Effect of surface roughness on diffusion limited reactions, a multifractal scaling analysis

Chaudhari, Ajay; Yan, Ching‐Cher Sanders; Lee, Shyi‐Long

doi:10.1016/s0009-2614(01)01419-1

Cited by 19 publications

(31 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The multifractal formalism 40 has been used for geometrical description of other physical and chemical phenomenon. 22,23,30,34,[41][42][43][44] We have applied the multifractal scaling which relates the analysis of the distribution of the reaction probabilities over the length of the rough surface. Two curves can be obtained from the multifractal scaling analysis 1) q Vs t(q) and 2) a Vs f(a), where q is the moment order, t(q) is the scaling exponent, a is the scaling exponent measuring the range of reaction probability and f(a) is its density function.…”

Section: Multifractal Scaling Analysismentioning

confidence: 99%

“…In our previous work, 30 we have analyzed Eley-Rideal reactions over one-dimensional rough surfaces of a random deposition model to study the surface heterogeneity effect on this reaction mechanism and obtained a wide range of reaction probability distributions for rough surfaces rather than for smooth surfaces. In this work, we are considering the Eley-Rideal reaction mechanism over two-dimensional rough surfaces.…”

Section: Introductionmentioning

confidence: 99%

“…In previous studies of ER reactions over rough surfaces, 30,34 the diffusion of the reacting particle was not considered, and the effect of surface diffusion of a reacting particle on reaction probability distribution has not been studied. In ref.…”

Section: Introductionmentioning

confidence: 99%

“…In ref. 30 the reacting particle either reacts at the top of the column selected randomly (RD) or at the top of one of the nearest neighboring columns (RDWD). In this work the reacting particles are allowed to diffuse over the surface (not only up to the nearest columns as in ref.…”

Section: Introductionmentioning

confidence: 99%

“…In this work the reacting particles are allowed to diffuse over the surface (not only up to the nearest columns as in ref. 30) till it finds a minimum height position. The reacting particle may diffuse over the surface for many reasons.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Computer Simulation of Eley‐Rideal Reactions Over Rough Surface

Chaudhari

Rabbani²,

Lee

2007

J Chinese Chemical Soc

Self Cite

View full text Add to dashboard Cite

The effect of surface roughness on an Eley-Rideal reaction mechanism is studied. The rough surfaces are generated over a 2-dimensional square lattice using the random deposition model. In an Eley-Rideal reaction mechanism, a reacting particle approaches from the bulk and reacts with an active site upon collision with it. Three different rough surfaces are considered for the study. Multifractal scaling analysis is performed where the complex distribution of reaction probabilities is analyzed. Two cases of reactions are considered. 1) The reacting particle reacts at its first contact to the surface and 2) the reacting particle diffuses till it finds the lowest-height position and reacts. The results obtained from the above two cases are compared. Significant differences between t(q) and f(a) multifractal spectra for these two cases are found. The larger deviation from linearity in the t(q) curves for the latter than the former gives wider f(a) spectra, indicating greater heterogeneity in the reaction probability distribution. Dynamic scaling theory is also applied on the Eley-Rideal reaction mechanism over the surface with different surface roughnesses to obtain the two scaling parameters a d and b d . The values of a d and b d are found to be negative.

show abstract

Section: Multifractal Scaling Analysismentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Computer Simulation of Eley‐Rideal Reactions Over Rough Surface

Chaudhari

Rabbani²,

Lee

2007

J Chinese Chemical Soc

Self Cite

View full text Add to dashboard Cite

show abstract

Collisions of ideal gas molecules with a rough/fractal surface. A computational study

Pańczyk

2006

J Comput Chem

View full text Add to dashboard Cite

The frequency of collisions of ideal gas molecules (argon) with a rough surface has been studied. The rough/fractal surface was created using random deposition technique. By applying various depositions, the roughness of the surface was controlled and, as a measure of the irregularity, the fractal dimensions of the surfaces were determined. The surfaces were next immersed in argon (under pressures 2 x 10(3) to 2 x 10(5) Pa) and the numbers of collisions with these surfaces were counted. The calculations were carried out using a simplified molecular dynamics simulation technique (only hard core repulsions were assumed). As a result, it was stated that the frequency of collisions is a linear function of pressure for all fractal dimensions studied (D = 2, ..., 2.5). The frequency per unit pressure is quite complex function of the fractal dimension; however, the changes of that frequency with the fractal dimension are not strong. It was found that the frequency of collisions is controlled by the number of weakly folded sites on the surfaces and there is some mapping between the shape of adsorption energy distribution functions and this number of weakly folded sites. The results for the rough/fractal surfaces were compared with the prediction given by the Langmuir-Hertz equation (valid for smooth surface), generally the departure from the Langmuir-Hertz equation is not higher than 48% for the studied systems (i.e. for the surfaces created using the random deposition technique).

show abstract

Dynamic scaling for Eley‐Rideal reactions over rough surface

Chaudhari¹,

Yan²,

Lee³

2004

Int J of Chemical Kinetics

Self Cite

View full text Add to dashboard Cite

Eley-Rideal reaction mechanism is studied over rough surface of random deposition model. Two types of rough surface are considered: (1) different rough surface with same surface density and (2) different rough surface with different surface density. Dynamic scaling theory, which is generally applied to the growing surface, is applied for this reaction mechanism to obtain the temporal and spatial scaling parameters α and β. The scaling parameters are found to be negative in contrast to the positive scaling parameters in surface growth model. The values of β are the same for both types of surface whereas the values of α are different.

show abstract

Effect of surface roughness on diffusion limited reactions, a multifractal scaling analysis

Cited by 19 publications

References 22 publications

Computer Simulation of Eley‐Rideal Reactions Over Rough Surface

Computer Simulation of Eley‐Rideal Reactions Over Rough Surface

Collisions of ideal gas molecules with a rough/fractal surface. A computational study

Dynamic scaling for Eley‐Rideal reactions over rough surface

Contact Info

Product

Resources

About