
[物化] 臨界膠團濃度
In this study they attempted to predict the critical micelle concentration (CMC).
在研究中,他們嘗試着預測臨界膠态粒子濃度(CMC)。
Critical micelle concentration is an important physicochemical property of surfactants.
臨界膠束濃度是表面活性劑的重要物理化學性質。
Its surface ten-sion, critical micelle concentration, wetting power, foaming power, etc were tested, thus reliable base was provided for further research, development, and application.
優化了合成工藝條件,測試了産品的表面張力、 臨界膠束濃度、 潤濕性、 起泡力等性能,為進一步研究開發和應用提供了可靠的依據。
By the incorporation kinetics experiments , the effects of cholesterol on the stability ratio and the critical mixed micelle concentration of liposome systems were investigated.
藉由嵌入動力學探讨膽固醇對微脂粒系統之安定比與臨界混合微胞濃度的影響。
Different aggregation state of CTAB molecules has different effects on the critical associating concentration of gelatin and the effect of CTAB monomer is greater than that of spherical micelle.
CTAB使得明膠的締合濃度下降,且CTAB單分子對明膠臨界締合濃度的影響程度大于球形膠束。
Their structures were confirmed by IR, and the properties of these surfactants such as acid number, interfacial tension, and critical micelle concentration and so on were stu***d.
通過紅外光譜确定了産物的結構,并對有機硼表面活性劑的酸值、表面張力以及臨界膠束濃度等性能進行了研究。
The surface tension and critical micelle concentration of SDS were influenced by the properties of the cyclodextrins added.
SDS的表面張力及臨界膠束濃度的變化與添加的環糊精的性質有關。
The critical micelle concentration(CMC) of surfactant in low-temperature dyeing assistant CWL was measured with the method of surface tension.
用表面張力法測試了自制低溫染色助劑CWL中表面活性劑的臨界膠束質量濃度(CMC)。
The water-solubility, emulsifying ability, surface tension, critical micelle concentration(CMC) of phosphate were determined.
測試了*********的水溶性、乳化力、表面張力、臨界膠束濃度等性能。
These direct measurements allow determination of a number of material and surface properties, such as dynamic contact angle, surface free energy, critical micelle concentration and wettability.
可直接測量許多材料和表面特性,例如動态接觸角,表面自由能,關鍵性膠束濃度和可濕性。
The results show:as the carbon chain of anionic surfactant increases, the critical micelle concentration decreases;
結果陰離子表面活性劑隨碳鍊的增長,其臨界膠束濃度值相應地減少;
RESULTS AND CONCLUSION: With the degree of substitution and molecular weights increased, the stability of the nanoparticles enhanced, critical micelle concentration decreased.
結果與結論:隨着相對分子質量和取代度的增加,粒子穩定性增強,臨界膠束質量濃度降低。
Critical micelle concentration;
臨界膠束濃度;
Plot of critical micelle concentration vsmolar fraction of SB12 in the mixtures.
圖2混合表面活性劑的臨界膠束濃度與SB12摩爾分數之間的關系Fig。
The results indicated that the product could decrease the surface tension of water, and had lower critical micelle concentration, better surface activity.
該種陽離子表面活性劑具有較好的表面活性。
臨界膠束濃度(Critical Micelle Concentration, CMC) 是膠體與界面化學中的一個核心概念,指表面活性劑在溶液中開始形成膠束(micelle)的最低濃度。當表面活性劑濃度低于CMC時,其分子主要以單體的形式分散在溶液中,并吸附在界面(如氣-液界面)上以降低表面張力。一旦濃度達到或超過CMC,表面活性劑單體在溶液内部的濃度達到飽和,多餘的分子會自發聚集形成膠束——一種疏水尾向内、親水頭向外的有序聚集體。這一濃度轉折點即為CMC 。
表面張力轉折點
CMC可通過測量溶液表面張力隨濃度變化的曲線确定。當濃度低于CMC時,表面張力顯著下降;達到CMC後,表面張力趨于穩定,形成平台區。這是因為膠束的形成消耗了新增的表面活性劑單體,使其無法進一步降低表面張力 。
增溶作用的起始濃度
膠束的疏水内核可包裹非極性物質(如油脂、藥物分子),顯著提升其在水中的溶解度。這一現象稱為“增溶”(solubilization),僅在濃度高于CMC時發生 。
常用實驗手段包括:
疏水鍊越長,疏水作用越強,CMC越低(例如C12烷基鍊表面活性劑的CMC通常低于C8)。
離子型表面活性劑(如SDS)因親水基電荷排斥作用,CMC高于非離子型(如Tween-80)。
溫度升高可能破壞膠束結構,提高CMC;添加電解質可屏蔽離子型表面活性劑的電荷排斥,顯著降低CMC 。
權威參考文獻
Critical Micelle Concentration(CMC),中文譯為臨界膠束濃度,是表面活性劑溶液的一個重要物理化學參數。以下是詳細解釋:
基本定義
CMC指表面活性劑分子在溶液中開始自發締合形成膠束(micelle)的最低濃度。當溶液濃度低于CMC時,表面活性劑以單分子形式分散;達到或超過CMC時,多餘的分子會聚集形成膠束(親水基朝外,疏水基向内)。
形成機制
影響因素
CMC值受溫度、表面活性劑結構(如碳鍊長度)、電解質濃度等因素影響。例如,疏水鍊越長,CMC通常越低。
測定方法
常用方法包括表面張力法、電導率法、光散射法等。例如,光散射技術通過檢測溶液中膠束形成時的散射強度變化确定CMC。
應用領域
CMC在洗滌劑、藥物遞送、化妝品等領域有重要意義。例如,洗滌劑需在CMC以上才能有效通過膠束增溶油污。
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