新型油田污水除油剂的制备及性能研究

采用共沉淀法合成出Fe_3O_4/氧化石墨烯(GO)纳米复合材料,然后通过静电作用将聚二烯丙基二甲基氯化铵(PDDA)修饰在Fe_3O_4/GO表面,制备出一种新型除油剂PDDA/Fe3O4/GO,并考察了Fe3O4与GO配比、p H、温度、反应时间和除油剂投加量等因素对除油效果的影响。实验结果表明:PDDA/Fe_3O_4/GO不仅除油性能良好,而且除油速度快;在室温20℃、反应时间10 min、投加质量浓度为300 mg/L的条件下,可将油田污水中的油降至50 mg/L以下。该除油剂具有制备方法简单、除油速度快、易于操作、可重复利用等特点,为油田污水处理提供了一种新的研究思路。     

Effects of rosin‐type nucleating agent and low density polyethylene on the crystallization process of polypropylene

In this article, the influence of rosin‐type nucleating agent (Nu–Na) and low density polyethylene (LDPE) on the crystallization process of polypropylene (PP) from the melt state was studied by differential scanning calorimeter and polarization microscope. It was found that LDPE obstructed the crystallization of PP, decreased the crystallization rate of PP. The rosin‐type nucleating agent Nu–Na substantially improved the rate of crystallization, and decreased the size of spherulites also. The cooperative effect of LDPE and Nu–Na made the crystallization rate of PP increase greatly, the spherulites of PP became much smaller and dispersed more uniformly, and the transparency of PP was further improved evidently. The crystallization temperature (T_c) and melting temperature (T_m) of PP and LDPE in PP/LDPE/Nu–Na (97:3:0.5) were not affected by the number of mixed passes—the nuclei migration from PP to PE had not happened in the mixed passes. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 2804–2809, 2003     

分散染料染色物若干色牢度问题分析和改进技术

近年涤纶染色物的变褪色和落色等色牢度问题以及色点、色斑等是分散染料存在的主要问题之一,本文分析了产生这些问题的原因与改进技术.     

NiO直接电化学还原制Ni制片条件对阴极片孔隙率影响研究

本文研究了NiO直接电化学还原制取Ni工艺过程中制片条件对阴极片孔隙率影响。设计正交实验研究了成型过程中粘结剂的浓度和用量、球磨时间和成型压力对阴极片孔隙率的影响。结果表明,其中成型压力影响最大。利用SEM、测定孔隙率等手段研究了成型压力、烧结时间和烧结温度对NiO片的影响。结果表明:三者对孔隙率影响程度由大到小依次为:烧结温度、成型压力、烧结时间;随着烧结温度压力和成型压力的增大,试样孔隙率逐渐减小;而烧结时间对试样孔隙率的影响不大。     

A new type of quaternary ammonium salt containing siloxane group and used as favorable dispersant in the surface treatment of C.I. pigment red 170

C.I. pigment red 170 is an important type of organic pigment. A new type of quaternary ammonium salt containing siloxane group was prepared and then used as a favorable dispersant in the surface treatment of pigment red 170. The quaternary ammonium salt was achieved from the reaction of N-(β-aminoethyl)-γ-aminopropyl-methyl-bimethoxy-silane and 3-chloro-2-hydroxypropyl-bimethyl-hexadecyl ammonium halide in isopropanol, and its structure was characterized by IR and NMR techniques. The flowability, dispersing extent, particle size, and wetting behaviors of pigment were determined and the results showed that a small amount of the above dispersant could bring to the high flowability, good dispersing stability, small particle size and excellent wettability of pigment red 170. We also proposed the scenarios of dispersing process of pigment red 170 based on the information obtained from above characterizations.     

Effects of extrusion process,type and content of clays,and foaming process on the clay exfoliation in HMS PP composites

The use of a high melt strength polypropylene (HMS PP) matrix reinforced with layered clays could be very useful to improve the properties of materials produced with processes involving melt stretching, like foaming. The control of the particles structure, that is, the degree of exfoliation and the clay distribution in the polymeric matrix, is the key to achieve the desired properties. In this study, the effects of the extrusion process, the clay type and content, and the foaming process on the morphology of different HMS PP based composites are studied. Both, natural and organomodified clays were used. The extrusion process has a negative effect in the composites containing natural clays as their interlayer distance decreases as the number of extrusion cycles increases. On the contrary, this process improves the intercalation of the organomodified clays. However, in both composites the interlayer spacing decreases when the clay content increases. While a percolated network is formed in the composites containing organomodified clays, no network is formed with the natural clays. Finally, the effect of the foaming process has also been analyzed. The Improved Compression Moulding (ICM) route was used to produce the foamed materials. This technique subjects the materials only to a temperature and a pressure gradient without applying any other external forces that could contribute to the clay exfoliation. In this way, only the effects of foaming and melt stretching are observed. In both composites, an increase in the interlayer distance is observed when the materials are foamed. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42828.     

