聚乙二醇对聚合氯化铝制备γ-Al2O3的影响（英文）

A polyaluminium chloride solution with high Al 13 content self-prepared was used as material for preparing the spherical γ-Al 2 O 3 by the sol-gel and oil-drop method. Polyethylene glycol with different molecular mass was used as surfactant to investigate the effect on property of γ-Al 2 O 3 . The physical property was characterized by 27 Al NMR (nuclear magnetic resonance) spectra, X-ray diffraction, FT-IR (Fourier transform infrared spectroscopy) and TG-DTA (thermogravimetric-differential thermal analysis). The results showed that surface area, pore volume and pore size of γ-Al 2 O 3 all increased with the increase of polyethylene glycol molecular mass in the experimental research range, and polyethylene glycol 10000 was the most suitable pore forming additive. γ-Al 2 O 3 with surface area of 339 m 2 ·g 1 , pore volume of 0.59 cm 3 ·g 1 and pore diameter of 6.9 nm were obtained at 450 °C.     

蠕虫形管状镧铝复合介孔材料的合成及表征

The lanthanum aluminum mesoporous materials were synthesized using sodium dodecyl sulfate as a template agent by ultrasonic hydrothermal method.The resulting samples were characterized by low angle X-ray diffraction(XRD),N2 adsorption-desorption studies,transmission electron microscopy(TEM)and surface morphology analysis(SEM),surface acid(NH3-TPD),reducibility properties(TPR),X-ray energy dispersive spectrometer(EDS)and thermogravimetric analysis(TG/DTG).A l/La composite mesoporous material were synthesized with n(Al)︰n(La)=70︰1.0,80°C of reaction temperature,20 h of reaction time,12 h of crystallization time,650°C of calcination temperature.The specific surface area of the sample is 273.90 m 2 ·g ?1 ,with the average diameter 5.642 nm and pore volume 0.2354 cm 3 ·g ?1 .The samples have mesoporous structure and its particles are similar to a worm-shaped tubular structure.The influence of calcination temperature on the surface physical and chemical properties of Al/La composited mesoporous materials was examined,and the results showed that the acid strength was increased but the amount of acidic sites is decreased as the calcination temperature increased.It was found that the sample calcined at 650°C had appropriate acid content,acid strength and better reducibility.     

Evolvement behavior of microstructure and H2O adsorption of lignite pyrolysis☆

The effect of pyrolysis on the microstructure and moisture adsorption of lignite was investigated with low field nuclear magnetic resonance spectroscopy. Changes in oxygen-containing groups were analyzed by Fourier transform infrared spectroscopy(FTIR), and H2 O adsorption mechanism on the surface of lignite pyrolysis was inferred. Two major changes in the pore structure of lignite char were observed as temperature increased in 105–200 °C and500–700 °C. Pyrolysis temperature is a significant factor in removing carboxyl and phenolic hydroxyl from lignite.Variation of ether bond content can be divided into three stages; the content initially increased, then decreased,and finally increased. The equilibrium adsorption ratio, content of oxygen-containing groups, and variation of pore volume below 700° were closely correlated with each other. The amount of adsorbed water on char pyrolyzed at700 °C increased. Moreover, the adsorption capacity of the lignite decreased, and the adsorption state changed.     

Hydrothermal treatment of metallic-monolith catalyst support with selfgrowing porous anodic-alumina film

Metallic-monolith catalyst support with self-growing porous anodic alumina(PAA) film was prepared by anodizing Al plate. The effect of hydrothermal treatment(HTT) on the crystalline state and textural properties of PAA film was investigated by XRD, BET, SEM and TG. The HTT treatment above 50 °C and the subsequent calcination above 300 °C could convert the amorphous skeleton alumina into γ-alumina and increase the specific surface area(SBET). However, SEM images showed the HTT modification was a non-uniform process along the thickness of PAA film. The promotion effect of HTT on SBETwas non-linear, and the slope of SBETgradually decreased with the HTT temperature or time increased. The limited HTT effect should be attributed to a changed pore structure caused by an unfavorable pore sealing limitation. Pore widening treatment(PWT) before HTT could break the pore sealing limitation, because of the reduced internal diffusion resistance of hydrothermal reaction. The synergistic combination of PWT and HTT developed a PAA support with a large SBETcomparable to commercial γ-alumina. In the catalytic combustion of toluene, the Pt-based catalyst prepared by using the PWT and HTT comodified PAA support gave higher Pt dispersion and more favorable catalytic activity than that treated by HTT alone. The presence of a bimodal pore structure was suggested to be a decisive reason.     

