Sorption of Zinc Ions by a Nonwoven Polypropylene Material Modified with Poly(acrylic acid) Grafted to the Fiber Surface: The Role of Grafting Density and Hydrogen Bonds

A microfiber carboxylic cationite is prepared via the photoinduced polymerization of acrylic acid on the surface of nonwoven polypropylene material. Changes in the amount of the graft polymer (grafting density) and in the strength of hydrogen bonds between its carboxyl groups, depending on the polymerization time, are investigated by attenuated total internal reflectance FTIR spectroscopy. The sorption properties of the obtained ionite in the acidic (COOH) and salt (COONa) forms with respect to Zn²⁺ ions at various grafting densities are studied. The sorption capacity of the investigated cationite in its salt form is higher than that in the acidic form, and this difference increases quickly with the grafting density. The data of IR spectroscopy showed that this behavior is caused by the formation of stronger hydrogen bonds between COOH groups of the grafted polyacrylic acid, complicating their ionization and, thus, preventing the ion exchange.     

Tuning the Properties of Tetracene-Based Nanoribbons by Fluorination and N-Doping

The structural stabilities and electronic properties are studied for the recently synthesized one-dimensional (1-D) tetracene-based nanoribbons with four-membered rings by using first-principles calculation. All three configurations (named as straight, zigzag, and armchair) are stable and exhibit an indirect band gap of 1.46, 0.73, and 0.32 eV, respectively. The band gaps can be effectively tuned by substituting hydrogen with fluorine atoms and by doping with nitrogen atoms. Substituting hydrogen with fluorine atoms leads to gradual decrease of the electronic band gaps of all configurations. Nitrogen doping changes the band gap from indirect to direct, displaying flexibility of tuning the band structure.     

氟化辅助电热蒸发/ICP-AES直接测定氧化铝粉末中痕量杂质钇

报道了以聚四氟乙烯（PTFE）悬浮体为氟化剂,悬浮体制样／氟化辅助电热蒸发（ETV）／ICP －AES直接测定两种AI2O3粉末样品中痕量杂质钇。考察了影响基体和待测元素蒸发过程的各种因素;对比研究了待测元素和基体的氟化蒸发行为。在优化实验条件下,方法的检出限为0．1μg/g,相对标准偏差为5．6％（n=5,c=8g/L悬浮体）。并与溶样法气动雾化（PN）－ICP－AES的分析结果进行了对比。本法简便、灵敏、无需任何化学前处理,可用于相关陶瓷生产过程中的质量控制。     

琥珀试样中痕量元素的直接同时测定--氟化辅助电热蒸发等离子体光谱法

本文报道了以聚四氟乙烯（ＰＴＦＥ）悬浮液为化学改进剂,采用悬浮体进样电热蒸发电感耦合等离子体原子发射光谱法（ＥＴＶ－ＩＣＰ－ＡＥＳ）直接同时测定琥珀样品中痕量元素的新方法。对石墨炉和ＩＣＰ之间的气体流路接口进行了改进;详细研究了载气／辅助载气流量、蒸发温度、蒸发时间及信号记录时间等因素对待测物信号强度的影响。在优化实验条件下,本法同时测定琥珀试样中痕量Ａｌ、Ｃａ、Ｃｒ、Ｃｕ、Ｆｅ、Ｍｇ、Ｍｎ、Ｎｉ     

Polypropylene Nanocomposites,Study of the Influence of the Nanofiller Nature on Morphology and Material Properties

Summary: In this paper we investigate the influence of various nanofilllers' aspect ratio, chemical nature and organic modification on some selected polypropylene properties, such as crystallinity, thermal and mechanical resistance and fire behaviour. Materials were prepared by twin-screw extrusion and characterized by means of scanning electron microscopy, X-ray diffraction, thermogravimetric analysis, tensile and cone calorimeter tests. Fillers characteristics were found to influence at different extents, and for different reasons, the material final properties.     

Targeted Manipulation of Metal–Organic Frameworks To Direct Sorption Properties

Metal–organic frameworks are promising materials for manifold applications. This Minireview highlights approaches for the fine‐tuning of specific sorption properties (e.g. capacity, selectivity, and breathing behavior) of this interesting class of materials. Central aspects covered are the control over the crystal morphology, the targeted tuning of sorption properties by judicious choice of metal centers and linkers, and the preparation of host–guest systems. We want to introduce the reader to these topics on the basis of the manipulation of a handful of outstanding prototypical metal–organic frameworks.     

