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The synthesis and characterization of MCM-41-type mesoporous silica nanoparticle (MSN) material with a large average pore diameter is presented. It is shown that these MSNs with large pores have served as a transmembrane delivery vehicle for controlled release of membrane-impermeable proteins in live cells.

An MCM-41 type mesoporous silica nanosphere-based (MSN) controlled-release delivery system is synthesized. The stimuli-responsive release profiles of vancomycin- and adenosine triphosphate-loaded MSN delivery systems are studied by using disulfide bond-reducing molecules and release triggers.

The microscopic, short-range coordination environments and mesoscopic, long-range structures of Eu3+ in contact with tetra-n-octyl diglycolamide (TODGA) confined on ordered mesoporous carbon (OMC) nanoparticles and Amberchrom CG-71 resin were probed using Eu L3-edge extended X-ray absorption fine structure (EXAFS) as well as small-angle and wide-angle X-ray scattering, SAXS and WAXS, respectively. A homoleptic Eu(TODGA)33+ coordination complex typical of liquid–liquid extraction (LLE) chemistry is present under low Eu3+ loading conditions on both solid supports. Deviations from this traditional structure motif appear at hyperstoichiometric Eu3+ loadings, above the 1 : 3 Eu3+ to TODGA mole ratio. Microcrystalline-like domains with multinuclear Eu speciation are templated by use of these high Eu3+ loading conditions with the functionalized OMC materials, highlighting a major departure of liquid–solid extraction chromatography (EXC) from the coordination chemistry of LLE. No such long-range spatial coherence was observed for analogous polyacrylic resin materials. These results demonstrate both the similarities and differences between multiscale structures in LLE and EXC, underscoring the opportunities for improved separation techniques based on solid supports with long-range spatial coherence (e.g., OMC systems) and without it (e.g., resin materials). Since crystallization was the first approach to adjacent lanthanide separations, the prospect of templating microcrystalline TODGA–lanthanide complexes that are otherwise not prone to crystallization by use of OMC nanoparticles represents a new entry to addressing long-standing issues in purification by liquid–solid phase separation. [ABSTRACT FROM AUTHOR]

This work investigates the one-electron reduction of Eu(III) to Eu(II) with ordered mesoporous carbon (OMC) in cavity microelectrode (CME) systems. OMC materials with and without tetra-n-octyl diglycolamide (TODGA) functionalization were subjected to voltammetric measurements and compared with commercial carbon black Vulcan® XC-72. The electrochemical reduction of solution Eu(III) with unfunctionalized OMC, XC-72, and TODGA-functionalized OMC—both within the electrode matrix and on the electrode surface—is reported. The complexation of Eu(III) by TODGA-functionalized OMC prior to electrode preparation incorporates Eu(III) as part of the bulk electrode matrix. Under these conditions, the high capacitance obscures the Eu(III)/Eu(II) redox couple. A signal emerges above the background (capacitive) currents when 2-octanol is added to the TODGA-functionalized OMC as a wetting agent. In contrast, surface Eu(III)–TODGA complexation, when Eu(III) contacts the electrode surface exclusively after electrode preparation, provides a strong response. The addition of 2-octanol to TODGA reduces the capacitance of the electrode and narrows the Eu(III)/Eu(II) redox peak widths. The desorption by reductive stripping of Eu(II) was demonstrated using a 2-octanol modified TODGA OMC CME, opening the possibility for selective separation of Eu from adjacent trivalent lanthanides. [ABSTRACT FROM AUTHOR]

BACKGROUND: Oils derived from plants, animal fats, and algae contain both saturated and unsaturated fatty acids. These fatty acids can be converted into liquid fuels and chemicals in the presence of active solid catalysts. RESULTS: Nickel‐based catalysts were supported on mordenite via ion exchange synthesis and evaluated for the deoxygenation of stearic acid to diesel fuels. By tuning the synthesis pH, loadings of over 20 wt% Ni were obtained. Catalysts synthesized at pH 8.5 displayed the highest Ni loading and the highest activity for the decarboxylation/decarbonylation of stearic acid under inert nitrogen gas atmospheres, yielding 47% heptadecane. Characterization included scanning transmission electron microscopy‐energy‐dispersive spectroscopy (STEM‐EDS), X‐ray diffraction (XRD), field emission scanning electron microscopy (FE‐SEM), inductively coupled plasma atomic emission spectroscopy (ICP‐AES), N2 physisorption and thermogravimetric analysis (TGA), providing new insights into the recyclability of the catalyst. The observed loss of catalytic activity upon recycling was attributed to the agglomeration of Ni nanoparticles and the accumulation of carbonaceous coke. CONCLUSION: This work demonstrates that Ni‐based catalysts supported on mordenite zeolite can effectively convert stearic acid into heptadecane. Yields to heptadecane were as high as 47%. Mechanistically, the reaction proceeds by decarboxylation and decarbonylation pathways. © 2019 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

The various mechanisms involved in the catalytic reactions of carbene precursors on the bulk gold metal powder are discussed. The nature of the gold particles present in the powder is shown to highly affect the catalytic activity of the gold powder.

A boronic acid-functionalized mesoropous silica nanoparticles-based drug delivery system (BA-MSN) is prepared for glucose-responsive controlled release of both insulin and cyclic adenosine monophosphate (cAMP). The glucose-responsive MSN-based double-release system has led to the new generation of self-regulated insulin releasing devices.

