多孔聚苯醚的合成及气体储存

通过厄尔曼缩合反应合成了一种具有dia-c5 拓扑结构的多孔聚苯醚JUC-Z6, 并对其结构进行了表征. 结果表明, 该化合物具有高热稳定性(214℃ 失重5%), 高化学稳定性、 高BET比表面积(192 m²/g)及窄孔径分布(1.36 nm). 低压气体吸附测试结果表明, JUC-Z6在多孔材料中具有较高的吸附焓(氢气4.1 kJ/mol, 二氧化碳33.7 kJ/mol, 甲烷4.1 kJ/mol).     

Impregnated Sulfur in Carbonized Nitrogen-containing Porous Organic Frameworks as Cathode with High Rate Performance and Long Cycle Life for Lithium-sulfur Batteries

The undesirable cycling performance caused by soluble poly sulfides shuttling between anode and cathode has been considered as the main challenge that has hindered its practical applications for lithium-sulfiir(Li-S) batteries. To solve tliis issue effectively, a nitrogen-containing porous carbon, namely JUC-Z2-900,developed from a porous organic framework, namely JUC-Z2, bearing a high surface area(805 m^2/g),small pore size(0.5 mil) and nitrogen doping(2.15%, mass fraction), has been used as a host material for Li-S batteries. The micropores of JUC-Z2-900 can confine the smaller sulfur molecules S2-4, which can essentially alleviate the critical problem of poly sulfide dissolution.Furthermore, nitrogen-containing JUC-Z2-900 can promote chemical adsorption of sulfur. The above two factors can improve the electrochemical performance of Li-S batteries effectively. To compare the eftects of sulfur contents and melt-difiusion strategy in JUC-Z2-900/S composites, a series of JUC-Z2-900/S composites was synthesized and tlieir electrochemical perfbnnances were explored, indicating good rate performance and excellent cycling stability of the composites contributed by both appropriate mass percentage of sulfiir and its confinement in the micropores.     

羟基官能化共价有机骨架化合物的设计合成及性质

本文设计并合成了一个具有共价有机骨架微孔结构的聚三（4-苯基）硅醇化合物。该化合物是利用乌尔曼反应,三（4-溴苯基）硅醇自聚合得到的。通过MAS NMR,FTIR,SEM,PXRD对化合物结构进行了表征。并通过TGA及氮气吸附表征化合物热稳定性及孔性质。该化合物具有高热稳定性（467 ℃失重5%）,高化学稳定性,高BET比表面积（739 m2g-1）及很窄的孔径分布（1.27 nm）。     

Solid-state 13C NMR studies on organic-inorganic hybrid zeolites

A novel type of organic-inorganic hybrid zeolite with organic lattice (ZOL) is studied in detail by solid-state (13)C magic angle spinning nuclear magnetic resonance (MAS NMR). The (13)C MAS NMR measurements employing several pulse sequences quantitatively demonstrate that methylene groups are really incorporated in the framework, although they are partially cleaved into methyl groups. The organic species in ZOL materials are open for adsorbates, which is evidenced by the (13)C MAS NMR measurements for an n-hexane-adsorbing ZOL material. This finding strongly suggests that organic moieties are incorporated as a zeolite framework, indicating that ZOL is not a physical mixture of a carbon-containing amorphous aggregate and a conventional zeolite but a true organic-inorganic hybrid zeolite.     

The Synthesis and Characteristics of Vanadoaluminosilicate MCM-41 Mesoporous Molecular Sieves

A series of vanadoaluminosilicate MCM-41 mesoporous molecular sieves with various compositions have been hydrothermally synthesized. Hexadecyltrimethylammonium bromide was used as a surfactant in the synthesis. The samples were characterized with nitrogen sorption, X-ray diffraction, differential thermal analysis, thermogravimetric analysis, Fourier transform-Infrared spectroscopy, UV-visible spectroscopy, scanning electron microscopy, transmission electron microscopy, and solid state NMR. The solid products had the MCM-41 structure and contained only atomically dispersed vanadium and aluminum consistent with framework vanadium and aluminum. The samples were hydrophobic and contained large amount of surfactant in the as-synthesized samples. The surfactant could be removed upon calcination at 450°C. N₂ sorption measurements and TEM demonstrate the high mesoporosity of [V, Al]-MCM-41. The incorporation of vanadium and aluminum into MCM-41 decreased the surface area to some extent. The morphologies of all the samples were the agglomerate of plates. ²⁹Si MAS NMR shows that the pore wall is amorphous. ²⁷Al MAS NMR shows that all of aluminum species were tetrahedrally coordinated even after calcination at 550°C.     

