The separation of oil and water is an important pursuit for saving endangered environments. In 2010, the Gulf of Mexico oil spill widely and seriously damaged the ocean and coast near the oilfield. The number of similar accidents is increasing with the development of industry, and materials that can reduce environmental pollution are in high demanded. At the same time, in the area of analytical chemistry, the efficient separation of molecules is a key technique, which determines the efficiency and accuracy of chemical analysis and detection. For these purposes, hydrophobic porous materials are in common use, because hydrophobic surfaces effectively adsorb/absorb oily target compounds that are mixed with an aqueous phase. Therefore, many researchers have been studying hydrophobic porous materials and their application as oil/water separation media. [1] Various chemical compositions have been investigated, such as carbon-based materials, [2] metal oxide nanowires (such as manganese [3,4] ), biomass nanofibers (such as cellulose [5,6] ), organic polymers (such as polyester, [7] polydivinylbenzene, and polythiophene [8] ) and hydrophobic macroporous aerogels. [9,10] Other materials based on polydimethylsiloxane (PDMS) or fluorocarboncoated materials, [3,7,10, 11] and the design of a biomimetic rough surface, through the use of etching techniques, to enhance hydrophobicity [6,12] are also widely reported. However, these methods have problems such as complicated and lengthy processes and high costs for reagents and devices, which prevents the use of these materials in practical and commercial applications.We have investigated hydrophobic porous polymethylsilsesquioxane (PMSQ, CH 3 SiO 1.5 ) materials, derived from methyltrimethoxysilane (MTMS), consisting of transparent aerogels and xerogels with mesoporous to macroporous monoliths that are created by controlling phase separation in the sol-gel process. [13] Polymethylsilsesquioxane gels have a superhydrophobic surface owing to methyl groups that are directly bonded to silicon atoms; this flexible network structure allows the material to spring back after compression. This mechanical feature allows the preparation of aerogel-like xerogels by ambient-pressure drying. Last year, we first reported bendable, marshmallow-like porous gels derived from a co-precursor system of MTMS and dimethyldimethoxysilane (DMDMS) in almost the same way as PMSQ gels. [14] Marshmallow-like gels not only show compression/ reexpansion properties similar to that of PMSQ gels, but also very soft and bendable mechanical features. A high sound absorption property has also been previously reported, owing to the soft networks. The flexiblity and intrinsic hydrophobicity indicate that these materials can be used like a sponge as an adsorption/absorption media for the quick removal of unwanted organic liquids. Herein, we report the outstanding capability of these materials for absorbing organic liquids over a wide temperature range, and discuss the possibility for their application as separation me...

The separation of oil and water is an important pursuit for saving endangered environments. In 2010, the Gulf of Mexico oil spill widely and seriously damaged the ocean and coast near the oilfield. The number of similar accidents is increasing with the development of industry, and materials that can reduce environmental pollution are in high demanded. At the same time, in the area of analytical chemistry, the efficient separation of molecules is a key technique, which determines the efficiency and accuracy of chemical analysis and detection. For these purposes, hydrophobic porous materials are in common use, because hydrophobic surfaces effectively adsorb/absorb oily target compounds that are mixed with an aqueous phase. Therefore, many researchers have been studying hydrophobic porous materials and their application as oil/water separation media. [1] Various chemical compositions have been investigated, such as carbon-based materials, [2] metal oxide nanowires (such as manganese [3,4] ), biomass nanofibers (such as cellulose [5,6] ), organic polymers (such as polyester, [7] polydivinylbenzene, and polythiophene [8] ) and hydrophobic macroporous aerogels. [9,10] Other materials based on polydimethylsiloxane (PDMS) or fluorocarboncoated materials, [3,7,10, 11] and the design of a biomimetic rough surface, through the use of etching techniques, to enhance hydrophobicity [6,12] are also widely reported. However, these methods have problems such as complicated and lengthy processes and high costs for reagents and devices, which prevents the use of these materials in practical and commercial applications.We have investigated hydrophobic porous polymethylsilsesquioxane (PMSQ, CH 3 SiO 1.5 ) materials, derived from methyltrimethoxysilane (MTMS), consisting of transparent aerogels and xerogels with mesoporous to macroporous monoliths that are created by controlling phase separation in the sol-gel process. [13] Polymethylsilsesquioxane gels have a superhydrophobic surface owing to methyl groups that are directly bonded to silicon atoms; this flexible network structure allows the material to spring back after compression. This mechanical feature allows the preparation of aerogel-like xerogels by ambient-pressure drying. Last year, we first reported bendable, marshmallow-like porous gels derived from a co-precursor system of MTMS and dimethyldimethoxysilane (DMDMS) in almost the same way as PMSQ gels. [14] Marshmallow-like gels not only show compression/ reexpansion properties similar to that of PMSQ gels, but also very soft and bendable mechanical features. A high sound absorption property has also been previously reported, owing to the soft networks. The flexiblity and intrinsic hydrophobicity indicate that these materials can be used like a sponge as an adsorption/absorption media for the quick removal of unwanted organic liquids. Herein, we report the outstanding capability of these materials for absorbing organic liquids over a wide temperature range, and discuss the possibility for their application as separation me...

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The combined use of cross-polarization/magic-angle spinning (CP/MAS) 13C NMR experiments and gauge-including projector-augmented wave (GIPAW) isotropic chemical shift calculations is an easy and useful method for the structural refinement of organic aggregates. In this study, the method is applied to an important material for organic light-emitting diodes, tris(8-hydroxyquinoline) aluminum(III) (Alq3). CP/MAS 13C NMR spectra include precise structural information of not only the conformation of the molecules but also the intermolecular packing. First, the structural refinements were performed for the Alq3 in the γ- and δ-crystalline forms employing the combined method. Second, information on intramolecular structures and intermolecular structures was distinguished by comparing GIPAW calculations for crystals under periodic boundary conditions and those for isolated molecules extracted from the crystals. It was found from the analysis that the γ-Alq3 and δ-Alq3 crystals have similar intramolecular structures both in the facial isomeric state, whereas their intermolecular packing is significantly different. Both the γ-Alq3 and δ-Alq3 crystals exhibit unusual blue emission, which is different from conventional green emission, and the origin of the difference has been debated. This investigation shows that the origin of the blue-shifted emission is the isomeric states of Alq3, not the intermolecular packing.