From Zeolites to Porous MOF Materials – the 40th Anniversary of International Zeolite Conference R. Xu, Z. Gao, J. Chen and W. Yan (Editors) © 2007 Elsevier B.V. All rights reserved.
Ordered mesoporous polymers and polymer-silica anocomposites Ruili Liu, Yan Meng, Dong Gu, Bo Tu and Dongyuan Zhao* Department of Chemistry, Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Fudan University, Shanghai 200433. Tel: 86-21-6564-2036; Fax: 86-21-6564-1740; Email: [email protected]
A family of highly ordered mesoporous polymers and carbon frameworks, including p6m, Ia3d, Im3m Fm3m, and Fd3m mesostructures, has been prepared by the organic-organic assembly of triblock copolymers PEO-PPO-PEO, reverse copolymer PPO-PEO-PPO and PEO-PS with resols via solvent evaporation-induced self-assembly (EISA) strategy. By using pre-hydrolyzed TEOS as an inorganic co-precursor, highly ordered mesoporous polymer-silica and carbon-silica nanocomposites with interpenetrating networks were also synthesized via a triconstituent co-assembly. After the removal of silica component from carbon-silica nanocomposites, ordered mesoporous carbons then can be derived with large pore sizes of 6.7 nm, pore volumes of 2.0 cm3/g, and high surface area of 2470 m2/g. 1. INTRODUCTION Self-assembly presents a spontaneous organization of diverse multicomponent structures driven by noncovalent interactions, such as hydrogen bonding, S-S interaction, and electrostatic effects . Inorganic-organic assembly, via organic surfactant templating has been used successfully to generate a large number of porous inorganic mesostructures, such as ordered mesoporous oxide solids, metals and metal sulfides. Recently, organic-organic self-assembly has been applied to synthesizing mesoporous organic polymer and carbon materials [2-10]. In our group [5-8], a family of ordered mesoporous polymers and carbons with diversified mesostructures can be obtained by simply adjusting the ratio of resol/surfactant or PEO/PPO. Water-soluble phenolic resins (resols) used as organic precursors; contain plenty of hydrophilic hydroxyl groups, which can strongly interact with block copolymer PPO-PEO-PPO via hydrogen bonds. A simple thermopolymerization at low temperature can cross-link the soluble resols to covalent phenolic resin networks. Heated at a temperature above 600oC, ordered polymers can transform to homologous carbon frameworks. This approach can obviate the shortages of two-step synthesis of mesoporous carbon replicas by nanocasting [11, 12], which is laborious, time-consuming, and costly. However, serious skeleton shrinkage during the high-temperature carbonization procedure results in small pore sizes (2 ~ 5 nm) for mesoporous carbon products. Organic-inorganic nanocomposites possess the advantages both of organic polymers like flexibility, toughness and hydrophobicity, and of inorganic components such as good mechanical and thermal stability . Until now, ordered mesoporous organic-silica
1722 nanocomposites have been obtained by surface functionalization , encapsulation of organic moieties in the channels of mesoporous silica materials , and direct synthesis of periodic mesoporous organosilicas (PMOs) , but these methods are not only expensive and difficult but also may take the risk of blocking the pores. We have demonstrated a triconstituent co-assembly approach to prepare well-ordered mesoporous polymer-silica and carbon-silica nanocomposites . The hybrid products have a “homogeneous” interpenetrating framework and a controllable composition, as well as large pores. This process is one-step, convenient and reproducible. More importantly, the resultant carbons obtained after the removal of silica from carbon-silica nanocomposite have high surface areas, large pore sizes and pore volumes. In this paper, we report a family of highly ordered mesoporous polymers and polymer-silica nanocomposites prepared via EISA method by using block copolymers as templates. The mesostructure and the pore sizes of the samples are controlled through tailoring the templates and the precursor/template ratio. The mesoporous polymers and polymer-silica nanocomposites can transform to homologous carbon frameworks with large pore sizes up to 22.6 nm, pore volumes of 2.0 cm3/g, and high surface area of 2470 m2/g. 2. EXPERIMENTAL SECTION 2.1. Preparation of mesoporous