About adsorption rate and adsorption rate - Database & Sql Blog Articles

In the physical adsorption industry, there are often many students, teachers, and even experts in the industry. They are not sure whether the physical quantity to be tested is called "adsorption speed, desorption rate, desorption rate" or "adsorption rate, desorption rate, desorption rate"; Many master's and doctoral thesis, even some of the more professional technical articles, often appear inconsistent. Since "speed" is relatively colloquial with respect to "rate", "rate" is more "academic" than "speed", so it is often found that many professional people call it "adsorption speed, desorption speed, desorption speed", etc. The parameters are called "adsorption rate, desorption rate, desorption rate". To find out whether it is called "adsorption speed" or "adsorption rate", we must first understand the difference between "speed" and "rate". Speed ​​is vector, with direction and size; rate is scalar, only size, no direction. For example: for points A, B, and C located at three corners of an equilateral triangle with a side length of 100 m, an object reaches the point B from A through C at a uniform velocity of 10 m/sec. It takes 20 seconds; In this case, the speed of the object from A to B is 5 m/sec, and the moving speed of the object is 10 m/sec. For another example, for a gas molecule or dust suspended in a gas that undergoes Brownian motion, the instantaneous velocity or rate of irregular motion is large, but when we discuss its speed from point A to point B, We use AB's linear distance divided by time, and the rate does not need to consider its directionality, "just look at the size." In our discussion of the physical adsorption of adsorbate on the surface of the adsorbent, two phenomena occur simultaneously due to adsorption and desorption. As we all know, when in the equilibrium state of adsorption, the adsorption rate and the desorption rate are not zero, but equal, but the adsorption speed and the desorption rate are zero. For another example, for all other adsorption equilibrium states in which all the conditions are the same except that the temperature is different, the adsorption rate or the desorption rate in the high temperature state may be relatively low, but the adsorption speed or the desorption rate is zero. . The "adsorption rate" or "desorption rate" is more apt to characterize the rate at which the adsorbate molecules simply accumulate on the surface of the adsorbent or simply leave the solid surface; while the "adsorption rate" or "desorption rate" is more The bias is to characterize the amount of adsorbate on the surface of the "net agglomerated" or "net away" adsorbent due to the difference in adsorption rate and desorption rate over time, due to "directionality", which tends to characterize "effect." Most of the instruments currently in the market involving "adsorption speed, desorption rate" test are actually increasing or decreasing the adsorbate surface on the adsorbent surface for a period of time. Then, such instruments should be called adsorption speed testers or The desorption rate tester is more appropriate and should not be called an adsorption rate tester or a desorption rate tester, an analyzer, etc., because it does not analyze the "rate size". In fact, the popularity of these "proprietary" nouns or concepts, mainly from textbooks, is not limited to the relevant businesses or research units. If there are too many people who understand the wrong, and there is no authority to correct and explain at the moment, the merchant may proceed from the commercial interests, follow the "trend" and "force" to abandon "rigorous"; like the word "adsorption speed", It may be that many domestic and foreign merchants actually understand what it should be called, but from a commercial point of view, for the sake of better acceptability and being recognized, they follow the public. Especially in the current situation where web search is the main promotion method, this situation is more obvious. A lot of easy-to-understand but not rigorous words are produced in this way. As a manufacturer and research unit engaged in gas adsorption and vapor adsorption analysis instruments, Bethes Instruments is responsible for giving scientific explanations and advocating the proper use of such terms as "adsorption speed" and "adsorption rate".