表面偏析法制备用于乙醇渗透蒸发脱水的整体PVA-PES复合膜(英文)

A facile surface segregation method was utilized to fabricate poly(vinyl alcohol)-polyethersulfone (PVA-PES) composite membranes. PVA and PES were first dissolved in dimethyl sulfoxide (DMSO), then casted on a glass plate and immersed in a coagulation bath. During the phase inversion process in coagulation bath, PVA spontaneously segregated to the polymer solution/coagulation bath interface. The enriched PVA on the surface was further crosslinked by glutaraldehyde. Scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and energy dispersive spectrometer (EDS) confirmed the integral and asymmetric membrane structure with a dense PVA-enriched surface and a porous PES-enriched support, as well as the surface enrichment of PVA. The coverage fraction of the membrane surface by PVA reached up to 86.8% when the PVA content in the membrane recipe was 16.7% (by mass). The water contact angle decreased with the increase of PVA content. The effect of co-agulation bath type on membrane structure was analyzed. The membrane pervaporation performance was evaluated by varying the PVA content, the annealing temperature, feed concentration and operation temperature. The mem-brane exhibited a fairly good ethanol dehydration capacity and long-term operational stability.     

椰油丙基酰胺甜菜碱/聚乙二醇水溶液的分相研究

Phase separation behavior of cocamidopropyl betaine/water/polyethylene glycol (PEG) system was studied. The effects of concentration and molecular weight of PEG on the phase separation behavior were investigated. Clouding occurred when the con-centration of PEG was large enough in the betaine aqueous solution, and the concentration of PEG at cloud point decreased with the increase of PEG molecular weight for a constant betaine concentration. The bottom phase was the PEG-rich phase, and the upper phase was the betaine-rich phase. The volumetric ratio of PEG-rich phase to betaine-rich phase, at the same difference between the PEG concentration and the one at the cloud point, Ccp (0.1 g•ml－1), decreased as the PEG molecular weight increased and approached 1 for higher PEG molecular weight (about 20000), which was similar to the typical aqueous two-phase system. This volumetric ratio depended on the initial PEG concentration, but independent of PEG molecular weight. The concentration ratio of betaine to PEG in both phases depended on the Ccp, independent of PEG molecular weight.     

A novel green inhibitor for C-steel corrosion in 2.0 mol·L~(-1) hydrochloric acid solution

The corrosion inhibition characteristics of aqueous extract of seeds of Melia azedarach L.(MA) have been studied as eco-friendly green inhibitor for corrosion control of C-steel in 2 mol·L~(-1) HCl solution by gravimetric and electrochemical methods. The results depict that, the extract inhibits efficiently the corrosion of carbon steel in hydrochloric acid. The efficiency of extract is increased with increasing the extract concentration but independent on the studied temperature. The adsorption of the extract components onto the steel surface was found to be spontaneous, and follows Langmuir adsorption isotherm. The surface morphology of C-steel, in the absence and presence of MA extract in 2.0 mol·L~(-1) hydrochloric acid solution, was studied using scanning electron microscopy(SEM).     

磁性聚合物微球在Cr(VI)吸附分离中的应用(英文)

The magnetic poly-(methacrylate-divinyl benzene) microspheres with micron size were synthesized by modified suspension polymerization method.Adsorption of Cr(VI) from aqueous solution by magnetic poly-(MA-DVB) microspheres with surface amination was investigated.The adsorption processes were carried out under diversified conditions of pH value,adsorption time and temperature to evaluate the performance of the mag-netic microspheres.The optimum pH value for Cr(VI) adsorption was found as 3.The adsorption capacity increased with adsorption time and attained an optimum at 60 min.The adsorption processes for magnetic microspheres was endothermic reaction,and the adsorption capacity increased with increasing temperature.     

