Nemeshwaree Behary

Adsorption of surfactin produced from Bacillus subtilis using nonwoven PET (polyethylene terephthalate) fibrous membranes functionalized with chitosan.

This article deals with an alternative method for bio-separation of surfactin produced by Bacillus subtilis using sorption method on nonwoven PET (polyethylene terephthalate) fibrous membranes functionalized with chitosan. In the first part of the study, surface functionalization of the PET nonwoven fibrous membranes is carried out with aqueous 65% deacetylated chitosan solution with or without a prior surface activation using air-atmospheric plasma treatment. Very small modification of the PET fibrous nonwoven air-permeability confirms the functionalization of PET fibre surface with little reduction of membrane porosity. The functionalized membranes are then characterized by physico-chemical methods: X-ray Photoelectron Spectroscopy (XPS), Wettability and zeta potential. Chitosan increases drastically the zeta potential of PET at all pH values though a prior plasma treatment of the PET membrane reduces slightly the increase in zeta potential values. Sorption of surfactin quantified by HPLC shows that the extent of surfactin sorption on PET nonwovens depends on the surface functionalization method. Surface functionalization with chitosan results in immediate sorption of the entire quantity of surfactin. A prior surface activation by air atmospheric plasma treatment of the PET membranes before chitosan application retards the sorption of entire surfactin which takes place after 1.5h, only. Increased zeta potential and increased hydrophobic behavior in the presence of chitosan without plasma activation would explain the interesting surfactin sorption results.

Bioactivation of PET woven fabrics using alginate biopolymer and the bacteriocin nisin

Bioactive antibacterial PET (polyethylene terephthalate) woven fabrics were produced by fixing a thin alginate coating with entrapped nisin at the PET fiber surface. These textiles may find applications in the field of hygiene or food packaging. In the first part of the study, thin solid alginate films (without nisin) capable of forming hydrogels in aqueous medium were deposited at the PET fiber surface and the properties of the resulting textiles characterized. Methods using padding with CaCl2 solution before or after sodium alginate deposition, with or without a prior PET fiber surface activation with air atmospheric plasma, were used. The following properties of the functionalized PET textile were tested: the durability and cohesion of the alginate film to the fiber surface, in water and in dry conditions under friction; the surface properties of the functionalized textile; and the water and moisture absorption capacity of the alginate films. These properties depend on the film adhesion to PET fibers and on the degree of alginate crosslinking. Entrapped bioactive nisin in the alginate film imparted antibacterial properties to the woven polyester fabric against Staphylococcus aureus. However, differences in inhibition zone were due to the method of alginate film formation, which had an impact on the rate of release of nisin.

Statistical analysis of use-phase energy consumption of textile products

PurposeThe purpose of this work was to present a methodology to assess the energy consumption, specifically the energy utilized in the washing and drying processes, of textile products in their use-phase with the help of statistical tools. Regardless of the environmental impacts associated with the use-phase of textile products, analysis of energy consumption in that phase is still lacking. There is a need to design methodology for identifying the hotspots and parameters influencing the energy consumption in the use-phase of textile products. A pragmatic method that consists of a life-cycle assessment (LCA) framework plus principle component analysis (PCA), extended by Procrustes analysis (PA), is used to determine the energy consumption and minimize the possible uncertainties in the use-phase of textile product systems.MethodsThe LCA plus PCA-PA method employed in this work to analyze the energy consumption of textile products in the use-phase comprises two statistical tools. First, PCA was applied to find the key parameters affecting the results. As an extension of PCA, PA was performed to highlight the most prominent variables within the dataset and extract the maximum amount of information. Lastly, hierarchical cluster analysis (HCA) was utilized for the classification of textile products on the basis of energy consumption variables and the similarity of their results.Results and discussionAmong various energy consuming parameters in the use-phase of a textile product, both geographical and physical aspects can be prominent variables that significantly can affect the results of the energy consumption. After the LCA plus PCA-PA methodology, country of the use-phase in the geographical aspect and in the physical aspect, the fiber type and weight of the products were the influential variables. Hotspots or influential parameters being identified, a number of steps can be taken that can play an important role in decreasing environmental impacts by reducing the energy consumption in the laundering process of textile products during the use-phase.ConclusionsThe methodology of LCA plus PCA-PA for energy consumption in textile products was employed to study the gap in currently available assessments. Using this method, the main influencing energy consuming parameters or hotspots in the use-phase of a textile product system could easily be identified and potential improvements of sustainability can be proposed.

