A sustainable recycling process and its life cycle assessment for valorising post-consumer textile materials for thermal insulation applications.

The textile industry along with construction, electronics and plastic generate huge amounts of waste posing challenges to the adoption of the circular economy. This research presents a sustainable and low-cost recycling technology for conversion of post-consumer textile (denim) wastes to useful insulation materials. To accomplish the objective, nonwoven materials were produced using varying proportions of post-consumer recycled denim (r-denim) fibre and hollow polyester (PET) fibre using different punch densities in the needle punching process. Kowalski, Cornell and Vining mixture design, a special type of design of experiments, was adopted to develop the samples. Developed nonwoven materials were characterised for thermal resistance and tensile properties. The results show that nonwoven materials containing the minimum proportion (20%) of r-denim fibres exhibited the highest thermal resistance (0.131 W-1m2K). However, by adjusting the process parameter of the nonwovens, that is, the punch density, the same thermal resistance (0.131 W-1m2K) is also achieved even with 39% r-denim fibres. Additionally, the nonwovens produced from this blend proportion (r-denim:PET = 39:61) demonstrate a reasonable strength of 2.43 cN/tex. Environmental benefits of the developed r-denim/PET nonwovens have been evaluated by the life cycle assessment approach. Results show that the use of ~40% r-denim fibre has reduced the environmental burden significantly. Therefore, the nonwoven materials produced from post-consumer textile wastes hold tremendous potential as an alternative to synthetic fibres in thermal insulation applications. This recycling approach has immense potential to contribute to the efficient utilisation of post-consumer textile waste materials paving the way for environmental sustainability.

Development of Wash-Durable Antimicrobial Cotton Fabrics by In Situ Green Synthesis of Silver Nanoparticles and Investigation of Their Antimicrobial Efficacy against Drug-Resistant Bacteria.

An environment friendly and wash-durable silver nanoparticle treatment of cotton fabrics was carried out by in situ reduction of silver nitrate using Azadirachta indica leaf extract. The wash durability of the silver nanoparticles treatment on the cotton fabric was improved by pretreating the fabrics by mercerization and by adopting hydrothermal conditions of 120 °C temperature and 15 psi pressure for the in situ synthesis. The silver nanoparticle treated fabrics were characterized using scanning electron microscopy, colorimetric analysis and inductively coupled plasma mass spectroscopy. The coating of silver nanoparticles was seen to be dense and uniform in the scanning electron micrographs of the treated fabrics. An evaluation of the antibacterial efficacy of the silver nanoparticle treated fabric against antibiotic-resistant Gram-positive and Gram-negative strains was carried out. The antibacterial efficacy was found to be the highest against Bacillus licheniformis, showing 93.3% inhibition, whereas it was moderate against Klebsiella pneumoniae (20%) and Escherichia coli (10%). The transmittance data of a UV spectrophotometer (290-400nm) was used for measuring the UV protection factor of the silver nanoparticle treated fabrics. All the silver nanoparticle treated fabrics showed good antimicrobial and UV protection activity. The treatment was also seen to be durable against repeated laundering. This paper contributes the first report on a novel green synthesis approach integrating mercerization of cotton fabrics and in situ synthesis of nanoparticles under hydrothermal conditions using Azadirachta indica leaf extract for improved wash durability of the multifunctional fabric.

Threat, challenges, and preparedness for future pandemics: A descriptive review of phylogenetic analysis based predictions.

For centuries the world has been confronted with many infectious diseases, with a potential to turn into a pandemic posing a constant threat to human lives. Some of these pandemics occurred due to the emergence of new disease or re-emergence of previously known diseases with a few mutations. In such scenarios their optimal prevention and control options were not adequately developed. Most of these diseases are highly contagious and for their timely control, knowledge about the pathogens and disease progression is the basic necessity. In this review, we have presented a documented chronology of the earlier pandemics, evolutionary analysis of the infectious disease with pandemic potential, the role of RNA, difficulties in controlling pandemics, and the likely pathogens that could trigger future pandemics. In this study, the evolutionary history of the pathogens was identified by carrying out phylogenetic analysis. The percentage similarity between different infectious diseases is critically analysed for the identification of their correlation using online sequence matcher tools. The Baltimore classification system was used for finding the genomic nature of the viruses. It was observed that most of the infectious pathogens rise from their animal hosts with some mutations in their genome composition. The phylogenetic tree shows that the single-stranded RNA diseases have a common origin and many of them are having high similarity percentage. The outcomes of this study will help in the identification of potential pathogens that can cause future pandemics. This information will be helpful in the development of early detection techniques, devising preventive mechanism to limit their spread, prophylactic measures, Infection control and therapeutic options, thereby, strengthening our approach towards global preparedness against future pandemics.

