Surface bonding of MN macrocyclic metal complexes with pyridine-functionalized multi-walled carbon nanotubes for non-aqueous Li-O batteries.

It is essential to develop bifunctional catalysts with high activity and stability for reversible oxygen reduction reactions (ORRs) and oxygen evolution reactions (OERs) in lithium-oxygen (Li-O) batteries. In this work, pyridine (Py) functionalized multi-walled carbon nanotubes (MWCNTs) were prepared to immobilize various solid MN macrocyclic metal complexes (MN-MC) as cathode electrocatalysts for Li-O batteries. Three types of MN-MC molecules, including iron phthalocyanine (FePc), cobalt phthalocyanine (CoPc) and iron protoporphyrin IX (Heme) were examined to evaluate the influence of central metal atoms and ligand substituents found in MN-MC molecules on the electrocatalytic performance of the study samples.

Effect of surface bonding of FePC with electrospun carbon nanofiber on electrocatalytic performance for aprotic Li-O batteries.

The bifunctional catalysts assist the complete reversible cycle of oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) with low polarization of a lithium-oxygen (Li-O) battery were known to be critical cathode components. In this work, electrospun nitrogen-doped carbon nanofibers (N-CNFs) were prepared to use as supports to anchor iron phthalocyanine (FePc) bifunctional catalyst for oxygen (O) electrode in Li-O batteries. By using FePc and N-CNFs, two different bonding composites were fabricated via diazonium reaction by refluxing and physical mixing methods which were resulting into covalent linkage via pyridine (Py) (denoted as FePc/Py/N-CNFs) and noncovalent interaction via π-π stacking (denoted as FePc/N-CNFs).

C NMR spectroscopy characterization of particle-size fractionated soil organic carbon in subalpine forest and grassland ecosystems.

Background: Soil organic carbon (SOC) and carbon (C) functional groups in different particle-size fractions are important indicators of microbial activity and soil decomposition stages under wildfire disturbances. This research investigated a natural Tsuga forest and a nearby fire-induced grassland along a sampling transect in Central Taiwan with the aim to better understand the effect of forest wildfires on the change of SOC in different soil particle scales. Soil samples were separated into six particle sizes and SOC was characterized by solid-state C nuclear magnetic resonance spectroscopy in each fraction.

Investigation of MnO₂ and Ordered Mesoporous Carbon Composites as Electrocatalysts for Li-O₂ Battery Applications.

The electrocatalytic activities of the MnO₂/C composites are examined in Li-O₂ cells as the cathode catalysts. Hierarchically mesoporous carbon-supported manganese oxide (MnO₂/C) composites are prepared using a combination of soft template and hydrothermal methods. The composites are characterized by X-ray powder diffraction, scanning electron microscopy, transmission electron microscopy, small angle X-ray scattering, The Brunauer-Emmett-Teller (BET) measurements, galvanostatic charge-discharge methods, and rotating ring-disk electrode (RRDE) measurements.

The Use of Spray-Dried Mn₃O₄/C Composites as Electrocatalysts for Li-O₂ Batteries.

The electrocatalytic activities of Mn₃O₄/C composites are studied in lithium-oxygen (Li-O₂) batteries as cathode catalysts. The Mn₃O₄/C composites are fabricated using ultrasonic spray pyrolysis (USP) with organic surfactants as the carbon sources. The physical and electrochemical performance of the composites is characterized by X-ray diffraction, scanning electron microscopy, particle size analysis, Brunauer-Emmett-Teller (BET) measurements, elemental analysis, galvanostatic charge-discharge methods and rotating ring-disk electrode (RRDE) measurements.

Characterization of soil organic matter in perhumid natural cypress forest: comparison of humification in different particle-size fractions.

Background: The Chamaecyparis forest is a valuable natural resource in eastern Asia. The characteristics of soil humic substances and the influence of environmental factors in natural Chamaecyparis forests in subtropical mountain regions are poorly understood. The study site of a perhumid Chamaecyparis forest is in the Yuanyang Lake Preserved Area in northcentral Taiwan.

A specific tumor-targeting magnetofluorescent nanoprobe for dual-modality molecular imaging.

Poly(acrylic acid) was decorated onto Fe(3)O(4) resulting in a highly water-soluble superparamagnetic iron oxide. The Poly(acrylic acid) iron oxide (PAAIO) complexes possess specific magnetic properties in the presence of an external magnetic field and are attractive contrast agents for magnetic resonance imaging (MRI). The free carboxylic groups of PAAIO exposed on the surface allow for covalent attachment of a fluorescent dye, Rhodamine 123 (Rh123) to form PAAIO-Rh123, which permits applications in fluorescence imaging.

