TY - JOUR
T1 - Three-dimensional observation of phase-separated siloxane sol-gel structures in confined spaces using laser scanning confocal microscopy (LSCM)
AU - Kanamori, Kazuyoshi
AU - Nakanishi, Kazuki
AU - Hirao, Kazuyuki
AU - Jinnai, Hiroshi
N1 - Funding Information:
Financial support by a Grant-in-Aid for Scientific Research from the Ministry of Education, Science, Sports, Culture, and Technology, Japan is gratefully acknowledged. H.J. is partially supported by the Grant-in-Aid for Scientific Research on Priority Areas (A), “Dynamic Control of Strongly Correlated Soft Materials” (No. 413/14045246) from the Ministry of Education, Science, Sports, Culture, and Technology.
PY - 2004/7/14
Y1 - 2004/7/14
N2 - 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/Λm becomes less than unity, wetting transition occurred. Here, Λm means 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.
AB - 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/Λm becomes less than unity, wetting transition occurred. Here, Λm means 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.
KW - Confined geometry
KW - Laser scanning confocal microscopy (LSCM)
KW - Phase separation
KW - Siloxane gel
KW - Wetting
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U2 - 10.1016/j.colsurfa.2004.04.022
DO - 10.1016/j.colsurfa.2004.04.022
M3 - Article
AN - SCOPUS:4143066107
VL - 241
SP - 215
EP - 224
JO - Colloids and Surfaces A: Physicochemical and Engineering Aspects
JF - Colloids and Surfaces A: Physicochemical and Engineering Aspects
SN - 0927-7757
IS - 1-3
ER -