介孔氧化硅分子筛吸附性能研究进展

介孔氧化硅分子筛具有比表面积高、孔容大、孔道介孔化及表面硅羟基丰富的特点,通过功能化改性,被广泛应用于吸附法治理环境问题。从吸附过程影响因素、吸附机理、吸附性能及吸附剂结构出发,概述了介孔氧化硅分子筛在吸附无机物(重金属离子和CO₂)和有机化合物(有机染料、硫化物和挥发性有机物)方面的最新研究进展。分析表明,吸附性能主要由氧化硅结构类型和改性条件决定,制备高选择性吸附剂、提高吸附剂可复用性及开发吸附成套工艺将是未来的发展趋势。     

介孔碳材料对染料大分子的吸附性能研究

采用嵌段共聚物聚氧乙烯-聚氧丙烯-聚氧乙烯(PEO-PPO-PEO,F127)和聚二甲基硅氧烷-聚氧乙烯(PDMS-PEO)为混合模板剂制备了有序介孔碳材料,并采用小角X射线散射(SAXS)和氮气吸附/脱附对其结构进行了表征,进一步研究了上述介孔碳材料对甲基橙、亚甲基蓝和碱性品红3种染料大分子的吸附性能。     

介孔氧化硅薄膜材料的研究进展

介孔氧化硅薄膜在膜分离、传感器件、异相催化、低介电常数微电子绝缘片的应用方面具有潜在应用价值。首先简要介绍了介孔薄膜的制备途径，然后重点综述了介孔氧化硅薄膜的研究进展。     

巯基功能化介孔氧化硅的合成及其对Pb(Ⅱ)的吸附

采用直接模板法,以三嵌段共聚物P123作为模板剂,酸性条件下制备出了具有规则孔道结构的介孔氧化硅.用有机硅烷MPTMS对其进行后续功能化,引入了对Pb2 离子有吸附能力的巯基基团.通过HRTEM、FTIR和N2吸附脱附等测试手段对功能化前后氧化硅的结构进行表征,结果表明,巯基功能团接枝在介孔氧化硅孔道内壁.吸附实验结果显示,巯基功能化氧化硅对水中Pb(Ⅱ)离子具有选择吸附性.当铅与铜、镉离子摩尔比为1:5时,巯基功能化材料对其吸附的分配系数之比分别为KdPb2 /KdCu2 =13.1和KdPb2 /KdCd2 =9.2.在Cu2 、Cd2 离子摩尔浓度相同时,此功能化介孔材料对Cd2 的吸附能力大于对Cu2 的吸附能力.     

有机粘土合成的介孔材料

有机粘土合成的介孔材料(MSCs)是用有机物或聚合物有机改性的粘土凝胶经过水热结晶，使得插层的粘土片层随机分散在聚合物基体中，然后焙烧脱去有机模板而制得。介孔半径的大小与聚合物质量百分含量及分子量大小有关。该类介孔材料可应用于加氢脱硫催化剂载体、分子的选择吸收、聚合物基纳米复合材料等领域。本文介绍了MSCs的制备方法及应用。     

介孔炭材料应用于电化学催化的研究进展

由于介孔炭材料具有高比表面、均一可调的孔径尺寸和形貌、良好的导电性和化学稳定性等优点,已被广泛应用到催化、吸附、分离和电化学储能等领域.近年来,多组分的掺杂与复合使介孔炭材料拥有可调变的功能性,已成为材料领域研究的一个热点.本文首先介绍介孔炭材料的合成,包括软模板法、硬模板法和无模板法等.接着论述介孔炭及其复合材料在电...     

新型锂电池正极材料——蒽醌/介孔炭寄生型复合物

将9,10-蒽醌（AQ）通过升华法填充在介孔炭（MC）的孔中,制备出蒽醌/介孔炭寄生型复合物。用TG/DSC、SEM、氮吸附等方法对介孔炭及复合材料进行了表征,应用恒流充放电、循环伏安法、交流阻抗等测试手段对复合材料的电化学性能进行了测试。结果表明炭/醌复合电极的比容量和循环性能较蒽醌电极有了很大程度的提高。其中蒽醌填充量为75%的复合材料首次放电比容量达到216mAh/g,50次循环之后,比容量仍有76mAh/g,是蒽醌电极比容量的2倍。     

介孔碳的合成及其在吸附中的应用研究进展

阐述了有序介孔碳材料的合成方法及各自的特点,总结了有序介孔碳在生物大分子、重金属离子和合成有机污染物吸附领域的应用情况,并展望了有序介孔碳材料在合成方法、表面改性及其在吸附应用方面的发展趋势.     

