http://hdl.handle.net/11189/1933 Tue, 13 Oct 2026 02:05:45 GMT 2026-10-13T02:05:45Z http://hdl.handle.net/11189/10897 Title: Detection of heavy metals and formaldehyde in fabric rolls usedA for manufacturing adult clothing Authors: MADUNA, LEBO; Nyamukamba, Pardon; Patnaik, Asis Abstract: Textile fabrics are treated with toxic heavy metals (e.g., lead, nickel, chromium, etc.) and chemicals like formaldehyde to impart certain desired fabric properties. If not removed from fabrics after application, they have been reported to cause diseases and discomfort. Because of these, it is important that the concentrations of heavy metals, formaldehyde, and pH levels in fabrics must meet the recommended limits. This study focuses on the determination and detection of metals and chemicals found in fabric rolls used to make clothing in South Africa. Heavy metal results showed that all fabrics contained heavy metals, except for brown polycotton fabric. The heavy metals concentrations in dark-blue polycotton fabric were higher than prescribed Oeko-Tex limits except for copper metal. White cotton, black polyester, and navy-blue wool fabrics exceeded the recommended limit for nickel. Chromium was found only in dark-blue polycotton and navy-blue wool fabric and its concentration exceeded the recommended limit only in dark-blue polycotton fabric whereas for navy-blue wool fabric it was below the limit. All fabrics contained formaldehyde, and its concentration was below the recommended limit. The pH of white cotton and black polyester fabrics was within the recommended range of 4 - 7.5 while that of dark-blue polycotton, brown polycotton, and dark-blue wool fabrics was above the limit. Wed, 01 Jan 2025 00:00:00 GMT http://hdl.handle.net/11189/10897 2025-01-01T00:00:00Z http://hdl.handle.net/11189/10896 Title: Advanced high performance, intelligent and eco-friendly geotextiles Authors: Tshifularo, Cyrus; Patnaik, Asis Abstract: Geotextiles are used for various traditional civil engineering applications, including reinforcement, filtration, separation, drainage, and sealing. With advancements in sensor technology, advanced geotextiles are developed using fibre optic sensors, thereby acting as smart materials that respond to changes in external conditions. Fibre optic-based sensors can monitor changes in temperature, pore pressure, humidity, and physical and chemical changes on the geotechnical structure, and repairs can be done earlier, which results in cost savings as well as saving lives. Intelligent geotextiles can be utilized simultaneously as sensors and reinforcement applications but the advantages of these sensors have to be set against the fact that they are expensive, and are not always reliable in that results can be influenced by moisture or electromagnetic interference. Natural fibre-based geotextiles are environmentally-friendly materials, but their performance can be further improved by various chemical modifications. One of the issues with such chemical treatments is their adverse environmental impact. This issue of Textile Progress discusses high-performance geotextiles, intelligent geotextiles, and natural fibre-based geotextiles and their modifications. Some of the important functional properties of geotextiles are discussed along with their applications in soil conservation, reinforcement, filtration, separation, and drainage. The environmental impacts of geotextiles and of micro- and nano-plastics from the geotextiles are also discussed. Wed, 01 Jan 2025 00:00:00 GMT http://hdl.handle.net/11189/10896 2025-01-01T00:00:00Z http://hdl.handle.net/11189/10895 Title: Abiotic degradation of polymeric personal protective equipment by artificial weathering Authors: Muniyasamy, Sudhakar; Patnaik, Asis Abstract: Personal protective equipment (PPE) like single-use face masks is discarded after a single use and poses a significant danger to the environment, resulting in plastic pollution. Most of the face masks are made from synthetic polymers and are non-biodegradable to the environment; hence, concerns are being raised about polymers’ environmental impact. Most of the previous studies so far focus on polypropylene (PP) disposable masks and limited data related to environmental abiotic degradation behavior. There is a lack of studies aiming to understand the degradation behavior of different masks and the influence of physical-chemical factors. In this paper, we report on the environmental abiotic degradation of cloth, surgical and respirator filter facepiece 1 (FFP1) masks by accelerated artificial