Pintu Pandit

Low-temperature dyeing of silk fabric using atmospheric pressure helium/nitrogen plasma

Silk fabric was plasma treated in an indigenously developed atmospheric pressure plasma reactor in the presence of helium and nitrogen (He/N2) gaseous mixture at a discharge voltage of 5 kV and frequency of 21–23 kHz. The samples were plasma treated for 1 to 10 min with a constant nitrogen flow of 50 ml/min. They were also plasma treated in varying nitrogen flow rates in the range of 33.3 to 225 ml/min, keeping a constant helium (He) flow rate at 450 ml/min. The effects of plasma treatment time and nitrogen (N2) gas flow rates on water wicking, physical and chemical properties of the fabric surface along with rate of dyeing were investigated in details. The formation of amine groups in the plasma treated samples helps in faster exhaustion of acid dye even at a lower temperature. It was possible to dye the plasma treated silk fabric at 40 ºC temperature instead of 90 ºC, as is used conventionally. Due to higher dye exhaustion, the plasma treated sample showed a deeper shade. The physical and chemical properties of the samples were analyzed using SEM, ATR-FTIR, secondary ion mass spectrometer (SIMS), and XRD. Results indicate that water took only 408 s and 309 s to travel up to a height of 6 cm in the plasma treated samples for 4 min and 10 min, respectively. This was much shorter as compared to 696 s observed in the untreated (control) sample. The effects of plasma treatment time and the amount of nitrogen (N2) gas flow had a similar effect on water wicking. The plasma treatment time and N2 gas flow rates showed only marginal effects on mechanical properties of silk.

Coconut shell extract imparting multifunction properties to ligno-cellulosic material

Flame retardant textiles are increasingly in demand. There have been a number of approaches by which textile material is made flame retardant. The plant extracts imparting such properties to lingo-cellulosic material has been studied in this work. The paper reports the application of green coconut (Cocosnucifera Linn) shell extract which is a natural waste source onto jute fabric. The acidic coconut shell extract was applied in neutral and alkaline conditions on jute fabric in different concentrations. The emerging fabric showed good flame retardant properties which were measured by different standard flammability tests. The limiting oxygen index value found to increase by 48% after application of alkaline coconut shell extract as such and on concentrating the coconut shell extract, it was found to increase 81%. The thermo gravimetric behaviour and degradation mechanism were studied by using thermo gravimetric analysis in nitrogen atmosphere. The presence of different elements, chemical groups and the structural topography of the untreated and coconut shell extract-treated lingo-cellulosic fabric were analysed by attenuated total reflection-Fourier transform infrared, Scanning electron microscopy, energy dispersive X-ray analysis and phytochemical analysis tests. In addition to the flame retardant property, the treated fabric showed natural colour (measured by colour strength value) and antibacterial property against both gram positive and gram negative bacteria.

Development of thermally stable and hygienic colored cotton fabric made by treatment with natural coconut shell extract

As far as the value addition of textile is concerned, flame retardancy of textile materials is considered to be one of the most important properties in textile finishing by both industries as well as academic researchers. Flame-retardant property with thermal stability was imparted to cotton by using green coconut (Cocos nucifera Linn) shell extract, a natural waste source of coconut. Coconut shell extract was analyzed by high-performance liquid chromatography, Fourier transform infrared spectroscopy, energy-dispersive spectrometry and its phytochemical analysis was also carried out. The coconut shell extract (acidic after extraction) was applied in three different pH (acidic, neutral, and alkaline) conditions to the cotton fabric. Flame-retardant properties of the untreated and the treated cotton fabrics were analyzed by limiting oxygen index and vertical flammability. The study showed that all the treated fabrics had good flame resistance property compared to that of the untreated fabric. The limiting oxygen index value was found to increase by 72.2% after application of the coconut shell extract from alkaline pH. Pyrolysis and char formation behavior of the concerned fabrics were studied using thermogravimetric analysis and differential scanning calorimetric analysis in a nitrogen atmosphere. The physicochemical composition of the untreated and coconut shell extract treated cotton fabrics were analyzed by attenuated total reflection–Fourier transform infrared, scanning electron microscope, and energy-dispersive X-ray spectroscopy. Also, treated cotton fabric showed natural brown color and antibacterial property against both Gram-positive and Gram-negative bacteria. The durability of the flame-retardant functionality to washing with soap solution has also been studied and reported in this paper.

