M. D. Teli

Acetylation of banana fibre to improve oil absorbency

Oil spill leaves detrimental effects on the environment, living organisms and economy. In the present work, an attempt is made to provide an efficient, easily deployable method of cleaning up oil spills and recovering of the oil. The work reports the use of banana fibres which were acetylated for oil spill recovery. The product so formed was characterized by FT-IR, TG, SEM and its degree of acetylation was also evaluated. The extent of acetylation was measured by weight percent gain. The oil sorption capacity of the acetylated fibre was higher than that of the commercial synthetic oil sorbents such as polypropylene fibres as well as un-modified fibre. Therefore, these oil sorption-active materials which are also biodegradable can be used to substitute non-biodegradable synthetic materials in oil spill cleanup.

Acetylation of Jute fiber to improve oil absorbency

Raw Jute was modified by acetylation process with acetic anhydride using N-bromosuccinimide (NBS) as a catalyst in a solvent free system which was found to be effective catalyst. The reaction parameters were optimized which were found to be time 1 h, temperature 120 °C, catalyst concentration 2 %, and solid to liquid ratio 1:20. The product so formed was characterized by FT-IR and TG and its degree of acetylation was also evaluated. The extent of acetylation was measured by weight percent gain (WPG). Acetylation resulted in significant increase in hydrophobic properties of the jute fiber. The oil sorption capacity of the acetylated jute was higher than that of the commercial synthetic oil sorbents such as polypropylene fibers as well as raw jute. Therefore, these oil sorption-active materials which are also biodegradable can be used to substitute non-biodegradable synthetic materials in oil spill cleanup.

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.

Superhydrophobic and ultraviolet protective nylon fabrics by modified nano silica coating

Superhydrophobic and UV protective textiles are of growing interest from the last few decades. In this study, silica nanoparticles (SiO2) were synthesized by the sol-gel method. The synthesized silica nanoparticles were applied on nylon knitted fabric by pad-dry-cure technique. The silica nanoparticles coating on fabric was modified by in situ deposition of zinc oxide (ZnO) followed by hydrophobic modification using sodium stearate (SS). The fabrics were characterized by Fourier transform infrared spectroscopy, X ray diffractometry, and scanning electron microscopy. The hydrophobic properties of the fabric were assessed by water contact angle measurement and ultraviolet protection properties of fabric were assessed by Australian/New Zealand Standard (AS/NZS 4399:1996). Modified fabric showed superhydrophobicity with water contact angle of 151°. The fabric also showed excellent ultraviolet protection with ultraviolet protection factor of 279.68. The fabric exhibited retention of hydrophobic and UV protection properties up to 10 washing cycles.

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.

Application of functionalized coir fibre as eco-friendly oil sorbent

Abstract Synthetic polymers are based on the use of crude oil as their raw material. Oil spillage takes place during production, storage, transportation and usage at the water bodies and land surfaces. This may be due to tanker disasters, wars, operation failures, equipment breaking down, accidents and natural disasters. The spilled oil into land, river or ocean imposes a major threat to the environment and endangers the aquatic life. To overcome this problem, oil sorbents are commonly used for cleaning the oil spills. In this paper, coir fibre which was obtained as a waste from coconut fruit was functionalized to increase its hydrophobicity and oil sorption capacity. The product so formed was characterized by FT-IR, TGA and SEM which confirmed grafting of butyl acrylate monomer onto the coir fibres. The effects of time, temperature and monomer concentration on the grafting of coir fibre and oil absorption capacity have also been investigated. Results demonstrated that the modified coir fibre absorbed fair amount of crude oil and studies also indicate that a simple squeezing was sufficient to remove most of the oil sorbed by the fibres so that the sorbents can be reused several times for oil spill clean-up.

Dyeing of cotton fabric for improved mosquito repellency

Abstract Recently, mosquito repellent textile materials are increasingly in demand from consumers as a preventive measure from mosquito-borne diseases like malaria, dengue. Mosquito repellent-treated textile material initially shows good repellency against mosquitoes but upon repeated washing cycles this effect gets washed off considerably. In the present work, 4-Amino-N, N-diethyl–3-methyl benzamide (MD) is synthesized from N, N-diethyl-m-toluamide (DEET) and it is used as base material for synthesis of azo group. This synthesized base MD was then coupled with three different napthols to get dyed cotton fabric using diazotization process. This dyed cotton fabric has imparted mosquito repellent finish in one, single operation of dyeing cum finishing. This approach is based on modification of universally used mosquito repellent and synthesizing an azo group-based dye in the fibre matrix of the cotton fabric. The chemical structures of the MD were characterized using FT-IR and 1H-NMR spectroscopy. The fastness properties of the dyed cum finished fabric were measured to evaluate the performance of the dyed fabric. Efficacy of mosquito repellency of the dyed cotton fabric was studied using standard methods. The dyed cotton fabric using napthols and MD showed very good and durable mosquito-repellent activity.