Membrane preparation carbon membranes

Figure 15.7 XPS spectra of the original PPESK membrane and as-prepared carbon membranes.

The method to prepare carbon membranes was described from wood pulp hydrolyzed to different extents by Lie and Hagg [66], Different heating protocols were also shown. A simple, energy effective and rapid regeneration method for membranes that are conductors or semi-conductors has been developed by applying low voltage, direct current on an iron-doped carbon. 

The catalyst inks were prepared by dispersing the catalyst nanoparticles into an appropriate amoimt of Millipore water and 5wt% Nafion solution. Then, both the anode and cathode catalyst inks were directly painted using a direct painting technique onto either side of a Nafion 117 membrane. A carbon cloth diffusion layer was placed on to top of both the anode and cathode catalyst layers [3-5]. The active cell area was 2.25cm. ... 

Sung JH, Kim HS, Jin HJ, Choi HJ, Chin IJ (2004). Nanofibrous membranes prepared by multi-walled carbon nanotube/poly(methyl methacrylate) composites. Macromolecules 37 9899-9902. 

We also prepared carbonate analogues by acylation of dihydro-QHS, consistent with Scheme 10. Although numerous analogues derived from DHQHS have appeared in the literature, linkage of DHQHS to cell-membrane components has not... 

N. Tanihara, H. Shimazaki, Y. Hirayama, N. Nakanishi, T. Yoshinaga and Y. Kusuki, Gas Permeation Properties of Asymmetric Carbon Hollow Fiber Membranes Prepared from Asymmetric Polymer Hollow Fibers, 7. Membr. Sci. 160, 179 (1999). 

H. Kita, H. Maeda, K. Tanaka and K. Okamoto, Carbon Molecular Sieve Membranes Prepared from Phenolic Resin, Chem. Lett. 179 (1997). 

In addition to the polymer and facilitated transport membranes, novel materials are being proposed and investigated to achieve membranes with economically attractive properties. Carbon molecular sieve (CMS) membranes prepared by pyrolysis of polyimides displayed much better performance for olefin/paraffin separation than the precursor membranes [39, 46, 47]. Results obtained with CMS membranes indicated properties well beyond the upper-bond trade-off curve, as shown in Figure 7.8. Nonetheless, this class of materials is very expensive to fabricate at the present time. An easy, reliable, and more economical way to form asymmetric CMS hollow fibers needs to be addressed from a practical viewpoint. 

Another example is the perturbing effect of eight calcium channel blockers on membranes prepared from two different lipids [68]. The authors used total lipids from rat brain and synaptosomal membranes. The spin probe was l-palmitoyl-2-stearoyl-phosphatidyl-choline labeled at the doxyl group at the carbon-16 position (16-PC). The apparent order parameter, S, is calculated from the apparent outer (Amax) and inner (Amin) splittings which were directly taken from the ESR spectra. It is used to describe the relative efficiency of the dmgs in perturbing the lipid membrane. 

The present work is the first attempt to develop the methods of preparation of carbon membrane catalysts with metal nanoparticles in a carbon membrane matrix. 

Gas transport coefficients of PVC and PVC modified with pyridine groups were studied. It was found that there is a strong time dependence of the permeability and diffusivity of oxygen, nitrogen, carbon dioxide and methane in membranes prepared by solvent casting of PVC and pyridine modified PVC. There is a two-fold reduction for PVC of the diffusion coefficients during the first two days,... 

Carbon molecular sieve membranes have been prepared on porous supports by controlled pyrolysis. For example, Chen and Yang [1994] prepar carbon molecular sieve membranes on porous graphite supports by coating a layer of polyfurfuryl alcohol followed by conu-olled pyrolysis with a Hnal temperature of 50O C. The procedure can be repeated to deposit a desired thickness of the carbon membrane. The choice of a graphite support is partially based on the consideration of the compatibility in thermal expansion between the carbon and the support. 

Vu DQ, Koros WJ, and Miller SJ. Mixed matrix membranes using carbon molecular sieves I. Preparation and experimental results. J. Membr. Sci. 2003 211 311-334. 

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