Exploiting specific interactions with titania (TiO) has been proposed for the separation and recovery of a broad range of biomolecules and natural products, including therapeutic polyphenolic flavonoids which are susceptible to degradation, such as quercetin. Functionalizing mesoporous silica with TiO has many potential advantages over bulk and mesoporous TiO as an adsorbent for natural products, including robust synthetic approaches leading to high surface area, and stable separation platforms. Here, TiO-surface-functionalized mesoporous silica nanoparticles (MSNPs) are synthesized and characterized as a function of TiO content (up to 636 mg TiO/g). The adsorption isotherms of two polyphenolic flavonoids, quercetin and rutin, were determined (0.05-10 mg/mL in ethanol), and a 100-fold increase in the adsorption capacity was observed relative to functionalized nonporous particles with similar TiO surface coverage. An optimum extent of functionalization (approximately 440 mg TiO/g particles) is interpreted from characterization techniques including grazing incidence X-ray scattering (GIXS), high-resolution transmission electron microscopy (HRTEM), and nitrogen adsorption, which examined the interplay between the extent of TiO functionalization and the accessibility of the porous structures. The recovery of flavonoids is demonstrated using ligand displacement in ethanolic citric acid solution (20% w/v), in which greater than 90% recovery can be achieved in a multistep extraction process. The radical scavenging activity (RSA) of the recovered and particle-bound quercetin as measured by a 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay demonstrates greater than 80% retention of antioxidant activity by both particle-bound and recovered quercetin. These mesoporous titanosilicate materials can serve as a synthetic platform to isolate, recover, and potentially deliver degradation-sensitive natural products to biological systems.

Nitric oxide (NO) removal from simulated flue gas is investigated using combined aqueous persulfate (Na 2 S 2 O 8 ) and ferrous ethylenediaminetetraacetate (Fe 2+ -EDTA) systems. The results at 23-70 °C showed significant improvement in NO removal using the optimally obtained molar ratio of 1:1 for the Fe 2+ and EDTA compared with temperature-only and combined temperatureFe 2+ activated persulfate systems with 0.1 M Na 2 S 2 O 8 and 0.01 M Fe 2+ in the absence of EDTA.Almost 100% NO conversion can be achieved at 70 °C (flue gas treatment inlet temperature generally at 50-70 °C) compared to temperature and Fe 2+ -activated persulfate systems which require ≥ 90 °C for such high removal efficiency. The percentage increases in NO removal were dependent on temperature, 25-30% and 5-10% at the lower (< 40 °C) and higher (> 40 °C) temperatures, respectively. A very high concentration of Fe II -EDTA appears to negatively impact NO removal. However, this process operates at an optimal NO removal pH of near neutral (~6.5) with efficiency decreasing at very low or high pH. This should reduce the use of auxiliary chemical for pH adjustment and help mitigate the important technological hurdle of undesired ferric product formation associated with Fe 2+ -only activated persulfate and other Fenton-like systems at pH (>3.5). The material balance on iron species (Fe 2+ , Fe 3+ and Fe 2+ -EDTA) was determined to better understand the chemistry of persulfate with Fe 2+ -EDTA for NO removal.The results demonstrate the feasibility of near complete NO removal at relatively lower temperatures (with the advantage of reduced energy usage), and sustained longtime high NO absorption capability.

The effects of persulfate (PS) and ethylenediaminetetraacetate (EDTA) concentrations at different temperature and pH on the removal of NO were studied using combined Na2S2O8 and Fe 2+-EDTA aqueous solutions. The experiments were conducted in the temperature and pH ranges of 23−70 °C and 2−12, respectively, using 0.05−0.20 M PS and 0.01 M Fe 2+ in the absence and presence of 0.005−0.050 M Na2-EDTA. The effect of SO2 was also preliminarily investigated. Increased temperature led to increased conversions of NO (percent inlet NO removed) at all PS levels but high concentrations of EDTA produced antagonistic effects with increasing temperature. With 0.10 M Na2S2O8, 0.01 M Fe 2+ and ≤ 0.01 M EDTA, NO conversion increased with temperature from 23 to 70 °C. At 70°C, NO conversion increased from 83.40 to 96.28 % as EDTA concentration increased from 0.005 to 0.01 M EDTA but decreased to 29.22 and 0.4 % with 0.02 and 0.05 M EDTA, respectively. The results at 40 and 50 °C showed optimal NO conversions in the pH range 6−8, and higher at 50°C. However, at higher pH (>11), NO conversion is higher at 40°C than at 50°C. The speciation and material balance of the iron species were determined at different Fe 2+ and EDTA concentrations. The results, which showed sustained NO absorption at lower temperatures and mid-pH, could in practice minimize process pH adjustment and energy usage in wet scrubbers. The process could be applicable to the simultaneous cleanup of NOx and SO2 from oil-and coal-fired power plant and industrial boiler.

The chemistry and kinetics of NO removal by aqueous solutions of sodium persulfate (Na 2 S 2 O 8 ) simultaneously activated by temperature and Fe 2+ were studied in a bubble reactor. Reaction pathways were proposed and a mathematical model utilizing the pseudo-steady-state-approximation technique and film theory of mass transfer were developed. The model was solved numerically using the fourth order Runge−Kutta method in Matlab to obtain species concentrations; correlate experimental data; and estimate mass transfer and kinetic rate parameters. The model was used to investigate the effects of Na 2 S 2 O 8 (0.01−0.2 M), Fe 2+ (0−0.1 M), gas-phase NO (500−1000 ppm) concentrations and temperatures (23−90 °C), and is a follow-up to an experimental study, which demonstrated that Fe 2+ activation further improved NO conversion by ∼10% at all temperatures. The model results, which appeared to fit those of the experiments remarkably well, were discussed and predicted kinetic data compared with available literature values.

