Microspectroscopic analyses of dye distribution characteristics in single microcapsules.
Microspectroscopic analyses of dye distribution characteristics in single microcapsules.
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单个微胶囊中染料分布特征的显微光谱分析。
DOI：
10.1021/ac970743b
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发表时间：
1998
影响因子：
7.4
通讯作者：
N. Kitamura
中科院分区：
文献类型：
--
作者：
H. B. Kim;S. Yoshida;A. Miura;N. Kitamura
采用激光捕获-吸收显微光谱技术研究了染料在含有染料/甲苯溶液的单层三聚氰胺树脂壁微胶囊中的分布特性。在分散橙 13 作为染料的情况下，从染料吸光度-胶囊直径 (d) 图的斜率确定的摩尔吸光率与在均匀甲苯溶液中观察到的结果非常吻合，表明染料均匀地溶解在胶囊内部的甲苯溶液中。然而，对于四苯基卟啉（MTPP： Zn(II)TPP、Co(II)TPP 或 H(2)TPP），吸光度的 d 依赖性显示出 S 形曲线。由于三聚氰胺树脂聚合之前 ZnTPP/甲苯液滴的吸光度随着液滴直径的增加而线性增加，因此吸光度的 S 型 d 依赖性被推断为源于染料在树脂壁中的分布。数据的详细分析表明，染料在甲苯相和树脂相之间的分配比取决于胶囊直径。基于所提出的模型和染料吸光度的 d 依赖性，讨论了单个微胶囊中 MTPP 的尺寸依赖性分布，得出的结论是，较大的微胶囊有利于 MTPP 在三聚氰胺树脂壁上的分布。
The distribution characteristics of a dye in single melamine resin wall microcapsules containing a dye/toluene solution are studied by a laser trapping-absorption microspectroscopy technique. In the case of Disperse Orange 13 as a dye, the molar absorptivity determined from the slope of a dye absorbance-capsule diameter (d) plot agrees well with that observed in a homogeneous toluene solution, indicating that the dye is solubilized homogeneously in the inner toluene solution of the capsule. For tetraphenylporphyrins (MTPP: Zn(II)TPP, Co(II)TPP, or H(2)TPP), however, the d dependence of absorbance shows a sigmoidal curve. Since absorbance of a ZnTPP/toluene droplet before polymerization of the melamine resin increases linearly with an increase in the droplet diameter, the sigmoidal d dependence of the absorbance is concluded to originate from distribution of the dye into the resin wall. Detailed analyses of the data indicate that the partitioning ratio of the dye between the toluene and resin phases is dependent on the capsule diameter. Size-dependent distribution of MTPP in single microcapsules is discussed on the basis of a proposed model and the d dependence of the dye absorbance, and it is concluded that the distribution of MTPP to the melamine resin wall is facilitated for larger microcapsules.