有机-无机氧化硅空心球的合成及VOCs吸附应用

介孔有机-无机复合氧化硅空心球(MOSs)在碱性条件下以反向胶束为模板经过正硅酸乙酯(TEOS)和1,2-双(三乙氧基甲硅烷基)乙烷(BTSE)共缩合被成功合成, 并通过不同手段对样品的结构和性能进行表征。MOSs用于去除挥发性有机物(VOCs), 研究其对水蒸气、正己烷、甲苯和92#汽油的静态吸附性能, 并以商业硅胶(SG)和活性炭(AC)为参考。实验结果发现, 初始BTSE/(BTSE+TEOS) 摩尔比为10%时, (MOS-10%)的样品具有均匀的中空介观结构和最大的VOCs吸附容量(1.28 g·g^-1正己烷, 1.25 g·g^-1甲苯和1.14 g·g^-1 92#汽油), 静态水蒸气吸附量最小(0.630 g·g^-1)。通过穿透曲线评估单一组分VOC(正己烷或甲苯)在MOS-10%上的动态吸附行为, 动态正己烷和甲苯吸附结果以及高湿度条件下的正己烷吸附性能表明, 与商业吸附剂相比, MOS-10%具有最佳的穿透时间、吸附能力和疏水性。对于二元组分同时吸附(正己烷和甲苯), MOS-10%的正己烷吸附性能优于甲苯。介孔有机-无机复合氧化硅空心球的动态VOCs吸附容量较大归因于有机基团、表面积和孔体积的共同作用。MOSs的VOCs去除能力强和可回收性优良, 显示出巨大的VOCs捕获潜力。     

氮掺杂生物炭吸附降解有机污染物的研究进展

生物炭是生物质热解和碳化后产生的高含碳物质。氮掺杂生物炭改善了生物炭的性能,使其在吸附降解有机污染物等方面的应用前景更为可观,引起了学者的广泛关注。而氮掺杂生物炭对有机污染物的吸附降解性能受多种因素影响,如生物炭的制备条件及其性质等。详细讨论了生物质原料和掺杂方式等因素对氮掺杂生物炭性质的影响,总结了氮掺杂生物炭吸附和降解有机污染物的影响因素及机理,并提出了氮掺杂生物炭的未来研究方向。     

New mesoporous silica/carbon composites by in situ transformation of silica template in carbon/silica nanocomposite

Hard template-based fabrication of mesoporous carbon unavoidably goes through the removal process of the template to generate template-free carbon replica, including troublesome disposal of template waste often accompanied by toxic etchant, which not only increases the fabrication cost of materials but also raises serious environmental concerns. As a novel strategy to overcome such problem, a direct in situ synthesis approach using silica waste in carbon/silica nanocomposite as a silica source and cetyltrimethylammonium bromide as a porogen under basic condition is reported in this study for the generation of a new composite composed of mesoporous MCM-41 silica and hollow carbon capsule. The resultant MCM-41/carbon capsule composite offers a 3-D interconnected multimodal pore system, which discloses a wide pore range of ordered uniform mesopores (ca 2.3?nm) resulting from MCM-41 silica and disordered uniform mesopores (ca 3.8?nm) and macropores (ca 300?nm) from hollow mesoporous carbon, respectively. The composite has a high specific surface area (ca 909?m²/g) and large pore volume (ca 0.73?cm³/g). The in situ transformation approach of silica waste into valuable mesoporous silica is considered as a promising scalable route for efficient new multi-functional composites useful for a wide range of applications such as adsorption of volatile organic compounds and radioactive wastes produced in a nuclear facility.     

