In-situ synthesis of NaP zeolite doped with transition metals using fly ash

Here, a novel approach has been proposed to synthesize NaP zeolite adsorbents doped with transition metals (M-NaP) using the Na₂SiO₃ and NaAlO₂ compounds extracted from fly ash via activation and stage treatment. The preparation process of M-NaP employed the in-situ synthesis in combination with organic complexation method. The effects of the addition amounts and valence state of transition metals on the zeolite products were investigated. The crystalline phase, morphology, and particle size of M-NaP were characterized using X-ray diffractometry (XRD), Scanning electron microscopy (SEM), and Laser particle size analyzer (PSD). The doping process was investigated using X-ray photoelectron spectroscopy (XPS) and Materials Studio. The adsorption performance of M-NaP was tested by the adsorption of Zn²⁺. The optimal molar ratio of n(Al₂O₃)/n(M) was identified as 8:1 for Co–NaP, Ni–NaP, and Fe–NaP, compared with 6:1 for Ti–NaP. The influence of transition metals on adsorption was: Co–NaP > Ni–NaP > Ti–NaP > Fe-NaP. Due to largest surface area of Co–NaP (162.5 m²/g, five times than that of NaP-RAW), the maximum removal rate of Zn²⁺ was above 99.50% at 25°C. The existence state of transition metals in M-NaP primarily included: isomorphous substitution and balance of the skeletal charge, with the latter in majority. The simulation of Materials Studio indicates that Si at T4 was first substituted and then, Si at T3 opposite T4 was replaced when the replacement of Si in different sites occurred.     

Nanodiamond-containing polyethyleneimine hybrid materials for lead adsorption from aqueous media

This study describes the preparation of new surface-modified nanodiamond (ND) particles containing urethane-based hybrid materials by photopolymerization of aliphatic urethane acrylate, trimethylolpropane triacrylate, glycidyl methacrylate monomers, and their usage for lead adsorption from aqueous media. ND and synthesized surface-modified ND were characterized by atom transfer radical addition Fourier transform infrared spectroscopy (ATR-FTIR) and scanning transmission electron microscopy analysis. Crosslinked adsorbent nanocomposites were then treated with polyethylene imine and all adsorbent nanocomposites were characterized by ATR-FTIR, scanning electron microscopy, thermogravimetric analysis, and contact angle measurements. The metal ion binding capacity of the surfaces of the nanocomposites containing high amine content was investigated. The effects of the percentage of functional monomer, pH, and contact time on adsorption, and the interaction of foreign metal ions have been tested. Optimum contact time was found to be 7 h at pH 5. The adsorption capacity of the synthesized nanocomposite adsorbent for lead (II) was determined as 17.12 mg g⁻¹. Langmuir and Freundlich isotherms were used to determine the adsorption behaviors and Langmuir isotherm model was found to be the most suitable model (R²: 0.9988). The amount of adsorption of Pb (II) ions of UV curable adsorbent film prepared in river water samples was investigated. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 48241.     

3D打印在催化和吸附材料制备领域的应用

3D打印是一种快速成型技术,该技术在催化和吸附材料制备领域的应用目前已受到广泛重视。3D打印技术一方面能够拓展整体式催化/吸附材料的涵盖范围,实现材料的宏观结构优化和活性组分控制,同时有利于强化催化和吸附过程中的传质/传热过程,而且操作灵活,可靠性强,因此适于工业生产和实验室研究。本文介绍了催化/吸附材料制备过程中常见的几种3D打印技术,同时从打印策略和打印材料方面入手,综述了目前3D打印技术在催化和吸附领域的各项应用,并由此指出,目前3D打印技术可以将聚合物、碳材料、金属及金属氧化物、分子筛等材料纳入到整体式催化体系中,通过对材料结构和分布的控制对其催化和吸附性能进行影响,因此3D打印在催化和吸附材料制备领域的应用有着广阔的前景。同时指出材料微观结构控制、打印耗材及流程的标准化,以及以计算为依托的催化/吸附材料的整体式结构和活性位点分布控制是今后的研究重点。     

