磁性共价有机框架的制备方法研究

磁性共价有机框架（magnetic covalent organic framework,MCOFs）是一种新型多孔结晶有机框架材料,由于其结合了磁性纳米颗粒和共价有机框架（covalent organic frameworks,COFs）的优点,具有比表面积大、热稳定性和化学稳定性良好、饱和磁化强度高等特点,能够快速实现污染物与溶液的分离,弥补了COFs难以分离和回收的缺点,因此在磁性固相萃取、生物检测、传感等方面具有巨大的潜在应用.然而关于MCOFs制备方法的文章鲜见报道,其制备方法根据磁性纳米颗粒与COFs不同的连接形式而不尽相同,根据2011—2019年关于MCOFs的重要文献,综述了目前MCOFs的制备方法,包括包覆法、单体聚合法及原位合成法等,指出了不同制备方法的优缺点,同时探讨了MCOFs今后的发展方向和潜在应用,希望能够为MCOFs研究提供理论依据.包覆法制备条件较温和,保存了磁性纳米颗粒的完整性,是最为广泛应用的一种策略方法;单体聚合法操作简单,但制备条件苛刻,可控性不强;原位合成法制备MCOFs更多依赖于单体聚合法制备的共价三嗪骨架,需要不断开发基于其他类型COFs的MCOFs制备条件.今后MCOFs的制备方法应从材料设计多样性、应用广泛性等方面进行考虑,并向有望实现大规模工业应用方面发展.      

金属有机骨架材料MOF-5利用C3H6选择性催化还原NO的研究

采用溶剂热法在不同温度（120、150、180℃）、不同时间（12、24、48 h）条件下制备MOF-5催化剂,利用热重分析仪（TG）、X射线衍射仪（XRD）、傅立叶红外光谱仪（FT-IR）对其进行表征,研究不同条件下MOF-5样品的水热稳定性及特征官能团、化学键等指标.结果表明,利用溶剂热法制备的MOF-5样品稳定性良好,390℃结构开始坍塌.对比FT-IR、XRD等表征结果,选择图线形状最好、出峰位置最多的120℃、24 h条件下的MOF-5样品作为载体,对其进行了Cu的负载,负载量依次为1%、3%、5%.根据TG曲线,选择在MOF-5维持稳定结构、同时与尾气排放环境中的温度较为接近的350℃作为反应温度,利用傅立叶原位红外技术考察不同负载量的Cu-MOF-5在不同温度条件下对NO吸附能力大小、吸附过程中间物的变化情况,初步研究以C₃H₆作为还原剂时的富氧HC-SCR反应的机理.根据原位红外反应结果看出,NO₃^-、—CNO、—CN是重要的中间产物,且以3% Cu负载量的催化剂中间产物变化最为丰富,催化效果最优.     

Carbon accounting of material substitution with biomass: Case studies for Austria investigated with IPCC default and alternative approaches

There is evidence that the replacement of carbon-intensive products with bio-based substitutes (‘material substitution with biomass’) can be highly efficient in reducing greenhouse gas (GHG) emissions. Based on two case studies (CS1/2) for Austria, potential benefits of material substitution in comparison to fuel substitution are analysed. GHG savings are calculated according to default IPCC approaches (Tier 2 method assuming first-order decay) and with more realistic approaches based on distribution functions. In CS1, high savings are achieved by using wood residues for the production of insulating boards instead of energy. The superiority of material substitution is due to the establishment of a long-term carbon storage, the high emission factor of wood in comparison to natural gas and higher efficiencies of gas-fired facilities.The biomass feedstock in CS2 is lignocellulosic ethanol being used for bio-ethylene production (material substitution) or replacing gasoline (fuel substitution). GHG savings are mainly due to lower production emissions of bio-ethylene in comparison to conventional ethylene and significantly lower than in CS1 (per unit of biomass consumed). While CS1 is highly robust to parameter variation, the long-term projections in CS2 are quite speculative.To create adequate incentives for including material substitution in national climate strategies, shortcomings of current default accounting methods must be addressed. Under current methods the GHG savings in both case studies would not (fully) materialize in the national GHG inventory. The main reason is that accounting of wood products is confined to the proportion derived from domestic harvest, whereas imported biomass used for energy is treated as carbon-neutral. Further inadequacies of IPCC default accounting methods include the assumption of exponential decay and the disregard of advanced bio-based products.     