Role of carboxylate chelating agents on the chemical, structural and textural properties of hydroxyapatite

Organically-modified hydroxyapatite materials were synthesized through the addition of oxalic, succinic, adipic and citric acids to a calcium hydroxide solution before neutralization by ammonium dihydrogenphosphate. All carboxylic acids have a significant influence on apatite crystallinity and nanoparticle size, as indicated by XRD and TEM. Chemical and thermogravimetric analyses as well as FTIR and {(1)H}-(13)C CP MAS NMR spectroscopies indicate that the additives are present in the final material. (1)H, {(1)H}-(31)P HPDec MAS, CP MAS and 2D {(1)H}-(31)P CP-HETCOR MAS NMR experiments suggest that carboxylic acids are localized on the apatite nanocrystallite surface, resulting in the formation of a disordered outer layer. Nitrogen sorption measurements indicate minor modifications of the specific surface area of the resulting mesoporous materials upon carboxylic acid addition but more significant variations in the average dimensions of the pores as well as in the chemical nature of the pore surface. Although these evolutions are mainly in good agreement with the ligand affinity for calcium ions in solution, an unexpected difference was observed between succinic and adipic acid, that may be attributed to steric constraints resulting from the interfacial nature of the calcium-ligand interactions. These data should provide useful guidelines to identify novel efficient additives to control apatite growth.     

新型锗中心多孔芳香材料的设计合成和表征

采用四(4-溴苯基)锗烷作为基块, 以1,4-苯二硼酸和4,4'-联苯基二硼酸作为桥联, 合成了两种锗中心的多孔芳香材料(Ge-PAFs). 通过FTIR, MAS NMR, TGA, PXRD, SEM, TEM及N2吸附对该化合物的结构及性质进行表征. Ge-PAF-1和Ge-PAF-2具有优良的热稳定性(420 ℃失重5%)及化学稳定性. 另外, 该材料成功地在聚合物中引入锗元素为其在半导体等方面的应用提供了可能^[1].     

Surfactant mediated control of pore size and morphology for molecularly ordered ethylene-bridged periodic mesoporous organosilica

A series of ethylene-containing mesoporous organosilica materials were fabricated via surfactant-mediated assembly of 1,2-bis(triethoxysilyl)ethylene (BTEE) organosilica precursor using alkyltrimethylammonium bromide (CnTAB) surfactants with different alkyl chain length (n=12, 14, 16, 18) as supramolecular templates. The presence of molecularly ordered ethylene groups in the resulting periodic mesoporous organosilica (PMO) materials was confirmed by XRD data along with 29Si and 13C MAS NMR analysis. Additional characterization techniques, namely nitrogen sorption, TEM, and TGA, confirmed the structural ordering and thermal stability of the molecularly ordered ethylene-bridged PMOs. The PMOs exhibit molecular-scale ordering (with a periodicity of 5.6 A) within the organosilica framework and tunable pore size, which depending on the alkyl chain length of the surfactant templates, varied in the range 23-41 A. Furthermore, depending on the alkyl chain length of the templates, the particle morphology of the PMOs gradually changed from monodisperse spheres (for C12TAB) to rod or cakelike particles (for C14TAB) and elongated ropelike particles for longer chain surfactants. Variations in the surfactant chain length therefore allowed control of both the pore size and particle morphology without compromising molecular-scale or structural ordering. The reactivity of ethylene groups was probed by bromination, which demonstrated the potential for further functionalization of the PMOs.     