Toxic blister agents: Chemistry, mode of their action and effective treatment strategies.

Since their use during the First World War, Blister agents have posed a major threat to the individuals and have caused around two million casualties. Major incidents occurred not only due to their use as chemical warfare agents but also because of occupational hazards. Therefore, a clear understanding of these agents and their mode of action is essential to develop effective decontamination and therapeutic strategies. The blister agents have been categorised on the basis of their chemistry and the biological interactions that entail post contamination. These compounds have been known to majorly cause blisters/bullae along with alkylation of the contaminated DNA. However, due to the high toxicity and restricted use, very little research has been conducted and a lot remains to be clearly understood about these compounds. Various decontamination solutions and detection technologies have been developed, which have proven to be effective for their timely mitigation. But a major hurdle seems to be the lack of proper understanding of the toxicological mechanism of action of these compounds. Current review is about the detailed and updated information on physical, chemical and biological aspects of various blister agents. It also illustrates the mechanism of their action, toxicological effects, detection technologies and possible decontamination strategies.

Tailoring the biodegradability of polylactic acid (PLA) based films and ramie- PLA green composites by using selective additives.

This study explores the effect of plasticisers (lotader AX8900, polyethylene glycol and triethyl citrate) on biodegradability of polylactic acid (PLA) and its composites with halloysite nanotubes and ramie fabric by soil burial method. Changes in surface morphology and mechanical properties were evaluated to quantify the degradation behaviour of all samples. The results showed that the relative loss in tensile strength of ramie-PLA composites was more than that of neat PLA or plasticised PLA films. Also, ramie-PLA composite, where ramie fabric was treated with diammonium orthophosphate, had degraded entirely after 60 days of soil burial. It was also confirmed by Fourier transform infrared spectroscopy that the chemical structures of neat PLA and plasticised PLA films changed after the soil burial test. The use of these additives not only reduces the brittleness of PLA but also accelerates the biodegradation rate of PLA. Thus, PLA, along with additives, can help in reduction of carbon footprint and other environmental issues customarily associated with petro based polymers. Therefore, the finding supports the notion of PLA usage as a viable alternative to fossil fuel-based materials.

Preparation, characterization and evaluation of the zinc titanate and silver nitrate incorporated wipes for topical chemical and biological decontamination.

Chemical and biological warfare agents have detrimental effects on biological systems. These agents are rapidly absorbed through skin and hence warrant immediate decontamination. Zinc titanate (ZnTiO3), is a well-proven moiety used for neutralizing chemical warfare agents (CWA) and silver is widely used as an antibacterial agent. Spacer fabric sheet, due to its ability to hold large amount of agents, was hydrothermally treated with silver nitrate (AgNO3) and incorporated with nano ZnTiO3 to prepare decontamination (deconwipes). Prepared deconwipe was characterized using X-ray diffraction (XRD) and Scanning Electron Microscopy (SEM). Uniform deposition of nano ZnTiO3 and AgNO3 in the wipe was demonstrated by SEM and XRD. In-vivo dermal decontamination efficacy of the prepared deconwipe was evaluated against nerve agent simulant (diethylchlorophosphate; DCP) and sulfur mustard simulant (2­chloroethyl ethyl sulfide; CEES) on rat model using SEM, Flow Cytometry, Comet Acetylcholinesterase (AChE) inhibition assay and Organ Histopathology. In-vitro antibacterial and antifungal efficacy of the prepared deconwipe was evaluated using growth inhibitory efficacy techniques followed by SEM analysis. SEM and histopathology at dermal level revealed the decontamination efficacy of the prepared deconwipe. Nearly 90% decrease in AChE inhibition was observed in decontaminated rat in place of rate model as compared to the DCP contaminated rats. No significant attenuation was observed in DCP and CEES-induced cell cycle distribution and DNA damage analysis in decontaminated group. Furthermore, >95% inhibition of bacterial and fungal growth, proved its antibacterial and antifungal activity respectively. Thus, prepared deconwipes exhibit promising skin decontamination property against Chemical and biological contaminants.