Removal of antimonite and antimonate from water using Fe-based metal-organic frameworks: The relationship between framework structure and adsorption performance

We investigated the adsorption performance of five Fe-based MOFs (Fe-BTC, MIL-100(Fe), MIL-101(Fe), MIL-53(Fe) and MIL-88C(Fe)) for removal of antimonite (Sb(III)) and antimonate (Sb(V)) from water. Among these MOFs, MIL-101(Fe) exhibited the best adsorption capacities for both Sb(III) and Sb(V) (151.8 and 472.8 mg/g, respectively) which were higher than those of most adsorbents previously reported. The effect of steric hindrance was evident during Sb removal using the Fe-based MOFs, and the proper diameter of the smallest cage windows/channels should be considered an important parameter during the evaluation and selection of MOFs. Additionally, the adsorption capacities of MIL-101(Fe) for Sb(V) decreased with increasing initial pH values (from 3.0 to 8.0), while the opposite trend was observed for Sb(III). Chloride, nitrate and sulfate ions had a negligible influence on Sb(V) adsorption, while NO₃^? and SO₄^2? improved Sb(III) adsorption. This result implies that inner sphere complexes might form during both Sb(III) and Sb(V) adsorption.     

MOFs凝胶膜片微固相萃取-气相色谱法测定水样中多溴联苯醚

为实现对环境水样中污染物PBDEs(多溴联苯醚)的预富集和分析,利用溶胶-凝胶法制取了一种MOFs(金属有机骨架材料)凝胶膜片微固相萃取装置,结合GC-ECD(气相色谱-电子捕获检测器)检测方法测定环境水样中的7种PBDEs,考察了MOFs用量、萃取温度、萃取时间和解吸时间对于萃取效果的影响. 结果表明,在MOFs用量为4mg、萃取温度为70℃、萃取时间为50min、解吸时间为15min的条件下,7种PBDEs单体的加标回收率为74.9%~98.1%,相对标准偏差为3.3%~5.7%,方法检出限均小于4.7ng/L.      

NON-EFFICIENCY OBJECTIVES AND DECISION-MAKING IN WATER RESOURCE DEVELOPMENTS1

ABSTRACT: In spite of the rather large volume of literature suggesting that non-efficiency objectives ought to be incorporated into water resource planning frameworks, little has been done to date. A partial explanation is that when goals are in conflict we have no “objective” criteria upon which to make the trade-offs. Also, there are problems of measuring the degree to which various policy actions lead to achievement of various goals. Nevertheless, this paper argues that given the magnitude of the possible gains from incorporating these considerations, considerable effort to overcome these problems is justified. Accordingly, we outline some procedures for making these trade-offs and suggest an alternative (practical) planning framework.     

Institutional frameworks to direct development and implementation of great lakes remedial action plans

Locally designed, institutional frameworks are being used to develop and implement remedial action plans (RAPs) to restore beneficial uses in 43 Great Lakes areas of concern. A 1993 Canada-United States roundtable was convened to learn from case studies and to develop recommendations regarding essential characteristics of RAP institutional frameworks, guidance to ensure linkages to other related plans, and ways of embracing new institutional frameworks from RAP development to implementation. Major roundtable recommendations are: (1) RAP institutional frameworks should be empowered to pursue their mission of restoring uses. Empowerment would be demonstrated by: a watershed focus, inclusive and shared decision-making, clear responsibilities and sufficient authority, creative funding capability, flexibility and continuity in the process, an iterative process of continuous improvement, and commitment to education and outreach. (2) RAP institutional frameworks should be used as mechanisms to coordinate programs at the local level. Such local coordination should be complemented with governmental commitments to intra- and interagency coordination in work plans. (3) RAP institutional frameworks can help build the capacity of governments to achieve their goals. Therefore, governments must adopt long-term, visionary goals and commit to a customer-driven RAP process of continuous improvement.     

