ABSTRACT
Renewed demand for incorporation of natural dyes (bio-colorants) in textile industry could be met through biotechnological production of bacterial pigments. Two new Streptomyces strains (NP2 and NP4) were isolated for the remarkable ability to produce diffusible deep blue and deep red pigment into fermentation medium. Crude mycelial extracts of both strains were used as bio-colorants in conventional textile dyeing procedures avoiding downstream purification procedures. The yields of bio-colorants obtained in this way were 62 and 84 mg per g of mycelia for Streptomyces sp. NP2 and Streptomyces sp. NP4, respectively. Through nuclear magnetic resonance analysis of crude extracts before and after dyeing procedures, it was shown that both extracts contained prodigiosin-like family of compounds that exhibited different dyeing capabilities towards different textile fibers. Polyamide and acrylic fibers were colored to the deepest shade, polyester and triacetate fibers to a noticeable, but much lower shade depth, while cotton and cellulosic fibers stained weakly. These results confirmed that crude bacterial extracts had the characteristics similar to those of ionic and disperse dyes, which was consistent with the identified polypyrrolic prodigiosin-like structures.
Subject(s)
Pigments, Biological/biosynthesis , Streptomyces/chemistry , Streptomyces/isolation & purification , Textile Industry , Coloring Agents/chemistry , Coloring Agents/metabolism , Magnetic Resonance Imaging , Phylogeny , Pigments, Biological/chemistry , Prodigiosin/biosynthesis , Prodigiosin/chemistry , Streptomyces/classificationABSTRACT
This study focuses on a microgel-based functionalization method applicable to polyester textiles for improving their hydrophilicity and/or moisture-management properties, eventually enhancing wear comfort. The method proposed aims at achieving pH-/temperature-controlled wettability of polyester within a physiological pH/temperature range. First, primary amine groups are created on polyester surfaces using ethylenediamine; second, biopolymer-based polyelectrolyte microgels are incorporated using the natural cross-linker genipin. The microgels consist of the pH-responsive natural polysaccharide chitosan and pH/thermoresponsive poly(N-isopropylacrylamide-co-acrylic acid) microparticles. Scanning electron microscopy confirmed the microgel presence on polyester surfaces. X-ray photoelectron spectroscopy revealed nitrogen concentration, supporting increased microscopy results. Electrokinetic analysis showed that functionalized polyester surfaces have a zero-charge point at pH 6.5, close to the microgel isoelectric point. Dynamic wetting measurements revealed that functionalized polyester has shorter total water absorption time than the reference. This absorption time is also pH dependent, based on dynamic contact angle and micro-roughness measurements, which indicated microgel swelling at different pH values. Furthermore, at 40 °C functionalized polyester has higher vapor transmission rates than the reference, even at high relative humidity. This was attributed to the microgel thermoresponsiveness, which was confirmed through the almost 50% decrease in microparticle size between 20 and 40 °C, as determined by dynamic light scattering measurements.
Subject(s)
Acrylamides/chemistry , Chitosan/chemistry , Gels/chemistry , Polyesters/chemistry , Polymers/chemistry , Absorption , Amination , Hydrogen-Ion Concentration , Iridoid Glycosides/chemistry , Iridoids , Light , Microscopy, Electron, Scanning , Microspheres , Polyethylene Glycols/chemistry , Polyethylene Terephthalates , Scattering, Radiation , Temperature , Textiles , WettabilityABSTRACT
The aim of this study was to highlight the potential use of recycled wool-based nonwoven material for the removal of diesel fuel, crude, base, vegetable and motor oil from water. Sorption capacity of the material in water and in oil without water, oil retention, sorbent reusability and buoyancy in static and dynamic conditions were investigated. The results show high sorption capacity of recycled wool for different kinds of oil. This sorbent also exhibited excellent buoyancy after 24h of sorption as well as a good reusability since the decrease in sorption capacity did not exceed 50% of the initial value after five sorption cycles in oil without water.
Subject(s)
Conservation of Natural Resources , Petroleum , Plant Oils/chemistry , Water Pollutants, Chemical/chemistry , Water Purification/methods , Wool/chemistry , Adsorption , Animals , Microscopy, Electron, Scanning , Polyesters/chemistry , Wool/ultrastructureABSTRACT
The aim of this study was to highlight the possibility of using recycled wool-based nonwoven material as a sorbent in an oil spill cleanup. This material sorbed higher amounts of base oil SN 150 than diesel or crude oil from the surface of a demineralized or artificial seawater bath. Superficial modification of material with the biopolymer chitosan and low-temperature air plasma led to a slight decrease of sorption capacity. Loose fibers of the same origin as nonwoven material have significantly higher sorption capacities than investigated nonwoven material. White light scanning interferometry analysis of the fibers suggested that roughness of the wool fiber surface has an important role in oil sorption. The laboratory experiments demonstrated that this material is reusable. Recycled wool-based nonwoven material showed good sorption properties and adequate reusability, indicating that a material based on natural fibers could be a viable alternative to commercially available synthetic materials that have poor biodegradability.