Study on the controllable synthesis of SH-MCM-41 mesoporous materials and their adsorption properties of the La3+, Gd3+ and Yb3+

Sulfhydryl MCM-41 (SH-MCM-41) mesoporous materials were prepared via a hydrothermal method, and -SH was successfully imported by a post-grafting method. The structure and surface properties of the materials were characterized using Fourier Transform infrared spectroscopy, X-ray diffraction and Transmission Electron Microscopy analysis. The low concentrations of La³⁺, Gd³⁺ and Yb³⁺ adsorption on the material were investigated. This paper discusses the effects of system factors, such as pH and the solid-liquid ratio, on the performance of the adsorption process. The adsorption thermodynamics and kinetics were also explored. Experimental results indicated that the materials were in good order and had high specific surface area (956 m²/g) with an average pore diameter of 2.1 nm; the mercapto groups were successfully grafted onto a molecular sieve, and the best grafted amount was 1.46 × 10^?3 mol/g. The materials showed preferable adsorption of La³⁺, Gd³⁺ and Yb³⁺ with maximum adsorption capacities of 560.56 mg/g, 467.60 mg/g and 540.68 mg/g, respectively. The adsorption process can be described by the Freundlich isotherm model, and the adsorption data fits pseudo-second-order kinetics. After repeating the elution-regeneration cycle four times, the adsorption capacity of rare earth ions was mostly maintained, indicating that the adsorbent can be regenerated well and recycled to save costs. It has potential in practical application.     

Regeneration of Chitosan-Based Adsorbents for Eliminating Dyes from Aqueous Solutions

Chitosan and its derivatives are effective for adsorbing dye molecules from aqueous solutions. However, their use can be limited by environmental concerns on their fate after adsorbent saturation. Desorbing dye molecules and regenerating adsorbents are alternatives to disposing spent adsorbent. In this review, most research topics related to regenerating chitosan-based adsorbents for dye removal are summarized and discussed. Numerous desorption agents, such as acids, alkalis, salts, and organic solvents, have been applied to regenerate chitosan-based adsorbents and recover the adsorbed dye molecules. In addition, the mechanism of desorbing dye molecules from these adsorbents is examined to provide information on selecting methods for recovering chitosan-based adsorbents.     

基于SERS标记免疫检测的再生性研究

具有高灵敏度,高选择性特点的表面增强拉曼散射(SERS)与免疫学中的特异吸附机理相结合形成的SERS标记免疫检测技术具有很大的研究及应用价值。文章重点研究了关于SERS标记免疫检测的再生性问题,力求增加此技术的循环利用价值。实验采用甘氨酸-HCl生物缓冲体系对三明治结构(固相抗体-抗原-标记免疫金溶胶)进行洗脱,通过酸碱度的改变,促使抗体抗原复合物发生解离。实验结果表明,洗脱24 h后,固相抗体上连接的抗原及标记免疫溶胶能得到很好的去除,去除后再次组装三明治结构,仍能通过对标记分子的识别进行SERS标记免疫检测。在此基础上还研究了此方法的稳定性与重复使用次数,发现其具有较好的稳定性,重复使用次数可达10次左右。     

氨对Cu/AC脱硫剂的选择性还原再生

通过XRD和EXAFS等表征技术对活性焦担载氧化铜脱硫剂在NH3气氛中的再生行为进行了表征,发现再生过程中NH3仅将硫化所生成CuSo4中的SO4^2-选择性还原为SO2,而未与Cu^2 发生反应,保持了铜物种在活性焦表面良好的分散性,从而使其脱硫活性完全再生。     

Adsorption of Remazol Red 3BS from aqueous solutions using APTES- and cyclodextrin-modified HMS-type mesoporous silicas

The removal of Remazol Red 3BS (C.I. 239) dye by HMS ordered mesoporous silica, aminopropyl-modified HMS (HMS-NH₂) and β-cyclodextrin-modified HMS (HMS-CD) materials was studied in the present work. The modified materials were functionalized in situ by adding the organic modifiers (3-aminopropyltriethoxysilane and a silylated derivative of MCT-β-CD) in the synthesis mixture and using dodecylamine as the mesopore structure directing agent. The successful incorporation of aminopropyl groups in HMS-NH₂ and of cyclodextrin moieties in HMS-CD was verified by means of FT-IR spectroscopy, elemental analysis and N₂ porosimetry. The HMS-CD material exhibited significantly higher adsorption capacity compared to that of the HMS-NH₂ material, while the parent HMS mesoporous silica showed negligible adsorption capability. The maximum adsorption capacities obtained (at the optimum pH 2) on the basis of the Langmuir analysis were 0.28 mmol/g for HMS-CD and 0.14 mmol/g for HMS-NH₂. It was shown that the HMS-CD sorbent can be effectively regenerated by the surfactant-enhanced regeneration method using SDS and that can be reused without significant loss of its adsorption capabilities.     

