Quinine Derivative Bonded the Hybrid Mesoporous Silicas Chiral Stationary Phase: Preparation and Application in Liquid Chromatography

A novel chiral stationary phase (QN‐APEPMOs) was synthesized by immobilizing quinine derivative (QN) onto spherical ammoniapropyl‐functionalized ethane‐bridged periodic mesoporous organosilicas (APEPMOs). The mesoporous material was prepared by a one‐step co‐condensation of 1,2‐bis (triethoxysilyl) ethane (BTSE) and 3‐ammoniapropyl triethoxysilane (KH‐550) using cetyltrimethyl‐ammoniumchlorine (C₁₈TACl) as a template with the aid of ethanol (co‐solvent) in basic medium. And O‐9‐(tert‐butyl carbamoyl) quinine derivative was immobilized on APEPMOs particles through the vinylic double bond. All of the products were characterized. The results showed that APEPMOs were perfect substrates for chiral stationary phase (CSP) and quinine moieties have been successfully immobilized onto the silica gel. To evaluate the chiral discrimination ability of the synthesized CSP, some analytes have been investigated on QN‐APEPMOs in high performance liquid chromatography (RP‐HPLC) in reversed phase. Three acidic compounds were baseline separated. The results demonstrated that QN‐APEPMOs had high selectivity for acidic compounds such as: carboxylic and sulfonic acids. And the reproducibility of the chiral column was good, while the stability was not very good.     

Self-assembled highly ordered ethane-bridged periodic mesoporous organosilica and its application in HPLC

Monodisperse spherical periodic mesoporous organosilicas (PMOs) with ethane integrated in the framework were synthesized and their application as stationary phase for chromatographic separation is demonstrated. The ethane-PMOs were prepared by condensation of 1,2-bis(triethoxysilyl)ethane (BTSE) in basic condition using octadecyltrimethylammonium chloride (C(18)TMACl) as template and ethanol as co-solvent. The morphology and mesoporous structure of ethane-PMOs were controlled under different concentrations of sodium hydroxide (NaOH) and EtOH. The results of scanning electron microscopy (SEM), transmission electron microscopy (TEM), powder X-ray diffraction (XRD), nitrogen sorption measurement, Fourier transform infrared spectroscopy (FT-IR) and elemental analysis showed that ethane-PMOs have spherical morphology, uniform particle distribution, highly ordered pore structure, high surface area and narrow pore-size distribution. The column packed with these materials exhibits good permeability, high chemical stability and good selectivity of mixtures of aromatic hydrocarbons in normal phase high-performance liquid chromatography (HPLC).     

IRMOF-1衍生介孔ZnO微球催化合成低聚聚碳酸酯二醇

IRMOF-1是一种最经典的IRMOF系列材料,通过直接在空气中不同温度下热处理IRMOF-1得到三种ZnO催化剂,并采用XRD、SEM、BET、CO_2-TPD等分析技术对所得样品的晶体结构、表观形貌、孔结构、表面碱性进行了表征。结果显示,ZnO为球状结构,是一种典型的介孔材料,BET比表面积和孔径分别为49.7~62.2 m2/g和2.18~2.92 nm。研究了ZnO微球在碳酸二苯酯(DPC)与新戊二醇(NPG)酯交换合成低聚碳酸酯二醇(PCDL)反应中的催化性能。结果表明,500℃下得到的ZnO微球在DPC与NPG酯交换反应中表现出良好的催化活性。     

镁热还原法制备有序介孔Si/C锂离子电池负极材料及其电化学性能

以SBA-15为前驱体,在660 ℃下通过镁热还原反应得到介孔硅材料,并对其进行碳包覆处理,成功地制备了有序介孔Si/C（OMP-Si/C）复合材料。该OMP-Si/C材料保留了SBA-15模板的有序蜂窝孔道,并且形成具有高堆积密度的莲藕链束结构。文中还提出了一个SBA-15镁热还原液态环境反应模型,探讨了660 ℃下硅的高度有序介孔与莲藕链束结构的形成机理。利用X射线衍射（XRD）仪、扫描电子显微镜（SEM）、透射电子显微镜（TEM）、氮气吸脱附法及拉曼光谱对样品物相和微观形貌进行了表征。这种高度有序介孔Si/C复合材料具有优异的电化学性能,展现出其在第二代锂电池负极材料领域中的潜在应用价值。     

