Templates pores

Rill, RL Locke, BR Liu, Y Dharia, J Van Winkle, D, Protein Electrophoresis in Polyacrylamide Gels with Templated Pores, Electrophoresis 17, 1304, 1996. 

Rill, RL Van Winkle, DH Locke, BR, Templated Pores in Hydrogels for Improved Size Selectivity in Gel Permeation Chromatography, Analytical Chemistry 70, 2433, 1998. 

MeAPO Species Structure Type Typical Template Pore Size (nm)... 

Tube-type carbons are obtained when organic compounds are carbonized in a thin-film state on the template pore walls [6], The tube-type carbon can be obtained even after the entire volume of pores is filled with carbon source, if the excess carbon source is removed before the carbonization is completed. For example, cylindrical pores are generated along the center of the carbon frameworks due to the systematic volume decrease when furfiiryl alcohol is pyrolyzed under vacuum after the initial polymerization. Alternatively, the tube-type carbons can be synthesized as follows carbonization can be controlled to occur partially by catalyst at the pore walls at moderate temperatures. The remaining carbon source is removed by evacuation, and the carbonization is completed by pyrolysis at high temperature. Chemical vapor deposition on the pore walls can also be used to produce the tube-type carbon [11] as well as the aforementioned rod-type carbons [12]. The structure of the resultant carbon depends on the thickness of the carbon deposition. 

Depending on the cases, the dimensions of the templated pores can range from molecular scale, where molecules are used as templates, to the macroscopic scale, where, for example, latex beads are precursors of the pore system. Obviously, the mechanisms by which a pore system develops will be very diverse. However, a favorable interaction between the templating species and the solid to be templated is mandatory, since otherwise the templating species would simply not be integrated and phase separation would occur. The smaller the size scale, the more imperative are such favorable interactions, because the interface between the solid and the template is increased with increasing dispersion (55). 

Ethylene oxide/propylene oxide triblock copolymers have been successfully used to template pore formation in ultra low-k films, and dielectric constants as low as 1.5 have been observed with polymer loading levels of 50 wt% (5). These films have good mechanical properties, a high breakdown voltage and a low moisture uptake. We have characterized the films with high-resolution solid-state proton NMR and found that the triblock copolymers form nm-sized core-shell structures with the propylene oxide block at the interface between the ethylene oxide block and the methyl silsesquioxane matrix (14). 

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