PROCESS OPTIMIZATION OF ECO-FRIENDLY FLAME RETARDANT FINISH FOR COTTON FABRIC: A RESPONSE SURFACE METHODOLOGY APPROACH

The n-methylol dimethyl phosphono propionamide (MDPA) flame retardant compounds are predominantly used for cotton fabric treatments with trimethylol melamine (TMM) to obtain better crosslinking and enhanced flame retardant properties. Nevertheless, such treatments are associated with a toxic issue of cancer-causing formaldehyde release. An eco-friendly finishing was used to get formaldehyde-free fixation of flame retardant to the cotton fabric. Citric acid as a crosslinking agent along with the sodium hypophosphite as a catalyst in the treatment was utilized. The process parameters of the treatment were enhanced for optimized flame retardant properties, in addition, low mechanical loss to the fabric by response surface methodology using Box–Behnken statistical design experiment methodology was achieved. The effects of concentrations on the fabric’s properties (flame retardancy and mechanical properties) were evaluated. The regression equations for the prediction of concentrations and mechanical properties of the fabric were also obtained for the eco-friendly treatment. The R-squared values of all the responses were above 0.95 for the reagents used, indicating the degree of relationship between the predicted values by the Box–Behnken design and the actual experimental results. It was also found that the concentration parameters (crosslinking reagents and catalysts) in the treatment formulation have a prime role in the overall performance of flame retardant cotton fabrics.

Immobilizing hydroxyapatite microparticles on poly(lactic acid) nonwoven scaffolds using layer-by-layer deposition

A composite porous scaffold for bone cell culture was fabricated by immobilizing HA (hydroxyapatite) (Ca10 (PO4)6 (OH)2) microparticles on PLA (poly(lactic acid)) nonwoven fibers using the layer-by-layer deposition technique. A nonwoven PLA of thickness 1 mm, with average pore size of 230 µm and a porosity of 94%, was used. The nonwoven was functionalized with aqueous 65% deacetylated chitosan followed by rinsing, and then a second padding with aqueous sodium alginate loaded with varying percentages of HA microparticles (0.01%, 0.1% and 0.2%), resulting in a composite porous nonwoven. Sodium alginate was revealed to be an efficient polymer for obtaining a stable dispersion of the HA microparticles in an aqueous medium. Atomic force microscopy and scanning electron microscopy images, zeta potential and wettability tests showed successfully the different surface modifications occurring at each step of surface functionalization. The chitosan coating cationized the PLA fiber surface, providing good adhesion of the HA-loaded anionic alginate coating. HA was almost homogeneously distributed at the PLA fiber surfaces with only a small reduction in the scaffold porosity, which reached 75%. The composite PLA/chitosan/alginate/HA nonwoven structures were tested as scaffold for adhesion and proliferation of rat pre-osteoblast MC3T3-E1 cells. The results showed that higher loading with HA improved the MC3T3 cell adhesion and proliferation after 3 and 6 days of culture.

Bioactive and multifunctional textile using plant-based madder dye: Characterization of UV protection ability and antibacterial activity

In the present work the natural madder dye (Rubia tinctorum L.) was applied to the simultaneous dyeing and functionalization of polyester (PET) fabric. In the first part of the study the color performance and the durability were revealed for exhaustion dyed fabric. The dyed fabric was then characterized with respect to ultraviolet (UV) protection ability and antibacterial activity against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli). CIELab color coordinates, namely the positive a* and b* values, confirmed a yellow/orange color of the dyed fabric. From durability tests, the color showed a moderate to good light fastness and good to excellent fastness to washing and rubbing. The madder dye improved both the UV protective performance and the antibacterial activity of the fabric. With 3 % on weight of fiber (owf) the UV protection factor increased up to 106, and the antibacterial activity up to 86 % against both types of bacteria tested.

Degradation Kinetics of Organophosphorus Flame Retardant from Cotton Fabric

The organophosphorus compound N-methylol dimethyl phosphonopropionamide (MDPA) is extensively used for durable flame retardant (FR) treatments for cotton fabrics. For optimum finishing treatment, MDPA is used with the Trimethylol melamine (TMM) or dimethylol dihydroxyethylene urea (DMDHEU) for cotton fabric treatments. The amino resins TMM known to pose severe toxic problems such as; breathing problems, headache and most importantly, cancer. In the production, consumption and eventually in the disposal phase of FR with TMM treated cotton fabrics, the release of TMM and toxic emissions cannot be ignored. In this study, mineralization and degradation of the organophosphorus FR compound from the cotton fabric using Advanced Oxidation Process (AOP) was successfully employed. The kinetics of degradation of FR substance from the cotton fabric was studied. The rate of degradation of the FR substance from the cotton fabrics was observed with chemical oxygen demand (COD). The kinetic rate constant equations and characterization of the mineralization and degradation of the FR substance by the AOP reaction was developed with the COD values. The organophosphorus FR on the fabric found to follow the first-order of kinetics of degradation from the cotton fabric.

Atomic Force Microscopy – For Investigating Surface Treatment of Textile Fibers

Textile fibers either natural or man-made (biodegradable and/or non biodegradable) are being increasingly used in non-traditional sectors such as technical textiles (automotive applications), medical textiles (e.g., implants, hygiene materials), geotextiles (reinforcement of embankments), agrotextiles (textiles for crop protection), and protective clothing (e.g., heat and radiation protection for fire fighter, bulletproof vests, and spacesuits).Textile structures (roving, knitted, woven or non woven) are also being increasingly used in textile reinforced composites.