聚芳撑乙炔微孔骨架材料的合成及其气体吸附

有机微孔聚合物（MOPs）在气体存储、吸附分离和非均相催化等领域具有优良性质而广受关注.近年来,聚芳撑乙炔微孔骨架材料的研究成为MOPs领域中的热点.分别以三（4-乙炔基）苯胺、甲基三（4-乙炔基苯基）硅烷、苯基三（4-乙炔基苯基）硅烷为基本构筑单元,通过端炔基氧化均聚的方法,制备了三种聚芳撑乙炔微孔骨架材料,研究了结构组成对制备聚合物孔道性能和气体吸附性能的影响.氮气吸附测试结果表明,聚合物的Brunauer-Emmett-Teller （BET）比表面积的范围在602~715 m²·g^-1.由于骨架中含有富氮基团（三苯胺）以及具有较大的比表面积,在1.13 bar/273 K条件下,聚三（4-乙炔基）苯胺（TEPA-MOP）的CO₂吸附能力为1.59 mmol·g^-1.此外,TEPA-MOP和聚苯基三（4-乙炔基苯基）硅烷（TEPP-MOP）具有优良的选择性吸附性能,对CO₂/N₂的选择性吸附分别是69.9和73.2.聚合物TEPA-MOP具有优异的CO₂/N₂的选择吸附性和适中的CO₂吸附能力,因此将在气体吸附与分离方面具有潜在的应用前景.     

Sorption and Selective Properties of Diatomite Adsorbents for Gas Chromatography,Modified by a Cu(II) Complex of a Camphor-Substituted Tetrapyrasinoporphyrazine

Russian Journal of General Chemistry - Modified adsorbents for gas chromatography were prepared using a Cu(II) complex of a camphorsabstituted tetrapyrasinoporphyrazine. The thermal stability of...     

Synthesis of Porous Covalent Quinazoline Networks (CQNs) and Their Gas Sorption Properties

The development of different classes of porous polymers by linking organic molecules using new chemistries still remains a great challenge. Herein, we introduce for the first time the synthesis of covalent quinazoline networks (CQNs) using an ionothermal synthesis protocol. Zinc chloride (ZnCl₂) was used as the solvent and catalyst for the condensation of aromatic ortho‐aminonitriles to produce tricycloquinazoline linkages. The resulting CQNs show a high porosity with a surface area up to 1870 m² g^?1. Varying the temperature and the amount of catalyst enables us to control the surface area as well as the pore size distribution of the CQNs. Furthermore, their high nitrogen content and significant microporosity make them a promising CO₂ adsorbent with a CO₂ uptake capacity of 7.16 mmol g^?1 (31.5 wt %) at 273 K and 1 bar. Because of their exceptional CO₂ sorption properties, they are promising candidates as an adsorbent for the selective capture of CO₂ from flue gas.     

Deposition of Gold Nanoparticles on Polypropylene Nonwoven Pretreated by Dielectric Barrier Discharge and Diffuse Coplanar Surface Barrier Discharge

The aim of this study was to examine and compare the potentials of two different ambient air plasma treatments: volume dielectric barrier discharge and diffuse coplanar surface barrier discharge, for the activation of polypropylene (PP) nonwovens surface. This was done in order to enhance the deposition of gold nanoparticles (AuNPs) onto PP surface. AuNPs were attached onto PP surface from colloidal solution prepared without stabilizers. Scanning electron microscopy, atomic force microscopy, attenuated total reflection-Fourier transform infrared spectroscopy, water absorption, and AuNPs uptake were used to assess the surface changes due to the plasma treatment, and to evaluate the durability of the achieved treatment effects. Finally, as a very important aspiration of the research, antibacterial activity of AuNPs loaded PP nonwovens against pathogens Staphylococcus aureus and Escherichia coli was evaluated in vitro. The plasma modified PP nonwovens have highly improved wetting and sorption properties. The PP nonwovens loaded with 17–62 mg/kg AuNPs exhibit antibacterial activity against tested pathogens. Surprisingly, this activity was enhanced by the first sample rinsing.     