weathering. Furthermore, physical-chemical properties of masks were characterized by Fourier Transform Infrared Spectroscopy (FTIR), Differential Scanning Calorimetry (DSC) and Thermo Gravimetric Analysis (TGA). The cloth and FFP1 masks are made from polyethylene terephthalate (PET) and surgical masks were made from polypropylene (PP). Masks were exposed to an accelerated weathering test, which simulates the effects of natural sunlight and reproduces the damage caused by weathering elements such as sunlight, rain and dew. Masks were exposed to Ultraviolet radiation (UV) for 120, 240 and 360 h followed by condensation at 50 °C for 4 h. The FTIR results show that PET cloth and FFP1 PET masks are not degrading with the 360 h maximum exposure duration, which is equivalent to ±180 days. The FTIR scan of the PP surgical mask after 120 h of exposure time shows that it was degraded and broken down into fragments. For the PET cloth mask, a 58% reduction in crystallinity and heat of enthalpy was observed after 120 h of exposure. UV exposure causes a chain scission reaction, breaking down the ester bond in the case of the PET cloth mask. In the case of the PET FFP1 mask exposed to UV for 120, 240 and 360 h, a drastic reduction in crystallinity was observed as compared to the neat (original) PET FFP1 mask. Neat PET cloth and FFP1 masks have higher onset and maximum degradation temperatures as compared to the 120, 240 and 360 h UV exposed masks. Neat PET cloth and FFP1 masks have better resistance to thermal degradation. Wed, 01 Jan 2025 00:00:00 GMT http://hdl.handle.net/11189/10895 2025-01-01T00:00:00Z http://hdl.handle.net/11189/10894 Title: Environmental degradation of footbed materials under different conditions Authors: Patnaik, Asis; Muniyasamy, Sudhakar; Goyal, Ashvani Abstract: Abstract Different types of polymeric materials are used as footbeds in shoes. Environmental degradation behavior of polymeric footbed materials is an important parameter for understanding materials’ environmental footprint. Most of the previous studies focus on geotextiles, polymeric insulation materials, and exposure behaviors that are not the same due to the nature of applications of geotextiles and insulations being completely different from the footbeds. There is a lack of studies to understand artificial weathering, the influence of physical–chemical factors, and the subsequent behavior of different types of footbeds. In this paper, we have selected three needle-punched nonwoven footbed materials and studied their environmental degradation behavior by subjecting them to artificial weathering using different exposure durations, viz. 120 h, 240 h, and 360 h. The physical–chemical properties of polymeric footbed materials were characterized by Fourier-Transform Infrared Spectroscopy (FTIR), Differential Scanning Calorimetry (DSC), and thermogravimetric analysis (TGA). The selected polymeric footbed materials were made from recycled polyester (RPET), hemp, and shoddy fibers. Furthermore, the RPET footbed was tested for biodegradation in soil and compost conditions for 120 days. The footbed materials were also tested for physical and performance (tensile and abrasion resistance) properties. Hemp footbed materials undergo abiotic degradation after 120 h, but in the case of RPET, it undergoes abiotic degradation after 360 h, resulting in a fragmentation process due to synergistic effects of chemical and hydrolytic degradations. From the DSC results, RPET undergoes a slight thermal transition under abiotic degradation after 360 h, indicating that environmental abiotic factors influence degradation behavior. The tensile and abrasion resistance properties of RPET were the highest, followed by hemp and shoddy materials. The tensile strength range of the materials was between 50.74 and 851.44 N. The weight loss range after abrasion resistance was 0.016–0.014%. From the RPET biodegradation test in soil and compost conditions, the evolved CO2 was 20% and 59%, respectively, after 110 days. The DSC and TGA results indicate that the hemp footbed materials have a higher rate of abiotic degradation as compared to the RPET and shoddy footbed materials. From the RPET biodegradation test in soil and compost conditions, the CO2 degradation values were 20% and 59%, respectively. The obtained degradation results indicate that the synergistic effect of abiotic and biotic conditions greatly influences footbed materials’ biodegradation under natural environmental conditions. Wed, 01 Jan 2025 00:00:00 GMT http://hdl.handle.net/11189/10894 2025-01-01T00:00:00Z