Variations in interfacial properties during cell conditioning and influence of heat-treatment of ionomer on the characteristics of direct methanol fuel cells

Variations in interfacial properties in the anode catalyst layer during cell conditioning were characterized, and influence of the heat-treatment of ionomer on the characteristics of direct methanol fuel cells was investigated in this work. The anode catalyst layer was made by mixing a solvent-substituted Nafion solution with unsupported Pt/Ru black and curing the mixture in an oven with an inert environment. Materials characterization (SEM and optical microscopy) and electrochemical characterization (cell polarization, anode polarization, electrochemical impedance spectroscopy, and CO-stripping cyclic voltammetry) were performed. During cell conditioning, the enhanced kinetics of MeOH electrochemical oxidation and severe limiting current phenomenon are due to the combination of variations in interfacial properties and swelling of ionomer in the anode catalyst layer over time. Ru oxides at the catalyst surface are reduced continuously during cell conditioning. The nearly constant integrated areas under the CO-stripping CV peaks and broadened peak shapes indicate a stable number of Pt/Ru bimetallic alloy surface sites, yet the surface composition distribution is broadened. Heat-treatment influences ionomer crystallinity, altering its swelling behavior and hence affecting the characteristics of the direct methanol fuel cell (DMFC) anode.     

Analysis of process parameters on the characteristics of liposomes prepared by ethanol injection with a view to process scale-up: Effect of temperature and batch volume

Liposomes have been extensively used as carriers of several compounds, due to their structural versatility in terms of size, composition, surface charge, lamellarity, and facility to incorporate hydrophilic and hydrophobic substances. Among the methodologies for liposomes production, the ethanol injection technique is probably the most suitable for implementation at industrial scale, mainly due to its simplicity. The effects of the aqueous phase temperature and preparation volume on the characteristics of liposomes produced by this technique were evaluated, seeking to attain criteria for its implementation in large scale. The aqueous phase temperature significantly affects the final characteristics of liposomes obtained by this methodology. By varying this parameter, it is possible to control size distribution and polydispersity of the lipid vesicles. Subsequently, process scale-up was carried out using a 10-fold scale ratio. The adapted power per unit of volume (P/V) scale-up criterion showed to be appropriate to reproduce in larger scale the final characteristics of liposomes produced in smaller scale. The results demonstrate that using the ethanol injection technique, it is possible to obtain a relatively narrow distribution of small unilamellar vesicles, appropriately modulating the experimental conditions. Therefore, the preparation of vesicles with the desired diameter and size distribution was essentially fulfilled.     

Effects of soft-start exposure on the curing characteristics and flexural strength in ceramic projection stereolithography process

Ceramic mask projection stereolithography (CMSL) is an additive manufacturing (AM) technology which is capable of implementing delicate structural designs of ceramic parts. Studies have shown that soft-start exposure mode has an effect on the polymer properties of the cured resin, such as conversion degree, curing speed etc. However, the effect of soft-start exposure on CMSL process has not received much attention. In this investigation, soft-start exposure was compared with constant exposure. The results showed that the soft-start exposure reduced the critical exposure energy (maximum reduction of 48.2%) of the slurry. The feature dimensional error of soft-start exposure was smaller than constant exposure by 25–45%. The soft-start exposure also had an effect on the strength of sintered parts. The bending samples fabricated by soft-start exposure had higher Weibull moduli (maximum increase of 47.2%), indicating that soft-start exposure stabled the curing process.     

