Fibers solutions

Fig. 20. A hoUow-fiber solution-spinning system. The fiber is spun into a coagulation bath, where the polymer spinning solution precipitates forming the...

Synthetic Fibers. Most synthetic fibers are sufficientiy white and do not requite bleaching. For white fabrics, unbleached synthetic fibers with duorescent whitening agents are usually used. When needed, synthetic fibers and many of theit blends are bleached with sodium chlorite solutions at pH 2.5—4.5 for 30—90 min at concentrations and temperatures that depend on the type of fiber. Solutions of 0.1% peracetic acid are also used at pH 6—7 for 1 h at 80—85°C to bleach nylon. 

With simple partition the situation is comparable to the partition of a solute between two solvents. The bonding forces involved between uncharged dye and uncharged fiber, and uncharged dye and uncharged solvent are considered to be the same. The dye is sometimes referred to as in soHd solution in the fiber. This type of isotherm is found in practice with disperse dyes on cellulose acetate and polyester. It represents the dyeing situation with the minimum restrictions for the dye to enter the fiber the only restriction is when the fiber solution becomes saturated. 

The taste bud is a polarized structure with a narrow apical opening, termed the taste pore, and basolateral synapses with afferent nerve fibers. Solutes in the oral cavity make contact with the apical membranes of the TRCs via the taste pore. There is a significant amount of lateral connectedness between taste cells within a bud both electrical synapses between TRCs and chemical synapses between TRCs and Merkel-like basal cells have been demonstrated to occur [39]. Furthermore, there are symmetrical synapses between TRCs and Merkel-like basal cells [39]. In addition, these basal cells synapse with the afferent nerve fiber, suggesting that they may function in effect as interneurons [39]. The extensive lateral interconnections... 

Doped silicon, conductivity in, 23 35 Doped/undoped electrochromic organic films, 6 580-582 Dope-dyeing, 9 197 Dope-making process, in acrylic fiber solution spinning, 11 204 Dope solids, in air gap spinning, 11 209 Doping, 23 838—839 calcium, 23 842-844 conducting polymers, 7 528-529... 

Lucent Technologies, Optical Fiber Solutions Norcioss, Georgia... 

Jose A. i.opez, Baylor College of Medicine. Houston. TX. http //www bcnumc.edu/. Nanotechnology iMoleculari Lucent Technologies, Optical Fiber Solutions. Notvtvss. G.4. Optical Fiber Systems... 

Two methods are used to prepare hollow fibers solution spinning and melt spinning [98,99], The most common process is solution spinning or wet spinning, in which a 20-30 wt% polymer solution is extruded and precipitated... 

Today s video applications employ a one- or two-fiber solution installed in either a point-to-point or physical star topology. The number of fibers depends on the sophistication of the proposed video system. Security video, for example, is a one-way, transmit type of application. However, certain systems require interaction at the camera for movement or voice communication and, thereby, require two fibers. 

Ring opening Seed fiber Solution casting Spinning Starches... 

Key words synthetic fibers, fiber extrusion, fiber melt spinning equipment, fiber solution spinning processes. 

TABLE 6.1 Control Parameters for Morphology and Diameter of Electrospun Fibers Solution properties... 

Kaushik and collaborators [37] obtained cellulose nanofibers from the wheat straw fibers using steam explosion (NaOH 10-12% solution and fiber/solution of 1 10), bleaching with 8% (v/v) solution, acid hydrolysis with 10% HCl (IN) and mechanical treatment. After the treatment it was possible to obtain mechanical defibrillation of cellulose nanofibers, which presented diameters between 10 and 60nm. The addition of these nanofibers to the starch thermoplastic matrix improved the barrier and mechanical properties of the nanocomposites. 

LiCl and DMAc were added to the swelled agave fibers in order to adjust the concentration of the solution to 1 wt%. The mixture was stirred at room temperature for 3 days until a viscous solution was obtained. Figure 19.4b shows pictures of the bleached fiber solution. The brown color remained depending on the NaOCl concentration, meaning that lignin components still remained in the case of lower NaOCl. 

PBI polymer solutions are prepared by dissolving the polymer resin in dimethyl acetamide (DMAc)/LiCl (lithium chloride) underpressure and temperature in an inert atmosphere. The LiCl is added to stabilize the solution, increasing the shelf-life from days to several months. Prior to further processing, the PBI dope solution is filtered to remove insolubles that could interfere with down-stream processing, such as spinning into fiber. Solutions may also be prepared without the added stabilizer, particularly at lower solids levels and for applications requiring the absence of metal or interfering additives. 

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