Degradable Superhydrophilic Iron-Pillared Bentonite Doped with Polybutylene Adipate/Terephthalate Open-Cell Foam: Its Application in Dye Degradation,Removal of Heavy Metal Ions,and Oil–Water Separation

Development of industrialization has brought convenience to people's lives; however, it has also brought serious harm to the environment, where, water pollution is the most obvious. Here, a polybutylene adipate terephthalate (PBAT) open-cell foam doped with iron-pillared bentonite (IPB) is prepared by using sugar as a pore-forming agent and solution phase separation, and then combined with a solution dipping method to coat the foam surface with a polyacrylamide/SiO₂, which makes the PBAT foam superhydrophilic. The static adsorption effect of superhydrophilic IPB-doped PBAT open-cell foam on methylene blue (MB) and Cu²⁺ is studied. The adsorption isotherm fitting shows that the adsorption conforms to the Langmuir model and it has biased toward monolayer adsorption. The adsorption kinetics fitting confirms that the adsorption process is in line with the pseudo-second-order adsorption model, which is dominated by chemical adsorption. The modified PBAT open-cell foam has an adsorption effect on Cu²⁺; however, it has weak cyclic adsorption capacity. It shows a good cyclic adsorption ability for the cationic dye MB and it has >95% photodegradation efficiency of the MB after five time's cyclic adsorption. The superhydrophilicity makes the foam to have better applications in oil–water separation.     

Impregnation of X Zeolite with Alkaline Hydroxide During the Synthesis

Enhancement of the basic properties of the X zeolite with FAU framework has been carried out during synthesis, without further treatment such as ion-exchange or impregnation. Control of the washing stage enables retention of the optimum amount of alkaline hydroxides, which increases the basic catalytic activity of X zeolite in the alkylation of toluene. This alkaline hydroxides neither affect the FAU framework nor the silicon/aluminium molar ratio of the X zeolite. The optimum (Na + K)/Al molar ratio of the improved catalyst was 1.06 corresponding to a washing volume of 200 mL. This X zeolite presented better catalytic activity than a cesium-zeolite prepared by ion-exchange. The presence of hydroxysodalite impurity in the X zeolite increased the amount of impregnated alkaline hydroxides but not the catalytic activity. The present study shows that it is possible to increase the basic properties of the X zeolite directly in the synthesis process.     

Evidence for non-site-isolation in ZSM-5 from ion-exchange and catalytic studies

Ion exchange of HZSM-5 samples with alkali metal cations, using metal chloride solutions, results in partially exchanged zeolites, MHZSM-5, M = Li, Na, K or Cs. The degree of exchange is found to increase with increasing ionic radius of the cations. The catalytic properties of the alkalized zeolites were evaluated using the reaction conditions under which the catalytic activity of the HZSM-5 samples in terms of n-hexane cracking is proportional to the aluminium content. From the residual catalytic activity exhibited by the Na-, K- and CsHZSM-5 samples it is concluded that each of the larger Na⁺, K⁺ and Cs⁺ ions is influencing more than one AlO ₄ ^– tetrahedron, implying that the aluminium sites in ZSM-5 are not isolated. The ion-exchange results are then interpreted in terms of non-isolated aluminium sites. The ion-exchange and catalytic properties of the zeolites as a function of aluminium content are also discussed.     

阳离子对SPI膜性能的影响

本论文采用湿法工艺制备可食性大豆分离蛋白膜(SPI),通过添加Na 、Zn2 、Fe3 ,考察了阳离子价态对SPI膜性能的影响。结果显示,阳离子价态对SPI膜的透光率(TP)没有影响;使SPI膜的水蒸气透过系数(WVP)增加;添加有0.5%(w/w SPI)的Fe3 的SPI膜的整体性能比较好。     

高庙子膨润土与北山地下水的长期作用试验

以内蒙古兴和县高庙子钠基膨润土和甘肃北山BS05号钻孔地下水为研究对象，依托低氧手套箱，在常温低氧条件下开展膨润土与地下水长期作用试验研究，获得了1年内膨润土 北山地下水体系pH和Eh值随时间的变化特征；得到了作用前后体系液相关键离子成分以及固相可交换阳离子、化学成分，依托拉曼光谱仪测定了作用前后膨润土的结构。结果表明，膨润土 北山地下水体系在本试验条件和时间范围内可以保持相对稳定的状态。     

Complex Formation of Divalent Cations with Carboxylic Acid Resins as a Factor Determining Different Stationary States of Their Swelling