polymers and carbons. The ordered mesoporous polymers with different Ia3d, p6m and Im3m mesostructures were prepared according to the literature method [5, 6]. These polymer samples are denoted as FDU-14, FDU-15 and FDU-16, respectively. In a typical preparation procedure, triblock copolymer (such as P123, F127 and F108) was dissolved in ethanol and then resol precursor was added. After stirring for 10 min, a homogeneous solution was obtained. The solution was poured into dishes to evaporate ethanol at room temperature for 5-8 h, followed by heating in an oven at 100oC for 24 h. The as-made products, transparent films, were scraped from the dishes and crushed into powders. Calcination was carried out in a tubular furnace under inert atmosphere flow for 3 h and above 600oC for 2 h to get mesoporous polymers and carbons, respectively. The mesostructures with different symmetries were obtained by simply adjusting the ratio of resol/surfactant or PEO/PPO. In details, the compositions were in the range of phenol/ formaldehyde/EtOH/P123 (molar ratio) = 1:2:50:0.018-0.019 for FDU-14, phenol/formaldehyde/EtOH/F127 = 1:2:50:0.010-0.015 for FDU-15, and phenol/formaldehyde/EtOH/F127 = 1:2:50:0.003-0.008 for FDU-16, respectively. 2.2. Preparation of mesoporous polymer-silica and carbon-silica nanocomposites. The polymer-silica nanocomposites were prepared by triconstituent co-assembly of resols, oligomer silicates from TEOS, and triblock copolymer F127 template . In a typical preparation, 1.6 g of block copolymer F127 was dissolved in 8.0 g of ethanol with 1.0 g of 0.2 M HCl and stirred for 1 h at 40oC to afford a clear solution. Then 2.08 g of TEOS and 5.0 g of 20 wt% resols’ ethanolic solution were added in sequence. After being stirred for 2 h, the mixture was transferred into dishes. The following procedures were the same as those for ordered mesoporous polymers. The as-made product was calcined at 350oC for 3 h and 900oC for 2 h in N2 to get polymer-silica and carbon-silica nanocomposites, respectively, named as MP-CS-46. The numerical value in “MP-CS-x” presents the mass percentage of the polymer content in the polymer-silica nanocomposites determined by TG analysis. After immersing the carbon–silica nanocomposites in 10 wt% HF solutions, silica was removed and mesoporous carbons were left. Calcination at 550oC for 5 h in air could remove carbon and
1723 generate mesoporous silicas. The mesoporous carbon products were named as MP-C-x and the mesoporous silica products were named as MP-S-x, respectively, corresponding to their mother nanocomposites. 2.3. Characterization. Small-angle X-ray scattering (SAXS) measurements were taken on a Nanostar U small-angle X-ray scattering system (Bruker, Germany) using Cu KĮ radiation (40 kV, 35 mA). Nitrogen adsorption isotherms were measured at 77 K with a Micromeritcs Tristar 3000 analyzer (USA). Before measurements, the samples were degassed in vacuum at 200oC for at least 6 h. Brunauer-Emmett-Teller (BET) method was utilized to calculate the specific surface areas (SBET) using adsorption data in a relative pressure range from 0.04 to 0.2. By using the Barrett-Joyner-Halenda (BJH) model, the pore volumes and pore size distributions were derived from the adsorption branches of isotherms, and the total pore volumes (Vt) were estimated from the adsorbed amount at a relative pressure P/P0 of 0.992. Transmission electron microscopy (TEM) experiments were conducted on a JEOL 2011 microscope (Japan) operated at 200 kV. TG analysis was monitored using a Mettler Toledo TGA-SDTA851 analyzer (Switzerland) from 25 to 900oC under nitrogen or air flow with a heating rate of 5oC/min. 2.4. Electrochemical measurements. To prepare an electrode, a usual mixture of 85 wt% carbon material (MP-C-36), 10 wt% conductive agent (carbon black) and 5 wt% poly(tetra- fluoroethylene) (PTFE) binder were homogeneously dispersed in isopropanol with stirring. The resulting clay was pressed onto a
Fig. 1. SAXS patterns (A) and N2 sorption isotherms (B) of mesoporous polymers with diverse structures. In both (A) and (B), FDU-14 prepared by using P123 as a template after calcinations at 350oC under 2.4%O2/N2; FDU-15 prepared by using F127 as a template and calcinations at 350oC under N2; and FDU-16 prepared by using F127 as a template and calcinations at 350oC under 2.4%O2/N2.
