球形載體含部份覆蓋活化體之分佈對擴散限制連續反應程序之效應

Effect of the Patch Distribution of A Sphere Surface on A Diffusion-Limited Consecutive Reaction Process

胡振興(Chen-Hsing Hu)

指導教授 ： 吳瑞璋

中原大學/工學院/化學工程研究所/碩士(2010年)

https://doi.org/10.6840/cycu201000015

摘要

本研究是以連續擴散結合反應機制探討微細粒子隨機擴散至含雙活性綴片(patch)懸浮粒體後結合之行為，屬於擴散限制的系統，表面結合反應速率為無窮大，研究於無因次化參數P(P＝D/kR)為零時，其正規化總反應速率常數(Normalized overall rate constant)之變化。
主要構想是探討擴散限制系統下，球體表面有二種不同綴片(大小相同)分佈，模擬配合首次通過時間理論(first-passage time theory)及加速布朗動力模擬 (Sped-up Brownian dynamic simulation)。目的是探討球體上有兩組綴片(大小相同)存在時，綴片大小變化、綴片群組是以最緊密、最鬆散或二者之間存在，綴片群組間以最緊密、最鬆散或二者之間時速率常數差異性。且探討綴片群組於不同分佈排列方式下，無因次群組分離指數(Isg)之變化。球體表面所覆蓋綴片之覆蓋率(f)變化、綴片活動分佈展開角度範圍變化對速率常數之影響。模擬時以總數1000000顆測試粒子，一次釋放一個的方式，觀察擴散及結合行為。
模擬結果發現，相同的覆蓋率(f)下，較小的綴片會得到較高的總反應速率常數。群組間分離指數(Isg)逐漸縮小(接近)時，總反應速率常數數值也會往上提升。球體表面覆蓋率提升，則總反應速率常數也是往上提升。綴片分佈的展開角度越來越大，總反應速率常數則隨著增大，上述等都可觀察到參數與總反應速率常數相關之正向趨勢。

關鍵字

無因次群組分離指數 ； 加速布朗動力模擬 ； 首次通過時間理論 ； 正規化總反應速率常數

並列摘要

The research is based on a continuous diffusion and incorporation reaction process, involving diffusion of small entities onto the surface of a much larger inclusion and incorporation into two kinds of patches on the inclusion. This system is a diffusion-limited system, whose surface reaction rate is infinite. The normalized overall rate constant of reaction is computed based on the assumption that the dimensionless parameter P(P＝D/kR ) is zero.
The inclusion is assumed a sphere surface, which is with two kinds different of patches (the same of size). The simulation is based on "the first-passage time theory "and "sped-up Brownian dynamic simulation" to explore a diffusion-limited system. The purpose is to investigate the changes of overall rate constant by changing the patch size and the distribution of two patch groups. The rate constant is calculated by varying the separation state of the distributed patch group, i.e. the dimensionless separation index of group (Isg), and the patch coverage fraction (f ) on the sphere surface. The simulation totally releases one million test particles, with releasing one at one time.
In result, we discovered the smaller the patch size, the larger the overall reaction rate constant will be obtained, when patch coverage fraction (f ) is the same. When the separation index of group (Isg) decreases, the overall rate constant will become higher. Increasing the sphere surface coverage also increases the overall rate constant. As well, when the distributed range spread angle increases, the overall rate constant increases. The reaction rate constant is correlated in a positive tread with all different parameters.

並列關鍵字

Separation index of group ； Sped-up Brownian dynamic simulation ； First-passage time theory ； Normalized overall rate constant

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