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K Anjali, M Ahmed, J Christopher, A Sakthivel
Rhodium containing macromolecules calix[4]pyrrole (RhCP) and tetraphenyl porphyrin (RhTPP) were prepared and grafted on the surface of functionalised molecular sieve materials. 1H and 13C NMR, CHNS and mass spectral analyses were used for the structural elucidation of homogeneous organometallic complexes.1H NMR and CHNS analyses confirm the formation of calix[4]pyrrole (CP) and tetraphenyl porphyrin (TPP). The introduction of rhodium ions into the macromolecule is well evident from the disappearance of the 1H NMR signal characteristic of N-H proton (7...
August 17, 2018: Dalton Transactions: An International Journal of Inorganic Chemistry
Diana Díaz-García, Diana Cenariu, Yolanda Pérez, Paula Cruz, Isabel Del Hierro, Sanjiv Prashar, Eva Fischer-Fodor, Santiago Gómez-Ruiz
The mesoporous silica-based material SBA-15 (Santa Barbara Amorphous-15) has been modified with the aminodiol ligand 3-[bis(2-hydroxyethyl)amino]propyltriethoxysilane (PADOH) to give the corresponding material SBA-PADOH. Subsequent functionalization with a diorganotin(iv) compound, SnPh2Cl2 (1), and with two titanocene derivatives, TiCp2Cl2 ([Ti(η5-C5H5)2Cl2] (2)) and TiCpCpPhNfCl2 ([Ti(η5-C5H5)(η5-C5H4CHPhNf)Cl2] (3) (Ph = C6H5; Nf = C10H7)), gave the materials SBA-PADO-SnPh2 (M1), SBA-PADO-TiCp2 (M2) and SBA-PADO-TiCpCp* (M3), respectively...
August 16, 2018: Dalton Transactions: An International Journal of Inorganic Chemistry
Xuelei Pang, Li Li, Yi Wei, Xudong Yu, Yajuan Li
Two novel luminescent organic-inorganic hybrid materials, Ln(L-SBA15)3phen (Ln = Eu, Tb), were designed and synthesized. The organic ligand phenylurea was modified by the silane coupling agent 3-(triethoxysilyl)propyl isocyanate (TESPIC) to form a precursor (L), which was covalently bonded onto a mesoporous SBA-15 backbone to form mesoporous L-SBA15 through co-hydrolysis and co-condensation reactions. 1,10-Phenanthroline monohydrate (phen) was selected as the second ligand to improve the luminescence of the final products, and the two mesoporous hybrid materials Ln(L-SBA15)3phen were obtained after the coordination reaction between the organic ligands (phen and L-SBA15) and Ln(iii) ions...
August 6, 2018: Dalton Transactions: An International Journal of Inorganic Chemistry
Andi Bai, Chao Wu, Xuan Liu, Huiling Lv, Xiaoyan Xu, Yue Cao, Wenjing Shang, Lili Hu, Ying Liu
Background: Biopharmaceutics classification system class II drugs have low solubility, which limits their extent and speed of absorption after oral administration. Over the years, mesoporous materials have been widely used to increase the dissolution rate and oral relative bioavailability of poorly water-soluble drugs. Objectives: In order to improve the dissolution rate and increase oral relative bioavailability of the poorly water-soluble drugs, a tin oxide carrier (MSn) with a mesoporous structure was successfully synthesized...
2018: Drug Design, Development and Therapy
Jing Li, Xudong Fang, Junjie Bian, Yuehong Guo, Chunhu Li
In this study, a novel route was proposed for microalgae biofuel production by catalytic upgrading of Chlorella hydrothermal liquefaction (HTL) derived biocrude. Al-SBA-15, CuO/Al-SBA-15, ZuO/Al-SBA-15, and CuO-ZnO/Al-SBA-15 catalysts were synthesized in a facile, one-pot way, and tested for methyl palmitate decarboxylation and biocrude upgrading without H2 addition. These modified SBA-15 catalysts enhanced alkane selectivity of methyl palmitate decarboxylation from 7.6 wt% up to 79.6 wt% at 340-350 °C...
