کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
5365849 1388339 2008 7 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Studies of the collision frequency of ideal gas particles with the surfaces of the objects created using the ballistic deposition technique
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی تئوریک و عملی
پیش نمایش صفحه اول مقاله
Studies of the collision frequency of ideal gas particles with the surfaces of the objects created using the ballistic deposition technique
چکیده انگلیسی

This paper is a continuation of our studies of the collision frequency of ideal gas particles with the rough/fractal surfaces. Here, we applied a more realistic surface growth model, i.e. ballistic deposition for creation of fractal objects. We found that the collision frequency with irregular surfaces is the linear function of pressure and this frequency per unit pressure is quite a complicated function of the surface fractal dimension as well as the diameter of colliding particle. The collision frequency with rough surfaces cannot be exactly described by the analytical formula called the Langmuir-Hertz equation. However, we have stated that the deviations of the true collision frequency from the Langmuir-Hertz prediction are not huge and in typical catalytic studies the error introduced by replacing the true frequency by the Langmuir-Hertz prediction can be safely neglected. We have also studied the probability of finding on the surface an atom which has been hit a certain number of times by a gas particle. This probability reveals an interesting behaviour for small gas particles, i.e. it perfectly correlates with the number of directions from which the surface atom is accessible from the gas phase. We have also estimated the evolution of the adsorption energy distribution with the increasing fractal dimension of the surface in the ballistic deposition.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Applied Surface Science - Volume 254, Issue 8, 15 February 2008, Pages 2285-2291
نویسندگان
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