Fig. 2. TEM images of the mesoporous polymers with various structures. Among them, (A) and (B) for FDU-14, viewed along the  (A) and  (B) directions; (C) and (D) for FDU-15, viewed along the  (C) and  (D) directions; (E) and (F) for FDU-16, viewed along the  (E) and  (F) directions.
current Ni grid and then tailored to a disc of ĳ = 12 mm, dried at 120oC for 12 h to remove the solvent and water. The electrochemical properties were investigated in aqueous 2.0 M KOH electrolyte. The three-electrode system was used, i.e.,carbon materials as a working electrode, Pt metal as a counter electrode, and SCE (Saturated Calomel electrode) as a reference electrode. Cyclic voltammetry was measured at different scan rates (5, 20, 50 mV/s) between -0.1~-1.0V vs. SCE. The electrochemical tests were done in a Land cell test instrument.
3. RESULTS AND DISCUSSION 3.1. Ordered mesoporous polymers Ordered mesoporous polymers with diverse structures can be synthesized by using block copolymer as a template via EISA method [5, 6]. SAXS patterns of mesoporous polymers calcined at 350oC in inert atmosphere show at least three-resolved diffraction peaks (Fig. 1A), suggesting a highly ordered mesostructure. FDU-14 prepared by using triblock copolymer P123 as a template gives four diffraction peaks, which can be indexed as 211, 220, 321 and 400 reflections (Fig. 1Aa), associated with three-dimensional (3-D) bicontinuous (Ia3d) mesostructure. FDU-15 prepared by using F127 as a template with low resol/F127 ratio shows a typical SAXS pattern (Fig. 1Ab) with three well-resolved diffraction peaks, associated with ordered 2-D hexagonal p6m mesostructure. The SAXS pattern (Fig. 1Ac) shows that FDU-16 prepared with relative high resol/F127 ratio has a body-centered cubic Im3m mesostructure. TEM images (Fig. 2) further confirm that FDU-14, -15 and -16 have bicontinuous cubic (Ia3d), 2-D hexagonal (p6m) and 3-D cubic (Im3m) mesostructures, respectively.
1725 All of the N2 sorption isotherms (Fig. 1B) show typical type-IV curves and a sharp capillary condensation step, implying the uniformity of mesopore. In details, FDU-14 with Ia3d symmetry has a BET surface area of 280 m2/g, a pore size of 3.9 nm and a pore volume of 0.23 cm3/g. FDU-15 with p6m symmetry exhibits a large pore size of 5.4 nm, a high BET surface area of 430 m2/g, and a pore volume of 0.40 cm3/g. FDU-16 with Im3m mesostructure has even a higher BET surface area of 460 m2/g and larger pore size of 6.6 nm. Mesoporous polymer (FDU-17) with face-centered cubic structure (Fd3m) can be synthesized by using lad-made reverse triblock copolymer PPO-PEO-PPO as a template via EISA method . 3.2 Ordered mesoporous carbons With further increasing the calcination temperature to above 600oC, the frameworks can be transformed to amorphous carbon networks [5, 6]. At least three resolved diffraction peaks can be observed in SAXS patterns for the resultant carbons (Fig. 3A), suggesting a highly thermal stability. Compared with that for mesoporous polymers, the q vectors move to higher values, implying a large contraction (~ 30%) of frameworks. All of the N2 sorption isotherms (Fig. 3B) of the mesoporous carbon products show typical type-IV curves. Compared to those of polymers calcined at 350oC, the clear capillary condensation steps (Fig. 3B) occur at lower relative pressure, implying that their pore sizes are reduced. Mesoporous polymer FDU-17 with face-centered cubic (Fd3m) structure can also be transformed to homologous carbon frameworks. Nitrogen sorption measurements show that mesoporous carbons C-FDU-17 have a bimodal pore size distribution .
