铀的复合吸附材料

铀是重要核燃料资源,也是放射性废液中主要的污染元素之一。铀的吸附涉及到溶液中铀的提取、含铀废水的处理和铀元素化学分析的预富集等。本文从有机官能团化学键合修饰基体的复合材料出发,从基体和有机官能团两方面对溶液中的铀的吸附行为进行了综述,分析了各种官能团所适用的水相pH值、对铀的吸附量和选择性。含有机磷类官能团的复合材料具有pH适用范围广、吸附量和选择性较好的优点,是一种具有良好发展前景的铀复合吸附剂。     

Water Adsorption and Transport on Oxidized Two-Dimensional Carbon Materials

Studies on the adsorption and transport of water molecules with oxidized two-dimensional (2 D) carbon materials have attracted increasing interest owing to their wide range of applications, such as sensing, energy conversion, and membrane separation. In this contribution, the interaction between water molecules and oxidized 2 D carbon materials (i.e., graphene oxide and graphdiyne oxide) is discussed, the influence of water adsorption and transport on the physicochemical properties of 2 D carbon materials is presented, and the recent progress on oxidized 2 D carbon material-based proton conduction, electricity generation, water transport, and humidity sensing is highlighted. The opportunities and challenges in these research fields are discussed, especially the structural stability and chemical modification of 2 D carbon materials.     

选择性油水分离材料

水是人类赖以生存的基础,其重要性不言而喻。但是,当前水环境日益恶化,水污染日益加重,尤其是石油泄漏和有机污染物肆意排放给环境和生态系统造成了不可挽回的损害。因此,高效油水分离已成为亟待解决的问题。当前主要通过物理吸附、化学分散以及生物降解等方法进行油污清理;化学分散和生物降解法易对海洋环境造成二次污染,而物理吸附具有易于回收及无污染等优点。本文综述了近年来物理过滤和物理吸附油水分离材料的研究现状及尚待解决的难点,同时也展望了该领域未来研究的热点及发展方向。     

介孔沸石材料

介孔沸石材料是含有丰富介孔的结晶沸石,不仅保留了沸石材料优良的酸性和水热稳定性,而且由于介孔的引入改善了其对大分子的吸附和扩散性能,在催化领域特别是涉及大分子的催化反应中是极有应用前景的材料。本文综述了介孔沸石材料的制备方法并进行了比较分析,概述了近年来介孔沸石材料在不同催化反应中的应用,探讨了介孔沸石材料今后的研究方向。     

微孔-微孔复合分子筛的结构特征及应用

微孔-微孔复合分子筛是指两种(或多种)微孔分子筛的复合晶体,不仅具备单一分子筛的特性,而且由于复合过程中产生的结构畸变使其具有独特的孔道结构和酸性质,进而体现出优异的催化反应特性,成为当今分子筛领域的研究热点。微孔-微孔复合分子筛可分为共晶分子筛和共生分子筛两种,前者通过两种分子筛晶体的无限成分单元重排,有利于构成新的完整的晶体结构,后者则是两种分子筛共生长过程中得到的两相交错生长的复合体,产生微结构畸变和界面效应。本文对微孔-微孔复合分子筛进行归纳和分类,并系统介绍了微孔-微孔复合分子筛的研究进展,着重阐述了共晶分子筛和共生分子筛的合成与微结构特点以及在催化反应领域中的应用。     

Synthesis of Micropore/Mesopore Composite Materials

The objective of this study was to synthesize micropore-mesopore composite materials by two-step crystallization. The colloidal MFI was first synthesized using a structure-directing agent tetrapropylammonium hydroxide as a template in the first step. This colloid was then self-assembled to form mesoporous structure by using cetyltrimethylammonium bromide as a surfactant. These materials were characterized by powder X-ray diffraction, nitrogen sorption, SEM and TEM. Due to the thick walls produced, it cannot sustain the local strain caused by the crystallization: the mesostructure is collapsed upon heating. The mixed phases of MFI and MCM-41 were obtained by optimizing the synthesis times and reaction temperatures.     

以天然植物为模板合成高度有序的多级复合孔材料

筛选出两种孔径较大且孔结构规则的植物为大孔模板, 以嵌段共聚物为介孔相模板成功合成了两种具有连续的骨架和贯通的大孔孔道(大孔孔径大于40 μm, 其孔壁为介孔相)的高度有序多级复合孔材料. 对该复合孔材料进行了水热稳定性研究. 用扫描电子显微镜(SEM)、粉末X射线衍射仪(XRD)、高分辨率透射电镜(HRTEM)以及N₂吸附-脱附等测试手段对合成的样品进行了表征. 结果表明, 合成的产物是孔道相互贯通的多级有序复合孔硅材料, 具有较好的水热稳定性. 采用此合成方法可精确地复制大孔植物模板.     

