
[物化] 临界胶团浓度
In this study they attempted to predict the critical micelle concentration (CMC).
在研究中,他们尝试着预测临界胶态粒子浓度(CMC)。
Critical micelle concentration is an important physicochemical property of surfactants.
临界胶束浓度是表面活性剂的重要物理化学性质。
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.
优化了合成工艺条件,测试了产品的表面张力、 临界胶束浓度、 润湿性、 起泡力等性能,为进一步研究开发和应用提供了可靠的依据。
By the incorporation kinetics experiments , the effects of cholesterol on the stability ratio and the critical mixed micelle concentration of liposome systems were investigated.
藉由嵌入动力学探讨胆固醇对微脂粒系统之安定比与临界混合微胞浓度的影响。
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使得明胶的缔合浓度下降,且CTAB单分子对明胶临界缔合浓度的影响程度大于球形胶束。
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.
通过红外光谱确定了产物的结构,并对有机硼表面活性剂的酸值、表面张力以及临界胶束浓度等性能进行了研究。
The surface tension and critical micelle concentration of SDS were influenced by the properties of the cyclodextrins added.
SDS的表面张力及临界胶束浓度的变化与添加的环糊精的性质有关。
The critical micelle concentration(CMC) of surfactant in low-temperature dyeing assistant CWL was measured with the method of surface tension.
用表面张力法测试了自制低温染色助剂CWL中表面活性剂的临界胶束质量浓度(CMC)。
The water-solubility, emulsifying ability, surface tension, critical micelle concentration(CMC) of phosphate were determined.
测试了*********的水溶性、乳化力、表面张力、临界胶束浓度等性能。
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.
可直接测量许多材料和表面特性,例如动态接触角,表面自由能,关键性胶束浓度和可湿性。
The results show:as the carbon chain of anionic surfactant increases, the critical micelle concentration decreases;
结果阴离子表面活性剂随碳链的增长,其临界胶束浓度值相应地减少;
RESULTS AND CONCLUSION: With the degree of substitution and molecular weights increased, the stability of the nanoparticles enhanced, critical micelle concentration decreased.
结果与结论:随着相对分子质量和取代度的增加,粒子稳定性增强,临界胶束质量浓度降低。
Critical micelle concentration;
临界胶束浓度;
Plot of critical micelle concentration vsmolar fraction of SB12 in the mixtures.
图2混合表面活性剂的临界胶束浓度与SB12摩尔分数之间的关系Fig。
The results indicated that the product could decrease the surface tension of water, and had lower critical micelle concentration, better surface activity.
该种阳离子表面活性剂具有较好的表面活性。
临界胶束浓度(Critical Micelle Concentration, CMC) 是胶体与界面化学中的一个核心概念,指表面活性剂在溶液中开始形成胶束(micelle)的最低浓度。当表面活性剂浓度低于CMC时,其分子主要以单体的形式分散在溶液中,并吸附在界面(如气-液界面)上以降低表面张力。一旦浓度达到或超过CMC,表面活性剂单体在溶液内部的浓度达到饱和,多余的分子会自发聚集形成胶束——一种疏水尾向内、亲水头向外的有序聚集体。这一浓度转折点即为CMC 。
表面张力转折点
CMC可通过测量溶液表面张力随浓度变化的曲线确定。当浓度低于CMC时,表面张力显著下降;达到CMC后,表面张力趋于稳定,形成平台区。这是因为胶束的形成消耗了新增的表面活性剂单体,使其无法进一步降低表面张力 。
增溶作用的起始浓度
胶束的疏水内核可包裹非极性物质(如油脂、药物分子),显著提升其在水中的溶解度。这一现象称为“增溶”(solubilization),仅在浓度高于CMC时发生 。
常用实验手段包括:
疏水链越长,疏水作用越强,CMC越低(例如C12烷基链表面活性剂的CMC通常低于C8)。
离子型表面活性剂(如SDS)因亲水基电荷排斥作用,CMC高于非离子型(如Tween-80)。
温度升高可能破坏胶束结构,提高CMC;添加电解质可屏蔽离子型表面活性剂的电荷排斥,显著降低CMC 。
权威参考文献
Critical Micelle Concentration(CMC),中文译为临界胶束浓度,是表面活性剂溶液的一个重要物理化学参数。以下是详细解释:
基本定义
CMC指表面活性剂分子在溶液中开始自发缔合形成胶束(micelle)的最低浓度。当溶液浓度低于CMC时,表面活性剂以单分子形式分散;达到或超过CMC时,多余的分子会聚集形成胶束(亲水基朝外,疏水基向内)。
形成机制
影响因素
CMC值受温度、表面活性剂结构(如碳链长度)、电解质浓度等因素影响。例如,疏水链越长,CMC通常越低。
测定方法
常用方法包括表面张力法、电导率法、光散射法等。例如,光散射技术通过检测溶液中胶束形成时的散射强度变化确定CMC。
应用领域
CMC在洗涤剂、药物递送、化妆品等领域有重要意义。例如,洗涤剂需在CMC以上才能有效通过胶束增溶油污。
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