The Comparison of the Effects of Β-Cyclodextrin Complex and Derivative Complex with Silver Nanoparticles on Cotton Fabric

In this study, sulfated β-cyclodextrin (S-β-CD) which is a β-cyclodextrin derivative was obtained by chemical treatment of natural β-cyclodextrin (β-CD) with sulfuric acid. Afterwards, β-CD and S-β-CD were applied to cotton fabrics. In different treatments, β-CD and S-β-CD were bonded to cotton fabrics with EDTA crosslinking agent. Then, all the fabrics were treated with antibacterial agent silver nanoparticles (AgNPs) and inclusion complexes were formed. The aims of this study were to increase the washing stability and the antibacterial activity against microorganisms and to compare the effects of β-CD complex and derivative complex with silver nanoparticles on treated cotton samples. So, for this purpose, the properties of the treated samples like antibacterial activity, washing stability, add-on, tensile strength, handle, thickness and color change were tested and compared to each other. In addition, characterization analyzes such as SEM, EDX and FT-IR were performed on the samples and XRD analysis was performed to characterize the AgNPs. As a result of the study, it was observed that AgNPs alone were not sufficient to obtain antibacterial textiles with strong antibacterial effect and good washing stability. The inclusion complexes formed with β-CD and S-β-CD had much more effective antibacterial activity and more robust washing stability. In addition, when the physical properties except stiffness and yellowness were considered besides antibacterial activity and washing stability, the treatment of derivative β-CD complex with AgNPs and crosslinking this complex to cotton sample by means of EDTA was found to be the most favorable method.

Endophytic bacterial communities and spatiotemporal variations in cotton roots in Xinjiang, China

Endophytic bacteria may be important for plant health and other ecologically relevant functions of cotton. However, the endophytic bacterial community structure and diversity in cotton is still poorly characterized. We investigated the community structure of endophytic bacteria in cotton roots growing in Xinjiang, China, using the Illumina amplicon sequencing. A total of 60.84 M effective sequences of 16S rRNA gene V3 region were obtained from cotton samples. These sequences revealed huge amount of operational taxonomic units (OTUs) in cotton, that is, 81-338 OTUs in a cotton sample, at 3% cutoff level and sequencing depth of 50000 sequences. We identified 23 classes from the resulting 2,723,384 sequences. Gammaproteobacteria were the dominant class in all cottons, followed by Alphaproteobacteria, Actinobacteria and Bacilli. A marked difference in the diversity of endophytic bacteria in cotton for different growth periods was evident. The greatest number of OTUs was detected during seedling (654 OTUs) and budding (381 OTUs). Endophytic bacteria diversity was reduced during flowering (350 OTUs) and boll-opening (351 OTUs). 217 OTUs were common to all four periods. There were more tags of Pantoea in Shihezi than other locations. While there were more tags of Erwinia in Hami than other locations. The dynamics of endophytic bacteria communities were influenced by plant growth stage. These results show the complexity of the bacterial populations present in inner tissues of cotton.

Investigating on the Iconic Gas Compositions Produced by Low-Temperature Heating Cotton

This study aims at achieving the generation laws of the iconic gas compositions produced during the process of the cotton smoldering. A mini tube furnace was used to heat a long-staple cotton sample from Xinjiang, China, and a gas chromatography-mass spectrometer (GC/MS) was applied to analyze the produced organic and inorganic gas composition at different low temperatures ranging from 95 °C to 185 °C. Besides, a thermogravimetric experiment under air atmosphere was done in order to verify the correctness of the inferences. The pathways of product generation by heating cotton were set forth, including the depolymerization of the cotton cellulose, the sequential generation of coke, low molecular weight products, long chain carboxylic acids, levoglucosenone, and acetone at 125 °C, and the generation of hydrogen at 95 °C, carbon dioxide, carbon monoxide at 145 °C, and methane during the heating process. The results showed that the alkanes, furans, alkenes, aldehydes, hydrazines, and acids could not be regarded as the iconic gas compositions because of their little proportion, the joint detection of the methane and hydrogen could be used to predicate the smoldering, and the acetone and carbon monoxide could be used to confirm the smoldering stage. The results of the thermogravimetric experiment are consistent with theoretical analysis, indicating that analyses are reliable. This work will provide significant practice foundation for the early warning and prevention of cotton fires.

