Surface Diels-Alder reactions as an effective method to synthesize functional carbon materials

The post-synthesis chemical modification of various porous carbon materials with unsaturated organic compounds is reported. By this method, amine, alcohol, carboxylate, and sulfonic acid functional groups can be easily incorporated into the materials. Different carbonaceous materials with surface areas ranging from 240 to 1500?m(2)g(-1) and pore sizes between 3.0 and 7.0?nm have been studied. The resulting materials were analyzed by elemental analysis, nitrogen sorption, FTIR spectroscopy, zeta-potential measurements, thermogravimetric analysis, photoelectron spectroscopy, and small-angle X-ray scattering. These analyses indicated that the degree of functionalization is dependent on the nature of the dienophile (reactivity, steric hindrance) and the porosity of the carbon material. As possible applications, the functionalized carbonaceous materials were studied as catalysts in the Knoevenagel reaction and as adsorbents for Pb(2+) from aqueous solution.     

Surface Diels–Alder Reactions as an Effective Method to Synthesize Functional Carbon Materials

The post‐synthesis chemical modification of various porous carbon materials with unsaturated organic compounds is reported. By this method, amine, alcohol, carboxylate, and sulfonic acid functional groups can be easily incorporated into the materials. Different carbonaceous materials with surface areas ranging from 240 to 1500 m² g^?1 and pore sizes between 3.0 and 7.0 nm have been studied. The resulting materials were analyzed by elemental analysis, nitrogen sorption, FTIR spectroscopy, zeta‐potential measurements, thermogravimetric analysis, photoelectron spectroscopy, and small‐angle X‐ray scattering. These analyses indicated that the degree of functionalization is dependent on the nature of the dienophile (reactivity, steric hindrance) and the porosity of the carbon material. As possible applications, the functionalized carbonaceous materials were studied as catalysts in the Knoevenagel reaction and as adsorbents for Pb²⁺ from aqueous solution.     

手性多孔材料在色谱分离分析中的应用

手性多孔有机骨架材料(Chiral porous organic frameworks,CPOFs)具有孔性质优异、比表面积高、稳定性好以及易功能化等诸多优点,已经在手性催化、识别和分离等领域中得到应用。手性多孔有机骨架材料主要有手性金属-有机骨架材料(Chiral metal-organic frameworks,CMOFs)和手性共价有机骨架材料(Chiral covalent organic frameworks,CCOFs)及其他材料,这类材料具有特殊的手性识别、吸附作用,在色谱分离分析领域中已成为研究热点之一。该文综述了手性多孔材料的合成及其在色谱分离和选择性吸附中的应用,展望了未来CPOFs材料可能的应用与发展方向。     

固相萃取材料在食品真菌毒素检测中的研究进展

被真菌毒素污染的食品可引发严重的健康问题,如癌症和畸形等,已成为全球公共卫生关注的焦点.因此,精准检测食品中痕量真菌毒素对保障人类健康具有重要意义.真菌毒素在食品中的浓度水平较低且易与复杂的食品基质成分结合,基质干扰严重影响检测的灵敏度,需采用有效的样品前处理技术进行富集和净化.固相萃取作为一种高效的样品前处理技术,其...     

Designing Hydrogen‐Bonded Organic Frameworks (HOFs) with Permanent Porosity

Designing organic components that can be used to construct porous materials enables the preparation of tailored functionalized materials. Research into porous materials has seen a resurgence in the past decade as a result of finding of self‐standing porous molecular crystals (PMCs). Particularly, a number of crystalline systems with permanent porosity that are formed by self‐assembly through hydrogen bonding (H‐bonding) have been developed. Such systems are called hydrogen‐bonded organic frameworks (HOFs). Herein we systematically describe H‐bonding patterns (supramolecular synthons) and molecular structures (tectons) that have been used to achieve thermal and chemical durability, a large surface area, and functions, such as selective gas sorption and separation, which can provide design principles for constructing HOFs with permanent porosity.     