焙烧温度对加氢脱氮催化剂性能的影响

A series of Mo/Ni-based hydrotreating catalysts calcined at different temperatures was prepared by impregnation method,and characterized by means of N₂ adsorption-desorption,NH₃-TPD and TPR techniques.The HDN performance of the catalysts was investigated in a microreactor.The results indicated that with the increase of calcination temperatures,the specific surface area of the catalysts was decreased,the average pore size was gradually increased,and the pore volume change was very small.The acid amount on the surface of the catalysts showed a tendency to ascend firstly, and then to descend with the increase of calcination temperatures, and the acid amount reached the maximum at 500 ℃. The activity of the hydrotreating catalysts was enhanced firstly and then reduced with the increase of calicination temperature,and the optimal calcination temperature was 500 ℃.On the whole,the activity of the catalysts could be improved prepared under suitable calcination temperature,and be suppressed obtained under high calcination temperature.     

微生物-化学耦合法再生活性炭的研究(英文)

In this study,spent activated carbon(AC) saturated with caramel was regenerated by using yeast and NaOH.The efficiency of regeneration was evaluated under parameters such as amount,treatment time,temperature,pH value,stirring temperature of yeast and NaOH concentration.The optimum condition for AC regeneration was 8 h for yeast treatment time,35 ℃ for 0.075% yeast culture temperature,a pH value of 6 for the yeast dealing with the spent AC,90 ℃ for NaOH stirring temperature of AC and 6% NaOH for washing after the spent AC was treated by yeast.Under these conditions,methylene blue(MB) adsorption was 213 mg·g-1 in comparison with 60 mg·g-1 of spent AC.The micro structure and surface area of the regenerated AC were characterized by scanning electron mi-croscope(SEM) and N2 sorption,respectively.The pore size distributions of virgin and regenerated AC were ana-lyzed by means of H-K equation,resulting in a mean pore diameter of 1.28 nm and a pore volume of 1.13 cm3·g-1.This study provides data for theoretical support of the AC regeneration technology.     

A study on formation of regular honeycomb pattern in polysulfone film

Regular polysulfone (PSF) honeycomb film with micron-sized cells was prepared by casting the solution in an atmosphere with high humidity. Water droplets acted as the template around which the PSF in the solution assemble. In this paper, the effects of atmosphere humidity, solution concentration, and the PSF molecular weight on pore size were discussed; the influence of storage time of casting solution on the pattern regularity was presented; the mechanism of pattern formation was proposed.     

静电纺丝纤维滤材表征及其气液过滤性能

以聚丙烯腈与二甲基甲酰胺为原料配制纺丝溶液,采用静电纺丝技术制备玻璃纤维/聚丙烯腈纤维/玻璃纤维三层复合滤材,研究了纺丝溶液浓度与纺丝电压等参数对纤维形貌及尺寸的影响,分析了复合滤材的过滤性能. 结果表明,控制不同纺丝溶液浓度可得形貌不同的纤维,且溶液浓度越大纤维尺寸越大;纺丝电压对纤维形貌的影响较小,但增加纺丝电压使静电纺纤维层的孔径减小. 相比玻璃纤维滤材,复合滤材过滤效率明显提升,稳态效率最大可提升21%,最易穿透粒径效率最大可提升39%,但复合滤材孔径较小时,过程压降增加了一段跳跃阶段,纳米纤维层表面形成液膜,使复合滤材稳态压降升高.     