Fig. 3 SAXS patterns (A) and N2 sorption isotherms (B) of the mesoporous carbons with diverse structures. In both (A) and (B), (a) FDU-14-800 prepared by using P123 as a template via EISA method after calcinations at 800oC under N2; (b) FDU-15-600 prepared by using F127 and calcinations at 600oC under N2; and (c) FDU-16-600 prepared by using F127 as a template and calcinations at 600oC under N2. The isotherms (b) of FDU-15-600 are offset vertically by 80 cm3/g.
1726 3.3. Ordered mesoporous polymer-silica and carbon-silica nanocomposites.
Fig. 4A shows SAXS patterns for the four typical polymer-silica nanocomposites, indicating highly ordered 2-D hexagonal mesostructures . TEM images (Fig. 5A and B) further confirm that the nanocomposites have a highly ordered 2-D hexagonal p6m mesostructure. N2 sorption isotherms of all polymer-silica nanocomposites (Fig. 4B) exhibit type-IV curves with distinct capillary condensation steps, suggesting narrow mesopore size distributions. Compared with FDU-15-350 with the same p6m symmetry, the framework shrinkage of the nanocomposites is smaller due to the presence of rigid silicates that act as a “reinforcing-steel-bar” in the polymer “concrete”. Therefore, these polymer-silica nanocomposites have large pore sizes of 8.5 nm, BET surface areas (~ 600 m2/g) and pore volumes (~ 0.7 cm3/g).
Fig. 4 SAXS patterns (A and C) and N2 sorption isotherms (B and D) of the mesoporous nanocomposites prepared with different compositions calcined at 350oC (A and C) and at 900oC in N2 (B and D), (a) MP-CS-27, (b) MP-CS-36, (c) MP-CS-46 and (d) MP-CS-61. The isotherms (B) for MP-CS-36, -46, and -61 calcined at 350oC in N2 are offset vertically by 300, 600, 900 cm3/g. The isotherms (D) for MP-CS-36, -46, and -61 calcined at 900oC in N2 are offset vertically by 50, 180, 250 cm3/g, respectively. After calcination at 900oC in N2, at least four well-resolved diffraction peaks can be observed in
1727 SAXS patterns (Fig. 4C), indicating that the highly ordered 2-D hexagonal mesostructure is thermally stable. TEM images (Fig. 5C, D) further confirm it. All carbon-silica nanocomposites show representative type-IV isotherms with H2 hysteresis (Fig. 4D), suggesting imperfect mesopore channels . As carbon contents increase in the carbon-silica nanocomposites, both BET surface areas and pore volumes increase from 160 to 460 m2/g and from 0.21 to 0.57 cm3/g, respectively. The pore size calculated is about 6.7 nm, which is greatly larger than that (2.9 nm) of C-FDU-15 with carbon framework. It implies that the framework shrinkage in the nanocomposites is considerably smaller.
Fig. 5. TEM images of mesoporous nanocomposites of MP-CS-46 calcined at 350oC (A, B) and at 900oC in N2 (C, D), viewed from the  (A, C) and  (B, D) directions. The insets are the corresponding FFT diffractograms.
