Advanced Materials Research Vol. 843

Abstract: Modified polyester fabric with pores was treated with self-synthesized TiO₂ under high-temperature (130°C) and high-pressure condition via one-bath process. By SEM, uniform holes and many particles could be seen on the treated fiber surface. EDX was used for analysis. Results show that materials deposited on the fiber surface were TiO₂. Shake flask test was selected to evaluate the antibacterial ability of the treated fabric. Antibacterial rate against E.coli and S.aureus were 96.24% and 92.00%, respectively. At the same time, the durability to laundering was also tested. The results indicated that antibacterial property of the treated fabric was still excellent even after it was washed 50 times

Abstract: Biomaterials used for vascular prostheses should possess certain strength that can keep the normal blood fluidity, as well as certain flexibility and elasticity that can resist blood pulsation pressure. In order to fabricate small diameter vascular prostheses (SDVP) that possess matchable mechanical properties with natural blood vessels, a bi-layered tubular structure composed of electrospinning blended nanofiber and silk fiber was designed and prepared in this study. The inner layer of the structure, prepared through electrospinning, was composed of Poly (L-lactide-co-ε-caprolactone) (PLCL) and silk fibroin (SF) blended nanofibers. Braided silk tube was used as the outer layer of the structure. Morphological, structural and mechanical properties including peak stress, peak strain, and Youngs modulus of the prototype bi-layered SDVP were characterized initially. Results showed that the diameter range of the blended nanofiber was between 100 and 900 nm, and the fiber diameter increased with the content increase of PLCL. Through blending PLCL together with SF, peak stress and peak strain of the electrospun inner layer were improved, and that of the Youngs modulus decreased. Meanwhile, the outer layer of SDVP was stronger and had higher Youngs modulus. Those mechanical performances of the prototype bi-layered SDVP fabricated in this study are similar to natural blood vessels, which provide a promising biomaterial that could be applied on tubular tissue engineering scaffolds.

Abstract: Fourier transform infrared spectroscopy was used to investigate the chemical structure of down fibers in this paper. Contact angle was calculated to determine the wetting property of down. Experiments demonstrated that the surface chemical structure affected the fiber wetting property strongly. The surface substance by FTIR was forecast to be the mixture of sterol and triphosphate ester. After Soxhlet-extracted the fibers contact angle increased greatly.

Abstract: Recent years, much attention has been paid to approaches for directly producing nanofibers along with a rising trend for their exploration and application in wide fields. Considering the melt blowing and bubble-electrospinning, a novel method called blown bubble-spinning was introduced by forcing airflow onto the polymer bubble. In this paper, a special hierarchical structure has demonstrated the ability to form micro yarn composed of nanofibers in this way. The resulting yarn is about 23 micrometers while the nanofibers 376 nanometers.

Abstract: Bubble electroblowing is employed by combining bubble-electrospinning with airflow to prepare silk fibroin nanofibers. The result indicated that not only nanofibers but also droplet-like beads were formed. Unlike traditional beads conjugating fibers, droplet-like beads accompanied fibers by sides. The average diameter of fibers is 572 nanometers while the special beads is 1909 nanometers.

Abstract: A belt-like superfine silk fibroin film was prepared via bubble-electrospinning from aqueous silk fibroin solution at concentration 15%. The morphology of film structures were characterized by scanning electron microscope (SEM). The average width was 1.17 micronmeters and the thickness was 377 nanometers.

Abstract: A mathematical model for diffusion of silver ions in hollow cylinders is established. In order to control the concentration of silver ions, an auxillary cylinder is introduced. The flux of of silver ions can be effectively adjusted by the radius of the auxillary cylinder.

Abstract: It is the most effective way to study the effect of global warming on plant morphology by analyzing a plant species on a mount along altitudinal gradients. Altitudinal increase means decrease of temperature and metabolic rate as well. This might affect the leaf morphology greatly. The SEM study reveals that the size of nanopore on the epidermis changes gradually along altitudinal gradients, and the absorbed fine particles on the leaf have almost same size, exhibiting high selectivity over other particles. The study gives a strong proof that morphology change links to global warming.

Abstract: A local fractional Richards equation is derived by considering the soil as fractal porous media, and an exact solution is obtained by a generalized Boltzmann transform and the fractional complex transform. The new theory predicts that the volumetric water content depends on the ratio (distance)^2a /(time), where a is the value of fractal dimensions of the porous soil, and its value is recommended for various soils.

Abstract: The modification of natural dyes tea polyphenols is discussed in the silk dyeing. Tea polyphenols and 3-chlorine-2 - hydroxypropyl trimethyl ammonium chloride (CHPTMA) are ionized in alkaline condition, and modified tea polyphenols are prepared. The effect of CHPTMA modifier dosage, pH, temperature and time condition to modification of tea polyphenols are studied systematically. The optimal process of modification is obtained. The dyeing & finishing functional performances on silk were performed experimentally and verified theoretically.