Sequestration of naphthenic acids from aqueous solution using β-cyclodextrin-based polyurethanes

The sorption characteristics of naphthenic acids (NAs) in their anion form with β-cyclodextrin (β-CD) based polyurethanes, as sorbents, from aqueous solutions that simulate the conditions of oil sands process water (OSPW) are presented. The copolymer sorbents were synthesized at various β-CD:diisocyanate monomer mole ratios (e.g., 1:1, 1:2, and 1:3) with diisocyanates of variable molecular size and degree of unsaturation. The equilibrium sorption properties of the copolymer sorbents were characterized using sorption isotherms in aqueous solution at pH 9.00 with electrospray ionization mass spectrometry to monitor the equilibrium unbound fraction of anionic NAs in the aqueous phase. The copolymer sorbents were characterized in the solid state using (13)C CP-MAS NMR spectroscopy, IR spectroscopy and elemental analysis. The sorption results of the copolymer sorbents with anion forms of NAs in solution were compared with a commercially available carbonaceous standard: granular activated carbon (GAC). The monolayer sorption capacities of the sorbents (Q(m)) were obtained from either the Langmuir or the Sips isotherm model used to characterize the sorption characteristics of each copolymer sorbent. The estimated sorption capacity for GAC was 142 mg NAs per g sorbent whereas the polymeric materials ranged from 0-75 mg NAs per g sorbent over the experimental conditions investigated. In general, significant differences in the sorption capacities between GAC and the copolymer sorbents were related to the differences in the accessible surface areas and pore structure characteristics of the sorbents. The Sips parameter (K(eq)) for GAC and the copolymer materials reveal differences in the relative binding affinity of NAs to the sorbent framework in accordance with the synthetic ratios and the value of Q(m). The diisocyanate linker plays a secondary role in the sorption mechanism, whereas the β-CD macrocycle in the copolymer framework is the main sorption site for NAs because of the formation of inclusion complexes with β-CD.     

Cubic Mesoporous Titanium Phosphonates with Multifunctionality

Cubic mesoporous titanium phosphonate materials with bridged organic groups inside the framework were synthesized by means of a one‐pot hydrothermal autoclaving process, with the assistance of cationic surfactant cetyltrimethylammonium bromide. 1‐Hydroxyethylidene‐1,1‐diphosphonic acid was used as the coupling molecule. A typical cubic mesophase with surface area of 1052 m² g^?1 and pore size of 2.6 nm was confirmed by XRD, TEM, and N₂ sorption analysis. The organophosphonate groups were homogeneously incorporated in the network of the mesoporous solids, as revealed by FTIR and magic‐angle spinning (MAS) NMR spectroscopy, and thermogravimetry and differential scanning calorimetry (TG‐DSC) measurements. The synthesized hydroxyethylidene‐bridged cubic mesoporous titanium phosphonates proved to be thermally stable up to 350 °C, with a well‐preserved hybrid framework and cubic mesoporous architecture. The obtained cubic mesophase could be transformed into a hexagonal mesophase by simply adjusting the molar ratios of the added raw materials, namely, a Ti/P molar ratio of 1:4 and a CTAB/Ti molar ratio of 1.9–2.3 for the cubic phase and Ti/P molar ratio of 3:4 and CTAB/Ti molar ratio of 0.1–0.4 for the hexagonal phase. The cubic hybrid materials could be used as efficient photocatalysts for the photodegradation of rhodamine B. Moreover, they were also used for adsorption of CO₂ and heavy metal ions and exhibited a significant capture amount of around 1.0 mmol g^?1 for CO₂ molecules at 35 °C and high adsorption capacity of 28.5 μmol g^?1 for Cu²⁺ ions with good reusability, which demonstrated their promising potential in environmental remediation.     

Bifunctional hybrid mesoporous organoaluminosilicates with molecularly ordered ethylene groups

We report the synthesis and characterization of crystal-like structurally well-ordered ethylene-containing hybrid mesoporous organoaluminosilicate materials, which exhibit molecular-level periodicity in the pore walls and enhanced hydrothermal stability. Distilled 1,2-bis(triethoxysilyl)ethylene (BTEE) was used as the organosilica precursor, aluminum isopropoxide as aluminum source, and cetyltrimethylammonium bromide as template. The materials are structurally well-ordered and exhibit high surface area (>1300 m(2)/g) and pore volume (>1.10 cm(3)/g). The presence of molecularly ordered ethylene groups was confirmed by powder X-ray diffraction, (29)Si and (13)C MAS NMR, and Raman spectroscopy. The ethylene groups are thermally stable up to a temperature of 300 degrees C. The presence of ethylene groups enhances the hydrothermal stability in boiling water of both organosilica and organoaluminosilicate materials. The organoaluminosilicate materials possess a bifunctional character arising from the presence of both tetrahedrally coordinated Al and molecularly ordered ethylene groups in their frameworks.     