3.4. Ordered mesoporous carbon and silica from carbon-silica nanocomposites. Etching with HF solution or combustion of nanocomposites in air can remove silica or carbon, leaving mesoporous carbon or silica frameworks. SAXS patterns (Fig. 6A) of mesoporous carbon materials except that of MP-C-27 with low carbon content show three or four diffraction peaks, revealing ordered 2-D hexagonal mesostructure with similar unit cell parameters of about 12 nm. As compared to mesoporous carbon C-FDU-15, these mesoporous carbons show remarkably larger unit cell parameters, which can be attributed to the inhibition of framework shrinkages by the presence of silica in nanocomposites during carbonization. Representative TEM images of the mesoporous carbon MP-C-46 (Fig. 6A, B), further confirm a highly ordered 2-D hexagonal p6m mesostructure. Mesoporous carbons except carbon MP-C-27 exhibit similar type-IV isotherms with distinct capillary condensation steps occurring at relative pressures of 0.6-0.7, corresponding to narrow pore size distributions of mesopores at about 6 nm. When the carbon content is in the range of 36-46 wt % in carbon-silica nanocomposites, the resultant carbons have high surface area of about 2400 m2/g and large pore volume 2.0 cm3/g. The pore size of mesoporous carbon prepared by using lab-made diblcok copolymer PEO125-PS230 (molecular weight 29700 g/mol) can be expanded
1728 to 22.6 nm. Our results show the obtained C-FDU-18 has highly ordered face-centered cubic (Fm3m) structure . The corresponding ordered mesoporous silica materials also have 2-D hexagonal p6m symmetry, as evidenced by well-resolved SAXS patterns (Fig. 6C) and TEM images (Fig. 7C and D). On the contrary to the similarity of unit cell parameters of ordered mesoporous carbons and carbon-silica nanocomposites, the cell parameters of mesoporous silica reduce with the increase of carbon contents in the nanocomposites. Type-IV N2 sorption isotherms with capillary condensation steps at a relative pressure of 0.70-0.85 are observed for all mesoporous silica materials (Fig. 6D), suggesting a uniform pore size distribution. Prolonging the aging time of TEOS under HCl acid-catalyzed condition increases the polymerization and cross-linking degree of silicates, resulting in the carbon-silica nanocomposites with larger-domain of silica aggregations. The removal of the silica framework brings about bimodal mesoporous carbons with detectable pore sizes of 2.6 and 5.8 nm. Also, the carbon has a high BET surface area of 2130 m2/g and a large pore volume of 2.02 cm3/g.
Fig. 6. SAXS patterns (A and C) and N2 sorption isotherms (B and D) for the mesoporous carbon (A and B) and silica (C and D) products obtained from the corresponding nanocomposites with different compositions calcined at 900qC in N2, in A and B: (a) MP-C-27, (b) MP-C-36, (c) MP-C-46 and (d) MP-C-61; in C and D: (a) MP-S-27, (b) MP-S-36, (c) MP-S-46 and (d) MP-S-61.
Fig. 7. TEM images for the products from the MP-CS-46 nanocomposite calcined at 900oC in N2: MP-C-46 (A and B) obtained after the removal of silicas by immersing in HF solution and MP-S-46 (C and D) obtained after the removal of carbons by combustion at 550oC in air. The TEM images were recorded along the  (A, C) and  (B, D) directions. The insets are the corresponding FFT diffractograms.
3.5. Understanding organic-organic self-assembly. Highly ordered mesoporous polymer and carbon materials (Scheme 1A) can be synthesized by organic-organic self-assembly via EISA method [19, 20]. The synthesis procedure includes five major steps: (1) resol precursor synthesis; (2) the formation of an ordered hybrid mesophase by organic-organic self-assembly during the solvent evaporation; (3) thermopolymerization of the resols around the template to solidify the ordered mesophase; (4) template removal; (5) carbonization. The beginning homogeneous solution is prepared by dissolving the triblock copolymer and resol precursor in ethanol, which is volatile. The preferential evaporation of ethanol progressively enriches the concentration of the copolymer and drives the organization of resol-copolymer composites into an ordered liquid crystalline mesophase. Furthermore, the ordered mesophase is solidified by the cross-linking of resols, which can be easily induced by thermopolymerization. The self-assembly approach allows the efficient synthesis of mesoporous polymers and carbons with controlled pore structures. More importantly, it improves mesoporous nanocomposite materials research by triconstituent or multicomponent co-assembly.
