Random sequential adsorption

Ramsden J J 1993 Review of new experimental methods for investigating random sequential adsorption J. Stat. Phys. 73 853-77... 

Ramsden, J. J., Review of new experimental techniques for investigating random sequential adsorption, J. Statist. Phys. 1993, 73, 853 877... 

M. Manciu, E. Ruckenstein Estimation of the available surface and the jamming coverage in the Random Sequential Adsorption of a binary mixture of disks, COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS 232 (2004) 1-10. 

The area available to a disk (or to a sphere) to be adsorbed on a surface during a random sequential adsorption (RSA) of a binary mixture of disks (spheres) is in general estimated via Monte-Carlo simulations, which are vety time consuming. A simple analytical expression is proposed, which provides good estimates of the jamming points for the RSA of a binary mixture of disks or spheres. The predictions of the simple formula have been compared with the Monte-Carlo simulations existing in the literature [8.10],... 

Estimation of the available surface and the jamming coverage in the Random Sequential Adsorption of a binary mixture of disks... 

A simple analytical expression is proposed for the area available to a disk on a surface for a Random Sequential Adsorption (RSA) of binary mixtures of disks. The expression was obtained by combining the low-order terms of the density expansion of the available area with the asymptotic behaviour of the surface coverage near the jamming point. Comparison with Monte Carlo simulations shows that this approach provides a fair estimation of the jamming coverage for both kinds of disks. 

Keywords Random Sequential Adsorption Jamming Disk mixture... 

The non-equilibrium problem is even more complicated. The large particles can have surface binding energy much larger than kT and in this case they neither diffuse nor desorb from the surface. The Random Sequential Adsorption (RSA) model [9] assumes that a particle, which arrives at a random location on a surface, is adsorbed only if there is... 

The RSA model received renewed attention after Feder [12] observed that the adsorption on the surface of apo-ferritin molecules (large iron-storage proteins with a diameter of about 10 nm), which adsorb irreversibly, reached saturation at a coverage (k = 0.518. Monte Carlo simulations of Random Sequential Adsorption of disks on a surface last prohibitively long in the vicinity of the jamming point however Feder [12] noted that in the vicinity of the jamming coverage, 9 has a power-law dependence on time ... 

POPC l-Palmitoyl-2-oleoyl-s -glycero-3-phosphocholine POPS l-Palmitoyl-2-oleoyl-s -glycero-3-phosphoserine QCM Quartz crystal microbalance RSA Random sequential adsorption SSM Solid supported membrane... 

On the basis of the model of a heterogeneous membrane, it is possible to create a simulation scheme based on dynamic Monte Carlo computer simulations of the adsorption and desorption process on heterogeneous surfaces to extract the involved rate constants as a function of the calcium ion concentration. A simple simulation based on a modified, partly reversible, random sequential adsorption (RSA) algorithm provides very good accordance between experiment and measurement. Figure 8 schematically depicts the assumed model. 

Most theories for polymer adsorption kinetics start from (combinations of) the models discussed earlier. Other theories, often proposed for (bio)polymer adsorption, are based on the random sequential adsorption (RSA) model. According to this model, the adsorbate molecules arrive randomly at the interface and they stick where they hit. It implies that both desorption and tangential motion of the adsorbate at the interface are absent. Because the center of a newly arriving spherical molecule cannot be accommodated within the shaded areas enclosed by the dashed circles shown in Figure 15.6, only the unshaded fraction < ) of the surface is available for adsorption. It is obvious that ( ) is a function of 0, the fraction of the surface that is covered by the adsorbate. For sphere-like molecules, 0 = niUi (R being the radius of the molecule). The following expressions for the available surface function < )(0) can be derived from the RSA theory ... 

FIGURE 15.6 Excluded interfacial area for deposition of molecules that adsorb according to the random sequential adsorption model. 

FIGURE 15.7 Available interfacial area for adsorption of spheres as a function of surface coverage, according to the random sequential adsorption model. The fuU-line curve represents c )(9) calculated using (15.9) whereas the other curves are calculated using Equation 15.10 taking two, three, and four terms of the series into account. 

FIGURE 15.8 Adsorption kinetics according to the random sequential adsorption mechanism for spherical and ellipsoidal particles having varying aspect ratios (a/b). 

When adsorption is completely irreversible, the particle description reduces to the random sequential adsorption (RSA) model (87-89). An RSA process is one in which hard objects are added randomly and sequentially to a surface at a given rate and in which any object placed in a position so as to overlap with another object is immediately removed. The governing kinetic equation is... 

Khripin,2008 ssDNA-dispersed SWCNT CHa-modified silicon Proposed a modified random sequential adsorption theory to predict density of combed molecules. 

C. Khripin, Random sequential adsorption of line segments with a finite jamming limit,/ Colloid Interface Sci., 323, 213-215 (2008). 

J. Feder, Random sequential adsorption, f Theor. Biol., 87, 237-254... 

R. Vigil and R. Ziff, Random sequential adsorption of unoriented rectangles onto a plane,/. Chem. Phys., 91, 2599-2602 (1989). 

P. Schaaf and J. Talbot, Kinetics of random sequential adsorption, Phys. Rev. Lett, 62,175-178 (1989). 

The theoretical approaches aimed at a description of nonlinear adsorption regimes are discussed next—in particular the elassieal, random sequential adsorption (RSA) model. The role of polydispersity, particle shape, orientation, and electrostatic interactions is elucidated. Then, the generalized RSA model is presented, which reflects the coupling of the surface transport with the bulk transfer step governed by external force or diffusion. 

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