精炼大豆油返色返酸防止措施

精炼一级大豆油进成品油罐,再分流到灌装车间的小油罐,在等待灌装期间或灌装后出现返色返酸现象。分析大豆油返色返酸原因,基于此得出从精炼设备配置、操作参数调整、脱色吸附剂选取方面防止返色返酸。为了达到企业包装油内控标准酸价(KOH) 0. 08 mg/g和色泽Y10/R1. 3,精炼车间控制出油色泽在Y7/R0. 7、酸价(KOH)在0. 05 mg/g以下,基本上可满足市场消费者的需求。     

新型吸附式制冷系统吸附床的研究进展

吸附床的传热传质性能是提高吸附式制冷效率的关键,优化吸附床的结构能够有效提高整个吸附床的传热传质效率,减少热量损失,提高系统的制冷效率（coefficient of performance, COP）和单位质量吸附剂制冷量（specific cooling power, SCP）。本文介绍了近年来几种新型吸附床的类型,综述了吸附剂侧的固化吸附剂和涂层吸附剂,以及换热器侧的新型换热器结构。最后阐述新型吸附床的未来发展方向和研究重点。     

Adsorption performance of mesoporous silicas towards a cationic dye. Influence of mesostructure on adsorption capacity

The dye adsorption performance of four mesoporous silicas with different structure and textural properties, MCM-41, MCM-48, SBA-15 and mesocellular silica foam (MCF), was studied and compared by using toluidine blue O (TBO) as dye model in aqueous solution. These materials were characterized by X-ray diffraction (XRD), small-angle X-ray scattering, nitrogen adsorption-desorption analyses, and transmission electron microscopy (TEM). The effect of some parameters such as adsorbent dosage, contact time, temperature, and pH on the TBO removal in aqueous solution was studied. Results showed that adsorption capacity raised when adsorbent dosage, contact time and pH solution were increased while an increase in temperature decreased the adsorption of TBO. Langmuir, Freundlich and Temkin isotherm models were employed to elucidate the adsorption mechanism while the adsorption rate data were analyzed according to the pseudo-first and second-order kinetic models. Results showed that adsorption of TBO onto MCM-48, SBA-15, and MCF fitted well the Freundlich isotherm model while the kinetic studies showed that adsorption process could be better described by the pseudo-second-order model for all mesoporous silicas. Finally, some solvents were evaluated to carried out dye desorption from the TBO-loaded mesoporous silicas founding that acetic acid was the most efficient.     

Cube-octameric silsesquioxane (POSS)-capped magnetic iron oxide nanoparticles for the efficient removal of methylene blue

Octavinyl polyhedral oligomeric silsesquioxane (POSS) was polymerized on the surface of Fe3O4 nanoparticles (NPs) and then the NPs were functionalized with carboxylic acid groups using thiol-ene click reactions with thioglycolic acid.The as-prepared Fe3O4@POSS-COOH magnetic hybrid NPs had mesoporous structures with an average particle diameter of 15 nm and a relatively high specific surface area of 447 m^2· g^-1.Experimental results showed that 4 mg of Fe3O4@POSS-COOH NPs efficiently adsorbed and removed methylene blue from water at 5 min.This is due to the presence of both carboxylic acid and pendant vinyl groups on the Fe3O4@POSS-COOH NPs.These NPs could be easily withdrawn from water within a few seconds under moderate magnetic field and showed high stability in acid and alkaline aqueous mediums.     

制冷用木屑基质复合吸附剂的制备及性能测试

为开发出用于吸附式制冷的高性能吸附剂,基于炭化造孔原理制备了木屑氯化钙复合吸附剂,测试了氨气作为制冷剂的吸附性能,考察了原料配比、炭化温度对复合吸附剂性能的影响,并利用扫描电镜和能谱分析仪观察了复合吸附剂的微观形貌和元素分布。结果表明：炭化法制备的复合吸附剂具有丰富的微孔结构,氯化钙的含量高,达到70%以上,而且氯化钙在样本吸附剂中分布均匀;样本吸附剂的烧失率随炭化温度的升高而增加,而样本的吸附量随着炭化温度的升高先增大后减小;样本中氯化钙的含量对吸附量具有重要的影响。样本SB4的最大单位质量吸附剂制冷功率（SCP）达到1418.16 W/kg,前10 min的平均SCP达到876.1 W/kg。实验结果表明,炭化法制备的复合吸附剂不仅解决了氯化钙吸氨过程中的膨胀结块现象,而且增加了传质速率。