Metal loaded fibers

Strength. Prediction of MMC strength is more compHcated than the prediction of modulus. Consider an aligned fiber-reinforced metal-matrix composite under a load P in the direction of the fibers. This load is distributed between the fiber and the matrix ... 

Tryk el al. studied GDEs composed of active carbon fiber and loaded with catalysts Ni, Fe, Pd metals, porphyrins, and phthalo-cyanines. The GDEs gave partial current density of CO2 reduction up to 80 mA cm 2 with production of CO under atmospheric pressure. They presumed that the nanopores present in active carbon fiber may provide quasi high pressure atmosphere due to nanoscale effect." Thus Ni electrocatalyst, which is practically inert for CO2 reduction under atmospheric pressure, may be activated in a similar manner as observed with Ni electrode under elevated pressure. " ... 

Table 4 The effect of support calcination temperature and catalyst metal loading on the initial reaction rate and the selectivity to citronellol over Ni/silica fibers.

The diffractograms of Pd/y-AlaOs/FeCrAlloy show the presence of two peaks at 20 = 44.695 and 64.852° characteristic of the fibers themselves [5]. The peaks detected at 66.761 and 45.788° related to the plans (440) and (400), respectively, can be attributed to the y-Al203 (file n° 29-0063) which has been deposited onto the fiber. The presence of a-Al203 (JCPDS file n° 46-1212), formed during the thermal treatment of the fibers at 1050°C, is confirmed by the peaks appearing at 26 = 35.152, 57.496, 43.355 and 25.578° related to the reflection plans (104), (116), (113) and (012), respectively. There are neither detected phases of palladium oxides nor of metallic palladimn even at higher noble metal loads. 

Jin et al. [52] have deposited 5 wt% Pd on activated carbon fibers by alkaline hydrolysis of palladium chloride and obtained metal dispersions of 55 to 77%. Dispersions of 40 to 50% have been reported by Farkas et al. [53], who prepared Pd/C by fast addition of NaOH solution to a suspension of carbon in an aqueous solution of K2PdCl4. More highly loaded Pd and Pt catalysts (10 wt%) have been prepared by dropwise addition of the metal salt solution to the suspension of carbon in Na2C03 solution. In this case [54], a Pt particle size of 10 nm and a Pd particle size of 17 nm were reported. Ion adsorption led to much lower particle sizes. By quick addition of NaOH solution to a suspension of carbon support in PdCl2 solntion, Cabiac et al. [55] obtained 5- to 10-nm Pd particles at a loading of about 4 wt%. Clearly, details of support, metal loading, and the method of mixing of reactants all play a vital role in the dispersion and distribution of the metal in the finished catalyst. 

Westwood et al. prepared SCR catalyst for NO reduction by impregnating a surface oxidized activated carbon fiber from aqneons solutions of ferric nitrate, nickel nitrate, or copper nitrate followed by calcinations at 300°C under nitrogen for 2 hr. The catalytic activity of these metal loaded ACFs was determined in a plug-flow microreactor using line FT IR analysis of the feed and flue gases containing 800 ppm... 

Filled polymers are intrinsically nonconductive polymers loaded with conductive fillers such as carbon black, graphite fiber, metal particles, or metal oxide particles (5-9). Filled polymers have the longest history and broadest application in electronic devices. These materials have been used since the 1930s in the prevention of corona discharge and later in advanced printed circuitries. The extensive use of these materials hes in their ease of processing, wide range of electrical properties, and relatively low cost. However, these materials are inhomogeneous. 

Fibrillated Fibers. Instead of extmding cellulose acetate into a continuous fiber, discrete, pulp-like agglomerates of fine, individual fibrils, called fibrets or fibrids, can be produced by rapid precipitation with an attenuating coagulation fluid. The individual fibers have diameters of 0.5 to 5.0 ]lni and lengths of 20 to 200 )Jm (Fig. 10). The surface area of the fibrillated fibers are about 20 m /g, about 60—80 times that of standard textile fibers. These materials are very hydrophilic an 85% moisture content has the appearance of a dry soHd (72). One appHcation is in a paper stmcture where their fine fiber size and branched stmcture allows mechanical entrapment of small particles. The fibers can also be loaded with particles to enhance some desired performance such as enhanced opacity for papers. When filled with metal particles it was suggested they be used as a radar screen in aerial warfare (73). 

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