October 2018: Bioresource Technology
Isabel Barroso-Martín, Antonia Infantes-Molina, Aldo Talon, Loretta Storaro, Elena Rodríguez-Aguado, Enrique Rodríguez-Castellón, Elisa Moretti
In this work, SBA-15 silica and silica-titania have been used as supports for photocatalysts based on AuCu alloy (Au:Cu = 1) to be used in the preferential oxidation of CO (CO-PROX) in excess of hydrogen at room temperature and atmospheric pressure both in the dark and under simulated solar light irradiation. To study their textural, structural, chemical and optical properties, the samples were characterized by X-ray diffraction (XRD), high-resolution transmission electron microscopy (HR-TEM), adsorption-desorption of N₂ at -196 °C, 13 C and 29 Si solid state nuclear magnetic resonance (NMR), X-ray photoelectron spectroscopy (XPS) and diffuse reflectance ultraviolet-visible (DRUV-vis) spectroscopy...
July 13, 2018: Materials
Maria-Cecília Krähenbühl Amstalden, José Diogo Oliveira, Mathias Strauss, Italo Odone Mazali, Daisy Machado, Thais Holtz Theisen, Marcelo Lancellotti
Streptococcus pneumoniae are natural competent bacteria which requires the presence of a pheromone-like molecule to do the transformation process. This study verified the influence of mesoporous silica (SBA-15 and SBA-16) on the transformation process in S. pneumoniae using a donor DNA obtained from a mutant strain of this microorganism (Sp360∆luxS). The results showed that mesoporous silica SBA-15 and SBA-16 particles doubled the transformation ratio frequency compared with negative control (without nanoparticles) in using SBA-15 (ratio 1...
July 14, 2018: Folia Microbiologica
Susana O Ribeiro, Beatriz Duarte, Baltazar de Castro, Carlos M Granadeiro, Salete S Balula
Different methodologies were used to increase the oxidative desulfurization efficiency of the Keggin phosphotungstate [PW12 O40 ]3- (PW12 ). One possibility was to replace the acid proton by three different ionic liquid cations, forming the novel hybrid polyoxometalates: [BMIM]₃PW12 (BMIM as 1-butyl-3-methylimidazolium), [BPy]₃PW12 (BPy as 1-butylpyridinium) and [HDPy]₃PW12 (HDPy as hexadecylpyridinium. These hybrid Keggin compounds showed high oxidative desulfurization efficiency in the presence of [BMIM]PF₆ solvent, achieving complete desulfurization of multicomponent model diesel (2000 ppm of S) after only 1 h, using a low excess of oxidant (H₂O₂/S = 8) at 70 °C...
July 12, 2018: Materials
Fangyu Fu, Changlong Wang, Qi Wang, Angel M Martinez-Villacorta, Ane Escobar, Hanbao Chong, Xin Wang, Sergio Moya, Lionel Salmon, Eric Fouquet, Jaime Ruiz, Didier Astruc
Ammonia borane hydrolysis is considered as a potential means of safe and fast method of H2 production if it is efficiently catalyzed. Here a series of nearly monodispersed alloyed bimetallic nanoparticle catalysts are introduced, optimized among transition metals, and found to be extremely efficient and highly selective with sharp positive synergy between 2/3 Ni and 1/3 Pt embedded inside a zeolitic imidazolate framework (ZIF-8) support. These catalysts are much more efficient for H2 release than either Ni or Pt analogues alone on this support, and for instance the best catalyst Ni2 Pt@ZiF-8 achieves a TOF of 600 molH2 ·molcatal -1 ·min-1 and 2222 molH2 ·molPt -1 ·min-1 under ambient conditions, which overtakes performances of previous Pt-base catalysts...