Multifunctionalised silk using Delonix regia stem shell waste

The use of natural dyes and natural finishes on textiles has become a matter of significant importance because of the increased environmental awareness to avoid some hazardous synthetic dyes and synthetic chemicals. The Delonix regia stem shells were extracted in distilled water methanol and ethanol solvents. Phytochemical analysis was carried out for the presence of bioactive chemical constituents such as saponin, terpenoid, flavonoid, glycoside, phenol and tannin using the standard procedure. All the tests showed positive for the presence of components except saponin in methanol and ethanol extract. The qualitative antibacterial analysis was done by AATCC 147 method with excerpts from three different solvents both against S. aureus (gram-positive) and E. coli (gram-negative) bacteria. Delonix regia stem shell extract (DSE) in distil water was used for natural dyeing of mulberry silk fabric. Pre-mordanting and post-mordanting of silk fabric were carried out using alum and myrobalan mordants. Treated fabrics showed a substantial increase in colour depth (K/S) and adequate wash, light and rubbing fastness properties without and with mordanted and dyed silk fabrics. Quantitative antibacterial analysis by AATCC 100 method was done on dyed silk fabric which showed very good resistance both against bacteria S. aureus and E. coli bacteria. Dyed silk fabric also showed good to very good ultraviolet (UV) protection property. The physicochemical composition of the untreated and without mordant treated silk fabrics were analysed by attenuated total reflection (ATR) Fourier transforms infrared (FTIR) spectroscopy, scanning electron microscope (SEM), energy dispersive spectrometry (EDS) and atomic absorption spectrophotometer (AAS). In addition to that wash, durability was also measured of dyed silk fabric for antibacterial and ultraviolet protection (UPF) properties according to AATCC 61 2A washing method.

A Novel Natural Source Sterculia foetida Fruit Shell Waste as Colorant and Ultraviolet Protection for Linen

ABSTRACT There has been a growing interest in natural dyes and consciousness about ill effects of ultraviolet rays on the human skin. This paper discusses dye extraction from the fruit shell waste of Sterculia foetida and its application on linen fabric for dyeing as well as ultraviolet protection (UPF) property. Optimal results were achieved for dyeing at 90°C for 60 min at 30% concentration of the dye on the weight of fabric using pre- and post-mordant dyeing techniques. Dyeing on linen fabric with and without mordant showed very good results in terms of different hues of color and UPF. Treated fabrics showed substantial increase in color depth and good to very good wash, light and rubbing fastness properties for both with and without mordant-dyed linen fabrics. The results confirmed that natural dye from Sterculia foetida fruit shell extract has potential applications for linen dyeing and producing a good to very good UPF.

Application of Sterculia Foetida Fruit Shell Waste Biomolecules on Silk for Aesthetic and Wellness Properties

There has been growing interest in the use of bioresource waste for natural dyeing and finishing. This paper discusses dye extraction from the novel source fruit shell waste of Sterculia foetida and its application on mulberry silk fabric to confer aesthetic coloration and wellness properties such as ultra-violet (UV) protection and antibacterial properties. Treated fabrics showed a substantial increase in color depth and adequate wash, light, and rubbing fastness properties for dyed silk fabrics with and without mordanting. Pre-and post-mordanting of silk fabrics were carried out using mordants such as alum, harda (myrobalan), and copper sulfate. UV-visible spectrophotometric analysis of fruit shell extract (FSE) at different pHs and FSE with three different mordants at neutral pH was used to understand the phenomena of dye-fiber interaction. The treated fabrics characterised by ATR-FTIR, SEM-EDS, and XRD analysis indicate the nature of dye fiber interaction justifying the multifunctional properties. The treated fabric also showed very good ultraviolet protection property and antibacterial properties both against S. aureus and E. coli bacteria even after ten washes. The results indicate that Sterculia foetida fruit shell extract offers an excellent potential as coloration, antibacterial, and ultraviolet protective agent for mulberry silk fabric.

Physical properties characterization of Natural Protein Fibre Peacock Feather Barbs

In the present study, the barbs of peacock feather were subjected to its physio-mechanical characterisation. Various properties of barbs viz., bundle strength, diameter, moisture regain, thermal stability, X-ray diffraction, colour intensity and FTIR was studied according standard analytical methods. The surface morphology of the barbs was examined using SEM images. The results indicate that the barb is a hollow vertical structure made up of protein. The average length and diameter of the barb was found to be 45 mm and 82 μm respectively. The FTIR study confirms the presence of characteristic peaks for protein, related to the keratinous material. The barbs seem to be semi-crystalline in nature, as indicated by X-ray study.