Three-dimensional observation of phase-separated siloxane sol–gel structures in confined spaces using laser scanning confocal microscopy (LSCM)
Three-dimensional observation of phase-separated siloxane sol–gel structures in confined spaces using laser scanning confocal microscopy (LSCM)
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DOI：
10.1016/j.colsurfa.2004.04.022
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发表时间：
2004-07
期刊：
影响因子：
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通讯作者：
K. Kanamori;K. Nakanishi;K. Hirao;H. Jinnai
中科院分区：
文献类型：
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作者：
K. Kanamori;K. Nakanishi;K. Hirao;H. Jinnai
采用溶胶-凝胶法制备了具有双连续结构的多孔甲基硅氧烷凝胶，并伴随有多种受限几何构型的调幅分解。所得的多孔结构中的二维模具已密切利用最近的激光扫描共聚焦显微镜（LSCM）检查。一个剧烈的结构变形，由于优先润湿的富甲基十六烷相导致在表面附近的细长的柱状结构。采用平行曲面法（PSM）计算了旋节线界面的面积平均曲率和高斯曲率。在表面附近，平均曲率的值略有偏离的各向同性的双连续结构，反映线性伸长的甲基硅氧烷凝胶骨架垂直于表面的功能。当样品的缩放厚度D/Λ m变得小于1时，发生润湿转变。这里，Λ m表示在三维自由体积中制备的本体凝胶的双连续结构的特征长度。在扫描电镜下观察了一维和零维模具中的多孔结构，发现发生了相似的变形和润湿转变。润湿转变的判据D/Λm<1在所有受限空间中是通用的。
Porous methylsiloxane gels with bicontinuous structure were prepared via sol–gel method accompanying spinodal decomposition in a variety of confined geometries. The resultant porous structure in a two-dimensional mold has been examined closely utilizing the recent laser scanning confocal microscopy (LSCM). A drastic structural deformation due to preferential wetting by methylsiloxane-rich phase has lead to elongated columnar structure in the proximity of the surfaces. The area-averaged mean and Gaussian curvatures of spinodal interfaces were obtained by parallel surface method (PSM). In the vicinity of the surfaces, values of the mean curvature were slightly deviated from that of the isotropic bicontinuous structure, reflecting linearly elongated features of methylsiloxane gel skeleton perpendicular to the surfaces. When a scaled thickness of the sample D/Λmbecomes less than unity, wetting transition occurred. Here, Λmmeans characteristic length of bicontinuous structure of bulk gel prepared in a three-dimensional free volume. In both one- and zero-dimensional molds, the porous structure was observed under SEM, revealed that the similar deformation and wetting transition occurred. The criterion for wetting transition, D/Λm<1, was universal in all confined spaces.