https://scholars.lib.ntu.edu.tw/handle/123456789/63891
標題: | 高分子添加劑對耐米粒子懸浮液相行為影響之研究 | 其他標題: | The effect of polymeric additives on the phase behavior of the nanosized particle suspension | 作者: | 諶玉真 | 關鍵字: | 耐米粒子;雙塊區間共聚合高分子;徑向分佈函數;電腦分子模擬;Nanosized particles;Diblock copolymer;Radial distribution func-tion;Computer molecular simulations | 公開日期: | 1999 | 出版社: | 臺北市:國立臺灣大學化學工程學系暨研究所 | 摘要: | 膠體粒子(colloid)在溶液中的穩 定性一直是食品工業與清淨程序操作中 的重要影響因素。近年來,由於耐米粒子 (nano-sized particle)在各式新興工業 的潛在應用價值,其合成與製造已在學術 領域中引起廣泛的研究興趣。然而在其製 造程序中,耐米粒子懸浮液的熱力學或動 力學穩定性更是扮演決定性的角色。 一般而言,耐米粒子之間具有長距 離的凡得瓦引力,它會導致粒子之間凝絮 而產生不穩定的沉降現象。本研究之目的 在探討添加高分子至耐米粒子懸浮液中 對其穩定性之影響。高分子種類包含非吸 附性高分子(nonadsorbing polymer)、吸附性高分子、雙塊區間共聚合高分子(di-block copolymer)。我們採用類似分子模擬的蒙地卡羅 法(Monte Carlo method),從微觀層次來 研究(a)耐米粒子之間,及(b)耐米粒子與 高分子之間的作用和結構;該系統穩定性 可反應於徑向分佈函數(radial dis- tribution function)。我們將比較未添 加高分子、添加非吸附性高分子、吸附性 高分子、及共聚合高分子的徑向分佈函 數。另外,我們也將討論耐米粒子濃度、 高分子濃度、及其鏈長對懸浮液穩定性的影響。 The addition of polymers to a col-loidal dispersion creates a change in the phase behavior and the local structure of the colloidal component. This effect is of great importance in dealing with treatment of colloidal suspensions. For example, it has been known that upon adding enough nonadsorbing polymer to the system, the colloidal particles tend to cluster. The presence of the polymers induces an en-tropic- originated attraction between the colloidal particles. On the other hand, the entropic effect can also cause steric hin-drance to prevent coagulation of the colloi-dal particles if the appropriate dopant, such as diblock copolymer, is added. To achieve the purpose of steric stabilization of a suspension, for a diblock copolymer, block A should have a prefer-ential affinity for the colloidal particle and block B for the continuum fluid. With block A adsorbed on the particle surface and block B extending out to the continu-ous phase, these diblock copolymers form protective layers to prevent colloidal parti-cles to come in contact with each other. As a consequence, the suspension is more stabilized. We intend to perform Monte Carlo simulation to investigate this phenomenon on the microscopic level. The system is studied in continuous space with the parti-cle interacting through the square-well po-tential. Important factors such the ratio of chain bead diameter to colloidal particle diameter, the chain lengths of block A and B, and the concentration of the added di-block copolymers will be carefully exam-ined and the effect of each factor on the thermodynamic properties such as the ra-dial distribution function, of the system will be determined. |
URI: | http://ntur.lib.ntu.edu.tw//handle/246246/9203 | 其他識別: | 882218E002046 | Rights: | 國立臺灣大學化學工程學系暨研究所 |
顯示於: | 化學工程學系 |
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882218E002046.pdf | 79.53 kB | Adobe PDF | 檢視/開啟 |
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