Folic acid-Pluronic F127 magnetic nanoparticle clusters for combined targeting, diagnosis, and therapy applications.

Superparamagnetic iron oxides possess specific magnetic properties in the presence of an external magnetic field, which make them an attractive platform as contrast agents for magnetic resonance imaging (MRI) and as carriers for drug delivery. In this study, we investigate the drug delivery and the MRI properties of folate-mediated water-soluble iron oxide incorporated into micelles. Pluronic F127 (PF127), which can be self-assembled into micelles upon increasing concentration or raising temperatures, is used to decorate water-soluble polyacrylic acid-bound iron oxides (PAAIO) via a chemical reaction.

Biodegradable amphiphilic copolymers based on poly(epsilon-caprolactone)-graft chondroitin sulfate as drug carriers.

The goal of this study was to develop a new type of core-shell micelles based on biocompatible and biodegradable amphiphilic copolymers, named PCL-CS, using chondroitin sulfate (CS) as a hydrophilic segment and poly(epsilon-caprolactone) (PCL) as a hydrophobic segment. The copolymers, prepared from the various compositions between CS and PCL, were characterized by Fourier transform infrared spectrometer, proton nuclear magnetic resonance spectrometer, and differential scanning calorimeter. The PCL-CS copolymers could be assembled into micelles using a simple emulsion.

Characterization of hydrogels prepared from copolymerization of the different degrees of methacrylate-grafted chondroitin sulfate macromers and acrylic acid.

Different degrees (between 20 and 75%) of methacrylate-grafted chondroitin sulfate (CS-MA) were synthesized. These CS-MA macromers were further copolymerized with acrylic acid (AA) at the molar ratio of 1 to 5 to form hydrogels. The sol percents of these CS-MA-AA hydrogels decreased and the cross-linking densities were studied with respect to the degrees of MA substitution onto CS-MA.

Controlled immobilization of chondroitin sulfate in polyacrylic acid networks.

Novel semi-interpenetrating polymer networks (semi-IPNs) of chondroitin sulfate (ChS) and acrylic acid (AA) were prepared with the aim of obtaining a hydrogel for use as a colon-specific drug carrier. By controlling the concentrations of cross-linking agent, diethylene glycol dimethacrylate (DEGDA), as well as the reaction solvent, high swelling percentages were obtained (approx. 1600%).

Characterization of chondroitin sulfate and its interpenetrating polymer network hydrogels for sustained-drug release.

The goal of this work was to utilize the chondroitin sulfate (CS) based hydrogels for a drug delivery matrix. CS is a good structure/disease-modifying anti-osteroarthritis drug (S/DMOAD). However, the readily water-soluble nature limits its application as a solid-state drug-delivery vehicle.

Chondroitin sulfate-based anti-inflammatory macromolecular prodrugs.

Macromolecular prodrugs of three non-steroidal anti-inflammatory drugs (NSAIDs), ibuprofen, ketoprofen, and naproxen, were prepared by the covalent attachment of the drugs onto chondroitin sulfate (ChS) using PEG 1000 as a spacer. Drug-PEG adducts were synthesized using 1,1'-carbonyl diimidazole as a coupling agent in dimethyl sulfoxide, followed by the reaction with ChS in highly dilute aqueous solution at pH 6.8 via N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride (EDAC) as a conjugation agent.

Characterization of polyelectrolyte complexes between chondroitin sulfate and chitosan in the solid state.

Chondroitin sulfate (ChS) was used to form polyelectrolyte complexes with chitosan (ChI), and its potential as a colon-targeted drug carrier was investigated. In order to determine the optimal conditions for the formation of a stable polyelectrolyte complex, the formation of ChS/ChI complexes was examined at two different pH values with various weight ratios, or at a fixed molar ratio of ChS/ChI of 1/2 under various pH conditions. The molar compositions of the various ChS/ChI complexes were quantitated with the use of solid-state 13C CP MAS NMR.

New approach to IR study of monomer-dimer self-association: 2,2-dimethyl-3-ethyl-3-pentanol in tetrachloroethylene as an example.

The dimerization of 2,2-dimethyl-3-ethyl-3-pentanol in tetrachloroethylene in the diluted region has been studied at four temperatures by IR spectroscopy. The aforementioned solute compound is chosen because self-association beyond dimerization is hampered by the steric hindrance generated by the bulky sidechains. The integrated absorbances of the monomer bands were treated based on Eq.