黄磷炉渣酸浸过程铁钙分离特性的研究

采用硝酸浸出黄磷炉渣可制取白炭黑产品,浸出过程中杂质成分氧化钙和铁的浸出分离效果明显影响产品质量。研究了浸出过程中浸出条件对铁、钙分离的影响。实验得到最佳浸出条件:反应温度为100℃、液固质量比为14∶1、硝酸质量分数为20%、反应时间为6 h、搅拌速度为350 r/min。在此最佳工艺条件下,氧化钙浸出率为99.94%,铁浸出率为92.71%,固相白炭黑中的铁含量为450 mg/kg;制得的固相白炭黑二氧化硅质量分数达99.20%,比表面积达252 cm2/g,白度为88.51%。     

硅钙摩尔比对准东煤燃烧过程中矿物演变及灰熔融特性的影响

选择准东高钙五彩湾(WCW)煤作为研究对象,通过改变煤灰中硅钙摩尔比(M)研究煤灰熔融特性及矿物演变的变化规律,进一步借助FactSage热力学计算软件进行矿物平衡预测。研究表明:在WCW原煤灰中,矿物CaSO₄演变生成低熔点矿物Ca₂MgSi₂O₇,使得原煤灰借助灰熔融温度(AFTs)预测其结渣、玷污时出现较大偏差。对于混煤灰,当M升高至3时,相比原煤灰,其中矿物CaSO₄的分解提前,SiO₂优先与CaO反应生成熔点较低的矿物CaMgSi₂O₆,进而引起混煤灰的熔点降低;当混煤灰中M升高至5时,充足的SiO₂会与MgO发生反应,生成高熔点矿物Mg₂SiO₄,使得此时混煤灰的AFTs显著提升,改善了煤灰熔融特性。热力学计算矿物平衡结果与X射线衍射分析(XRD)结果吻合较好,吉布斯自由能结果验证了矿物演变过程的合理性。     

复极离子膜电解工艺中氯氢压差控制系统的探讨

介绍了复极离子膜电解工艺中氯氢压差控制系统的基本原理、技术细节,以及回路调试等方面的实际经验。     

利用等离子反应器从SiF_4与CH_4制备HF和SiC的探索研究

研究了一个新型反应,即SiF_4气体与CH_4气体反应生成无水HF气体和SiC固体。该反应在最大能量为20eV的等离子反应器的固定床中进行,反应一段时间后,收集反应器壁上固体,通过分析固体中的碳含量来判断四氟化硅和甲烷的反应情况。结果表明:四氟化硅和甲烷可以发生反应,但是速度十分缓慢。     

分离型热管蒸发段流动特性和传热特性的试验研究

对分离型热管管内蒸发段流动特性和传热特性进行了试验研究 :在保证热管工作效率及安全性的前提下 ,分离型热管蒸发段工质流动形式除单相液流和泡状流 (低热流密度时为弹状流 )外 ,在蒸发段上部约有 42 %～ 50 %的不稳定飞溅降膜区 ;合理充液率随热流密度的增加而减少 ;随着热流密度的增加 ,核态沸腾区及飞溅降膜区的换热系数均增加 ,蒸发段总换热系数也增加。     

Influence of Ag mid-layer in the optical and thermal properties of ZnO/Ag/ZnO thin films on the glass used in Buildings as insulating glass unit (IGU)

The low-emissivity (low-E) coatings are multiple ultra thin layers on glass used for producing spectrally selective glazing. The use of low-E glazing in building windows makes it possible limit the radiative heat transfer without reducing the visible transmittance perceptibly and accordingly alter the necessary natural lighting in low energy buildings. In this study, we investigate ZnO/Ag/ZnO thin films deposited on glass substrate via RF and DC sputtering by ZnO and Ag targets respectively, in various deposition time of Ag layer. We tried to diminish the NIR transmittance by using a feasible and affordable method with a low number of ultra thin layers and by reducing the cost of the vacuum.Presented results are related to electrical, optical and thermal properties for tri-layers based on sandwiched Ag by ZnO in deposition time of 10–45?s at room temperature.     