Sorption and Diffusion of Propylene and Ethylene in Heterophasic Polypropylene Copolymers

Summary: Sorption experiments of ethylene and propylene in different polypropylene powder samples, both homopolymer and heterophasic copolymers with different rubber content, have been carried out in a high-pressure magnetic suspension balance at 10 bars pressure and 70 °C. The gross solubilities measured can be well correlated with the rubber content of the polymer samples. Solubility of ethylene and propylene in the rubber phase differ from solubility in the amorphous fraction of the homopolymer, especially the concentration ratio of propylene to ethylene differs significantly between rubber phase and amorphous fraction of the homopolymer. From the slope of monomer uptake, information on kinetics of mass-transfer can be gained. No significant differences were observed in terms of mass-transfer for ethylene and propylene. With increasing rubber content, effective diffusion coefficients increased slightly. By combined sorption studies with powder samples and compressed films, information about both effective diffusion coefficients and the effective length scale of diffusion could be gained. It could be shown, that the particle radius is not the characteristic length of diffusion in the studied powder samples. Mass transfer of nearly all samples could be described by a constant diffusion length of 120 to 130 µm, independently on particle size. This indicates that the effective scale of diffusion in polymer particles is in between microparticle and macroparticle scale used in classical particle modeling.     

Determination of Metal Traces in Polypropylene by Gas Chromatography

A procedure was developed for determination of metal traces in polypropylene on chromatographic sorbents and phases of various polarities. The thermal stability of volatile aluminum, chromium, and gallium acetylacetonates under the conditions of gas chromatography was studied. The influence exerted on the determination process by the column material, temperature, and polarity of phases was examined.     

Control over the Wettability of Colloidal Crystal Films by Assembly Temperature

Summary: A facile method to fabricate colloidal crystal films with tunable wettability from an amphiphilic material polystyrene‐block‐poly(methyl methacrylate)‐block‐poly(acrylic acid) is presented. The wettability of the film can be tuned from superhydrophilic (CA, 0°) to superhydrophobic (CA, 150.2°) by varying the assembly temperature, while the position of the photonic bandgap of the colloidal crystal films remains virtually unchanged. The method could open new application fields of colloidal crystals in diverse environments.

The relationship of assembly temperature with water CA (inset is the water droplet profile of the relative water CA).     

Three New MOFs Induced by Organic Linker Coordination Modes: Gas Sorption,Luminescence, and Magnetic Properties

By using a new 4,6‐bis(imidazol‐1‐yl) isophthalic acid ligand (H₂bimip) with imidazolyl and carboxyl bifunctional groups, three new MOFs, [Co(bimip)(H₂O)_0.5] ? 0.5 H₂O ( 1 ), [Zn(bimip)] ( 2 ), and [Mn(bimip)(H₂O)₂] ? H₂O ( 3 ), have been solvothermally synthesized in different solvent systems. H₂bimip displays three different coordinated modes through the imidazolyl and carboxyl groups, and different cis–cis and trans–cis configurations, which result in distinct 3D topological frameworks: a (4,8)‐connected scu net for 1 ; a twofold interpenetrated (4,4)‐connected pts net for 2 ; and a four‐connected sra net for 3 . Compounds 1 and 3 show antiferromagnetic properties, and 2 emits strong solid‐state blue luminescence. Compound 1 shows good chemical stability in acidic and basic environments and in boiling water. Additionally, the polar channels in 1 , which are decorated by uncoordinated carboxylate O atoms and imidazolyl fragments, allow it to adsorb CO₂ molecules selectively over CH₄, and the CO₂ binding sites in the framework were distinguished by molecular simulations.     

聚并苯纳米颗粒与聚丙烯复合制备新型抗静电阻燃材料

用聚并苯纳米颗粒作为新型导电填料代替导电炭黑和石墨等, 制备出具有抗静电阻燃性能的纳米聚并苯/聚丙烯复合材料. 测定了复合材料的渗流转变区, 讨论了纳米聚并苯含量对复合材料体积电阻率和表面电阻率的影响. 实验结果表明, 所制备复合材料的渗流转变发生在纳米聚并苯质量分数为16.7%-28.6%范围内, 当纳米聚并苯含量为28.6%时, 体积电阻率下降至2.09×107 Ω·cm. 另外, 阻燃性能研究结果表明, 当纳米聚并苯质量分数为23.1%时, 复合材料在空气中可以自熄, 因而可应用于矿井中抗静电阻燃塑料管道.