低截留分子量聚醚砜超滤膜

以聚醚砜(PES)为原料，均苯三甲酸(TMA)为添加剂，采用浸没沉淀相转化法制备聚醚砜超滤基膜，之后将聚乙烯醇(PVA)溶液涂覆在膜表面，经加热交联得到低截留分子量超滤膜。实验结果表明，随着聚乙烯醇浓度升高，截留分子量先减小再增加；随着热处理温度的升高，水通量减少，截留分子量减小。聚乙烯醇质量浓度为0.1%，80℃加热10 min，膜的截留分子量为900，纯水通量为6.10 L/(m²·h)。红外光谱分析证实PVA与TMA反应生成了交联结构。     

The formation of honeycomb structure in polyphenylene oxide films

The ordered honeycomb polyphenylene oxide (PPO) film was prepared by casting the solution on a solid substrate in a high humid environment in this paper. It was found that PPO/CHCl₃ solution could form regular microporous film in a large range of solution concentration (2-70 g/L) and their pore size was almost equal when the concentration varied from 5 to 30 g/L. Based on these phenomena, the mechanism of the formation of PPO honeycomb film was proposed. Moreover, several solvents were chosen to investigate the influence of the compatibility between PPO and solvents, and the volatility of solvents on the pattern regularity. It was found that good compatibility between PPO and solvents, and the appropriate volatility of solvents were important for the fabrication of honeycomb structure. Finally, some other affecting factors, such as the environment temperature and the molecular weight of PPO, were also tested.     

Preparation,characterization and performance studies of polyethersulfone (PES) - pyrolytic carbon (PyC) composite membranes

Polyethersulfone (PES) is one of the most common polymers used to manufacture membranes. This work focuses on introducing and developing a novel polymer-based membrane applicable in the bio-artificial pancreas. The novel membrane based on the mixture of PES and Pyrolytic carbon (PyC) was studied and compared to PES as a reference. The PES/PyC blend membranes were characterized by top surface SEM, cross section SEM, AFM, contact angle pure water flux, insulin rejection, rejection of immune cells and molecules, and insulin diffusivity performance. In addition, the porosity of the membranes, mean pore size and mean pore density were also measured. The AFM and SEM images indicate that addition of synthesized PyC in the casting solution results in a membrane with high surface and sub-layer porosity and the addition 0.1 wt.% PyC to the casting solution reduced the surface roughness from 22.4 nm to 4.8 nm. The contact angle measurements reveal that the hydrophobicity of pure PES membrane enhanced with increasing the PyC concentration in the casting solution. With the increase of PyC from 0.0 wt.% to 0.1 wt.% in the casting solution, pure water flux reduces from 184 to 153 (L/m²h), insulin rejection reduces from 12 to 9.3%, rejection of immune cells and molecules reduce from 91.8 to 83% and insulin diffusivity increased from1.22E-8 to 1.46E-8. Furthermore, the resulting numbers for the mean pore size, mean pore density, and porosity of the PES-PyC(0.1 wt.%) membrane indicate a considerable improvement compared to pure PES membrane with increasing from 5.5 nm to 7 nm, 26 to 43 pores/area (area stand for the size of membrane surface in which pores were counted), and 68.3% to 84.6%, respectively. At the end, the statistical analysis was performed.     

Development of novel surface modified phase inversion membranes having hydrophobic surface-modifying macromolecule (nSMM) for vacuum membrane distillation

Eleven PES membranes, into which newly synthesized surface-modifying macromolecule (nSMM) was incorporated, were prepared by using the ‘phase inversion technique’ with different preparation conditions to find the effects of membrane casting parameters on the characteristics and performances of the surface modified PES membranes. The membranes so prepared were characterized by solute separation data from ultrafiltration experiments. The results showed that the mean pore size as well as the surface hydrophobicity increased with an increase in evaporation time for the casting solution blended with nSMM (without PVP). When PVP was added into the casting solution, the mean pore size as well as the contact angle decreased while the pure water permeation flux increased. The surface hydrophobicity decreased with an increase in gelation bath temperature.Four membranes were further prepared and subjected to vacuum membrane distillation (VMD). They were characterized by different analytical instruments and pure water permeation test before being used to VMD. The results showed that a distinctive surface layer was formed in nSMM blended PES membranes. It was also found that nSMM blended PES membranes were sufficiently hydrophobic and porous to be used for the separation of an ethanol/water mixture.     

