Wild Silkworm Cocoon Waste Conversion into Tough Regenerated Silk Fibers by Solution Spinning.

Wild silkworm silk fibers have garnered attention owing to their softness, natural color, lightweight, and excellent mechanical properties. Because most wild silkworm cocoons obtained are pierced or dirty after the eclosion process, it is difficult to reel the long filament from the pierced cocoons to use as textile materials. Therefore, damaged wild silkworm cocoons are typically removed during the industrial process.

Non-woven fabrics of fine regenerated cellulose fibers prepared from ionic-liquid solution via wet type solution blow spinning.

A wet type solution blow spinning system with a water-mist coagulation chamber was developed to spin fine regenerated cellulose fibers from the non-volatile ionic liquid solvent 1-ethyl-3-methylimidazolium diethyl phosphate. The molecular weight distribution of cellulose, and the rheological properties and spinnability of its spinning solution were evaluated. Scanning electron microscope observations indicated that the fine water mist/vapor was important for efficient coagulation of the stretched solution jets.

Outstanding reinforcing effect of highly oriented chitin whiskers in PVA nanocomposites.

To utilize the extreme reinforcing performance of chitin whiskers (ChWs), the current work was undertaken to fabricate nanocomposites embedded with highly uniaxial oriented ChWs into the matrix polymer. Fibers of poly(vinyl alcohol) (PVA)/ChWs were prepared by gel spinning and the fibers were subjected to a hot drawing to their maximal draw ratio. WAXD analysis revealed the very high orientation of ChWs in the PVA matrix.

Assessment of the anti-biofouling potentials of a copper iodide-doped nylon mesh.

We propose a copper iodide (CuI)-doped nylon mesh prepared using polyiodide ions as a precursor toward anti-biofouling polymer textile. The CuI-doped nylon mesh was subjected to the prevention of biofouling in marine environments. The attachment of the marine organisms was markedly inhibited on the CuI-doped nylon mesh surface until 249 days.

Mechanistic studies on the formation of silver nanowires by a hydrothermal method.

Silver (Ag) nanowires were fabricated from silver chloride (AgCl) by the hydrothermal method. The successful formation of Ag nanowires relied on the low solubility of AgCl as a precursor and the structural change of glucose to polymer on the Ag nanowire (protective layer). The Ag(+) ion concentration in the reaction solution containing AgCl was initially low, but after a reaction time of over 12 h, Ag(+) gradually reduced to Ag metal.

Toward "strong" green nanocomposites: polyvinyl alcohol reinforced with extremely oriented cellulose whiskers.

To exploit the maximum potential of cellulose whiskers (CWs), we report here for the first time the successful fabrication of nanocomposites reinforced with highly oriented CWs in a polymer matrix. The nanocomposites were prepared using polyvinyl alcohol (PVA) and a colloidal suspension of cotton-derived CWs. The macroscopically homogeneous PVA-CW suspensions were extruded into cold methanol to form gel fibers followed by a hot drawing.

Physical properties and dyeability of silk fibers degummed with citric acid.

Silk fibers from Bombyx mori silkworm was degummed with different concentration of citric acid, and the physical properties and fine structure were investigated to elucidate the effects of citric acid treatment. The silk sericin removal percentage was almost 100% after degumming with 30% citric acid which resulted in a total weight loss of 25.4% in the silk fibers.

Electrical conductivity of microwave heated polyaniline nanotubes and possible mechanism of microwave absorption by materials.

In the course of experiments to perform deprotonation and carbonization of doped polyaniline (PANI) nanotubes (NTs) by irradiating directly 2.45 GHz microwave (MW) in our microwave heating system (MWHS), we have discovered that the PANI-NTs self heat by absorbing the MW but the temperature of the PANI-NTs stops rising around 300 degrees C in spite of the heightened MW power Furthermore, we have found that the MW irradiated PANI-NTs have transferred from electrical conductor to insulator depending on the temperature of the PANI-NTs. By measuring electron spin resonance (ESR) spectra of the MW heated PANI-NTs, the existence of the unpaired electrons is shown to have a strong correlation between the degree of MW absorption and the transition in the electrical conductivities.

Structural characteristics and properties of Bombyx mori silk fiber obtained by different artificial forcibly silking speeds.

To study the spinning condition of natural biopolymer silk, the silk fibers were directly acquired from Bombyx mori silkworm, N140 x C140 by a simple artificial forcibly silking method at the speed of 60, 120, 180 and 240 cm min(-1), respectively and its microstructure and physical properties were evaluated. The fine silk fibers (about 8 microm) were obtained at faster spinning speed, 240 cm min(-1). The tensile properties of silk fibers were remarkably increased with raising the forcibly spinning speeds.

[Peripheral venous stenoses of hemodialysis shunts: improved long-term patency rates with stent placement].

Purpose: The purpose of this study was to evaluate the effectiveness of endovascular stents placed in the peripheral veins of hemodialysis shunts.

Materials And Methods: 156 endovascular stents were placed in the peripheral veins of 155 hemodialysis shunts with 220 stenoses. Among these, 106 stenoses of 93 hemodialysis shunts had been treated by percutaneous transluminal angioplasty (PTA) before stent placement.