Physical and performance characteristics of nonwoven aviation wipers composed of various staple fibers including raw cotton

Several nonwoven materials were evaluated as candidates for wipe fabrics intended for sensitive applications, namely aviation maintenance. Wipes designed for this purpose must conform to specific guidelines delineated by the appropriate governing bodies. Fabric selections included both synthetic and natural staple fibers such as polyester, Lyocell and raw cotton varieties. A thorough evaluation of extractable material in an array of solvents revealed that cotton-based nonwovens as well as Lyocell have some of the lowest percentages of leachable solids. The resistance of these fabrics to abrasion and the damage incurred by them was also studied. Environmental scanning electron microscopy taken before and after the linting procedure showed that the greige cotton sample demonstrated some of the least damage. Fourier-transform infrared spectroscopy examinations of hexane extracts confirmed the absence of any silicone grease contamination on the wipes materials. Standardized tensile testing indicated that the cotton samples, especially mechanically cleaned greige cotton, have robust tensile properties that are important characteristics for wiping materials. These results indicate that cotton nonwovens, particularly greige cotton, are promising candidates for the development of future aviation and other wipes materials.

An Experimental Study Regarding the Vibratory Behaviour for Some Textile Composites

The paper presents the results of our research in the elaboration and characterization of composites type epoxy - textile fiber and vibration behaviour. These were made by pressing, and the textile fibers we tested were cotton, flax, hemp and wool. Starting from the dynamic response of composite beam with damping (which is in free vibration), there is established a way to determine the damping factor. There has been experimentally determined the damping factors for some samples: sample 1 – built from cotton; sample 2 – built from hemp; sample 3 – built from flax; sample 4 – built from whool.

Procedures for Moisture Analytical Tests Used in Cotton Ginning Research

Cotton post-harvest processing research requires moisture content determination for seed cotton, cottonseed, and lint. Methods for determining moisture content have changed and are no longer consistent between laboratories. This research compared standard procedures documented in 1972 and those currently practiced for finding moisture content by oven drying, and quantified the variability. Seed cotton from four modern cultivars (ranging from 9.4% to 36.8% foreign matter), lint, and cottonseed were brought from dry conditions, blended, and then stored for more than 30 days in a controlled environment (21°C, 65% RH) to reach uniform moisture content. Additionally, 150 seed cotton samples were placed in plastic zipper bags and sent by air freight to a distant location and back or stored on-site. Drying baskets (652 cm3) were loaded, in random order, with 25, 35, 50, 71, and 100 g seed cotton or 10, 14, 20, 28, and 40 g lint. Cottonseed was placed in 45 cm3 aluminum cups (10 g) or 800 cm3 aluminum baskets (50 g). Wet weights were determined in the controlled environment. After drying, replicated sets of seed cotton, lint, and cottonseed samples were weighed inside a drying oven and then outside the oven while still hot. Some samples were dried for twice the recommended duration. Sample location in the ovens was tracked. Weighing hot seed cotton samples outside the oven after drying increased apparent moisture content by approximately 0.5% due to air buoyancy; weighing lint samples outside the oven increased apparent moisture content by 1%. Smaller differences in apparent seed cotton moisture content were found when halving or doubling the amount of material in drying baskets or doubling the drying duration. Foreign matter had a minor influence on apparent moisture content. Storage for three days and shipping by air freight in plastic zipper bags did not measurably change the apparent moisture content of seed cotton. Sample location within the drying oven made no difference. Current practices are satisfactory if dry weight location is taken into consideration. Measurement uncertainty has decreased compared to 50 years ago, but the recommended minimum number of samples per treatment was increased slightly for greater statistical power. Keywords: Cotton lint, Cottonseed, Moisture content, Oven drying, Seed cotton.