Simultaneous preconcentration of polar and non‐polar organophosphorus pesticides from water samples by using a new sorbent based on mesoporous silica

A new mesoporous silica based on the sol–gel material cyanopropyltriethoxysilane (CNPrTEOS) was successfully synthesized by the hydrolysis and condensation of CNPrTEOS in the presence of ammonium solution as catalyst and methanol as solvent. It was used as a solid‐phase extraction sorbent for the simultaneous extraction of three organophosphorus pesticides, namely, polar dicrotophos and non‐polar diazinon and chlorpyrifos. Analysis was performed using high‐performance liquid chromatography with UV detection. CNPrTEOS was characterized by FTIR spectroscopy, field‐emission scanning electron microscopy and nitrogen gas adsorption. The surface area and average pore diameter of the optimum sol–gel CNPrTEOS are 379 m²/g and 4.7 nm (mesoporous), respectively. The proposed solid‐phase extraction based on CNPrTEOS exhibited good linearity in the range of 0.8–100 μg/L, satisfactory precision (1.15–3.82%), high enrichment factor (800) and low limit of detection (0.072–0.091 μg/L). The limits of detection obtained using the proposed solid‐phase extraction method are well below the maximum residue limit set by European Union and are also lower (13.6–48.5×) than that obtained by using a commercial CN‐SPE cartridge (0.98–4.41 μg/L). The new mesoporous sol–gel CNPrTEOS showed promising alternative as SPE sorbent material for the simultaneous extraction of polar and non‐polar organophosphorus pesticides.     

Uniform and size-tunable mesoporous silica with fibrous morphology for drug delivery

A family of mesoporous silica microspheres with fibrous morphology and different particle sizes ranging from about 400 to 900 nm has been successfully synthesized through a facile self-assembly process. The structural, morphological, and textural properties of the samples were well characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), nuclear magnetic resonance (NMR), Fourier transform infrared spectroscopy (FT-IR), N(2) adsorption/desorption, and thermal gravimetry (TG). The results reveal that this silica-based mesoporous material exhibits excellent physical properties, including a fibrous spherical morphology, good thermal stability, large pore volume, high specific surface area and narrow size distribution. Additionally, the size and textural properties can be tuned by altering the silica precursor/template molar ratio. The formation and the self-assembly evolution process have also been proposed. The obtained materials were further used as a drug delivery carrier to investigate the in vitro drug release properties using doxorubicin (DOX) as a representative model drug. It was found that this kind of silica exhibits good biocompatibility and obvious sustained drug release properties, suggesting its potential application in biological fields.     

Structure and microstructure of nanoscale mesoporous silica spheres

The addition of alcohol to the synthesis of a mesoporous silica material will induce a transition from hexagonal (MCM-41) to cubic (MCM-48) to a lamellar phase and finally to silica spherical particles (SSP), as the alcohol adopts the role of cosurfactant. This will evolve to a cosolvent function as the alcohol concentration is further increased. X-ray diffraction suggests that a phase regression phenomenon occurs, in contradiction with the g-value. Transmission electron microscopy reveals the structure and the microstructure of the mesoporous silica spherical particles. It is shown that the SSP consists of a core of a truncated octahedron with the MCM-48 cubic structure and radial cylindrical pores grown on the surface of the truncated octahedron. This structure model and a possible formation mechanism are discussed.     