衍生多孔碳材料在固相微萃取中的应用研究进展

固相微萃取是一种集采样、萃取、富集和进样于一体的样品前处理技术,其萃取效果与涂层材料密切相关。多孔碳材料具有比表面积大、多孔结构可控、活性位点多和化学稳定性好等优点,广泛应用于电池、超级电容器、催化、吸附和分离等领域,也是一种热门的用作固相微萃取探针的涂层材料。衍生多孔碳材料因种类丰富、可设计性强被广泛研究,研究主要集中在对衍生多孔碳材料的结构优化方面。但是衍生多孔碳材料在固相微萃取中的应用还存在如下问题:(1)共价有机框架衍生多孔碳材料的制备已取得较大进展,但将其应用于固相微萃取领域的研究仍较少;(2)有待进一步明确制备出的衍生多孔碳材料用作固相微萃取涂层表现出优异提取能力的机理;(3)有待进一步深入研究将衍生多孔碳材料用作固相微萃取涂层以实现对不同物理化学性质污染物的广谱高灵敏度分析。文章综述了近3年衍生多孔碳材料在固相微萃取中的应用研究,并展望了未来衍生多孔碳材料在固相微萃取中的研究前景。引用文献共56篇,主要来源于Elsevier。     

水热碳材料在分离分析中的应用研究进展

水热碳材料是一种由糖类或含碳有机物经过水热反应制备的新型功能材料,具有来源丰富、绿色环保、亲水性、易修饰等优点,已广泛应用于催化剂载体、能源电极材料、环境吸附剂等方面。其中,水热碳在吸附领域的应用显示出其与特定分子的相互作用,近年来,水热碳材料作为分离富集固相基质,在色谱固定相以及生物样品处理领域逐渐得到应用。该文主要综述了水热碳材料在离子化合物、极性化合物、磷酸化肽段和糖基化肽段分离分析等方面的最新应用,讨论了水热碳材料在实际分离分析应用中的优点和局限性,并就水热碳材料在该领域的应用前景进行了展望。     

新型样品前处理材料在环境污染物分析检测中的研究进展

针对复杂样品的分析和痕量目标物的检测,样品前处理是必不可少的,高效的样品前处理技术不仅可以去除或减小样品基质干扰而且能够实现分析物的富集,提高分析检测的准确性和灵敏度.近年来,固相萃取、磁分散固相萃取、枪头固相萃取、搅拌棒萃取、固相微萃取等高效的样品前处理技术已在环境污染物分析检测中获得广泛关注,萃取效率主要取决于萃取...     

纳米材料掺杂聚合物整体柱的构筑及在前处理领域的应用

聚合物整体柱是由单体、交联剂、引发剂和致孔剂在模具中通过原位聚合而成的棒状整体.与传统的填充式固相萃取柱相比,聚合物整体柱吸附剂凭借制备简单、柱压低、传质快及pH使用范围宽泛等优点已广泛应用于食品分析、生物医药和环境卫生等领域的前处理中.然而,通常由于聚合方式难以控制,聚合物整体柱在制备过程中容易产生颗粒堆积、孔道不均...     

石墨烯应用于样品前处理的研究进展

样品前处理技术在样品分析中发挥着越来越重要的作用,而对分析物的富集能力和对样品基体的净化程度主要取决于高效的样品前处理材料,所以发展高性能的样品前处理材料一直是该领域的前沿研究方向。近年来,各类先进材料已经被引入样品前处理领域,发展了多种高性能的萃取材料。由于独特的物理化学性质,石墨烯已在各个研究领域获得广泛关注,在样品前处理领域也发挥着重要作用。基于高的比表面积、大的π电子结构、优异的吸附性能、丰富的官能团和易于化学改性等优点,石墨烯和氧化石墨烯基萃取材料被成功应用于各种样品的前处理,对不同领域中多种类型分析物表现出优异的萃取性能。该论文总结和讨论了近3年来石墨烯材料(石墨烯、氧化石墨烯及其功能化材料)在柱固相萃取、分散固相萃取、磁性固相萃取、搅拌棒萃取、纤维固相微萃取和管内固相微萃取等方面的研究进展。基于多种萃取机理如π-π、静电、疏水、亲水、氢键等相互作用,石墨烯萃取材料能够高效萃取和选择性富集不同类别的目标分析物,如重金属离子、多环芳烃、塑化剂、雌激素、药物分子、农药残留、兽药残留等。基于新型石墨烯萃取材料的各种样品前处理技术与多种检测技术如色谱、质谱、原子吸收光谱等联用,广泛应用于环境监测、食品安全和生化分析等领域。最后,总结了石墨烯在样品前处理领域中存在的问题,并展望了未来的发展趋势。     

Mixed‐Matrix Membranes

Research into extended porous materials such as metal‐organic frameworks (MOFs) and porous organic frameworks (POFs), as well as the analogous metal‐organic polyhedra (MOPs) and porous organic cages (POCs), has blossomed over the last decade. Given their chemical and structural variability and notable porosity, MOFs have been proposed as adsorbents for industrial gas separations and also as promising filler components for high‐performance mixed‐matrix membranes (MMMs). Research in this area has focused on enhancing the chemical compatibility of the MOF and polymer phases by judiciously functionalizing the organic linkers of the MOF, modifying the MOF surface chemistry, and, more recently, exploring how particle size, morphology, and distribution enhance separation performance. Other filler materials, including POFs, MOPs, and POCs, are also being explored as additives for MMMs and have shown remarkable anti‐aging performance and excellent chemical compatibility with commercially available polymers. This Review briefly outlines the state‐of‐the‐art in MOF‐MMM fabrication, and the more recent use of POFs and molecular additives.     