Three samples of carboxylic acid gel-type cross-linked polyelectrolytes were examined by registering the extent and kinetics of their volume change depending on the temperature, concentration, and nature of external electrolyte solutions, as well as the initial state (ionic form, water content) of the bead. It is found that in some systems the swelling of the bead (as a result of lowering the temperature) proceeds much more slowly than the preceding shrinking (as a result of the increase of temperature). Moreover, the initial volume of the bead is not restored, and a new stationary state of swelling is established. By means of optical dilatometry, it is found that in the systems in which the differences in the stationary states of swelling are found, the beads display plasto-elastic properties, whereas in the absence of such differences the beads show elastic properties. It is found that different stationary states of swelling are also established when the beads of copolymer of methacrylic acid cross-linked with divinylbenzene in Na⁺ form in the dry state and in the NaCl solution-swollen state are placed into a solution of a divalent cation salt. The difference in the stationary states of swelling reaches 12% in 4 N NiCl₂ solution. The substantial differences in the swelling behavior and viscoelastic properties of the resins in their Na⁺, Mg²⁺, Ca²⁺, and Ni²⁺ forms are interpreted in terms of formation of different kinds of complexes of functional groups of the polymer with Ca²⁺ and Ni²⁺ ions.     

烷基季铵阳离子改性制备有机粘土的研究及应用进展

蒙脱石是属于2∶1型层状硅酸盐类粘土矿物,具有优异的物理化学性能。近年来,烷基季铵盐改性的有机膨润土作为一种新型的化学、化工原料在环境保护和新材料等应用方面引起了广泛的关注并且已成为当前材料科学的研究热点之一。本文概括了蒙脱石、烷基季铵盐的结构特征;阐述了有机膨润土的制备原理及合成工艺;介绍了有机蒙脱石的表征技术和现阶段研究成果;最后对有机粘土应用及发展前景进行了概述和展望。     

Polymer brush coatings for combating marine biofouling

A variety of functional polymer brushes and coatings have been developed for combating marine biofouling and biocorrosion with much less environmental impact than traditional biocides. This review summarizes recent developments in marine antifouling polymer brushes and coatings that are tethered to material surfaces and do not actively release biocides. Polymer brush coatings have been designed to inhibit molecular fouling, microfouling and macrofouling through incorporation or inclusion of multiple functionalities. Hydrophilic polymers, such as poly(ethylene glycol), hydrogels, zwitterionic polymers and polysaccharides, resist attachment of marine organisms effectively due to extensive hydration. Fouling release polymer coatings, based on fluoropolymers and poly(dimethylsiloxane) elastomers, minimize adhesion between marine organisms and material surfaces, leading to easy removal of biofoulants. Polycationic coatings are effective in reducing marine biofouling partly because of their good bactericidal properties. Recent advances in controlled radical polymerization and click chemistry have also allowed better molecular design and engineering of multifunctional brush coatings for improved antifouling efficacies.     

Two‐dimensional electrolyte nature of exfoliated montmorillonite nanoplatelets fabricated by soap‐free emulsion polymerization and their affinity for cations

Montmorillonite (MMT) nanoplatelets, fabricated by the exfoliation of MMT during participating in the soap‐free emulsion polymerization of methyl methacrylate, were well‐dispersed in water and performed like a two‐dimensional electrolyte. Their ionic conductivity roughly follows the Manning's limiting law for the conduction of a polyelectrolyte. The dissociated MMT nanoplatelets that carry negative charges in water were able to rapidly adsorb cations, such as tris(2,2′‐bipyridyl)ruthenium(II) (Ru(bpy)) and methylene blue (MB⁺), and recover into a smectic configuration floating as a separating phase. By using the Langmuir equation, we were able to estimate the occupied surface areas of MMT nanoplatelets by each Ru(bpy) and MB⁺ cations as 4.708 and 1.806 nm²/ion, respectively. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

A novel anions and cations co-doped strategy for developing high-performance cobalt-free cathode for intermediate-temperature proton-conducting solid oxide fuel cells

The sluggish activity of cathode at intermediate-temperature limits commercialization of proton-conducting solid oxide fuel cells (H-SOFCs). In this investigation, a novel cathode of Ba_0.95Ca_0.05Fe_0.85Sn_0.05Y_0.1O_2.9−δF_0.1 was successfully developed by co-doping of anion F and cations Ca, Sn, Y. We studied the effect of F⁻-doping on phase structure, electrical conductivity and electrochemical properties of the cell. Compared with Ba_0.95Ca_0.05Fe_0.85Sn_0.05Y_0.1O_3−δ, F⁻-doped Ba_0.95Ca_0.05Fe_0.85Sn_0.05Y_0.1O_3−δ exhibited higher conductivity. Composite cathode consisting of Ba_0.95Ca_0.05Fe_0.85Sn_0.05Y_0.1O_2.9−δF_0.1 and Sm_0.2Ce_0.8O_2−δ was applied in H-SOFCs with BaZr_0.1Ce_0.7Y_0.2O_3−δ electrolyte which achieves an encouraging performance with the maximum power density of 1050 mW cm⁻² and polarization resistance of 0.04 Ω cm² at 700 °C. The result of First-principles calculations based on spin-polarized Density Functional Theory shows that doping of F⁻ reduces the activation energy required for migration of oxygen ions. These results demonstrate that the anions and cations co-doped strategy can provide a new horizon for the cathode in H-SOFCs.