Silver-Doped TiO2 -Coated Cotton Fabric as an Effective Photocatalytic System for Dye Decolorization in UV and Visible Light.

In this study, titanium tetra-isopropoxide was used as a precursor of TiO2 for in situ coating on cotton fabric by sol-gel method. Subsequently, silver nitrate was used as doping agent to prepare silver-doped TiO2 -coated cotton fabric during hydrothermal treatment. The treated samples were characterized through field-emission scanning electron microscopy, energy-dispersive X-ray analysis, inductively coupled plasma-mass spectroscopy and UV-visible absorption spectroscopy to study morphology, composition of deposited elements and light absorption behavior of treated samples. X-ray photoelectron spectroscopy was carried out to analyze the electronic state of silver in TiO2 -coated fabric after hydrothermal treatment. Doping of silver on TiO2 -coated fabric and subsequent hydrothermal treatment was found to enhance dye decolorization rate of rhodamine B dye solution in both UV and visible light radiations with respect to undoped TiO2 . The study shows that an optimal level of silver-doped TiO2 -coated fabric can be used repeatedly for dye decolorization without significant loss in its photocatalytic activity. The self-cleaning properties of samples were also studied using methylene blue as a staining agent. It was observed that the presence of 1.8% silver on the weight of titanium in doped samples provides almost 82% of stain degradation.

Development of Cotton Fabrics with Durable UV Protective and Self-cleaning Property by Deposition of Low TiO2 Levels through Sol-gel Process.

In this article, the deposition of TiO2 on cotton fabric using sol-gel technique has been described. Various process routes (pad-dry-cure, pad-dry-hydrothermal and pad-dry-solvothermal) were examined to impart a stable coating of TiO2 on fabric. The role of precursor concentration, process temperature and time of treatment were studied to aim at a wash durable, UV protective and self-cleaning property in the treated fabric. EDX and ICP-MS techniques were used to examine the add-on percentage of TiO2 on cotton fabrics treated via different routes. It has been found that the TiO2 remains largely amorphous and nondurable if it is given a short thermal treatment. To convert the deposited TiO2 to its anatase crystal form, a prolonged hydrothermal treatment for at least 3 h needs to be given. TiO2 deposition levels of less than 0.1% were found to be effective in imparting reasonable degree of UV protection and self-cleaning property to the cotton fabric. The self-cleaning ability of the treated fabric against coffee stain was also studied and was found to be related to the process route and the deposition levels of TiO2 .

Development and performance optimization of knitted antibacterial materials using polyester-silver nanocomposite fibres.

The development and performance optimization of knitted antibacterial materials made from polyester-silver nanocomposite fibres have been attempted in this research. Inherently antibacterial polyester-silver nanocomposite fibres were blended with normal polyester fibres in different weight proportions to prepare yarns. Three parameters, namely blend percentage (wt.%) of nanocomposite fibres, yarn count and knitting machine gauge were varied for producing a large number of knitted samples. The knitted materials were tested for antibacterial activity against Gram-positive bacteria Staphylococcus aureus. Statistical analysis revealed that all the three parameters were significant and the blend percentage of nanocomposite fibre was the most dominant factor influencing the antibacterial activity of knitted materials. The antibacterial activity of the developed materials was found to be extremely durable as there was only about 1% loss even after 25 washes. Linear programming approach was used to optimize the parameters, namely antibacterial activity, air permeability and areal density of knitted materials considering cost minimization as the objective. The properties of validation samples were found to be very close to the targeted values.