Monodisperse chloromethyl-functionalized macroporous polymer particles by seeded polymerization in aqueous media

This study presents a method to produce monodisperse chloromethyl-functionalized macroporous poly(styrene-co-divinylbenzene) polymer particles by seeded polymerization in aqueous media. We observed that the molecular structure of polystyrene seed particles, the composition of the secondary monomer mixtures, and the type of solvents were very important factors that determine the morphology and porosity of the final particles. This study proposes that the molecular chemistry of polystyrene seed polymers, increasing molecular weight or crosslinking, is another factor that can control the porosity of the final particles. Also, the selection of a poor solvent was effective in forming the larger surface area. In this study, it was confirmed that the chloromethyl groups introduced on the surface of porous particles were quantified chemically and their effective incorporation had a close relationship with the surface area.     

The adsorption of endothelin 1 to phospholipids is governed by electrostatic interactions: A monolayer and fluorescence study

In order to elucidate the influence on the lipidic environment on the recognition process of its membrane associated receptor, the interactions of the vasoconstrictor peptide endothelin 1 with various phospholipids have been investigated using different lipidic model membranes: monolayers at constant surface pressure, vesicles and micelles. A monolayer study of ET1 adsorbed onto the water surface has shown that the C-terminus of the peptide points towards the aqueous phase. Penetration measurements into lipidic monolayers indicate that ET1 adsorbs to phospholipids with an orientation similar to that of the air–water interface and fluorescence measurements are in agreement with such an orientation of the peptide. This adsorption is selective for neutral phospholipids and indicates that the nature of the phospholipid headgroups is of major importance for the approach of the membrane associated receptor.     

Molecular self-assembled monolayers of ruthenium(II)-terpyridine dithiol complex on gold electrode and nanoparticles

We describe the formation of stable dithiol-bifunctionalized Ru(II)-terpyridine monolayer onto gold electrode. The coverage-dependent behavior onto gold electrode has been studied by electrochemical technique. The stability, surface charge coverage, and electron-transfer kinetics were assessed by cyclic voltammetry. Functionalized monolayer-protected Au clusters (MPCs) were also prepared. The spectroscopic characterization data of MPCs using UV-Vis and TEM techniques are discussed. TEM images showed that functionalized spherical nanoclusters of 4.7 ± 0.3 and 4.3 ± 0.2 nm were produced. The particle sizes are uniform with a narrow size distribution. The morphology of Au(1 1 1) metal surface modified with MPCs was imaged using atomic force microscopy (AFM). The nanoparticle layer exhibits a distinct surface morphology, irregularly shaped domains with dimensions from 20 to 60 nm and root mean square heights of 2.401 nm.     

ToF-SIMS analysis of surface-anchored organometallic clusters

ToF-SIMS analysis of the organometallic cluster Os₃(μ-H)(CO)₁₀(μ-SCH₂CH₂SH) chemically attached onto a silver or gold surface, and of the cluster fragment Os₃(μ-H)(CO)₁₀(μ-OSi) on a silica surface, allows for identification of the surface organometallic species, and also gives information on its reactivity.     

Applicability of glass fiber as a support material for generation of gaseous standard mixtures using thermal decomposition of the surface compound. Calibration of analytical equipment

The use of glass fiber as a support material for a surface compound serving to generate gaseous standard mixtures of ethene is described. The technique is based on the process of thermal decomposition of the surface compound in a desorber connected on‐line via a multi‐port valve to the calibrated device. The surface compound undergoes thermal decomposition at 245°C, yielding known amounts of ethene. The method enables on‐line preparation of a standard mixture immediately before the calibration step. Consequently, it can be also applied for the generation of standard mixtures containing volatile, malodorous, unstable, and toxic compounds.     

Detection of environmental chemicals by SPR assay using branched cyclodextrin as sensor ligand

We obtained the association constants Ka of estrogen (E2) and environmental chemicals by the surface plasmon resonance (SPR) assay using the immobilized mono-6-O-α-maltosyl-β-CD (G₂βCD) compared with the immobilized β-CD and the immobilized estrogen receptor (ER). The association behavior of G₂βCD was shown as a ER model compound. The calibration curve was determined by the initial rate of association depending on the various concentrations, and the minimum detectable concentrations in the order of parts per billion were calculated. The SPR assay has advantages that the pre-treatment of the sample is not necessary and the immobilized ligand is stable and useful for the repeated measurement.     

Interfacial tension and fluorine evolution on a carbon anode

During electrolysis of molten KF-2HF, strongly adherent fluorine bubbles are generated at the surface of carbon anode. The current was passing even if the horizontal anode was fully covered with gas film. The formation and growth of gas bubbles were studied by transient electrochemical techniques. It was observed that the fluorine bubbles do not have the spherical cap shape predicted by the classical theory. The curvature radius of the interface profile is not constant, the edge of the bubble being flat with a contact angle close to zero. The results are interpreted in the frame of a model which takes into account the predominant role of the interfacial properties.     

水中矿物元素的ICP-MS分析

用ICP－MS对地下水、地表水和饮用水中的矿物元素进行了分析测定，实验证明用ICP－MS可以同时测定地下水，地表水和饮用水中矿物元素；该法灵敏度、精密度和准确度都能满足有关标准的要求，具有多元素同时分析，样品前处理简单，干扰少，测定快速，省事省力等优点。     

Adsorption of water molecules in slit pores

We report molecular dynamics (MD) simulations on the adsorption of water in attractive and repulsive slit pores, where the slit and a bulk region are in contact with each other. Water structure, surface force and adsorption behavior are investigated as a function of the overall density in the bulk region. The gas–liquid transition in both types of pores occurs at similar densities of the bulk region.     

Modification of solids with volatile organics III: Natural zeolites

Summary The effect of pre-adsorbed benzene and ethanol on the adsorptive properties of natural zeolite (clinoptilolite) has been studied by gas-solid chromatography. It has been shown that modification of the solid surface by volatile organics has a significant influence on the adsorptive properties. The modification is of the same order as the more difficult modification by inorganics, as illustrated here by clinoptilolite modification with Co²⁺. Energy distribution of surface adsorptive sites appears to be continuous and confirms previous finding that only a small proportion of active sites is responsible for most adsorbate retention. Part II reference [4]