Synthesis of bifunctionalized mesoporous organosilica spheres for high-performance liquid chromatography

Phenyl-functionalized mesoporous ethane-silicas with spherical morphology were synthesized by one-step co-condensation of phenyltrimethoxysilane (PTMS) and 1,2-bis(trimethoxysily)ethane (BTME) using a triblock copolymer EO(20)PO(70)EO(20) (P123) as template with the aid of a co-surfactant (cetyltrimethylammonium bromide, CTAB) and a co-solvent (ethanol) in acidic medium. Powder X-ray diffraction (XRD), nitrogen sorption measurement and scanning electron microscopy (SEM) show that phenyl-functionalized ethane-silica has wormhole-like mesostructure and perfect spherical morphology. The chemical stability of phenyl-functionalized mesoporous ethane-silica in basic medium is greatly improved owing to the ethane groups bridged in the mesoporous framework. This work also demonstrates that the phenyl-functionalized mesoporous ethane-silica spheres are excellent packing materials for potential application in the reversed-phase high-performance liquid chromatography (HPLC).     

基于L-谷氨酸的手性硅胶球的制备及其应用

无机介孔硅球因其具有足够的机械强度、热稳定性,以及适应多种流动相的优点,成为高效液相色谱(HPLC)柱填料中使用最广泛和最重要的材料.但在此研究领域中,并未见球形的全无机手性硅胶用作HPLC手性固定相.该文以无机球形介孔硅胶作为研究对象,通过堆砌硅珠法,以硅溶胶为原料,L-谷氨酸(L-Glu)为手性源,在手性环境中制造...     

温度对介孔二氧化硅形貌和介相结构有序性的影响

1992年Kresge等科学工作者首次报道了一种新颖的介孔二氧化硅材料,介孔二氧化硅的合成及其性能表征引起了广泛的研究兴趣[1,2]。这种材料由于具有高比表面积(1000~1400m2·g-1)、孔道排列有序、孔径分布窄并可以在2~10nm范围内可调等优点,所以有望用于催化与吸附、化学传感、纳     

Preparation of mesostructured barium sulfate with high surface area by dispersion method and its characterization

The spherical and cubic mesoporous BaSO(4) particles with high surface area were successfully produced via one-step process through precipitation reaction in aqueous solution of Ba(OH)(2) and H(2)SO(4) with ethylene glycol (n-HOCH(2)CH(2)OH) as a modifying agent. The BaSO(4) nanomaterial revealed that the high surface area and the mesoporous was stable up to 400 degrees C. Agglomerate mesoporous barium sulfate nanomaterials were obtained by the reaction of Ba(2+) and SO(2-)(4) with ethylene glycol aqueous solution. The ethylene glycol was used to control the BaSO(4) particle size and to modify the surface property of the particles produced from the precipitation. The dried and calcined mesoporous BaSO(4) nanomaterials were characterized by X-ray diffraction (XRD), BET surface area and N(2) adsorption-desorption isotherm, scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared resonance (FTIR) and thermogravimetric analysis (TGA). The as-prepared mesoporous dried BaSO(4) possesses a high BET surface area of 91.56 m(2) g(-1), pore volume of 0.188 cm(3) g(-1) (P/P(0)=0.9849) and pore size of 8.22 nm. The SEM indicates that the morphology of BaSO(4) nanomaterial shows shell like particles up to 400 degrees C, after that there is drastically change in the material due to agglomeration. Synthesis of mesoporous BaSO(4) nanomaterial is of significant importance for both sulphuric acid decomposition and oxidation of methane to methanol.     

Application of tetrahydrofuran dispersant in microemulsion for fabricating titania mesoporous thin film

A new strategy was used to fabricate titania mesoporous thin film by incorporating tetrahydrofuran (THF) into the CTAB/n-butyl alcohol/cyclohexane/water reverse microemulsion as a micelle disperser. Highly dispersed and congregated TiO(2) particles in the microemulsion with and without THF were observed by transmission electron microscopy (TEM), respectively. The photographs observed by field-emission scanning electron microscopy (FE-SEM) show that a uniform titania mesoporous thin film with monodisperse TiO(2) spherical nanoparticles of ca. 20 nm was obtained using the microemulsion with THF.     