Influence of processing parameters on regeneration kinetics and morphology of porous cellulose from cellulose–NaOH–water solutions

The kinetics of cellulose regeneration in acetic acid bath from cellulose–8% NaOH–water solutions and gels is studied as a function of gelation conditions, acid concentration and bath temperature. The diffusion coefficient of NaOH from cellulose solution or gel into regenerating bath was calculated. It does not depend either on gelation mode or on acid concentration. On the contrary, cellulose regeneration from non-gelled solutions is slower than from a gel. The increase in bath temperature induces diffusion coefficient increase obeying Arrhenius law. Scanning electron microscopy images of regenerated swollen-in-water freeze-dried cellulose and of the same samples dried in supercritical CO₂ show highly porous morphology. CEMEF is a Member of the European Polysaccharide Network of Excellence (EPNOE), .     

Solid phase extraction of polyhalogenated pollutants from freshwater using chemically modified multi‐walled carbon nanotubes and their determination by gas chromatography

This paper describes the application of pristine and chemically modified multi‐walled carbon nanotubes (MWCNTs) as packing materials for the preconcentration and determination of various polyhalogenated organic pollutants, pentachlorophenol, 2,4,5‐trichlorophenol, 3,3′,4,4′‐tetrachlorobiphenyl, and 2,2′,5,5′‐tetrabromobiphenyl from real water samples based on solid‐phase extraction. MWCNTs were chemically modified by octadecyl amine and polyethylene glycol, separately, and the resulting nano materials were used as packing materials for solid phase extraction. Method development, applicability, and suitability of the above mentioned adsorbents for the solid phase extraction were studied. Method development showed great reproducibility and sensitivity, and low limits of detection within a considerable linear range. The regeneration and reusability of the SPE cartridges were studied using Rideau River (Ottawa, Canada) surface water samples and the results showed that cartridges could be used for three cycles of adsorption/desorption with no loss of efficiency. In general, the results suggested that modification of MWCNTs affords a novel class of adsorbents, which could be used for the SPE of various analytes from aqueous solutions with great efficiency, recovery, reproducibility, sensitivity, and precision, within a wide range of analyte concentrations.     

Activation of Growth-associated Protein by Intragastric Brazilein in Motor Neuron of Spinal Cord Connected with Injured Sciatic Nerve in Mice

The purpose of this study is to explore the expression of growth-associated protein(GAP-43) in spinal cord segments connected with injured sciatic nerve by the treatment with brazilein in mice. Unilateral sciatic nerve interruption and anastomosis were performed. Physiological saline(blank group), high dose, middle dose and low dose of brazilein were administrated intragastrically to healthy adult BALB/c mice in separate groups. L4―6 spinal segments connected with the sciatic nerve were harvested. Real-time...     

Mccrearamycins A–D,Geldanamycin‐Derived Cyclopentenone Macrolactams from an Eastern Kentucky Abandoned Coal Mine Microbe

Four cyclopentenone‐containing ansamycin polyketides (mccrearamycins A–D), and six new geldanamycins (Gdms B–G, including new linear and mycothiol conjugates), were characterized as metabolites of Streptomyces sp. AD‐23‐14 isolated from the Rock Creek underground coal mine acid drainage site. Biomimetic chemical conversion studies using both simple synthetic models and Gdm D confirmed that the mccrearamycin cyclopentenone derives from benzilic acid rearrangement of 19‐hydroxy Gdm, and thereby provides a new synthetic derivatization strategy and implicates a potential unique biocatalyst in mccrearamycin cyclopentenone formation. In addition to standard Hsp90α binding and cell line cytotoxicity assays, this study also highlights the first assessment of Hsp90α modulators in a new axolotl embryo tail regeneration (ETR) assay as a potential new whole animal assay for Hsp90 modulator discovery.