July 24, 2018: Journal of the American Chemical Society
Jialu Li, Hao Ren, Xiaoqin Zou, Kun Cai, Nian Zhao, Guangshan Zhu
This work reports a new synthesis strategy called hard-template synthesis to create hierarchical pores in porous organic framework materials. Two different mesoporous silicas (SBA-15 and B56-E-20) were used as the hard templates and biphenyl was employed as the single organic precursor. PAF-45 was prepared by in situ coupling biphenyl within the voids of mesoporous silica. After etching silica, controlled mesopores with sizes ranging from 3 to 10 nm were generated and microporosity was inherited as well in the mesoporous PAF-45HX materials...
July 24, 2018: Chemical Communications: Chem Comm
Tahnee J Dening, Lynne S Taylor
Ordered mesoporous silica materials have shown great potential as oral drug delivery systems for poorly soluble drugs. However, the ability of these delivery systems to generate drug supersaturation has not been widely investigated, and the recently noted phenomenon of incomplete drug release is not well understood. Therefore, the aim of this study was to comprehensively evaluate the release of hydrophobic drug molecules into solution from ordered mesoporous silica, focusing on the extent and duration of drug supersaturation...
July 23, 2018: Molecular Pharmaceutics
Wenyan Chen, Shijuan Zhang, Jinmao You, Zhi Chen, Mingbo Yue
The extraction and analysis of free fatty acids (FFAs) in the whole natural plants are reported. The aminopropyl-functionalized SBA-15 was designed to increase the efficiency of the matrix solid-phase dispersion (MSPD) extraction method. MSPD extraction was performed using to extract FFAs via acid-base interactions. The optimum parameters for the MSPD extraction were N-SBA-15 30 mg, grinding time 120 s and elution solvent methanol-HCl (6:4, v/v). After extraction, the FFAs were analyzed by HPLC with fluorescent labeling...
July 6, 2018: Journal of Chromatographic Science
Mark A Isaacs, Brunella Barbero, Lee J Durndell, Anthony C Hilton, Luca Olivi, Christopher M A Parlett, Karen Wilson, Adam F Lee
Healthcare-associated infections and the rise of drug-resistant bacteria pose significant challenges to existing antibiotic therapies. Silver nanocomposites are a promising solution to the current crisis, however their therapeutic application requires improved understanding of underpinning structure-function relationships. A family of chemically and structurally modified mesoporous SBA-15 silicas were synthesized as porous host matrices to tune the physicochemical properties of silver nanoparticles. Physicochemical characterization by transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), X-ray absorption near-edge spectroscopy (XANES) and porosimetry demonstrate that functionalization by a titania monolayer and the incorporation of macroporosity both increase silver nanoparticle dispersion throughout the silica matrix, thereby promoting Ag₂CO₃ formation and the release of ionic silver in simulated tissue fluid...
July 3, 2018: Antibiotics
Liuye Mo, Wanjin Yu, Huangju Cai, Hui Lou, Xiaoming Zheng
In this work, mesoporous silica materials SBA-15 functionalized with propyl/ phenyl-sulfonic acid group were synthesized and loaded with Pt to form bifunctional catalysts. SAXRD, WAXRD, N2 adsorption-desorption, TEM techniques were used to characterize the above bifunctional catalysts. These bifunctional catalysts were applied to the reaction of hydrodeoxygenation (HDO) of bio-derived phenol (PhOH) to produce cyclohexane fuel and showed very good catalytic performances. There were strong synergies between the metal sites and the acid sites on the bifunctional catalysts...
2018: Frontiers in Chemistry
Chia-Hsin Chen, Daphna Shimon, Jason J Lee, Frederic Mentink-Vigier, Ivan Hung, Carsten Sievers, Christopher W Jones, Sophia E Hayes
We have identified a hydrated bicarbonate formed by chemisorption of 13 CO2 on both dimethylaminopropylsilane (DMAPS) and aminopropylsilane (APS) pendant molecules grafted on SBA-15 mesoporous silica. The most commonly used sequence in solid-state NMR, 13 C CPMAS, failed to detect bicarbonate in these solid amine sorbent samples; here, we have employed a Bloch decay ("pulse-acquire") sequence (with 1 H decoupling) to detect such species. The water that is present contributes to the dynamic motion of the bicarbonate product, thwarting CPMAS but enabling direct 13 C detection by shortening the spin-lattice relaxation time...