Hierarchical Mesoporous SnO Microspheres as High Capacity Anode Materials for Sodium‐Ion Batteries

Mesoporous SnO microspheres were synthesised by a hydrothermal method using NaSO₄ as the morphology directing agent. Field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM) and high‐resolution transmission electron microscopy (HRTEM) analyses showed that SnO microspheres consist of nanosheets with a thickness of about 20 nm. Each nanosheet contains a mesoporous structure with a pore size of approximately 5 nm. When applied as anode materials in Na‐ion batteries, SnO microspheres exhibited high reversible sodium storage capacity, good cyclability and a satisfactory high rate performance. Through ex situ XRD analysis, it was found that Na⁺ ions first insert themselves into SnO crystals, and then react with SnO to generate crystalline Sn, followed by Na–Sn alloying with the formation of crystalline NaSn₂ phase. During the charge process, there are two slopes corresponding to the de‐alloying of Na–Sn compounds and oxidisation of Sn, respectively. The high sodium storage capacity and good electrochemical performance could be ascribed to the unique hierarchical mesoporous architecture of SnO microspheres.     

以纳米微晶纤维素为模板的酸催化水解法制备球形介孔TiO_2

以纳米微晶纤维素(NCC)为模板剂,采用酸催化水解法制备了球形介孔TiO2(SP-TiO2).并采用扫描电镜、透射电镜、X射线衍射、紫外-可见漫反射光谱和低温N2吸附-脱附等手段对其进行了表征.结果表明,所制SP-TiO2为直径100～200nm的规整球形颗粒,单个球形颗粒由粒径为10～20nm的TiO2小晶粒组成.其介孔孔径为8.2～13.5nm,且随焙烧温度的升高而增大.NCC长链结构之间羟基键合所形成的狭小空间构成的微反应器,可有效限制TiO2前驱体的生长和团聚,诱导其晶粒自组装成球形结构,并抑制由锐钛矿相向金红石相转变.600oC焙烧的SP-TiO2表现出最高的光催化活性,对苯酚降解率达89%.     

苯基桥键型介孔材料的制备与表征

以1,4-二(三乙氧基硅基)-苯为硅源,聚氧乙烯-聚氧丙烯-聚氧乙烯三嵌段共聚物为模板剂,十六烷基三甲基溴化铵为共模板剂,乙醇为共溶剂,在酸性条件下合成了球形的苯基桥键型有序介孔材料。X射线衍射和透射电镜表征结果表明,该材料具有有序的二维六方相介观结构;傅立叶红外变换、13C和29S i固体核磁共振表征证实硅胶骨架中成功引入了苯基桥键,且在合成和模板移除过程中未发生S i—C键断裂;元素分析表明材料含碳量为34%~39%;热重分析说明材料稳定温度可达300℃;氮气吸附脱附揭示了材料有较高的比表面积(500~600 m2/g)和窄的孔径分布(3.21~3.95 nm)。将该苯基材料不经化学改性直接用作反相高效液相色谱固定相,并与商品键合硅胶苯基色谱柱比较,发现桥键型苯基材料对芳香类化合物具有很好的分离选择性,残留硅羟基明显减少,作为一种新的液相色谱填料具有很好的应用前景。     

Mixed-phase Mesoporous TiO2 Film for High Efficiency Perovskite Solar Cells

Mesoporous scaffold structures have played great roles in halide perovskite solar cells(PSCs),due to the excellent photovoltaic performance and commercial perspective of mesoporous PSCs.Here,we reported a mixed-phase TiO2 mesoporous film as an efficient electron transport layer(ETL)for mesoporous perovskite solar cells.Due to the improved crystal phase,fihn thickness and nanopartMe size of TiO2 layer,which were controlled by varying the one-step hydrothermal reaction time and annealing time,the PSCs exhibited an outstanding short circuit photocurrent density of 25.27 mA/cm^2,and a maximum power conversion efficiency(PCE)of 19.87%.It is found that the ultra-high Jsc attributes to the excellent film quality,light capturing and excellent electron transport ability of mixed-phase TiO2 mesoporous film.The results indicate that mix-phase mesoporous metal oxide fihns could be a promising candidate for producing effective ETLs and high efficiency PSCs.     

