Cubic and Hexagonal Mesoporous Carbon in the Pores of Anodic Alumina Membranes

Abstract

Cubic and circular hexagonal mesoporous carbon phases in the confined environment of the pores of anodic alumina membranes (AAM) were obtained by organic-organic self-assembly of a preformed oligomeric resol precursor and the triblock copolymer templates Pluronic F127 or P123, respectively. Casting and solvent evaporation were followed by self-assembly and the formation of a condensed wall material by thermopolymerization of the precursor oligomers, thus resulting in mesostructured phenolic resin phases. Subsequent thermal decomposition of the surfactant and carbonization were achieved through thermal treatment at temperatures up to 1000 °C under an inert atmosphere. The resulting hierarchical mesoporous composite materials were characterized by small-angle X-ray scattering and nitrogen-sorption measurements. The structural features were directly imaged in TEM cross-sections of the composite membranes. For both structures, the AAM pores were completely filled and no shrinkage was observed due to strong adhesion of the carbon-wall material to the AAM pore walls. As a consequence, the pore size of the mesophase system stays almost constant even after thermal treatment at 1000 °C.

Formation of hexagonal and cubic fluorescent periodic mesoporous organosilicas in the channels of anodic alumina membranes

“…The SAXS pattern recorded with the calcined sample shows the typical peaks assigned to a body centered cubic Im 3m phase (Fig. 4A), similar to recent observations with other cubic phases in AAM hosts, 36,39 indicating that a new 3a-OPV-PMO with a cubic structure was formed. The formation of the cubic mesostructure was also conrmed by the TEM micrographs.…”

“…1A) shows both in-plane (01) and out-of-plane (10) peaks that are characteristics of a circular hexagonal structure conned in AAM channels. 35,38,39 The d-values calculated from the diffraction pattern are 14.5 nm and 15.6 nm, corresponding to d 01 and d 10 respectively. The TEM image (Fig.…”

“…We note that the orientation of the hexagonal mesostructures could be inuenced by the size and shape of AAM channels. 39 In a small number of the AAM channels, a hexagonal columnar structure was observed as a side phase (e.g. the channel on the le side in Fig.…”

Hierarchically structured biphenylene-bridged periodic mesoporous organosilica

“…5A), similar to recent observations with other PMO and mesoporous polymer phases in AAM hosts. 43,57 The formation of a cubic mesostructure was also confirmed by the following TEM micrographs. A plan-view TEM micrograph obtained from F127-cubic-200 Bp-PMO is displayed in Fig.…”

Fabrication of ordered mesoporous carbon hollow fiber membranes via a confined soft templating approach

“…[6][7][8][9] This method enables the generation of OMC with various morphologies by nely controlling the self-assembly of the phenolic resin and block copolymer. In particular, self-standing OMC membranes 4 and supported OMC membranes on different substrates (such as anodic alumina 10,11 and porous ceramic tube 12 ) have been successfully prepared.…”