uv absorbency
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2020 ◽  
Vol 17 (2) ◽  
pp. 603-612
Author(s):  
Rupashinii A/P Thana Singam ◽  
Noraini Bt Marsi ◽  
Azrin Hani Bt Abdul Rashid ◽  
Siti Hana Bt Nasir ◽  
Siti Aida Bt Ibrahim ◽  
...  

This review paper reports the studies available on the characteristics and applications of the henna (Lawsonia inermis) as a natural dye. Textile materials are mainly from synthetic dyes and fibers which are not renewable and not biodegradable. Around 30 million of tonnes was estimated for the global consumption of textiles and was expected to grow up to 3% per annum while 70,000 tonnes of dyes were released to the environment. The population of people who will have allergic to the chemicals will grow up to 60% by year 2020 which was stated in business week. Apart from that, natural dyes can be extracted and process from various sources such as plants, leaves, minerals, roots, barks and insect sections. Plants that was found in the world approximately 20% were for the pharmaceutical or biological test and new antibiotics were introduced in the market are obtain from natural or semi-synthetic resources. For the biological test, henna oil was tested against Staphylococcus aureus which was 870 μg/mL and Neisseria gonorrhoeae was 87 μg/mL respectively while henna leaves extraction using methanol of 95% showed significant in-vitro antihyperglycemic effect. Chemical contains in the henna are carbohydrates as 33.62%, fibers as 33.5%, fatty oils as 10–11% and essential oil as 0.01–0.02%. Moreover, the good UV absorbency for the henna dyed cotton was at 900 °C for 60 minutes and the colour fastness for the fabric which was dyed with henna is 4 which is good. Henna dye has slightly negative charge for the higher pH 9 for the washing fastness. The optimize condition for the pre-mordant is 4% for the copper sulphate (CuSO4) for cotton with the extraction of henna leaves. Furthermore, the optimum condition for the henna to remove lead Pb (II) from wastewater are pH 6, contact time is 80 minutes, 10 ppm for the initial metal concentration and 0.75 g/L for adsorbent dosage.


2016 ◽  
Vol 16 (3) ◽  
pp. 154-159 ◽  
Author(s):  
Mohammad Ghane ◽  
Ehsan Ghorbani

Abstract The destructive effects of sun UV radiation on human skins are now very clear to everyone. Most of the present studies were focused on the fabrics’ structural parameters such as density, warp and weft yarns finenesses, fabric pattern and printing or finishing treatments applied to the fabrics. The aim of this work is achieving a technique through which the produced fabrics possess a higher UV-protection ability. For this purpose, two different metals including aluminium and copper yarns were employed in fabrics production process and their effects on UV-protection ability of the produced fabrics were investigated. Six different fabric samples comprised of either cotton/polyester, nylon yarns as the warp yarns as well as either aluminium or copper yarns as the weft yarns were produced. Using the spectrophotometer technique, which is known as one of the UPF measuring method, the absorbency and reflectivity of fabrics within the specified range of electromagnetic waves (specially the UV radiation) were determined. The results illustrated that the higher UV absorbency was related to the fabric possessing the copper yarns in their structures. It was concluded that the absorption ability of nylon fabrics is higher than that of the cotton/polyester samples.


NANO ◽  
2012 ◽  
Vol 07 (06) ◽  
pp. 1250052 ◽  
Author(s):  
BAO-MIN WANG ◽  
YUAN ZHANG ◽  
ZHI-QIANG GUO ◽  
YU HAN ◽  
HAI-NAN MA

Carbon nanofibers (CNFs) were purified by the method of heat treating, and stable homogeneous suspensions of heat-treated CNFs were prepared by using methylcellulose (MC) as a surfactant. The heat-treated CNFs were characterized by differential thermal analysis (DTA) and thermogravimetry analysis (TGA), and the sonication-driven dispersion of CNFs in aqueous solution was investigated by measuring ultraviolet absorbency (UV absorbency), zeta potential, adsorption isotherm of MC on CNFs and surface tension of CNF suspensions. In these CNF suspensions, the zeta potentials of CNFs progressively increase with increasing MC concentration, and change from -15.4–0 mV. The surface tension of CNF suspensions decrease from 38.87 mN/m to 36.54 mN/m. The adsorption isotherm of MC on CNFs shows an adsorption platform (namely "L" style), and the adsorption isotherm reaches the saturation plateau at MC concentration of about 0.4 g/L. All results show that the optimum concentration ratio of MC to CNFs is 2:1 for dispersion.


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