Scheme 1. Organic-Organic Self-assembly to Ordered Mesoporous Polymer (A) and Triconstituent Co-assembly to Ordered Mesoporous Polymer-Silica Nanocomposite (B) via EISA method.
3.5.1.Triconstituent co-assembly. Ordered mesoporous polymer-silica nanocomposites with interpenetrating networks can be obtained by triconstituent co-assembly of resols, silica oligomers from acid-catalyzed hydrolysis of TEOS and triblock copolymers F127 via EISA method (Scheme 1B). The continuous ethanol evaporation promotes co-assembly of these species and drives the organization of surfactant-resols-silica composites into ordered mesophase. During this process, resols show low condensation rates under acidic condition at room temperature and phase separation from silicate species, and form nanosized “concrete” structures in the nanocomposites. However, silicate oligomers undergo a cooperative process, during the assembly with the block copolymers, and further condense and cross-link together to form the frameworks. Because of the tetrahedral structures, the cross-linkage of silicate species can occur around nanosized resols to generate 3-D “reinforcing-steel-bar” frameworks. Large domain sized polymer resin “concrete” frameworks interpenetrated with silicate networks during the thermopolymerization of resols at 100oC inside the framework mesostructure. Therefore, the controllable triconstituent co-assembly of amphiphilic block copolymer, resols, and silica oligomers can be achieved with “homogeneous” distribution of resols and silicates around triblock copolymer F127. By varying the initial mass ratio of TEOS to resols, the obtained nanocomposites can possess a continuous composition with the ratio ranging from zero to infinity.
3.5.2.Control of mesostructures. Diverse mesostructures such as hexagonal p6m, cubic Ia3d, Im3m, Fm3m and Fd3m structures have been synthesized. It is known that the phase transformation of liquid crystalline mesophases is from lamellar to bicontinuous cubic, hexagonal, and body centered cubic as the hydrophilic-hydrophobic balance number grows. A low ratio of phenol/P123 yields a lamellar mesostructure. As the ratio increases, the appropriate interfacial curvature should change due to the change of the hydrophilic/hydrophobic volume ratio. As a result, the mesostructure changes to cubic bicontinuous Ia3d and hexagonal p6m structures. Similar results are obtained in the copolymer F127 self-assembly system. Adding more F127 template into the synthetic solution can make the mesophase transformation from hexagonal p6m to body-centered cubic Im3m mesostructures. Therefore, the progression of mesostructures induced by triblock copolymers can be understood according to the enlargement of hydrophilic/hydrophobic ratios of resol-surfactant mesophases. Only reverse triblock
1731 copolymer PPO-PEO-PPO can yield face-centered cubic Fd3m mesostructure in a narrow range, which may be related the characteristic phase behaviors.
3.5.3.Pore size. In view of the different reactivity of triblock copolymer templates and phenolic resins, simple calcination at 300-400oC under N2 efficiently decompose the templates to generate ordered mesoporous polymer resin frameworks. Further calcination at above 600oC, serious skeleton shrinkage occurs and the resultant carbon mesostructures have small pore sizes, low surface areas and low pore volumes. The introduction of a rigid silica in nanocomposites can effectively reduce framework shrinkage, which facilitates one to prepare polymer-silica and carbon-silica nanocomposites with large pore sizes. Further removing silica can lead to carbon materials with two kinds of pores. The primary pore diameter is determined by the size of the hexagonal arranged micelles that are assembled with block copolymer, resols and silica oligomers. This kind of pores is large and almost similar to that of carbon-silica nanocomposites. The others are small pores in carbon walls caused by etching of silica frameworks. Because of the 3-D “reinforcing-steel-bar” frameworks, the pores on the “concrete” carbon walls are quite small (< 2.5 nm). In contrast with C-FUD-15 heated at 900°C, this kind of mesoporous carbons shows considerably larger pore sizes of about 6.7 nm and higher surface areas up to 2470 m2/g. At the same time, the pore size in the carbon frameworks can be controlled by adjusting the initial hydrolysis and condensation degree of silica. Therefore, highly ordered mesoporous carbon can be obtained with obvious bimodal pores at 2.6 and 5.8 nm by prolonging the aging time of TEOS. Using hydrophobic PEO125-PS230 diblock copolymer with high molecular weight can yield a large pore (22.6 nm) mesoporous carbon with cubic structure (Fm3m).
