RESUMEN
Millions of tons of feather are produced worldwide each year and considered as a solid waste owing to technical or cost constraints to provide valuable functional characteristics. In this study, a novel and ecofriendly method to recycle waste feather and obtain a type of explosion down via flash explosion with a supercritical fluid of carbon dioxide (SCF-CO2) was developed for the first time. The effects of flash explosion parameters on the structures and properties of feather were explored by orthogonal experiments. A mechanism involving two-step procedures for the developed SCF-CO2 flash explosion is proposed. The obtained results indicate that reinforcements of flash explosion conditions, particularly the system pressure, were readily conducive to transfer the original feather to a soft down with an improved separation ratio, as well as easily weaken or break hydrogen and disulfide bonds associated in feather macromolecules. Moreover, efficient modifications of the physical characteristics, structures and surface morphologies of the waste feather were obtained by the SCF flash explosion to produce a uniform, slender and fibrous explosion down, as demonstrated by scanning electron microscopy, Fourier-transform infrared spectroscopy, and X-ray diffraction analysis. Further tests on the SCF explosion down treated at 70.0 °C at 15.0 MPa for 30.0 min and at 90.0 °C at 20.0 MPa for 20.0 min showed remarkable enhancements in warmth retention along with comparable thermal degradation nature, as well as enhanced softness, down-proof, and other service properties in comparison to the original feather. The SCF-CO2 flash explosion is a promising approach with environment-friendly characteristics to obtain high efficiency and quality of the explosion down by recycling of waste feather.
RESUMEN
During spinning, the chemical component content of natural fibers has a great influence on the mechanical properties. How to rapidly and accurately measure these properties has become the focus of the industry. In this work, a grey model (GM) for rapid and accurate prediction of the mechanical properties of windmill palm fiber (WPF) was established to explore the effect of chemical component content on the Young's modulus. The chemical component content of cellulose, hemicellulose, and lignin in WPF was studied using near-infrared (NIR) spectroscopy, and an NIR prediction model was established, with the measured chemical values as the control. The value of RC and RCV were more than 0.9, while the values of RMSEC and RMSEP were less than 1, which reflected the excellent accuracy of the NIR model. External validation and a two-tailed t-test were used to evaluate the accuracy of the NIR model prediction results. The GM(1,4) model of WPF chemical components and the Young's modulus was established. The model indicated that the increase in cellulose and lignin content could promote the increase in the Young's modulus, while the increase in hemicellulose content inhibited it. The establishment of the two models provides a theoretical basis for evaluating whether WPF can be used in spinning, which is convenient for the selection of spinning fibers in practical application.
RESUMEN
In this work, a personal thermal management (PTM) device based on single walled carbon nanotubes (SWCNTs) functionalized polyester fabrics had been studied. Polyester fabrics were functionalized with SWCNTs through coating method with poly (butyl acrylate) emulsion as the adhesive. The SEM images exhibited that SWCNTs formed high-efficiently conductive networks due to the large aspect ratio and uniform dispersion. A steady-state temperature of 40 °C was achieved at the input voltage of 2.5 V within 7 s, which exhibited excellent electro-thermal performance. Even under periodic heating-cooling conditions, heating system still displayed relatively stable temperature and relative resistance, which could have potential application for wearable clothes.