Polysaccharide-Based Composite Hydrogels as Sustainable Materials for Removal of Pollutants from Wastewater

Nowadays, pollution has become the main bottleneck towards sustainable technological development due to its detrimental implications in human and ecosystem health. Removal of pollutants from the surrounding environment is a hot research area worldwide; diverse technologies and materials are being continuously developed. To this end, bio-based composite hydrogels as sorbents have received extensive attention in recent years because of advantages such as high adsorptive capacity, controllable mechanical properties, cost effectiveness, and potential for upscaling in continuous flow installations. In this review, we aim to provide an up-to-date analysis of the literature on recent accomplishments in the design of polysaccharide-based composite hydrogels for removal of heavy metal ions, dyes, and oxyanions from wastewater. The correlation between the constituent polysaccharides (chitosan, cellulose, alginate, starch, pectin, pullulan, xanthan, salecan, etc.), engineered composition (presence of other organic and/or inorganic components), and sorption conditions on the removal performance of addressed pollutants will be carefully scrutinized. Particular attention will be paid to the sustainability aspects in the selected studies, particularly to composite selectivity and reusability, as well as to their use in fixed-bed columns and real wastewater applications.     

钙钛矿型复合氧化物材料

从钙钛矿复合氧化物独特的电子结构及晶体结构出发，分析归纳了其作为功能材料的理论规律，综述了它在导体透氧膜、气敏传感器、固体燃料电池、磁制冷和氧化还原催化剂等领域的研究新成果和应用进展，提出进一步研究的策略方案。     

海藻酸盐复合凝胶吸附材料的合成及其在水处理中的应用

海藻酸钠是一种天然多糖,因其成凝胶条件及工艺简单,并具有生物安全性和生物相容性等特点,受到广泛关注。通过和其他物质复合,可进一步改善和丰富海藻酸钠凝胶的性能,拓宽其在水处理中应用前景。本文主要综述了海藻酸盐复合凝胶发展现状及其结构特点、理化性质和吸附特性,总结和归纳了海藻酸盐复合凝胶的分类和制备方法等,并深入对比和分析了海藻酸盐复合凝胶作为吸附剂在水处理中的研究进展和存在的问题,并对其后续研究和应用进行展望。     

Composite Materials of Synthetic Mordenite and AgI

Composite materials made up of silver iodide and synthetic mordenite in sodium Na-MD or potassium form K-MD have been prepared by sintering a mixture of silver iodide and Na-MD or K-MD, by modified way of preparation. The prepared composites Na-MD/AgI and K-MD/AgI were characterised by X-ray powder diffractometry and thermal analysis. By integrating certain X-ray peaks quantitative reaction values were obtained. The composite Na-MD/AgI with 19 wt% of AgI content was also characterised by EDS analysis and ac conductivity measurements.     

SPI/S-BEA复合质子交换膜的制备及电池性能

通过在磺化聚酰亚胺(SPI)中加入具有高温保水功能的无机纳米粒子磺化多孔沸石(S-BEA)制备SPI/S-BEA复合质子交换膜(PEM).扫描电镜显示当S-BEA含量为10％时(H1),无机颗粒较为均一的分散在SPI PEM中,当S-BEA的含量提高到20％时(H2),无机颗粒团聚增多,可明显观察到有机/无机宏观相分离界面.SPI/S-BEA复合PEM H1的离子交换容量(IEC)较SPI PEM M1下降了12％,由于S-BEA粒子的存在,吸水率并未有下降,膜中单位磺酸基团的水分子摩尔数从原来的23提高到10％杂化量时的26.由于无机颗粒表面的羟基和高分子链的氢键作用,复合PEM在干燥和润湿环境下的尺寸变化并无明显增加,且保持良好的机械性能.适量加入S-BEA的复合PEM的IEC值虽然有所下降,但低湿度下的质子传导率并未明显降低.当S-BEA含量达到20％时,其明显的宏观相分离界面不利于质子在膜内的有效传导,质子传导率有所下降.燃料电池性能测试表明,在90℃下,SPI/S-BEA复合PEM H1与SPI PEM M1相比较并未有明显的提高.当电池温度提高到110 ℃后,由于无机粒子S-BEA的高温保水性能,复合PEM的电池性能要明显好于SPI PEM,如H1电池最大输出功率为0.61 W cm-2,相对M1提高了30％.     

纳米锡锌复合氧化物贮锂材料的合成和性质

用液相沉淀-热解法合成了一系列结构和组成不同的锂离子电池纳米锡锌复合氧化物贮锂材料, 通过XRD、TEM和电化学测试对材料进行了表征. 测试结果表明, 非晶态ZnSnO3负极材料的初始可逆贮锂容量为844 mA·h/g, ZnO·SnO2负极材料的初始可逆贮锂容量为845 mA·h/g, SnO2·Zn2SnO4复合物负极材料初始可逆贮锂容量为758 mA·h/g, 循环10周后, 三者的充电容量分别为695, 508和455 mA·h/g, 表明非晶态结构的锡锌复合氧化物具有较好的电化学性质, 随着样品中晶体的形成, 该类型负极材料的贮锂性能下降.     