Sol–gel synthesis of porous inorganic materials using “core–shell” latex particles as templates

Here we report on the sol–gel synthesis of porous inorganic materials based on manganese, molybdenum, and tungsten compounds using the “core–shell” siloxane-acrylate latex as a template. The chemical composition and structural characteristics of the materials obtained have been investigated. It was shown that temperature conditions and gaseous media composition during the template destruction controlled the composition and structure of porous materials. To obtain porous inorganic materials for catalytic applications, the “core–shell” latex template was preliminarily functionalized by gold and palladium nanoparticles obtained by thermal reduction of noble metal ions-precursors in a polycarboxylic “shell”. Upon the template removal, noble metals nanoparticles of a size of dozens of nanometers were homogeneously distributed in the material porous structure. The evaluation of the catalytic activity of macroporous manganese, tungsten, and molybdenum oxides under the conditions of liquid phase catalytic oxidation of organic dyes has been performed. The prospects of employing macroporous oxide systems with immobilized nanoparticles of noble metals in the processes of hydrothermal oxidation of radionuclide organic complexes in radioactive waste decontamination have been demonstrated.     

Light Hydrocarbon Separations Using Porous Organic Framework Materials

Light hydrocarbons (C₁–C₃) are used as basic energy feedstocks and as commodity organic compounds for the production of many industrially necessary chemicals. Due to the nature of the raw materials and production processes, light hydrocarbons are generated as mixtures, but the high-purity single-component products are of vital importance to the petrochemical industry. Consequently, the separation of these C₁–C₃ products is a crucial industrial procedure that comprises a significant share of the total global energy consumption per year. As a complement to traditional separation methods (distillation, partial hydrogenation, etc.), adsorptive separations using porous solids have received widespread attention due to their lower energy costs and higher efficiency. Extensive research has been devoted to the use of porous materials such as zeolites and metal-organic frameworks (MOFs) as solid adsorbents for these key separations, owing to the high porosity, tunable pore structures, and unsaturated metal sites present in these materials. Recently, porous organic framework (POF) materials composed of organic building blocks linked by covalent bonds have also shown excellent properties in light hydrocarbon adsorption and separation, sparking interest in the use of these materials as adsorbents in separation processes. This Minireview summarizes the recent advances in the use of POFs for light hydrocarbon separations, including the separation of mixtures of methane/ethane, methane/propane, ethylene/ethane, acetylene/ethylene, and propylene/propane, while highlighting the relationships between the structural features of these materials and their separation performances. Finally, the difficulties, challenges, and opportunities associated with leveraging POFs for light hydrocarbon separations are discussed to conclude the review.     

Method for estimating the residual silanol activity of reversed-phase chromatographic adsorbents

The retention of some organic bases on reversed-phase adsorbents was studied as a function of the concentration of KH₂PO₄ in the mobile phase. It was shown that, for some adsorbents, retention decreases with an increase in the salt concentration, while an opposite dependence was observed for the other adsorbents. Such behavior of adsorbates can be explained by the prevailing silanophilic interactions in the former case and hydrophobic interactions in the latter case. The observed dependence can be used to change the chromatographic selectivity in the analysis of complex mixtures containing organic bases and to assess the properties of reversed-phase columns. Diphenhydramine hydrochloride was proposed as a test substance to assess the properties of the columns in the analysis of multicomponent pharmaceutical preparations. It was used in the comparative study of the properties of some adsorbents.     

Hydrogen-Bonded Organic Frameworks: Functionalized Construction Strategy by Nitrogen-Containing Functional Group

The construction of hydrogen-bonded organic framework materials by intermolecular hydrogen bonding forces has been rapidly developed in the last decade, among which, the strong intermolecular hydrogen bonding and functional binding sites exhibited by nitrogen-containing functional groups have made them favorites for designing organic components to customize functionalized porous materials. This review systematically introduces the types of nitrogen-containing monomers used to prepare porous hydrogen-bonded organic backbones and the principles of their construction, summarizes the design advantages of crystalline materials from an elemental perspective, and presents the applications of such HOFs in the fields of gas adsorption/separation, molecular recognition, plasmonic conductivity, biomedical, and luminescent materials, etc. Finally, the prospects for the development of such materials are discussed and potential directions for future work are analyzed.     