介孔分子筛Ti-AlKIT-1的制备、表征与催化性能

分别采用直接(ds)和后合成法(ps)合成含铝的介孔分子筛Al(ds or ps)KIT-1。 以钛酸四丁酯Ti（OEt）4为钛源,将钛嫁接在AlKIT-1表面制备出Ti-AlKIT-1样品。 用傅里叶变换红外光谱、X射线粉末衍射、固体核磁共振(MAS NMR)、固体紫外 可见漫反射光谱（DRS）、能谱(EDS)和N2吸附-脱附对样品进行了表征,并以双氧水氧化环己醇为探针考察了样品的催化活性。 实验结果表明,分子筛Ti-AlKIT-1具有规整的介孔孔道结构,钛进入介孔分子筛骨架而成为四配位的骨架钛,铝的存在形式与样品AlKIT-1的预处理有关,经铵溶液洗涤的Al(ds)KIT-1中没有非骨架铝。 Ti-AlKIT-1在催化双氧水氧化环己醇反应中铝和钛存在明显的协同作用。 样品Ti-Al(ds)KIT-1表现出更高的催化作用,这与其具有较高的比表面积、较大的孔容和较高钛铝比有关,80 ℃反应48 h,重复使用3次后,环己醇的转化率降低至51.3%,仅下降4.31%。     

Investigation of the sorption properties of β-cyclodextrin-based polyurethanes with phenolic dyes and naphthenates

The sorption of p-nitrophenol (PNP), phenolphthalein (phth) and naphthenates (NAs) with β-cyclodextrin (β-CD) based polyurethane sorbents from aqueous solutions are reported. The copolymer sorbents were synthesized at various β-CD/diisocyanate monomer mole ratios (e.g., 1:1, 1:2, and 1:3) with diisocyanates of variable molecular size and hydrogen deficiency. The copolymer sorbents were characterized in the solid state using (13)C CP-MAS NMR spectroscopy, IR spectroscopy and elemental (C,H,N) analysis. The equilibrium sorption properties of the copolymer sorbents in aqueous solution were characterized using isotherm models at pH 4.6 and 9.0 for PNP, pH 9.0 for naphthenates and pH 10.5 for phth. UV-Vis spectroscopy was used to monitor the unbound fraction of the phenolic dyes in the aqueous phase, whereas, electrospray ionization mass spectrometry was used to monitor the unbound fraction of naphthenates. The sorption results of the copolymer sorbents were compared with a commercially available carbonaceous standard; granular activated carbon (GAC). The sorption properties and capacities of the copolymer sorbents (Q(m)) were estimated using the Sips isotherm. The sorption capacity for GAC was 2.15 mmol PNP/g, 0.0698 mmol phth/g, and 142 mg NAs/g, respectively, whereas the polymeric materials ranged from 0.471 to 1.60 mmol/g (PNP), 0.114 to 0.937 mmol/g (phth), and 0 to 75.5 mg/g (naphthenates), respectively, for the experimental conditions investigated. The observed differences in the sorption properties were attributed to the accessible surface areas and pore structure characteristics of the copolymer sorbents. The binding constant, K(eq), for copolymer materials for each sorbate is of similar magnitude to the binding affinity observed for native β-CD. PNP showed significant binding onto the copolymer framework containing diisocyanate domains, whereas, negligible sorption to the sites was observed for phth and naphthenates. The β-CD inclusion sites in the copolymer framework are concluded to be the main sorption site for phth and naphthenates through the formation of well-defined inclusion complexes.     