Fig. 8 Cyclic voltammetry for mesoporous carbon in 2.0 M KOH electrode with a scan rate of 5, 20 and 50 mV/s between -0.1 ~ -1.0 V. The three-electrode system was used: carbon materials as a working electrode, Pt metal as a counter electrode, and SCE (Saturated Calomel electrode) as a reference electrode. Capacitance calculated from cyclic voltammetry by using the current at -0.50 V (Capacitance = current/voltage sweep rate).
1732 3.6. Applications of mesoporous carbons for electrochemical double layer capacitor (EDLC). Electrochemical double layer capacitor (EDLC) has attracted increasing interest and attention in research because of its potential in high power output and high energy density applications . The carbon with 2-D pore symmetry is favorable for ionic transports, thus resulting in better capability for high-drain-rate operations among ordered mesoporous carbons. Fig. 8 shows cyclic voltammetry for MP-C-36 with different voltage sweep rate from 5 to 50 mV/s. At the low voltage sweep rate of 5 mV/s, MP-C-36 material shows rectangular shape with excellent capacity. The cyclic voltammetry maintains good box-like shape when voltage sweep is increased to 50 mV/s. To calculate the specific capacitance from the cyclic voltammetry measurement, the current (mA) at -0.50 V is taken and divided by a the scan rate. Carbon MP-C-36 shows high capacitance of 194 F/g at sweep rate of 5 mV/s, and especially maintains most of the capacitance of 176 F/g even at very high sweep rate of 50 mV/s. This high capacitance is attributed to the high surface area and large pore size with interconnected channels, which facilitate ionic transportation to demonstrate excellent high-frequency performance. 4. CONCLUSION A family of highly ordered mesoporous polymer and carbon materials with the space groups of p6mm, Ia3d, Im3m, Fm3m, and Fd3m, have been successfully synthesized by organic-organic self-assembly of resols and triblock copolymers PEO-PPO-PEO (F127, P123 and F108), or PPO-PEO-PPO or PEO-PS via an EISA strategy. In the presence of silicates precursors, ordered mesoporous polymer-silica and carbon-silica nanocomposites with “reinforced-concrete”-like structure have been proposed for the first time. Ordered mesoporous carbons with high surface area (up to 2470 m2/g) and large pore size (up to 22.6 nm) can be obtained after the removal of silica component from the carbon-silica nanocomposites. The organic-organic self-assembly and triconstituent co-assembly approaches can allow the efficient synthesis of mesoporous polymers and organic-inorganic nanocomposites with controlled pore structure. More importantly, it brings an evolution into mesoporous materials from the synthesis of inorganic to organic to nanocomposites. The desired nanocomposites with designed structures and functions are expected to synthesize. ACKNOWLEDGMENTS
This work was supported by the NSF of China (20421303, 20373013, and 20521140450), the State Key Basic Research Program of the PRC (2006CB202502), the Shanghai Science & Technology Committee (06DJ14006, 055207078, 05DZ22313, 04JC14087), Shanghai Nanotech Promotion Center (0652nm024), and Fudan Graduate Innovation Funds. We thank Dr. S. H. Xie and L. J. Zhang for experimental and characterization assistance. REFERENCES  J. M. Lehn, Angew. Chem. Int. Ed. ,29 (1990) 1304.  C. D. Liang, K. L. Hong, G. A. Guiochon, J. W. Mays and S. Dai, Angew. Chem. Int. Ed., 43 (2004) 5785.
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