Formation of Mesoporous Carbon With a Face‐Centered‐Cubic Fd$\bar 3$m Structure and Bimodal Architectural Pores From the Reverse Amphiphilic Triblock Copolymer PPO‐PEO‐PPO

Abstract

Diamond, a crystalline form of carbon, shows exceptional physical and chemical properties, such as the highest known hardness and elastic modulus. These characteristics have been attributed to its specific 3D atomic packing and strong sp 3 tetrahedral covalent bonds. [1,2] Attempts to design analogous materials, including molecular sieves and metal-organic frameworks (MOFs), [3,4] have centered on ensuring the same packing as that of diamond, which has 3D facecentered-cubic Fd3 m symmetry.Ordered mesoporous materials have received enormous attention owing to their high surface areas, regular frameworks, and large pore sizes with narrow distribution, all of which lead to multiple potential applications. [5,6] Ordered mesoporous carbon, which is one of the most promising materials, possesses both remarkable functional properties and excellent chemical/thermal stability, which makes it suitable for applications in catalysis, [7] sensing, [8] bioreactor construction, [9] and energy storage. [10] Recently, a family of highly ordered mesoporous carbon with p6mm, Im3 m, and Ia3 d symmetries has been synthesized by an organic-organic self-assembly strategy with PEO-PPO-PEO triblock copolymers as templates (PPO: polypropyleneoxide; PEO: polyethyleneoxide). [11][12][13][14][15] Among the various mesostructures, 3D cubic mesopore geometries are attractive owing to their promise, especially in host-guest chemistry. [16,17] However, the synthesis of mesoporous materials with a 3D cubic Fd3 m structure, which is a unique structure with a bimodal pore size distribution, has not been reported to date by using triblock copolymers as templates. This attractive mesostructure with a silicate composition has only been obtained thus far by using laboratory-made tri-head-group cationic (for FDU-2) [18] and anionic (for AMS-8) surfactants as templates [19,20] under very strict synthetic conditions. In addition, the mesoporous silicas obtained have small lattice parameters and their bimodal mesopore systems cannot be detected by N 2 sorption measurements owing to the smaller size of the surfactant molecules compared to block copolymers.Amphiphilic PEO-PPO-PEO triblock copolymers, which are commercially available as Pluronics or Synperonics, have been proven to be versatile and efficient templates for the fabrication of ordered mesoporous silicas with different symmetries.[21] PPO-PEO-PPO triblock copolymers are another family of commercial surfactants that have the hydrophilic PEO block located in the middle and the hydrophobic PPO blocks at either end of the polymer chain. They are rarely used in the synthesis of ordered mesoporous silicas, however, because of the difficulty of forming oil-inwater micelles. [22][23][24] Reverse PPO-PEO-PPO copolymers with long PEO segments can reduce the curving energy and result in micellar interconnected networks, [24] the possible fascinating phase behaviors of which may provide them with good structure-directing properties for the fabrication of facecentered-cubic Fd3 m mesostructures with high curv...

Organically Functionalized Mesoporous Silica by Co‐structure‐Directing Route

“…[36][37][38][39][40][41] However, using anionic surfactants as the template normally give rise to a disordered or lamellar mesophase, [ 3 ] which could possibly be attributed to the diffi culty in achieving proper interactions. Under acidic conditions, the anionic surfactant is normally highly protonated, which significantly weakens the S − I + interactions with the positively-charged silica oligomers.…”

Synthesis of Ordered Mesoporous Carbon Materials with Semi-Graphitized Walls via Direct In-situ Silica-Confined Thermal Decomposition of CH4 and Their Hydrogen Storage Properties

“…Chemical vapor deposition (CVD) has also been applied to the synthesis of OMCs using gases or vapors such as acetylene, propylene, ethylene and styrene as carbon precursors [15][16][17][18][19]. Recently, soft-template methods for the synthesis of OMCs have been developed [20][21][22][23][24][25]. By using amphiphilic tri-block copolymers as templates and low-molecular-weight phenolic resin as carbon precursor, our group reported a series of novel OMCs [22][23][24][25].…”

“…Recently, soft-template methods for the synthesis of OMCs have been developed [20][21][22][23][24][25]. By using amphiphilic tri-block copolymers as templates and low-molecular-weight phenolic resin as carbon precursor, our group reported a series of novel OMCs [22][23][24][25].…”

Synthesis and Catalytic Performance of Highly Ordered Ru-Containing Mesoporous Carbons for Hydrogenation of Cinnamaldehyde

“…Due to the multi steps involved and low yield of the carbon, this method is lack of commercial interest. The other attracting strategy is the soft template approach [9][10][11][12][13][14], which involves polycondensation of resorcinol and formaldehyde under the presence of a surfactant template. This method not only allows for largescale production, but also yields ordered mesoporous carbons with various macroscopic forms like films, powders, monoliths, etc.…”