三嵌段共聚物EO20PO70EO20相分离行为的耗散粒子动力学模拟

采用耗散粒子动力学(DPD)方法研究了嵌段共聚物EO₂₀PO₇₀EO₂₀(P123)在水、乙醇/水溶液及二氧化硅溶胶体系中的相分离行为. 不同质量分数的P123在水溶液中共形成4种相分离状态: 球状胶束(10%); 椭球胶束(20%)、棒状胶束(30%)和三维立方胶束(50%). 在模板剂质量分数为10%的乙醇/水溶液中, 模板剂胶束稳定性随着乙醇含量的增加而变差. 在二氧化硅溶胶体系中, 模板剂质量分数低于5%时无胶束形成; 模板剂质量分数增至10%时, P123发生相分离形成三维球状胶束; 随着模板剂质量分数的进一步增加, 模板剂分子夹含着水分子形成三维椭球状结构(20%)、三维立方结构(40%)和层状结构(60%). 模拟结果与实验结果一致, 说明DPD模拟可以从计算角度推测模板剂对介孔材料结构的影响.     

以大蓟髓芯为模板制备复合孔生物活性玻璃及其体外成骨性能

以天然植物大蓟髓芯为大孔模板, 以嵌段共聚物为介孔软模板, 制备了孔径为60~100 μm、孔壁为介孔相的高度有序多级复合孔生物活性玻璃. 用扫描电子显微镜(SEM)、粉末X射线衍射仪(XRD)、高分辨率透射电镜(HRTEM)及N2吸附-脱附等测试手段对合成的样品进行了表征. 结果表明, 合成的材料精确地复制了植物模板的形貌, 同时具有较高的比表面积和较大的孔容. 通过体外模拟生理体液测试表明, 这种复合孔生物活性玻璃可诱导羟基磷灰石晶体在其表面形成, 具有良好的体外成骨性能, 因而在骨组织修复方面具有潜在应用前景.     

L-苏氨酸手性分子印迹硅胶分离固定相的制备及分离性能研究

本文使用堆砌硅珠法以硅溶胶为原料、苏氨酸(L-Thr)为手性源构造手性环境,制备具有手性分离能力的全无机介孔手性硅胶球,对其进行元素分析、红外光谱法分析、透射电镜、扫描电镜和氮气吸附等表征,采用HPLC法探究无机介孔硅胶球制备的固定相对手性异构体和苯系位置异构体的拆分性能,成功分离了9对外消旋化合物和8种苯系位置异构体...     

Synthesis of hollow spherical silica with MCM-41 mesoporous structure

Hollow spherical mesoporous silica was synthesized by using sodium silicate as a precursor and a low concentration of cetyltrimethylammonium bromide (CTAB) (0.154 mol dm^–3). The resulting hollow spherical particles were characterized with scanning electron microcopy (SEM), small-angle X-ray diffraction (SXRD), transmission electron microscopy (TEM), and N₂ gas adsorption and desorption techniques. The results showed that regular spherical mesoporous silica could be obtained only if the molar ratio of propanol to CTAB was in the range of approximately 8:1–9:1. The spherical particles were hollow (inside), and the shell consisted of smaller particles with a pore structure of hexagonal symmetry. With an increase of the molar ratio of propanol to CTAB, the distance (a value) between centers of two adjacent pores increased, and the pore structure of mesoporous silica became less ordered. N₂ adsorption–desorption curves revealed type IV isotherms and H1 hysteresis loops; with an increase of the molar ratio of propanol to CTAB, the pore size with Barrett–Joyner–Halenda (BJH) diameter of the most probable distribution decreased, but the half peak width of the pore size distribution peak increased