苯基磺酸官能化中孔硅基材料的制备及催化性能研究

通过溶胶-凝胶法制得了苯基聚硅氧烷, 进一步磺化制备了苯基磺酸官能化的中孔硅基催化材料, 并通过BET, SEM和固体核磁技术对其进行了表征. BET结果表明, 该催化剂比表面积为722 m²/g, 平均孔径为9.06 nm, 孔容0.59 mL/g. ¹³C CPMAS NMR和²⁹Si CPMAS NMR表征显示磺酸基键合于苯环间位, 苯基以共价方式进入无机-有机杂化硅基材料的内部结构. 该固体酸的活性中心磺酸基在表面呈均匀分布, 在芳族羧酸和取代酚的直接酯化反应中表现出优异的催化性能.     

Towards guest-zeolite interactions: an NMR spectroscopic approach

Guest(metal)-zeolite interactions in a two component heterogeneous catalyst have been investigated by high-field and high-speed (27)Al MAS NMR, and two-dimensional (27)Al MQ MAS NMR experiments as well as ab initio DFT methods. It was established that strong interactions between guest and zeolite occur in a metal/zeolite system, with the metal anchored to the tetrahedral aluminum framework site through two oxygen bridges. It disturbs the tetrahedral environment of associated aluminum framework, changing AlO(4) geometry from near T(d) to C(2v); this enables us to resolve this species from the undisturbed aluminum framework species in high-field (27)Al MAS NMR and two-dimesional (27)Al MQ MAS NMR experiments.     

Sr(II)-UPRM-5 titanium silicate framework thermally induced contraction: in situ high temperature XRD and 29Si MAS NMR

The thermally induced contraction process of a titanosilicate prepared with tetraethylammonium hydroxide and ion exchanged with Sr(II) (Sr-UPRM-5) after detemplation has been characterized via in situ high temperature X-ray diffraction (XRD) and (29)Si magic angle spinning nuclear magnetic resonance (MAS NMR). The as-synthesized material was prepared via conventional and microwave-assisted hydrothermal methods, the latter resulting in a reaction time an order of magnitude shorter than the former case. In situ high temperature XRD tests performed on Sr-UPRM-5 indicate that at 120 °C, water coordinated to the structure is released initiating the collapse of the framework. At much higher temperatures, the material eventually becomes an amorphous phase. Indexing of the XRD patterns indicates that lattice constant a was more affected by the heat treatment, probably related to the material's pore system, while the unit cell volume experienced a 44% reduction. (29)Si MAS NMR analyses for as-synthesized UPRM-5 confirmed two different silicon environments: Si(2Si, 2Ti(octa)) and Si(3Si, 1Ti(semi-octa)), which are similar to those exhibited by titanosilicate ETS-4. On the other hand, in situ high temperature (29)Si MAS NMR analyses for Sr-UPRM-5 demonstrated that changes in the silicon environment due to the presence of titanium centers possessing additional multiple coordination states, which arise from elimination of framework coordinated water molecules, are responsible for the structure collapsing. In general, these results underline the importance of avoiding complete removal of tenacious water molecules in order to preserve the Sr-UPRM-5 properties suitable for adsorption and catalysis applications.     

Study of the adsorption of organic molecules on transition metal exchanged zeolites via solid state NMR. Part 2: adsorption of organic molecules on zeolite NaX, CaX, and CaCoX

Literature [Denayer et al. Microporous Mesoporous Mater. 2007, 103, 1 and Denayer et al. Microporous Mesoporous Mater. 2007, 103, 11] shows that zeolite NaX exchanged with Ca(2+) and Co(2+) ions is able to remove cyclopentadiene (CPD) impurities from a 1-octene feed with high selectivity. In the present work, the adsorption of dicyclopentadiene (DCPD), CPD, 1-octene, and n-octane on zeolite X, exchanged with Ca(2+) and/or Co(2+) ions, has been investigated via (1)H magic-angle spinning (MAS) NMR spectroscopy. The liquid adsorbate was dosed under inert atmosphere in an MAS rotor filled with dry adsorbent, at a pore filling degree of 70%. Next, the evolution in time was recorded of the (1)H MAS NMR spectrum and the (1)H spin-lattice and spin-spin relaxation times of the adsorbed components. For the various adsorbate-adsorbent systems, a plot is made of the signal intensity versus the square root of the contact time. It is found that, over the considered time interval, Fickian diffusion takes place. On the basis of the change in time of the spin-lattice relaxation time, a transport diffusion coefficient ranging between 1 and 2 x 10(-15) m(2) x s(-1) is calculated. Moreover, there appear to be two sorption regimes, with different diffusivities. A comparison is made between the (1)H spin-lattice relaxation behavior of DCPD, 1-octene, and n-octane, indicating that 1-octene and n-octane are located closer to the paramagnetic ions than DCPD. The average distance between the adsorbate molecules and the paramagnetic ions is derived from relaxometric data. By analyzing the chemical shifts of the resonance lines, it is found that the pi-interaction of CPD and 1-octene is stronger than that of DCPD.     