Aqueous heavy metals removal by adsorption on amine-functionalized mesoporous silica

Amino functional mesoporous silica SBA-15 materials have been prepared to develop efficient adsorbents of heavy metals in wastewater. Functionalization with amino groups has been carried out by using two independent methods, grafting and co-condensation. Three organic moieties have been selected to incorporate the active amino sites: aminopropyl (H(2)N-(CH(2))(3)-), [2-aminoethylamino]-propyl (H(2)N-(CH(2))(2)-NH-(CH(2))(3)-) and [(2-aminoethylamino)-ethylamino]-propyl (H(2)N-(CH(2))(2)-NH-(CH(2))(2)-NH-(CH(2))(3)-). Materials have been characterized by XRD, nitrogen sorption measurements and chemical analysis. We have found that all materials preserve the mesoscopic order and exhibit suitable textural properties and nitrogen contents to act as potential adsorbents. Metal removal from aqueous solution has been examined for Cu(II), Ni(II), Pb(II), Cd(II), and Zn(II); adsorption performances of materials prepared by the two functionalization methods have been compared. In addition, copper adsorption process has been thoroughly studied from both kinetic and equilibrium points of view for some selected materials. Aqueous Cu(II) adsorption rates show that the overall process is fast and the time evolution can be successfully reproduced with a pseudo-second-order kinetic model. Whole copper adsorption isotherms have been obtained at 25 degrees C. Significant maximum adsorption capacities have been found with excellent behavior at low concentration.     

Using phenol–formaldehyde resin as carbon source to synthesize mesoporous carbons of different pore structures

In this research communication, we performed the phenol–formaldehyde (PF) resin as an alternative carbon source and various mesostructured silicas as the nano-templates to conveniently prepare the mesoporous carbons of high surface area (850–1500 m² g⁻¹), large pore size (2.0–22.0 nm) and great pore volume (0.65–1.15 cm³ g⁻¹). It was reasonably supposed that there exist interaction matching between the negative-charged silica surface of the silica template and PF resin. Therefore, the PF oligomers could be homogeneously adsorbed into the nanochannels or cages of the mesoporous silicas via an impregnation process. Because the thermosetting PF resin only requires a simple heat treatment process at 100 °C to form the cross-linked polymeric structure, the replication of the mesostructure of the mesoporous silica template could be readily achieved without adding any polymerization catalysts.     

Synthesis of spheroidal ordered mesoporous carbon materials from silica/P123/butanol composites

Spheroidal ordered mesoporous carbon materials with diameter of 2–10 μm were synthesized by direct carbonization of silica/triblock copolymer P123/butanol composites using P123 and butanol as the structure-directing agents and carbon precursors. The morphologies, structures and pore characteristics of the carbon materials were investigated by scanning and transmission electron microscopes, X-ray diffraction, and nitrogen sorption. It was found that the material possesses a cubic ordered mesoporous structure with Ia3d symmetry. The butanol addition directly affects the carbon morphology and pore structure. When the mass ratio of butanol to P123 is 0.5:1, the product exhibits a perfectly spheroidal morphology with a specific surface area of 1236 m² g⁻¹ and a total pore volume of 1.26 cm³ g⁻¹. The formation mechanism of the spheroidal ordered mesoporous carbon materials is discussed briefly.     

Fabrication of mesoporous silica/carbon black nanospheres and load-sensitive conducting rubber nanocomposites

Mesoporous silica nanospheres (MSNs) with regular pores have been fabricated using cetyltrimethylammonium bromide (CTAB) as surfactant in high pH solution. The average size of the MCM-41 silica nanospheres was reduced from 95 to 48€nm, while the concentration of CTAB increases from 7.7 to 11.5mmol/L. Carbon black was deposited on MSNs using hexane as the carbon source. By mixing such materials with silicone rubber, the composites become conducting when equivalent carbon volume fraction is higher than a certain region, which is less sensitive to the morphology of the deposited carbon. The improved piezoresistance repeatability has been found on the composite sample of MSNs/carbon plus extra high conducting carbon black. The load and strain sensitive range up to 0.35MPa and 0.10, respectively, with less resistance fluctuation during multiple press loading cycles.     

