Tunable colors and conductivity by electroless growth of Cu/Cu2O particles on sol-gel modified cellulose

Nano Research - Development of colored surfaces by formation of nano-structured aggregates is a widely used strategy in nature to color lightweight structures (e.g. butterflies) without the use of...     

The ferromagnetic shape memory system Fe–Pd–Cu

A new ferromagnetic shape memory thin film system, Fe–Pd–Cu, was developed using ab initio calculations, combinatorial fabrication and high-throughput experimentation methods. Reversible martensitic transformations are found in extended compositional regions, which have increased fcc–fct transformation temperatures in comparison to previously published results. High resolution transmission electron microscopy verified the existence of a homogeneous ternary phase without precipitates. Curie temperature, saturation polarization and orbital magnetism are only moderately decreased by alloying with nonmagnetic Cu. Compared to the binary system; enhanced Invar-type thermal expansion anomalies in terms of an increased volume magnetostriction are predicted. Complementary experiments on splat-fabricated bulk Fe–Pd–Cu samples showed an enhanced stability of the disordered transforming Fe₇₀Pd₃₀ phase against decomposition. From the comparison of bulk and thin film results, it can be inferred that, for ternary systems, the Fe content, rather than the valence electron concentration, should be regarded as the decisive factor determining the fcc–fct transformation temperature.     

Bleaching of indigo-dyed denim fabric by electrochemical formation of hypohalogenites in situ

The use of hypochlorite, formed in situ by anodic oxidation of sodium chloride solution, for bleaching indigo-dyed denim has been studied at room temperature and at 50 °C. A direct relationship between the charge flow applied and the bleaching effect was observed. This enables consistent oxidative bleaching to be achieved by controlling the electrochemical process. The use of mixed anolytes containing small concentrations of bromide ions enhanced the bleaching effect considerably, even after lowering the temperature to room temperature. The molar concentration of bromide ions required was much lower than that of chloride in the anolyte.     

Modification of cellulose fiber with silk sericin

Cellulose fiber surface was modified with silk sericin (or simply, sericin). Sericin fixation on cellulose was confirmed by environmental scanning electron microscopy (ESEM) and Fourier transform infrared spectrophotometry–attenuated total reflectance (FTIR‐ATR). Sericin content in finished samples was estimated by dyeing treated fabrics with an acid dye, Supranol Bordeaux B, and determining K/S and L values of the dyed fabrics. The treated fabrics were tested for free formaldehyde content, crease recovery, tensile strength, electrical resistance, water retention, and biocidal activity. From ESEM and FTIR‐ATR results, it was found that sericin coated onto cotton surfaces as a film. Increasing sericin content in the finishing solution increased the amount of coated sericin, and a greater depth of color in dyed samples and reduced free formaldehyde content in treated samples were observed. The sericin content in samples was found to have a negligible influence on tensile strength and crease recovery angle. With increasing sericin content, electrical resistivity of the samples dramatically decreased and water retention increased, indicating that sericin‐treated fabrics may be comfortable to wear because of its maintenance of moisture balance with respect to human skin. Because cotton textile coated with sericin exhibited low formaldehyde content and no biocidal activity against Klebsiella pneumoniae and Staphylococcus aureus, the fabric may reduce skin irritation and disturbance of physiological skin flora arising from textile contact. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 1421–1428, 2005     

The development of indigo reduction methods and pre‐reduced indigo products

The continuing importance of blue denim maintains indigo as an important vat dye industrially. In this review, we examine the various methods that have been used in the past and are currently used to reduce and dissolve indigo for dyeing. We discuss recent insights into the bacterial fermentation technology, the advantages and disadvantages of the direct chemical methods that have predominated for the last century and potentially cleaner technologies of catalytic hydrogenation and electrochemistry, which are becoming increasingly important. With considerations of environmental impact high on the dyeing industry’s agenda, we also discuss the developments that have led to the production of pre‐reduced indigo.     

Miniaturized ceramic differential scanning calorimeter with integrated oven and crucible in LTCC technology

A miniaturized ceramic differential scanning calorimeter (MC-DSC) with integrated oven and crucible is presented. Despite its small size of only 11 mm × 39 mm × 1.5 mm, all functions of a conventional DSC apparatus are integrated in this novel device - including the oven. The MC-DSC is fully manufactured in thick-film and green glass ceramic tape-based low temperature co-fired ceramics (LTCC) technology. Therefore, production costs are considered to be low. Initial results using indium as a sample material show a good dynamic performance of the MC-DSC. Full width at half maximum of the melting peak is 2.4 °C (sample mass approx. 11 mg, heating rate approx. 50 °C/min). Repeatability of the indium melting point is within ±0.02 °C. The melting peak area increases linearly with the sample mass up to at least 26 mg. Simulations of a strongly simplified finite element model of the MC-DSC are in a good agreement with measurement results allowing a model-based prediction of its basic characteristics.     

Throughput of a satellite channel communication

Summary The throughput of a satellite channel communication is depending upon the link protocol. It is well known that the classical HDLC protocol is inadequate when applied to satellite links instead of short terrestrial links. Several modifications have been proposed to overcome this problem. The present paper gives an analysis and evaluation of a new class of protocols called Virtual Subchannel schemes which splits the satellite link into several components; these subchannels are assigned for transmission in cyclic order and are controlled independently of each other by the classical HDLC procedure.     

Alkaline treatment of cotton in different reagent mixtures with reduced water content. II. Influence of finishing procedure

Changes in cotton fabrics brought about by different swelling agents and different types of finishing procedures have been studied in this work, using a single‐step swelling of cotton in the reagent. Cotton fabrics were treated with different alkalis and mixtures of alkalis and other additives and finished with a modified type of 1,3‐dimethylol‐4,5‐dihydroxyethylene urea, using wet‐on‐wet and wet‐on‐dry technique. Properties generally used to characterize mercerized cotton were selected that are technologically important, such as water retention, shrinkage, stiffness, and crease recovery angle. Water retention method has been used to compare the degree of swelling for different samples. Differences in properties among these samples were observed and some practically important conclusions were arrived at. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 1194–1201, 2006     

Fibrillation tendency of cellulosic fibers,part 6: Effects of treatments with additive polymers

The influences of the treatments with various polymers on fibrillation and abrasion resistances of lyocell materials were investigated with respect to the type of polymer, the polymer concentration, and the drying temperature. Fibril number, generated with agitation using ball‐bearings (FN_ball), was decreased with increasing the concentration of aminofunctional polysiloxane because of reduction in water retention capacity (WRV) in fibers. The never‐dried lyocell fiber showed smaller decrease in FN_ball because of its higher WRV when compared to dried fibers. The treatment with aminofunctional polysiloxane enhanced not only the fibrillation resistance but also abrasion resistance, which was indicated as rotation number of abrasive bar in the abrasion test (RN_abr). No fibrillation was obtained in the fiber treated with 10 g/L aminofunctional polysiloxane at 120°C for 20 min, while the fibers treated at 60 and 170°C for 15 min were fibrillated in the agitation and abrasion tests. The addition of secondary polyethylene derivative also reduced the fibrillation tendency of lyocell; however, the extent of the reduction was lesser when compared with aminofunctional polysiloxane. The treatments with polyacrylate, polyurethane, and polyisocyanate derivatives improved the fibrillation resistance in lyocell fabrics, while fiber abrasion resistance was not significantly improved by the treatment with those additives, except in polyisocyanate. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 4140–4147, 2006