Comparative Evaluation of Steam Stability and Catalytic Properties of Four Common Aluminosilicate Mesostructures Prepared by Post‐Grafting Method

Four common mesostructured aluminosilicates (e.g. AlMCM‐41, AlMCM‐48, AlMSU‐1 and AlSBA‐15, Si/Al = 7.5) with different pore framework structures were prepared via post‐synthetic method utilizing aluminum isopropoxide as the aluminating agent and characterized by ²⁷Al MAS NMR, XRD, N₂‐adsorption isotherm and NH₃‐TPD. It was found that, on the basis of the above analysis results, AlMCM‐41, AlMSU‐1 and AlSBA‐15 retained more mesoporosity than cubic Al/MCM‐48 after exposure to pure steam at 800 °C, which may be responsible for their much higher activities in bulky 1,3,5‐triisopropylbenzene (TIPB) conversion.     

Thiol-functionalized MCM-48： an Effective Absorbent of Mercury Ions

Water polluted by toxic metals remains an important environmental issue, and there hasrecently been a growing interest in the research of materials capable of removing toxicmetal ions from contaminated water. Mercury is one of the heavy metal ions that ha…     

Sandia octahedral molecular sieves (SOMS): structural and property effects of charge-balancing the M(IV)-substituted (M = Ti, Zr) Niobate framework

Sandia octahedral molecular sieves (SOMS) is an isostructural, variable composition class of ion exchangers with the general formula Na(2)Nb(2-x)M(IV)(x)O (6-x)(OH)(x).H(2)O (M(IV) = Ti, Zr; x = 0.04-0.40) where up to 20% of the framework Nb(V) can be substituted with Ti(IV) or Zr(IV). This class of molecular sieves is easily converted to perovskite through low-temperature heat treatment (500-600 degrees C). This report provides a detailed account of how the charge imbalance of this Nb(V)-M(IV) substitution is compensated. X-ray powder diffraction with Rietveld refinement, infrared spectroscopy, thermogravimetric analysis, (23)Na MAS NMR, and (1)H MAS NMR were used to determine how the framework anionic charge is cation-balanced over a range of framework compositions. All spectroscopic evidence indicated a proton addition for each M(IV) substitution. Evidences for variable proton content included (1) increasing OH observed by (1)H MAS NMR with increasing M(IV) substitution, (2) increased infrared band broadening indicating increased H-bonding with increasing M(IV) substitution, (3) increased TGA weight loss (due to increased OH content) with increasing M(IV) substitution, (4) no variance in population on the sodium sites (indicated by Rietveld refinement) with variable composition, and (5) no change in the (23)Na MAS NMR spectra with variable composition. Also observed by infrared spectroscopy and (23)Na MAS NMR was increased disorder on the Nb(V)/M(IV) framework sites with increasing M(IV) substitution, evidenced by broadening of these spectral features. These spectroscopic studies, along with ion exchange experiments, also revealed the effect of the Nb(V)/M(IV) framework substitution on materials properties. Namely, the temperature of conversion to NaNb(1-x)M(IV)(x)O(3) (M = Ti, Zr) perovskite increased with increasing Ti in the framework and decreased with increasing Zr in the framework. This suggested that Ti stabilizes the SOMS framework and Zr destabilizes the SOMS framework. Finally, comparing ion exchange properties of a SOMS material with minimal (2%) Ti to a SOMS material with maximum (20%) Ti revealed the divalent cation selectivity of these materials which was reported previously is a function of the M(IV) substitution in the framework. A thorough investigation of this class of SOMS materials has revealed the importance of understanding the influence of heterovalent substitutions in microporous frameworks on material properties.