以纳米SO_2粒子为模板由不同炭前躯体制备中孔炭(英文)

以纳米SO2粒子为模板,酚醛树脂、中间相沥青和聚丙烯腈为炭前躯体制备中孔炭。利用氮气吸附、元素分析和X-射线光电子能谱等分析了不同种类炭前躯体对中孔炭的影响。结果表明:在炭化温度和纳米粒子添加量相同的情况下,不同炭前躯体所制中孔炭的孔结构和表面化学性质不同。中间相沥青基中孔炭中微孔和中孔含量最少,酚醛基中孔炭中含有丰富的微孔和中孔,聚丙烯腈基中孔炭中含有大量的含氮官能团。     

Chemiluminescence immunoassay based on dual signal amplification strategy of Au/mesoporous silica and multienzyme functionalized mesoporous silica

A chemiluminescent dual signal amplification strategy for the determination of α-fetoprotein (AFP) was proposed based on a sandwich immunoassay format. Monoclonal antibody of AFP immobilized on the gold nanoparticles doped mesoporous SiO₂ (Au/SiO₂) were prepared and used as a primary antibody. Horseradish peroxidase (HRP) and HRP-labeled secondary antibody (Ab₂) co-immobilized into the mesoporous SiO₂ nanoparticles (HRP-Ab₂/SiO₂) were used as the labeled immunological probe. Due to the high ratio surface areas and pore volumes of the mesoporous SiO₂, not only the amount of AFP monoclonal antibody but also the amount of the modified HRP and Ab₂ in HRP-Ab₂/SiO₂ were largely increased. Thus the chemiluminescent signal was amplified by using the system of luminol and H₂O₂ under the catalysis of HRP. Under the optimal conditions, two linear ranges for AFP were obtained from 0.01 to 0.5 ng mL⁻¹ and 0.5 to 100 ng mL⁻¹ with a detection limit of 0.005 ng mL⁻¹ (3σ). The fabricated signal amplification strategy showed an excellent promise for sensitive detection of AFP and other tumor markers.     

短通道介孔二氧化硅的制备与水蒸气吸附性能EI北大核心CSCD

在高速搅拌条件下调整分子组装过程的外界应力,制备出短通道(500~700 nm)、条棒状的有序介孔二氧化硅,研究不同模板剂脱除方式对介孔二氧化硅的水蒸气吸附性能影响,获得强化介孔二氧化硅吸附性能的方法。结果表明:在短通道、条棒状介孔二氧化硅的制备过程中模板剂脱除的温度对材料表面羟基浓度影响较大,选择萃取与低温煅烧相结合方法脱除模板剂,萃取4次,250℃煅烧脱除模板剂的材料水蒸气吸附性能最好,在实验条件下平衡吸附时间约为7.5 min,是商品SBA-15的78.95%;平衡吸附量0.73 g·g^(-1),是商品SBA-15的1.49倍。     

Magnetic motive,ordered mesoporous carbons with partially graphitized framework and controllable surface wettability: preparation,characterization and their selective adsorption of organic pollutants in water

Magnetically active, ordered and stable mesoporous carbons with partially graphitized networks and controllable surface wettability (PR-Fe-P123-800 and PR-Ni-P123-800) have been synthesized through direct carbonization of Fe or Ni functionalized, and ordered mesoporous polymers at 800°C, which could be synthesized from self assembly of resol (phenol/formaldehyde) with block copolymer template (P123) in presence of Fe³⁺ or Ni²⁺, and hydrothermal treatment at 200°C. PR-Fe-P123-800 and PR-Ni-P123-800 possess ordered and uniform mesopores, large BET surface areas, good stabilities, controllable surface wettability and partially graphitized framework. The above structural characteristics result in their enhanced selective adsorption property and good reusability for organic pollutants such as RhB, p-nitrophenol and n-heptane in water, which could be easily regenerated through separation under constant magnetic fields and washing with ethanol solvent. The unique magnetically active and adsorptive property found in PR-Fe-P123-800 and PR-Ni-P123-800 will be very important for them to be used as efficient absorbents for removal of various organic pollutants in water.