A synthetic approach to obtain functional mesoporous silica nanoparticles (MSNs) and the henceforth-controlled release and biological relevant applications are described. It is thus possible to synthesize functionalized MSNs with control over particles and pore morphology and degree of functionalization.

The synthesis and photoreactivity of a mesoporous silica-supported uranyl material (U(sub aq)O(sub 2)(super 2+)-silica) using a co-condensation method is described. The synthesis is carried out under acidic conditions, where the anionic sodium dodecyl sulfate (SDS) surfactant provides the template for the uranyl cation and silicate to condense.

Energy-efficient and scalable harvesting and lipid extraction processes must be developed in order for the algal biofuels and bioproducts industry to thrive. The major challenge for harvesting is the handling of large volumes of cultivation water to concentrate low amounts of biomass. For lipid extraction, the major energy and cost drivers are associated with disrupting the algae cell wall and drying the biomass before solvent extraction of the lipids. Here we review the research and development conducted by the Harvesting and Extraction Team during the 3-year National Alliance for Advanced Biofuels and Bioproducts (NAABB) algal consortium project. The harvesting and extraction team investigated five harvesting and three wet extraction technologies at lab bench scale for effectiveness, and conducted a techoeconomic study to evaluate their costs and energy efficiency compared to available baseline technologies. Based on this study, three harvesting technologies were selected for further study at larger scale. The selected harvesting technologies: electrocoagulation, membrane filtration, and ultrasonic harvesting, were evaluated in a field study at minimum scale of 100 L/h. None of the extraction technologies were determined to be ready for scale-up; therefore, an emerging extraction technology (wet solvent extraction) was selected from industry to provide scale-up data and capabilities to produce lipid and lipid-extracted materials for the NAABB program. One specialized extraction/adsorption technology was developed that showed promise for recovering high value co-products from lipid extracts. Overall, the NAABB Harvesting and Extraction Team improved the readiness level of several innovative, energy efficient technologies to integrate with algae production processes and captured valuable lessons learned about scale-up challenges. [ABSTRACT FROM AUTHOR]

The synthesis of a series of organically functionalized mesoporous silica nanoparticles (MSNs) is reported and the mechanism and efficiency of endocytosis of these materials are investigated with different charge profiles on human cervical cancer cells (HeLa). The results have indicated that these surface functionalities might also affect MSN's ability to escape endosomal entrapment, which is a vital factor in designing effective intracellular delivery vehicles.

Metal carbide catalysts are essential to many widely used chemical processes. Fischer-Tropsch synthesis, methane dehydroaromatization and biomass conversion catalysts are typically prepared in situ from a metal oxide precursor with a carbon-containing gas. The reduction process of the metal oxide affects the final catalyst, as does the carburization gas mixture and metal promoters. By looking at materials that are carburized in situ, new insights can be gained about catalyst activation, fuel processing, and deactivation stages. The main focuses of this Review are iron carbide, molybdenum carbide and nickel carbide; analyzing catalyst synthesis methods, reduction steps, in situ carburization and improvements to the native processes. By combining years of research on these catalysts, trends and similarities are observed that can be used to improve current catalytic studies. [ABSTRACT FROM AUTHOR]

Production of value-added furans and phenols from biomass through catalytic fast pyrolysis of pine using molybdenum supported on KIT-5 mesoporous silica was explored. Catalysts containing different loadings of molybdenum were synthesized and characterized by X-ray diffraction, physisorption and chemisorption analysis, various electron microscopic techniques and X-ray photoelectron spectroscopy. Characterization studies indicate that molybdenum is homogeneously distributed over the KIT-5 silica support in a +6 oxidation state. Fast pyrolysis of pine using molecular beam mass spectrometry with fresh Mo catalyst preferentially produced furans and phenols over conventionally observed aromatic hydrocarbons. Detailed investigation of model biopolymers indicates that the furans originated from the carbohydrate portion of the biomass and the phenols emerged predominantly from the lignin portion of biomass. Results obtained from MBMS were complemented using pyrolytic-GCMS. [ABSTRACT FROM AUTHOR]

Recent breakthrough research on mesoporous silica nanoparticle (MSN) materials has illustrated their significant potential in biological applications due to their excellent drug delivery and endocytotic behavior. We set out to determine if MSN, covalently functionalized with conformation specific bioactive molecules (either linear or cyclic RGD ligands), behave towards mammalian cells in a similar manner as the free ligands. We discovered that RGD immobilized on the MSN surface did not influence the integrity of the porous matrix and improved the endocytosis efficiency of the MSN materials. Through competition experiments with free RGD ligands, we also discovered a conformation specific receptor-integrin association. The interaction between RGD immobilized on the MSN surface and integrins plays an important role in endosome trafficking, specifically dictating the kinetics of endosomal escape. Thus, covalent functionalization of biomolecules on MSN assists in the design of a system for controlling the interface with cancer cells. [ABSTRACT FROM AUTHOR]

Well-defined and monodispersed rhodium nanoparticles as small as approximately 2 nm were encapsulated in situ and stabilized in a mesoporous silica nanoparticle (MSN) framework during the synthesis of the mesoporous material. Although both the activity and selectivity of MSN-encapsulated rhodium nanoparticles in CO hydrogenation could be improved by the addition of manganese oxide as expected, the carbon selectivity for C2 oxygenates (including ethanol and acetaldehyde) was unprecedentedly high at 74.5 % with a very small amount of methanol produced if rhodium nanoparticles were modified by manganese oxide with very close interaction. [ABSTRACT FROM AUTHOR]