A series of immiscible crystalline–crystalline diblock copolymers, poly(ethylene oxide)-b-(ε-caprolactone) (PEO-b-PCL), were synthesized through ring-opening polymerization and then blended with phenolic resin. FT-IR analyses demonstrate that the ether group of PEO is a stronger hydrogen-bond acceptor with the hydroxyl group of phenolic resin than is the carbonyl group of PCL. Phenolic, after being cured with hexamethylenetetramine (HMTA), results in the excluded and confined PCL phase based on analyses by differential scanning calorimetry (DSC). This effect leads to the formation of a variety of composition-dependent nanostructures, including disorder, gyroid and short-cylinder structures. The self-organized mesoporous phenolic resin was found only at 40–60 wt % phenolic content by an intriguing balance of the contents of phenolic, PEO, and PCL. In addition, the mesoporous structure was destroyed at higher PCL/PEO ratios in the block copolymers, as determined by small-angle X-ray scattering (SAXS) and transmission electron microscopy (TEM) experiments. In addition, the large and long-range order of bicontinuous gyroid-type mesoporous carbon was obtained from mesoporous gyroid phenolic resin calcined at 800 °C under nitrogen.

Highly ordered mesoporous resol-type phenolic resin and the corresponding mesoporous carbon materials were synthesized by using poly(ethylene oxide-b-caprolactone) (PEO-b-PCL) diblock copolymer as a soft template. The self-assembled mesoporous phenolic resin was found to form only in a specific resol concentration range of 40-70 wt % due to an intriguing balance of hydrogen-bonding interactions in the resol/PEO-b-PCL mixtures. Furthermore, morphological transitions of the mesostructures from disordered to gyroid to cylindrical and finally to disordered micelle structure were observed with increasing resol concentration. By calcination under nitrogen atmosphere at 800 °C, the bicontinuous mesostructured gyroid phenolic resin could be converted to mesoporous carbon with large pore size without collapse of the original mesostructure. Furthermore, post-treatment of the mesoporous gyroid phenolic resin with melamine gave rise to N-doped mesoporous carbon with unique electronic properties for realizing high CO adsorption capacity (6.72 mmol g at 0 °C).

In this study, we prepared ordered mesoporous phenolic resins templated by poly(ethylene oxide)-b-(3caprolactone) (PEO-b-PCL) diblock copolymers blended with a star PEO octa-functionalized polyhedral oligomeric silsesquioxane (PEO-POSS) homopolymer. Increasing the PEO-POSS content, and thereby increasing the PEO-to-PCL ratio in the template film, allowed us to tune and enhance the long-range order of the mesoporous phenolic resin. The increased pore size and the more ordered structure were accompanied by a narrower pore size distribution. In addition, we observed an orderedto-ordered mesophase transition, from a bicontinuous gyroid to a hexagonally packed cylinder structure, upon blending with the star PEO-POSS homopolymer. We anticipate that this approach could be extended to the preparation of other large-pore, long-range-ordered mesoporous materials, such as silica and other metal oxides.

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In this study, in situ small‐angle X‐ray scattering (SAXS), in situ Fourier transform infrared (FTIR) spectroscopy, and transmission electron microscopy (TEM) are used to monitor the formation of ordered mesophases in cured mixtures of phenolic resin and the diblock copolymer poly(ethylene oxide‐block‐ε‐caprolactone) (PEO‐b‐PCL). SAXS and TEM analyses reveal that the mesophase of the phenolic/PEO‐b‐PCL mixture transforms sequentially from disordered to short‐range‐ordered to hexagonal‐cylindrical to gyroidal during the curing process when using hexamethylenetetramine (HMTA) as a cross‐linking agent, indicating that a mechanism involving reaction‐induced microphase separation controls the self‐assembly of the phenolic resin. In situ SAXS is also used to observe the fabrication of mesoporous phenolic resins during subsequent calcination processes.

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In this study,s amples of activated mesoporous carbon are fabricated with pore structures with cylinder and gyroid nanostructures through the templatinge ffect of amphiphilic poly(ethylene oxide-block-caprolactone)( PEO-PCL) and by using specific resol/PEO-PCL weightr atios (e.g., 60:40 for cylinders;5 5:45 for gyroids). After carbonization and KOH activation, the activated mesoporous carbons were tested as electrode materials for electric double-layerc apacitor (EDLC)s upercapacitors. The electrochemical properties were examined by using three-electrode (6 m KOH (aq) as electrolyte) and CR2032c oin-cell (1 m tetraethylammonium tetra-fluoroborate (TEABF 4 )/CN as the electrolyte) systems. The gyroid carbon samples provided specific capacitances higher than those of the cylinder carbon samples in both aqueous and organic systems:1 55 Fg À1 compared with 135 Fg À1 in 6 m KOH (aq) ,a nd 105.6 compared with 96 Fg À1 in 1 m TEABF 4 / MeCN, after 100 charge/discharge cycles. It is suspected that the bi-continuous mesochannels of the gyroid-type activated mesoporousc arbonsp rovided ar elatively higher effective adsorption surfacea rea;i no ther words, the greater surface area for energy storageo riginated from am oderate pore size and an interconnected pore structure.[a] Dr.

Abstract:In this study, we prepared a mesoporous carbon with hexagonally packed mesopores through evaporation-induced self-assembly (EISA)-with the diblock copolymer poly(ethylene oxide-b-ε-caprolactone) (PEO-b-PCL) as the template (EO 114 CL 84 ), phenolic resin as the carbon precursor, hexamethylenetetramine (HMTA) as the curing agent, and star octakis-PEO-functionalized polyhedral oligomeric silsesquioxane (PEO-POSS) as the structure modifier-and subsequent carbonization. We then took the cylindrical mesoporous carbon as a loading matrix, with AgNO 3 and Pd(NO 3 ) 2 as metal precursors, to fabricate Ag nanowire/mesoporous carbon and Pd nanoparticle/mesoporous carbon nanocomposites, respectively, through an incipient wetness impregnation method and subsequent reduction under H 2 . We used transmission electron microscopy, electron diffraction, small-angle X-ray scattering, N 2 isotherm sorption experiment, Raman spectroscopy, and power X-ray diffraction to investigate the textural properties of these nanometal/carbon nanocomposites. Most notably, the Raman spectra of the cylindrical mesoporous carbon, Ag/mesoporous carbon, and Pd/mesoporous carbon revealed interesting phenomena in terms of the ratios of the intensities of the D and G bands (I D /I G ), the absolute scattering intensities, and the positions of the D bands.