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References 1. Dobrynin, A.V., Obukhov, S.P. and Rubinstein, M., 1999. Long-Range Mutichain Adsorption of Polyampholytes on a Charged Surface. Macromolecules, 32(17), 5689-5700. 2. Dobrynin, A.V., Zhulina, E.B. and Rubinstein, M., 2001. Structure of Adsorbed Polyampholyte Layers at Charged Objects. Macromolecules, 34(3), 627-639. 3. Fleer, G.J., Cohen Stuart, M.A., Scheutjens, J.M.H.M., Cosgrove, T. and Vincent, B. Polymers at Interfaces, Chapman & Hall, 1993. 4. Simmons, C., Webber, S.E. and Zhulina, E.B., 2001. Association of Ionized polymer Micelles with Oppositely Charged Polyelectrolytes. Macromolecules 34 (14), 5053- 5066. 5. Zhulina, E.B., Dobrynin, A.V. and Rubinstein, M., 2001. Adsorption of a Polyampholyte on a Charged Spherical Particle. Eur. Phys. J. E , 5(1), 41-49. 6. Zhulina, E.B., Dobrynin, A.V. and Rubinstein, M., 2001. Adsorption Isotherms of Polyampholytes at Charged Spherical Particles .J. Phys. Chem. B, 105(37), 8917-8930.
MEAN-FIELD THEORY FOR THE ADSORPTION OF FLEXIBLE POLYMERS DURING FLOW THROUGH GRANULAR POROUS MEDIA P. L.J. Zitha Delft University of Technology, Department of Applied Earth Sciences, Mijnbouwstraat 120, 2628 RX Delft, The Netherlands email: p.l.j.zitha@citg.tudelft.nl ABSTRACT We have developed a mean-field theory for the adsorption of flexible polymers during flow through granular porous media. There exist two situations (Fig. 1): (a) At low velocity gradients (weak flows) the chains retain the coil conformation and adsorb according to the classic layer mode. The adsorption density w increases with time θ, first according to a linear kinetic equation leading to an exponential saturation law w( θ) = w e[1−exp( θ / τ)] and then following a non-linear kinetic process. The transition from the linear to the non-linear regimes is associated with the development of a strong reptation barrier scaling like w 9/4 , when the adsorbed chains begin to overlap. This occurs at a well-defined critical adsorption density w* corresponding to the critical overlap concentration for the bulk polymer solution. (b) At high velocity gradient (strong flow), the coiled chains coexist with strongly stretched ones giving rise to a bi-modal adsorption: the coiled chains adsorb according to the layer mode while the long (stretched) ones bridge over the smallest pores (bridging adsorption). These two adsorption modes are strongly correlated and the corresponding adsorption densities w and z obey a system of coupled non-linear kinetic equations. The transition from linear to non-linear regimes occurs now at a concentration v* = ( w + κ z ) , where κ is the fraction of segments of the bridging chains that are in the adsorbed layer. Remarkably, the mechanical trapping of the stretched chains overcomes the reptation barrier when bridging adsorption is consecutive to layer adsorption. Figure 1. Cross-section of a pore showing the adsorbed layer (hydrodynamic thickness εH) and one bridging chain. Two portions of the bridging chain (degree of polymerisation Nb,1 and Nb,2) penetrate the adsorbed layer while the central portion (degree of polymerization Nb,c) is exposed to flow.
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Frontis - Wageningen International
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Prof. dr. Hans Fraaije Leiden Unive
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Prof. Ullrich Steiner University of
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Preface Self-consistent field model
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covered by polymers), and R. Rajago
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FIRST-ORDER WETTING TRANSITION AT F
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MOLECULAR SCF MODELLING OF PORES IN
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COLLAPSE OF POLYMER BRUSHES GRAFTED
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SURFACE FORCES, SUPRAMOLECULAR POLY
Page 19 and 20: SWEET BRUSHES: SYNTHESIS AND INTERF
Page 21 and 22: EFFECT OF MIXING OF TWO CHARGED PHO
Page 23 and 24: Figure 2 show a semi-log comparison
Page 25 and 26: MODELING OF STATIONARY POLYMER DIFF
Page 27 and 28: THEORY AND SIMULATION OF BILAYER ME
Page 29 and 30: Figure 1. Time evolution of the she
Page 31 and 32: SALT EFFECT TO RAYLEIGH DROPLETS OF
Page 33 and 34: MACROMOLECULES AT INTERFACES, A FLE
Page 35 and 36: APPLICATION OF HETEROGENEOUS LATTIC
Page 37 and 38: 8. Linse, P., 1993b. Phase behavior
Page 39 and 40: MODELING INTERFACIAL EFFECTS ON THE
Page 41 and 42: Using this patterned electrode, we
Page 43 and 44: span the gap between the electrodes
Page 45 and 46: desirable to use a probe with a muc
Page 47 and 48: span the gap between the electrodes
Page 49 and 50: MEMBRANE FUSION: RESULTS FROM SIMUL
Page 51 and 52: the transition temperature T * when
Page 53 and 54: PROTEIN ADSORPTION ON SURFACES WITH
Page 55 and 56: MODELLING STRUCTURE AND ADHESION AT
Page 57 and 58: References 1. Fischel, L.B. and The
Page 59 and 60: MULTIDOMAIN CONFORMATIONS OF RANDOM
Page 61 and 62: SUPRAMOLECULAR COORDINATION POLYMER
Page 63 and 64: INFLUENCE OF POLYMERS ON THE BENDIN
Page 65 and 66: SPINODAL DECOMPOSITION IN BINARY PO
Page 67 and 68: PERSISTENCE LENGTH OF WORM-LIKE MIC
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