Non-contact Method for Measurement of Colour Variation in a Cotton Sample

Colour is the visual perceptual property in the cotton grade classification of Universal Cotton Standards. We undertook an experimental study on the variation in cotton colour using the Non-contact method. Rd (degree of reflectance) and +b (yellowness) are globally recognized colour parameters of cotton, which are measured by HVI (High Volume Instrument). The Non-contact method is used for the evaluation of colour variation within cotton samples. The results obtained from the Non-contact method were compared with those of other conventional methods used globally for the color measurement of cotton fibers. Additionally image analysis is interpreted with the variation in cotton colour. Results confirmed a strong co-relation between the Non-contact method and image analysis for the colour variation of cotton.

Roles of Novel Reactive Cationic Copolymers of 3-Chloro-2-hydroxypropylmethyldiallylammonium Chloride and Dimethyldiallylammonium Chloride in Fixing Anionic Dyes on Cotton Fabric

The roles of novel reactive cationic copolymers (P(CMDA-DMDAAC)s) of 3-chloro-2-hydroxypropylmethyldiallylammonium chloride (CMDA) and dimethyldiallylammonium chloride (DMDAAC) in fixing anionic dyes on cotton fabric were studied by modern instrumental analysis technologies such as FT-IR spectra and SEM analysis, to achieve the new theoretical guides for the wide applications of those dye fixatives. The FT-IR spectra of the obtained insoluble-water color lakes verified that they could be formed from the electrostatic interactions of the P(CMDA-DMDAAC)s with anionic dyes, which were further confirmed by the FT-IR analysis of the anionic dyes on dyeing cotton sample fixed by P(CMDA-DMDAAC)s. The FT-IR spectra of cotton samples fixed by P(CMDA-DMDAAC)s showed the absorptions of P(CMDA-DMDAAC)s and the signs similar to the formation of new ether linkage on cotton fabric even after being repeatedly washed, which were further confirmed by the SEM analysis of the fixed dyeing cotton samples. Thus, the reactive units (CMDA) of the obtained P(CMDA-DMDAAC)s could be expected to bring about the covalent bonds with the hydroxyl groups of cotton (cellulose) to form an ether linkage when fixing, resulting in the stronger interactions of P(CMDA-DMDAAC)s with cotton fabric, as well as their electrostatic forces with anionic dyes to produce the insoluble-water color lakes, for the development of fastness of anionic dyes on cotton fabric.

Antimicrobial Properties of Orthopaedic Textiles after In-Situ Deposition of Silver Nanoparticles

Materials exhibiting an antimicrobial effect are especially advantageous for medical textiles which are in very close and long-term contact with human skin. Orthopaedic stockings made of terry cotton and polyamide were coated with silver nanoparticles by a simple dip coating process under mild conditions. Both textiles released silver ions over at least 28 days. The silver ion release for both materials is governed by diffusion. The amount of silver ions released by the cotton textile was higher than by the nylon stockings by about a factor of 4. The reason was a larger silver reservoir in the cotton sample, because it contains much more silver than the nylon fabric. As expected from the results of the Ag+ release tests, both these silver coated textiles were active against Escherichia coli.

Using High-Speed Image Analysis to Estimate Trash in Cotton

Two new scanning type cotton trashmeters are being developed to indicate the amount of trash and foreign matter in lint cotton. These instruments are primarily intended to replace the current visual method of grading cotton for market quality. They both perform a two dimensional surface scan using a black and white television camera. High-speed microprocessors provide an analysis of the TV signal at video scan rates. Only a fraction of a second of time is required to complete all scanning, signal processing, and data analysis for each cotton sample exposure. This article discusses some common problems in TV image analysis and how they relate to cotton scanning. Also discussed are instrument precision and design features and a method of calibrating each instrument.