitro evaluation of UV protection abilities of ...sunscreen, such as in vitro UVA-PF and critical wavelength for the Broad-spectrum approval. In our previous studies, inhomogeneity in the thickness of a pseudo-sunscreen layer applied on a flat quartz plate was observed to alter UV transmission. Thus, the surface roughness of the standard plates should have a significant influence on the in vitro evaluation. In the present study, we have analyzed the surface structures of three cosmetic standard PMMA UV evaluation plates : Helioplates HD6 (Sa = 6 μm) and ISO plates (Ra = 2 and 5 μm) . A decamethylcyclopentasiloxane and 2-propanol-mixed solvent solution of acrylsilicone resin was prepared, and the solution was added dropwise onto the plates. After the evaporation of the solvents, the plates were cut and the cross section was analyzed using SEM-EDS. The distribution of silicon atoms at the cross-section suggested that the maximum depth of penetrating of acrylsilicone resin was larger than Ra for all the standard plates, and the surface structure was significantly different for each standard plate. In addition, cracks into which the acrylsilicone resin deeply penetrated were observed on the surface of some plates. Clear-solution-type pseudo-sunscreen samples in which UV absorbers and acrylsilicone resin were dissolved were deposited on the standard roughened PMMA plates. It was observed that the addition of acrylsilicone resin drastically changed the net UV transmission. The degree to which the hollows of the roughened surface were filled with the pseudo-sunscreen samples determined the variation of UV transmittance.
Carbon nanodots (CNDs) are more and more being exploited for various applications including biological ones. To this end, they have been thoroughly studied for their potential as antibacterial, wound ...healing, and bioimaging agents. In this study, we examined the sun protection properties of CNDs. Dunaliella salina was selected as a promising precursor for the synthesis of CNDs which were compared with those produced by citric acid, a widely used precursor for such materials. The CNDs were examined spectrophotometrically, and the sun protection factors were calculated. Additionally, in vitro experiments were carried out to evaluate their UV protection properties and to obtain better insight into whether CNDs are suitable to be used as filters for the development of new sunscreens. The results were conclusive that both CNDs possess favorable properties that potentiate their use for the development of sunscreens. However, the CNDs from Dunaliella salina were found to be superior to those derived from citric acid. Therefore, they can further be exploited as sun protection filters.
Ultraviolet resistant cotton fabrics were developed by coating with ZnO and TiO2 nanoparticles. The ZnO nanoparticles applied on cotton yarns were found to withstand the knitting operation. ...Meanwhile, the TiO 2 nanoparticles applied on the bleached as well as reactive dyed cotton fabrics by the sol-gel and linking agent methods were found to be intact after various cycles of domestic washing. Knitted fabrics containing ZnO nanoparticles showed moderate to high ultraviolet protection factor (UPF) values, whereas 50+ UPF values were measured for the TiO2-coated samples. Further it was found that the rutile phase was better than anatase phase in blocking UV rays. The developed process can be easily adapted to the existing textile machinery, making it industrially viable.
Summary
Harmful effects of ultraviolet rays and protection against them have been long discussed. Numerous synthetic dyes, finishes, UV absorbers, and optical brightening agents are present in the ...market for decades for achieving UV protection through textiles. However, due to environmental impacts of these chemical agents, textile industry is looking for alternatives. In this regard, some natural dyes and plant extracts have shown promising results. However, use of colorless plant extracts as UV protective finishes is still rare. In this study, ultraviolet protection factor (UPF) rating of bleached cotton fabric has been improved by the application of plant extracts with minimal change in fabric's color. For this purpose, two medicinal plants, that is, Solanum nigrum and Amaranthus viridis were selected and bleached cotton fabric was treated with their methanolic and aqueous extracts. Fabrics treated with both extracts exhibited excellent UPF ratings.
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