Subcritical water: Use in chemical analysis

The review shows prospects of the use of subcritical water instead of organic solvents and aqueous–organic mixtures at different stages of analysis. Subcritical water was applied to the extraction of target compounds from natural samples, such as soils, sand, and plant raw materials. The use of subcritical water expands possibilities of HPLC. The use of subcritical water as an eluent in HPLC is complicated by the possible destruction of the adsorbent and the decomposition of substances to be determined at elevated temperatures. Adsorbents based on zirconium and titanium oxides, some polymeric adsorbents, and porous graphitized carbon are stable in the medium of subcritical water. Subcritical water can be used at several stages of analysis, for example, for the extraction and subsequent chromatographic separation of analytes.     

Porous Materials for Water Purification

Water pollution is a growing threat to humanity due to the pervasiveness of contaminants in water bodies. Significant efforts have been made to separate these hazardous components to purify polluted water through various methods. However, conventional remediation methods suffer from limitations such as low uptake capacity or selectivity, and current water quality standards cannot be met. Recently, advanced porous materials (APMs) have shown promise in improved segregation of contaminants compared to traditional porous materials in uptake capacity and selectivity. These materials feature merits of high surface area and versatile functionality, rendering them ideal platforms for the design of novel adsorbents. This Review summarizes the development and employment of APMs in a variety of water treatments accompanied by assessments of task-specific adsorption performance. Finally, we discuss our perspectives on future opportunities for APMs in water purification.     

A Coordinative Solubilizer Method to Fabricate Soft Porous Materials from Insoluble Metal–Organic Polyhedra

Porous molecular cages have a characteristic processability arising from their solubility, which allows their incorporation into porous materials. Attaining solubility often requires covalently bound functional groups that are unnecessary for porosity and which ultimately occupy free volume in the materials, decreasing their surface areas. Here, a method is described that takes advantage of the coordination bonds in metal–organic polyhedra (MOPs) to render insoluble MOPs soluble by reversibly attaching an alkyl‐functionalized ligand. We then use the newly soluble MOPs as monomers for supramolecular polymerization reactions, obtaining permanently porous, amorphous polymers with the shape of colloids and gels, which display increased gas uptake in comparison with materials made with covalently functionalized MOPs.     

用于食品安全分析样品前处理的共价有机聚合物的制备及应用进展

食品安全关系身体健康和生命安全,是全球关注的热点之一。食品基质复杂,痕量有毒有害物质分析之前必须经过有效的前处理。目前发展的前处理技术如固相萃取、磁固相萃取、固相微萃取等,其关键是吸附介质。共价有机聚合物是一类通过共价键连接而成的有机多孔材料,具有质轻、稳定性好、比表面积大、结构可控、易于修饰等特性,是一类优异的新型吸附材料。该文综述了近年来共价有机聚合物(COPs)在食品安全分析前处理中的应用进展。共价有机聚合物及其功能化复合材料通过简单的装填、聚合反应或化学键合固定到小柱或毛细管柱中用作固相萃取的吸附介质;通过一锅法、原位还原法、原位生长法或共沉淀法生成具有磁性的固相萃取吸附介质;或者通过物理涂覆、化学键合、溶胶凝胶法及原位生长法制备固相微萃取纤维。基于以上高吸附容量共价有机聚合物的样品前处理技术,食品中农残兽残、添加剂、环境污染物及生物毒素等得到了有效富集。最后,展望了COPs在食品分析样品前处理应用中的发展方向:简单高效绿色制备方法的开发,功能化COPs的设计合成;萃取机理的研究;高通量、高灵敏度分析方法研究。这些研究将促进COPs在样品前处理领域获得更广泛的应用。     

Porous Aerogels and Adsorption of Pollutants from Water and Air: A Review

Aerogels are open, three-dimensional, porous materials characterized by outstanding properties, such as low density, high porosity, and high surface area. They have been used in various fields as adsorbents, catalysts, materials for thermal insulation, or matrices for drug delivery. Aerogels have been successfully used for environmental applications to eliminate toxic and harmful substances—such as metal ions or organic dyes—contained in wastewater, and pollutants—including aromatic or oxygenated volatile organic compounds (VOCs)—contained in the air. This updated review on the use of different aerogels—for instance, graphene oxide-, cellulose-, chitosan-, and silica-based aerogels—provides information on their various applications in removing pollutants, the results obtained, and potential future developments.