Synthesis and characterization of polyethersulfone membranes

Phase inversion method was used to prepare polyethersulfone (PES) ultrafiltration (UF) membranes. Polyethylene glycol (PEG); N, N-dimethyl formamide (DMF) and water were utilized as pore-forming additive, solvent and non-solvent, respectively. Effects of PES and PEG concentrations in the casting solution, PEG molecular weight (MW) and coagulation bath temperature (CBT) on morphology of the prepared membranes were investigated. Taguchi experimental design was applied to run a minimum number of experiments. 18 membranes were synthesized and their permeation and rejection properties to pure water and human serum albumin (HSA) solution were studied. It was found out that increasing PEG concentration, PEG MW and CBT, accelerates diffusional exchange rate of solvent (DMF) and non-solvent (water) and consequently facilitates formation of macrovoids in the membrane structure. The results showed that, increasing PES concentration, however, slows down the demixing process. This prevents instantaneous growth of nucleuses in the membrane structure. Hence, a large number of small nucleuses are created and distributed throughout the polymer film and denser membranes are synthesized. A trade-off between water permeation and HSA rejection was involved, with membranes having higher water permeation exhibited lower HSA rejection, and vice versa. Hence, optimizing preparation variables to achieve high pure water permeation flux along with reasonable HSA rejection was inevitable. Analysis of variance (ANOVA) showed that all parameters have significant effects on the response (water flux and HSA rejection). However, CBT and PES concentration were more influential factors than PEG concentration and MW on the responses.     

Formation of honeycomb‐patterned microporous films based on a fluorinated poly(siloxane imide) segmented copolymer

The preparation of honeycomb‐patterned microporous films from a soluble fluorinated poly(siloxane imide) segmented copolymer (PSI) by means of water‐droplet templating is reported first in this article. The fluorinated PSI was synthesized from 4,4′‐(hexafluoroisopropylidene)diphthalic anhydride, 2,2‐bis[4‐(4‐aminophenoxy)phenyl]hexafluoropropane, and diamine‐terminated poly(dimethyl siloxane) by condensation polymerization. The obtained copolymer had good solubility in chlorinated solvents (chloroform, dichloromethane, and 1,2‐dichloroethane), good thermal stability, and a microphase‐separated amorphous structure. The effects of the copolymer concentration, atmospheric humidity, and solvent properties on the pattern formation were investigated. The results show that the film fabricated from the copolymer solution with chloroform as the solvent at a humidity of 90% and a concentration of 0.5 g/L had the most regular honeycomb‐patterned micropores. We could tailor the pore shape and size by changing the copolymer concentration or the atmospheric humidity. The prepared regular honeycomb‐patterned microporous PSI films have potential applications in cell culture and tissue engineering. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Effect of surface‐modifying macromolecules and membrane morphology on fouling of polyethersulfone ultrafiltration membranes

Polyethersulfone (PES) ultrafiltration (UF) membranes with and without surface‐modifying macromolecules (SMMs) were prepared and characterized in terms of the mean pore size and pore‐size distribution, surface porosity, and pore density. The results demonstrated that both the mean pore size and the molecular weight cutoff (MWCO) of the SMM‐modified membranes are lower than those of the corresponding unmodified ones. Membrane fouling tests with humic acid as the foulant indicated that the permeate flux reduction of the SMM‐modified membranes was much less than that of the unmodified ones. Therefore, fouling was more severe for the unmodified membranes. Moreover, the dry weight of the humic acid deposited on the membrane surface was considerably higher for the unmodified membranes. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 3132–3138, 2003     

Effect of Microstructure of ZnO Nanorod Film on Humidity Sensing

In this study, a simple thick‐film humidity sensor was fabricated by coating wet‐synthesized ZnO nanorods on screen‐printing interdigitated electrodes. We investigated the influence of the coating procedure on the microstructure of ZnO nanorod films and thereby on humidity sensing. The experimental results revealed that the specific surface area (SSA) decreased and the average pore size (APS) increased with increasing the sintering time and the number of coating layer. The humidity response depended significantly on the pore properties of the ZnO nanorod films. By virtue of the incipient wetness analysis, it was found that the adsorption of water molecules on the ZnO surface led to the decrease in electrical resistance even though the ZnO was rod like, n‐type semiconductor. While tuning the pore structure of the ZnO nanorod film, the thick‐film humidity sensor might display near‐linear response in the full range of 0%–100% relative humidity (RH).