Contrast Variation Small-Angle Neutron Scattering Study of Solubilization of Perfumes in Cationic Surfactant Micelles
Contrast Variation Small-Angle Neutron Scattering Study of Solubilization of Perfumes in Cationic Surfactant Micelles
复制标题
阳离子表面活性剂胶束中香料增溶的对比度变化小角中子散射研究
DOI：
10.1021/acs.langmuir.1c01489
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发表时间：
2021
期刊：
影响因子：
3.9
通讯作者：
Sakai Hideki
中科院分区：
文献类型：
--
作者：
Akamatsu Masaaki;Saito Kai;Iwase Hiroki;Ogura Taku;Sakai Kenichi;Sakai Hideki
香料增溶是生产商业产品如饮料、食品和化妆品的重要过程。采用小角中子散射（SANS）方法研究了香料在十六烷基三甲基溴化铵（CTAB）胶束中的增溶行为。芳樟醇（LL）和l-薄荷醇（MT），这是相对亲水性的香料，增溶，并没有改变的CTAB胶束的大小，虽然香料被纳入胶束中，如散射长度密度的减少所示。另一方面，增溶d-柠檬烯（LN），疏水香料，导致CTAB胶束的溶胀。通过对CTAB分子的氘代反应进行了内对比度变化SANS研究，以直接观察胶束中的香料。d-CTAB胶束增溶LL和MT的半径与h-CTAB的半径相当，表明这些香料被容纳在胶束的栅栏层中，并均匀地分布在胶束中。另一方面，LN形成小液滴，如SANS曲线所示，这意味着LN分子在CTAB胶束的核心中增溶。我们发现，相对亲水性的香料（LL和MT）的阳离子胶束的大小相比，非离子胶束的影响较小。因此，SANS的内部对比度变化方法允许直接观察具有不同亲水性-疏水性平衡的香料的增溶位点。该方法是确定影响香料增溶能力、挥发或释放速度的增溶状态的有力工具。
Perfume solubilization is an important process in the production of commercial products such as beverages, foods, and cosmetics. In the present study, small-angle neutron scattering (SANS) experiments were performed to investigate the solubilization behavior of perfumes in cetyltrimethylammonium bromide (CTAB) micelles. The solubilization of linalool (LL) andl-menthol (MT), which are relatively hydrophilic perfumes, did not change the size of the CTAB micelles although the perfumes were incorporated in the micelles, as indicated by a decrease in scattering length density. On the other hand, the solubilization ofd-limonene (LN), a hydrophobic perfume, led to the swelling of CTAB micelles. An internal contrast variation SANS study was performed by the deuteration of CTAB molecules to directly observe the perfumes in the micelles. The radius ofd-CTAB micelles solubilizing LL or MT corresponds to that ofh-CTAB, which indicates that these perfumes are accommodated in the palisade layers of the micelles and are homogeneously distributed in the micelles. On the other hand, LN formed small droplets, as indicated by the SANS profile, which implies the solubilization of LN molecules in the core of the CTAB micelles. We found that the relatively hydrophilic perfumes (LL and MT) show less impact on the sizes of the cationic micelles in comparison to nonionic micelles. Thus, the internal contrast variation method of SANS allowed the direct observation of the solubilization sites of perfumes with different hydrophilicity–hydrophobicity balances. This method is a powerful tool to determine the solubilization states that affect the solubilization capacity, volatilization, or release speed of perfumes.