Morphological, optical and electromagnetic characterization of polybutylene terephthalate/silica nanocomposites

Polybutylene terephthalate (PBT) composites containing 1 %, 3 % and 5 % silica nanoparticles were prepared by melt compounding method. The characteristics of the nanocomposites were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), differential scanning calorimetry (DSC), thermal gravimetric analysis (TGA), tensile strength test (TST), reflectance spectroscopy (RS), electromagnetic transition test (ETT) and atomic force microscopy (AFM). XRD method showed successful incorporation of silica into the polymer matrix. SEM and AFM results showed the presence of silica aggregates on the surface of PBT sheets. Thermal analysis results demonstrated some changes in crystallinity of PBT after addition of silica. The PBT/silica nanocomposites were found to have higher electromagnetic reflection compared with the pure PBT. Silica nanoparticle is thus suggested as a good candidate for electromagnetic shielding purposes.     

SiO2-kaolinite affecting the surface properties of ternary poly(vinyl chloride)/silica/kaolinite nanocomposites

The products from the dispersion of nanoscale particulates such as the layered clays or the spherical inorganic minerals within the polymeric matrices are called polymeric nanocomposites. In this paper, we prepared poly(vinyl chloride) (PVC) based nanocomposites containing SiO₂-kaolinite by melt compounding. The influence of SiO₂-kaolinite on the surface properties of PVC was investigated by the use of various surface analysis techniques including a ttenuated total reflectance spectroscopy (ATR), wide angle X-ray diffractometry (WAXD), atomic force microscopy (AFM), scanning electron microscopy (SEM), electron dispersive X-ray spectrometer (EDX), contact angle measurement (CAM), and reflectance spectroscopy (RS). ATR spectroscopy showed possible interaction between layered kaolinite and PVC at surface. Microscopic methods illustrated an increased surface roughness compared to the pure PVC. Contact angle measurements of the resultant PVC nanocomposites demonstrated that the wettability of substrates depends on the surface interactions between kaolinite layers and PVC matrix. Optical properties of nanocomposite films were finally measured by the aid of reflectance spectrophotometer. It can be seen from optical studies that reflectance values were increased after incorporation of SiO₂-kaolinite in nanocomposite.     

Ultrasound for efficient emulsification and uniform coating of an anionic lubricant on cotton

In this paper, a softener of aliphatic acid ester was treated with an ultrasonic bath and coated on cotton. The particle size distribution of the softener in water was evaluated by a particle size analyzer. Physical and surface properties of the fabric after coating with the ultrasonic treated softener were compared with a control sample. Different technical measurements were utilized for this purpose including bending lengths measurement (BLM), friction coefficient measurement (FCM), evaluation of crease recovery angle (CRA), moisture regain measurement (MRM), evaluation of contact angle (CA), reflectance spectroscopy (RS), atomic force microscopy (AFM) and scanning electron microscopy (SEM). Results showed that ultrasound enhances softener distribution in water and it improves the drapeability, friction behavior, wrinkle recovery and water repellency of cotton due to uniform coating of softener.     

Dyeing of wool with Marigold and its properties

This research work involves the dyeing of wool with Marigold as a source of yellow colour. To do this, wool yarns pre-treated with Alum as a colorless mordant, dyed with Marigold and then treated with different percentages of ammonia solutions. The chromaticity co-ordinates of samples measured in CIELAB system. TheL* values of all ammonia treated samples decreased and the values ofa*,b*,C* dependent on the ammonia solution. It can also indicate that the reflectance spectrum of treated samples decreases due to ammonia treatment. The rate of vertical wicking decreases on Marigold dyed treated with ammonia. Color hue of the Marigold dyed wool alters after washing with standard soap and ammonia after-treatment has no influence on washing fastness. The samples dyed with Marigold and after-treated with ammonia show a lower light fastness.     

Various nano-silica particles affecting dyeability of poly(ethylene terephthalate)/silica nanocomposite films

Poly(ethylene terephthalate) [PET] based nanocomposites containing three differently modified silica particles were prepared by melt compounding. The influence of type of nano-silica on dispersibility, thermal and dyeing properties of the resultant nanocomposite was investigated by various analytic techniques, namely, polarized optical microscopy (POM), scanning electron microscopy (SEM), differential scanning calorimetry (DSC), thermal gravimetric analysis (TGA), reflectance spectroscopy (RS), and light fastness. Optical microscopy images illustrated that nano-silica particles tended to increase the number of spherulites in the PET matrix which were dependent on nano-silica type and content. Thermal studies of the resultant nanocomposites showed a slight decrease in the melting temperature compared to a pristine PET. Silica nanocomposites were finally dyed with a disperse dye and their reflectances were determined by the aid of reflectance spectrophotometer. Such reflectances were converted to the corresponding color coordinate values which are indicative of dyeability of such nanocomposites.     

New insight into compressive shrinkage finishing in a garment company: The effects on physical,mechanical and colorimetric properties of cotton woven fabrics

Compressive shrinkage or compressive shrinkage finishing is one of the most important finishing procedures in the textile industry to improve the dimensional stability of cotton fabrics. Study of the physical and mechanical properties of compressive shrinkage finished fabrics could be useful for optimizing the treatment conditions. This research was carried out in a production line of a recognized garment company on cotton woven fabrics with two different woven patterns (twill and plain). The samples were first dyed with reactive and sulfur dyes in a jigger dyeing machine and finished with a silicone softener. The dried fabrics were then processed in a compressive shrinkage machine. Several physical and mechanical properties of the samples were evaluated including area shrinkage, crimp percentage, thickness, abrasion resistance, drapeability, mechanical and colorimetric properties. The results showed that the thickness of all treated samples increased due to compressive shrinkage. The fabrics were analyzed with a Martindale Abrasion Tester to determine the abrasion resistance. Interestingly, we noted an increase in the abrasion resistance. After the compressive shrinkage process, the strength of the plain woven fabrics decreased in the warp direction, but increased for twill woven cotton fabrics. On the contrary, the strength of all samples increased in the weft direction. Colorimetric evaluation of the samples showed that the effect of compressive shrinkage on the color of all samples was negligible.     

Polyvinylpyrrolidone/Carbon Nanotube/Cotton Functional Nanocomposite: Preparation and Characterization of Properties

In the last decade, preparation of multifunctional composites have attracted researchers around the World for multi-purpose application. In this regard, we produced polyvinylpyrrolidone/carbon nanotubes/cotton (PVP/CNTs/cotton) nanocomposite by coating cotton fabric via pad-dry-cure under UV irradiation. Several characterization methods were used to investigate the functionality and durability including scanning electron microscopy, thermo-gravimetric analysis, flammability test, reflectance spectroscopy, tensile strength test, water absorption and antibacterial analysis. The interactions among PVP molecular chains, CNT particles and cellulose were confirmed by Raman spectroscopy. We observed a uniform coating of PVP/CNTs on the fiber surface. An advantage of our developed method was the strong interfacial interaction among compositions, high durability along with multifunctional properties. PVP/CNT nanocomposite was able not only to improve the thermal stability of cotton, but also provided a reduced flammability and good antibacterial properties. Here, we confirm a simple and versatile method for fabrication of PVP/CNTs/cellulose nanocomposite for multi-purpose applications.