Developing the ethical matrix as a decision support framework: GM fish as a case study

The Ethical Matrix was developed to help decision-makers explore the ethical issues raised by agri-food biotechnologies. Over the decade since its inception the Ethical Matrix has been used by a number of organizations and the philosophical basis of the framework has been discussed and analyzed extensively. The role of tools such as the Ethical Matrix in public policy decision-making has received increasing attention. In order to further develop the methodological aspects of the Ethical Matrix method, work was carried out to study the potential role of the Ethical Matrix as a decision support framework. When considering which frameworks to apply when analyzing the ethical dimensions of the application of agri-food biotechnologies, it is important to clarify the substantive nature of any prospective framework. In order to further investigate this issue, reflections on the neologism “ethical soundness” of an ethical framework are presented here. This concept is introduced in order to provide more structured evaluations of a range of ethical tools, including ethical frameworks such as the Ethical Matrix. As well as examining the philosophical dimensions of the method, theoretical analysis and literature studies were combined with stakeholder engagement exercises and consultations in order to review the Ethical Matrix from a user perspective. This work resulted in the development of an Ethical Matrix Manual, which is intended to act as a guide for potential user groups.     

超滤膜负载UiO-66@Fe3O4@UiO-66强化PPCPs去除和膜污染控制

本研究通过聚偏氟乙烯(PVDF)膜内负载具有协同吸附和催化作用的金属有机骨架(MOFs),吸附去除水中药品及个人护理品(PPCPs),并且达到膜滤过程中多功能材料吸附能力再生和膜污染控制的双重目的.在膜吸附方面,共混基质膜(MMMs)内MOFs材料UiO-66@Fe₃O₄@UiO-66能够有效吸附以水杨酸(SA)和邻-苯二甲酸二甲酯(DMP)为模板化合物的两种常见PPCPs.在膜催化再生方面,UiO-66@Fe₃O₄@UiO-66中的Fe₃O₄能够催化H₂O₂生成强氧化性的羟基自由基(HO·),实现对MOFs/PVDF膜吸附能力再生和膜内污染控制的耦合.结果表明,pH=7±0.1条件下,10%MOFs/PVDF膜对0.1 mmol·L^-1SA和DMP吸附去除率最高,它们的去除率可分别达到64.2%和46.1%.除此之外,膜内UiO-66@Fe₃O₄...     

Fluorescence detection of phosphate in an aqueous environment by an aluminum-based metal-organic framework with amido functionalized ligands

● A novel Al-MOF was successfully synthesized by a facile solvothermal method. ● Al-MOF showed superior performance for phosphate detection. ● High selectivity and anti-interference for detection were demonstrated. ● The high coordination between Al-O and PO₄³⁻ was the key in fluorescence sensing. The on-site monitoring of phosphate is important for environmental management. Conventional phosphate detection methods are not appropriate to on-site monitoring owing to the use of complicated detection procedures, and the consequent high cost and maintenance requirements of the detection apparatus. Here, a highly sensitive fluorescence-based method for phosphate detection with a wide detection range was developed based on a luminescent aluminum-based metal-organic framework (Al-MOF). The Al-MOF was prepared by introducing amine functional groups to conventional MIL to enhance phosphate binding, and exhibited excellent fluorescence properties that originated from the ligand-to-metal charge transfer (LMCT). The detection limit was as low as 3.25 μmol/L (0.10 mg/L) and the detection range was as wide as 3–350 μmol/L (0.10–10.85 mg/L). Moreover, Al-MOF displayed specific recognition toward phosphate over most anions and metal cations, even for a high concentration of the co-existent ions. The mechanism of phosphate detection was analyzed through the characterization of the combination of Al-MOF and phosphate, and the results indicated the high affinity between Al-O and phosphate inhibited that the LMCT process and recovered the intrinsic fluorescence of NH₂-H₂BDC. The recovery of the developed detection method reached a satisfactory range of 85.1%–111.0%, and the feasibility of on-site phosphate detection was verified using a prototype sensor for tap water and lake water samples. It was demonstrated that the prepared Al-MOF is highly promising for on-site detection of phosphate in an aqueous environment.