Vibrational Spectra of Zeolite Y as a Function of Ion Exchange

Zeolite Y is one of the earliest known and most widely used synthetic zeolites. Many experimental investigations verify the valuable ion exchange capability of this zeolite. In this study, we assessed the effects of ion exchange on its vibrational spectra. We applied classical lattice dynamics methods for IR and Raman intensity calculations. Computed spectra of optimized zeolite Y structures with different cations were compared with experimental data. The spectra obtained in this study are in agreement with previous experimental and computational studies on zeolites from the faujasite group.     

New Bio-Based Furanic Materials Effectively Absorb Metals from Water and Exert Antimicrobial Activity

Development of sustainable bio-based materials for removal of toxic contaminants from water is a high priority goal. Novel bio-based binary and ternary copolymers with enhanced ion-exchange, adsorption and antibacterial properties were obtained by using plant biomass-derived diallyl esters of furandicarboxylic acid (FDCA) as crosslinking agents and easily available vinyl monomers. The synthesized copolymer materials showed higher sorption capacities for Ni^II, Co^II and Cu^II compared to the commercial ion-exchange resins, and they maintained their high metal adsorption capacities for over 10 cycles of regeneration. The synthesized copolymer gels containing 1–5 wt % of the crosslinker showed excellent water absorption capacities. The synthesized copolymers with 1 % crosslinker content showed swelling ratios high enough to also act as moisture absorbents. Synthesized copolymers with crosslinker content of 10 wt % performed as contact-active antibacterials by inhibiting the growth of Gram-positive (S. aureus) and Gram-negative bacteria (E. coli, K. pneumonia) in suspension tests.     

阳离子化纳米纤维素晶体增强壳聚糖复合膜的制备及性能

利用水相连续法实现了纳米纤维素晶体(NCC)的高碘酸钠氧化及阳离子化,然后将阳离子化纳米纤维素晶体(CDAC)悬浮液与壳聚糖(CTS)醋酸溶液混合,并采用流延法制得壳聚糖-纳米纤维素(CTS-CDAC)复合膜。采用红外光谱(FT-IR)、透射电镜(TEM)、X射线衍射(XRD)、Zeta电位及粒径分析表征了改性前后NCC的结构与性能,并研究了制得的CDAC悬浮液与CTS醋酸溶液混合时的相容性及CTS-CDAC复合膜中CDAC质量分数对复合膜力学性能、水溶胀性的影响。结果表明:CDAC悬浮液与CTS醋酸溶液混合时相容性良好,CDAC在CTS基质中分散均匀,CTS-CDAC复合膜的力学性能较纯CTS膜明显提高。当复合膜中CDAC的质量分数为12%时,拉伸强度达到最高。另外,CTS-CDAC复合膜在水中的溶胀度较纯CTS膜明显降低,稳定性变好。     

碳纳米管基复合材料研究进展

碳纳米管基复合材料具有优良的性能,已在化学、化工、材料、生物、医学等领域受到广泛关注.本文主要综述了功能材料包覆碳纳米管的制备方法及其力学、磁学、光学、电化学等性质,以及当前研究的焦点和存在的问题.     

Composite materials based on zeolite 4A for adsorption heat pumps

Some additives and binders were chosen for the preparation of 4A-zeolite-based composites with high equivalent thermal conductivity for heat pumps application. Additives (SiC, Si₃N₄, graphite) and binders (PTFE, Al(OH)₃) were tested for their effectiveness in terms of equivalent thermal conductivity and maximum water adsorption capacity of the composites. The influence of the equivalent thermal conductivity of the composite adsorbents on the specific power of the heat pump was also calculated. Results show a significant improvement in the equivalent thermal conductivity of the composite samples which are prepared using aluminum hydroxide as binder, over that of zeolite pellet beds. Such composite materials could be used to build adsorption heat pumps with higher specific power and, consequently, with lower investment cost.     

乙酸乙酯水溶液中水在3A分子筛上的吸附平衡与动力学

乙酸乙酯水溶液中水在3A分子筛上的吸附平衡与动力学;乙酸乙酯;水;吸附平衡与动力学;表面扩散系数;3A分子筛     

ZSM-5/Y复合分子筛的酸性及其重油催化裂化性能

 ZSM-5/Y是本研究组合成的一种新型复合分子筛材料. 用“两次交换,两次焙烧”和磷 酸氢二铵浸渍方法对该复合分子筛材料进行了改性,采用红外光谱表征了复合分子筛的酸性,研究了磷改性对复合分子筛样品羟基区谱学性质的影响,并与相应的机械混合分子筛样品进 行了对比. 红外光谱数据表明,磷改性后复合分子筛的B酸(主要是中强酸)增加,而机械混合分子筛在各个酸强度区域的B酸量和L酸量都减少. 以新疆重油为原料考察了改性后复合分子 筛样品和机械混合分子筛样品的催化裂化性能. 与相应的机械混合分子筛催化剂相比,磷改 性复合分子筛催化剂具有较高的柴油选择性,其柴油产率增加了4.1个百分点,柴汽比增加了0.11,总轻油产率与机械混合分子筛相当. 用气体产物中的CMR(裂化机理比)和C3/C4比 值分析了复合分子筛的催化性能与其聚集体结构的关系.