Effect of Membrane Thickness

Effect of membrane thickness on permeation rate and separation factor... 

Different results concerning the effect of membrane thickness on pervaporation performance was reported in the literature [39,40,42]. 

Table I shows the effect of membrane thickness on the response times for the two different types of Dacron mesh support (internal and external) used for the membranes in the flow cell. Thickness increases the response time for both the pH and glucose concentration changes. Use of the internally incorporated Dacron mesh may possibly decrease the response time due to an increase in the porosity of the gel allowing greater solute transport within the membranes.

Figure 3.18. Schematic of the PEMFC geometry and basic electric circuit showing the membrane electrode assembly (MEA) and the gas diffusion layers (GDLs) at both anode and cathode [33], (Reprinted from Electrochimica Acta, 51(13), Tsampas MN, Pikos A, Brosda S, Katsaounis A, Vayenas CG, The effect of membrane thickness on the conductivity of Nafion, 2743-55. 2006, with permission from Elsevier.)...

Tsampas MN, Pikos A, Brosda S, Katsaounis A, Vayenas CG (2006) The effect of membrane thickness on the conductivity of Nafion. Electrochimica Acta 51(13) 2743-55... 

Matsuyama H, Masui K, Kitamura Y, Maki T, and Teramoto M. Effect of membrane thickness and membrane preparation condition on facilitated transport of CO2 through ionomer membrane. Sep. Purif. Tech. 1999 17 235-241. 

Figure 12.5(a) and (b) shows the results of the diffusion of the six proteins through our n-type and p-type porous SiC membranes, respectively. Membranes of both n-type and p-type SiC exclude proteins in the same size range. The n-type material allowed much more protein to diffuse through, by a factor of as much as four times (for myoglobin). We have not yet investigated the effect of membrane thickness. Each membrane... 

Figure 6. Effect of membrane thickness on RX conversion and catalytic effectiveness.

Figure 9.23 The effect of membrane thickness on flux through a coupled transport membrane.20 (Membrane Laminated Celgard 2400/various reagents. Feed 0.2% copper, pH 2.5. Product 100 g/C H2SO4).

Figure 9.24 The effect of membrane thickness on the coupled transport flux of nickel through reaction rate limited membrane.73 (Membrane Laminated Celgard 2400/30% Kelex 100 dissolved in Kermac 470B. Feed 0.2% nickel, pH 6.0. Product 100 g/fi HjSO. ...

Fig. 14.6 Effect of membrane thickness on hydrogen recovery through the membrane...

Fig. 1.38 Methanol permeability studies Effect of membrane thickness upon permeability.

Figure 2.7 Effect of membrane thickness on the Hj permeation flux of SrCeogjTmoojOjj membranes [111].

The effect of membrane thickness is shown in Figure 24.5. Opposing influences are exerted by reaction and permeation, resulting in an optimum thickness of 0.1 cm. 

Figure 24.5 Dehydrogenation of cyclohexane effect of membrane thickness on conversion (from the results of Itoh et al., 1985)...

Figure 3 Effect of membrane thickness on the release of salicylic acid (10 w/w) from laminated Eudrugit filins. comprising a drug containing reservoir coated by a drug-free polymer. (Front Ref. lH. Reproduced with permission of the American Pharmaceutical Association. I...

Raisi A, Aroujalian A. 2011. Aroma compound recovery by hydrophobic pervaporation The effect of membrane thickness and coupling phenomena. Sep. Purif. Technol. 82 53-62. 

Adnadjevid et al. (1997) studied the effect of three different types of hydrophobic zeolites (ultrastable zeolite type Y, pentasyl-type zeolite (ZSM-5), and ALPO-5 type zeolite) on the PV properties of zeolite-tilled PDMS membranes. The physiochemi-cal properties of the zeolite used, primarily the degree of hydrophobicity, as well as the sorption capacity for EtOH, the specific pore volume, specific area, and mean crystallite size of the zeolite, significantly influence the membrane s PV properties. An increase in the zeolite content results in an increase in both membrane permeability and membrane selectivity, while an increase in the PV temperature results in an increase in the permeability and a decrease in the selectivity, as opposed to the effect of membrane thickness. 

H. H. Nijhuis, M. H. V. Mulder, and C. A. Smolders, Removal of trace organics from aqueous solutions. Effect of membrane thickness, J. Membrane Sci., 61, 99 (1991). 

Since it is believed that membrane degradation occurs because molecular H2 and O2 react to form membrane-degrading species such as H2O2 or reactive radicals, and because membrane thickness is related to reactant gas crossover, some groups have investigated the effect of membrane thickness on membrane degradation. 

Effect of Membrane Thickness. Permeation rates were measured through a single membrane, a two-membrane laminate and a three-membrane laminate. HOlOA membranes were used as the support membrane. The effect of total membrane thickness on the permeation rate of CO2 is shown in Figure 4. It is seen that as anticipated, the permeation rate decreases with increasing Ae membrane thickness. 

To examine the effect of membrane thickness, a hypothetical calculation was performed for the MEA membranes of various thickness and the calculated results are shown in figure 4. It is seen that as the thickness decreases, Rcq2 increases. It is also seen that en L = 1pm, Rco2 is almost independent of the CO2 partial pressure since the CO2 permeates through the thin membrane in the region of physical... 

Fig. 8.25 Effect of membrane thickness on the flux (a) and the separation factor (b) The mole fraction in the feed, temperature and the feed gas presser are 0.5, 300 K and 0.5 MPa, respectively. (From [12])...

Fig. 14.2 The effect of membrane thickness on direct methanol fuel cell performance. T = 60°C, 1.0 M methanol feed, ambient pressure air at 500 seem, (circle) and (filled rectangle) Nafion 117 (215 pm wet thickness) (triangle) and (filled triangle) Nafion 112 (60 pm wet thickness)...

Fig. 14.4 The effect of membrane thickness on MEA performance curves for a direct methanol fuel ceU operating at 60°C with a 1.0 M methanol feed...

The effect of membrane thickness on DMFC performance for three different methanol feed concentrations (1.0, 5.0, and 10.0 M) is shown in Fig. 14.6. A 215- jm membrane is much more sensitive to increases in methanol feed concentration (a more significant downshift in the V-i curves with methanol concentration) than the thicker membranes (420 and 540 pm). The V-i curves for the 540 pm Nafion were nearly independent of methanol feed concentration (indicating that methanol crossover was small), but were suppressed as compared with those with a thinner Nafion film due to a high IR drop. 

Fig. 14.14 Effect of membrane thickness and methanol feed concentration on the maximum power density from MEAs composed of Nafion 117 and 50/50 Nafion/FEP (50- and 100-p.m thickness). Fuel cell operating conditions 60°C, 2 ml min" methanol feed flow rate, ambient pressure air at 500 seem. (From [18], reproduced by permission of The Electrochemical Society, Inc.)...

Figure 2.11 Fuel cell polarization curves (empty symbols) and power densities (filled symbols) of Pt cathodes in pure oxygen showing the effect of membrane thickness on...

Figure 29.6 Effect of membrane thickness on tuU cell performance with two commercial Nafion membranes. R denotes the membrane areal resistance (a) PEMFC and (b) DMFC.

Teranishi K, Tsushima S and Hirai S (2005) Study of the Effect of Membrane Thickness on the Performance of Polymer Electrolyte Fuel Cells by Water Distribution in a Membrane, Electrochemical and Solid-State Letters, 8, A281-A284. 

The effect of membrane thickness on surface morphology has been studied for homogeneous PPO membrane cast from solutions of PPO in TCE by using AFM technique. 

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