July 18, 2018: Journal of the American Chemical Society
Pegah S Nabavi Zadeh, Milene Zezzi do Valle Gomes, Maria Abrahamsson, Anders E C Palmqvist, Björn Åkerman
Fluorescence spectroscopy of protein-bound molecular rotors Cy3 and Cy5 is used to monitor the effective viscosity inside the pores of two types of mesoporous silica (SBA-15 and MCF) with pore diameters between 8.9 and 33 nm. The ratio of the peak intensities is used to measure viscosity independently of solvent polarity, and the response of the lipase-bound dyes is calibrated using glycerol/water mixtures (no particles). The two dyes are either attached to the same protein or separate proteins in order to investigate potential effects of energy transfer (FRET) on the fluorescence properties, when using them as reporter dyes...
June 27, 2018: Physical Chemistry Chemical Physics: PCCP
Andrew W Knight, Austen B Tigges, Anastasia G Ilgen
Nano-scale spatial confinement can alter chemistry at mineral-water interfaces. These nano-scale confinement effects can lead to anomalous fate and transport behavior of aqueous metal species. When a fluid resides in a nanoporous environments (pore size under 100 nm), the observed density, surface tension, and dielectric constant diverge from those measured in the bulk. To evaluate the impact of nano-scale confinement on the adsorption of copper (Cu2+ ), we performed batch adsorption studies using mesoporous silica...
June 26, 2018: Geochemical Transactions
Sara Maleki, Payman Hashemi, Fahimeh Rasolzadeh, Saba Maleki, Ali Reza Ghiasvand
SBA-15 and MCM-41 nanoporous silica sorbents were synthesized and functionalized by amine groups and used, for the first time, for packing a needle trap device (NTD). The characteristics of the synthesized SBA-15 and MCM-41 sorbents were investigated by X-ray diffraction, scanning electron microscopy and Fourier transfer infrared spectroscopy. The NTD coupling to gas chromatography with a flame ionization detector (GC-FID) was carried out to extract and determine polycyclic aromatic hydrocarbons (PAHs) in contaminated soil samples...
June 12, 2018: Journal of Chromatographic Science
Ghodsi Mohammadi Ziarani, Faezeh Aleali, Negar Lashgari, Alireza Badiei, Ali Abolhasani Soorki
A simple, efficient, and environmentally friendly method has been developed for the synthesis of a series of tricyclic fused pyrazolopyranopyrimidines via a one-pot three-component reaction of barbituric acids, aromatic aldehydes, and 3-methyl-5-pyrazolone in the presence of SBA-Pr-SO3 H. SBA-15 mesoporous silica material functionalized with propyl sulfonic acid groups was used as a heterogeneous Brønsted acid catalyst with hexagonal structure, high surface area, thick walls, and large uniform pores. All reactions were performed under reflux conditions in water in the presence of a catalytic amount of SBA-Pr-SO3 H...
2018: Iranian Journal of Pharmaceutical Research: IJPR
Xiaobo Jia, Lanlan Li, Jingjing Yu, Xiujun Gao, Xiaojing Yang, Zunming Lu, Xinghua Zhang, Hui Liu
Boron carbon oxynitride quantum dots (BCNO QDs) with blue emission were prepared via the template of SBA-15 (a typical mesoporous silica). A modulated photoluminescence sensor was developed based on the different quenching effects of Cu2+ or Hg2+ ions on the luminescence intensity of BCNO QDs. The Cu2+ or Hg2+ ions have an interaction with BCNO QDs due to the electrons transfer between the BCNO and Cu2+ or Hg2+ ions, and the detection limit of Cu2+ or Hg2+ ion concentration can be as less as 10 nM. The BCNO-Cr6+ mixture can be served as a turn-on fluorescent sensor for detecting the ascorbic acid based on the inner filter effect since overlapping of excitation and emission spectra between Cr6+ ions and BCNO QDs...
October 5, 2018: Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy
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