Incorporation of lipid assemblies on the surface and within pores of mesoporous silica particles provides for biomimetic approaches to analyte sensing and separations using high surface area platforms. This work investigates the effect of pore confinement on the location and the diffusivity of lipid assemblies in mesoporous silica spherical particles (SBAS) as a function of nanopore diameters (nonporous, 3.0, 5.4, and 9.1 nm), which span the range of the thickness of the 1,2‐dipalmitoyl‐sn‐glycero‐3‐phosphocholine lipid bilayer (≈4 nm). Large‐diameter SBAS are imaged with sufficient spatial resolution to distinguish lipids at the exterior surface and in the center of the particles. Lipids incorporated on the silica by evaporation deposition exist as exterior lipid bilayers on all particles and lipid assemblies in the pores of 5.4 and 9.1 nm pore diameter materials. Lipid diffusivity increases with pore size and decreases in the presence of bilayer tethering functional groups. Lipid diffusivity in the core of the particles is similar to the surface diffusivity, consistent with long‐range mobility in accessible, ordered (but randomly oriented) mesopores of SBAS materials. This work presents a framework for interpreting high density loading of lipid bilayers and their function within mesoporous materials.

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TiO 2 films of varying thicknesses (up to ≈1.0 µm) with vertically oriented, accessible 7-9 nm nanopores are synthesized using an evaporation-induced self-assembly layer-by-layer technique. The hypothesis behind the approach is that epitaxial alignment of hydrophobic blocks of surfactant templates induces a consistent, accessible mesophase orientation across a multilayer film, ultimately leading to continuous, vertically aligned pore channels. Characterization using grazing incidence X-ray scattering, scanning electron microscopy, and impedance spectroscopy indicates that the pores are oriented vertically even in relatively thick films (up to 1 µm). These films contain a combination of amorphous and nanocrystalline anatase titania of value for electrochemical energy storage. When applied as negative electrodes in lithium-ion batteries, a capacity of 254 mAh g −1 is obtained after 200 cycles for a single-layer TiO 2 film prepared on modified substrate, higher than on unmodified substrate or nonporous TiO 2 film, due to the high accessibility of the vertically oriented channels in the films. Thicker films on modified substrate have increased absolute capacity because of higher mass loading but a reduced specific capacity because of transport limitations. These results suggest that the multilayer epitaxial approach is a viable way to prepare high capacity TiO 2 films with vertically oriented continuous nanopores.insertion of Li + between two electrodes with simultaneous removal and addition of electrons to store or release electrical energy. [2] However, the performance of LIBs depends strongly on the electrode materials and their interaction with the electrolyte. [3] Although many high capacity LIB negative electrode materials are available including Si, Ge, and Sn, they cannot be used in bulk form due to their low range of operating voltage, high stress generated by intercalation of Li + , and the consumption of Li + by unstable solid-electrolyte interface layers during cycling. [4] TiO 2 is a suitable candidate for negative electrodes in LIBs for applications requiring high rate performance and high electrolyte solution stability. [5] Although the theoretical capacity of TiO 2 (330 mAh g −1 ) [6] is lower than that of Sn, Si, or graphite, TiO 2 negative electrodes offer better safety, [6,7] which is one of the major criteria for practical use of batteries. [1b] The relatively high Li + discharge voltage plateau (1.7 V) of TiO 2 avoids the formation of solid-electrolyte interphase layers and electroplating of Li + during cycling. [8] TiO 2 also possesses low volume expansion during Li + insertion, and therefore low strain, which makes it less susceptible to structural deformation and the associated loss of performance on cycling. [6] However, the major barrier in using bulk TiO 2 in LIBs is its poor Li + ionic and electrical Nanoporous Films [+] Present address: Intel Corp.,

Amine-functionalized mesoporous silica nanoparticles (MSNPAs) are ideal carriers for oligonucleotides for gene delivery and RNA interference. This investigation examines the thermodynamic driving force of interactions of double-stranded (ds) RNA with MSNPAs as a function of RNA length (84 and 282 base pair) and particle pore diameter (nonporous, 2.7, 4.3, and 8.1 nm) using isothermal titration calorimetry, extending knowledge of solution-based nucleic acid−polycation interactions to RNA confined in nanopores. Adsorption of RNA follows a two-step process: endothermic interactions driven by entropic contribution from counterion (and water) release and an exothermic regime dominated by short-range interactions within the pores. Evidence of hindered pore loading of the longer RNA and pore sizedependent confinement of RNA in the MSPAs is provided from the relative contributions of the endothermic and exothermic regimes. Reduction of endothermic and exothermic enthalpies in both regimes in the presence of salt for both lengths of RNA indicates the significant contribution of short-range electrostatic interactions, whereas ΔH and ΔG values are consistent with conformation changes and desolvation of nucleic acids upon binding with polycations. Knowledge of the interactions between RNA and functionalized porous nanoparticles will aid in porous nanocarrier design suitable for functional RNA delivery.