An L9 orthogonal design methodology to study the impact of operating parameters on particulate emission and related characteristics during pulse-jet filtration process

This study embodies experimental characterization of emitted particulate and filtration performance under varied situation in a pulse-jet cleaning process. Tests were conducted under simulated condition in a filtration apparatus consisting four bags. The effect of four different factors such as fabric punch density, baffle plate height, air to cloth ratio and cycle time have been investigated on the key parameters; emission, pressure drop along with PM_2.5 and average particle diameter of emitted particulate matter in a pulse-jet filtration process. Experimental investigation based on L₉-orthogonal design shows that emission is reduced with the increases in punch density and pulse cycle time; but it increases up to a certain extent with the increase in air to cloth ratio. However baffle plate height has no effect on the emission. On the other hand pressure drop across the tube sheet increases with the material consolidation, air to cloth ratio and pulse cycle time; but the above parameter first decrease with the increase in baffle plate height. PM_2.5 (based on the number distribution) is found to be mainly affected by the baffle plate height and cycle time; as it first increases and then decrease with the increase in baffle plate height but it shows reverse trend with the increase in cycle time. Average particle diameter based on number volume is found to be mainly affected by the baffle plate height and cycle time. With the increase in time of filtration, both emission and pressure drop tend to increase without affecting PM_2.5 and average particle diameter based on number volume.     

绿色化学工程与工艺对化学工业节能的促进性分析

近几年我国经济水平不断发展,科学技术得以广泛应用,随之而来的是由于化学发展而引起的环境污染问题。通过分析化学研究过程中发生的化学反应以及现象都是未知性的,所以在化学反应中可能会对人类以及环境产生有害的物质,要想有效减少危害物质的发生,必须要发展绿色化学工程以及相关工艺,这也是当前化学研究工作者急需解决的重点问题。所以必须要构建绿色化学,能够从源头上控制化学反应中的原料,使用应用无害反应物以及溶剂、催化剂等,能够有效减少对不可再生资源的使用量,通过提出绿色化学工程概念,一定程度上的缓解了化工材料对于生态环境的污染,切实提高了化学工业的能源利用效率。分析了探究绿色工艺以及绿色化学的主要操作工艺,并提出绿色化学工程与工艺对节能降耗产生的积极作用。     

New insight in the solid state characteristics, in the possible intermediates and on the reactivity of Pd–Cu and Pd–Sn catalysts, used in denitratation of drinking water

Bimetallic palladium-based supported catalysts were tested in the liquid phase hydrogenation of nitrates. They were characterised by XPS, CO chemisorption, TPD–TPR and DRIFT. The effect of the preparation method, the support, the precursors, the relative amount of active metals and their role in the formation of intermediates and products are tentatively discussed. The catalytic activity and the formation of intermediate nitrite depend on the Pd–Cu ratio. Catalysts presenting a Pd/Cu atomic ratio >1 display the highest activity and the lowest intermediate nitrite than those presenting a Pd/Cu atomic ratio <1. Sol–gel method gives catalysts with a high activity and a low nitrite formation. The Pd–Cu-based catalyst supported on zirconia is more active and selective in N₂ compared to the corresponding Pd–Sn catalyst. An enrichment of the surface by Pd is responsible for a low intermediate nitrite formation and high selectivity in N₂. The reduction of NO is activated on Pd–Cu catalysts, contrary to Pd–Sn catalysts. Sn promotes the formation of ammonia.     

Preparation of functionalized and non-functionalized fullerene thin films on ITO glasses and the application to a counter electrode in a dye-sensitized solar cell

Several thin films of [60]fullerene and the derivatives (3-5) have been prepared on ITO glasses by a common coating method using organic solutions and/or by an electrolytic micelle disruption method using surfactants with ferrocenyl moiety 2. In particular, the surface of the film formed by the electrolysis method was confirmed by SEM and AFM measurements, and then these images clearly exhibited that the entire surface of the ITO glass was uniformly covered with [60]fullerene. The UV-vis spectroscopy obviously showed that the thickness increased with the electrolysis time. For example, the thickness of the film formed by the electrolysis for 2 h was ca. 2,000 Å. Furthermore, we investigated the potential utilization as a counter electrode material instead of Pt in a dye-sensitized solar cell (DSC). Consequently, these films, except for that of derivative 5 prepared by the coating process, were found to act as a counter electrode materials in a DSC. These photovoltaic efficiencies of the films prepared by the electric micelle disruption method were higher than those of the films prepared by the common coating method. In addition, the highest efficiency was obtained in the cases with the fullerene thin film formed by the electrolysis for 2 h.     

An investigation on the progressive change in filament characteristics from outer to inner layers of mulberry and tasar cocoons

The physical properties and residual sericin content of the silk filament were evaluated in relation to its position in different layers of the cocoons corresponding to Daba (Antheraea mylitta), oak tasar (Antheraea proylei), and bivoltine mulberry (Bombyx mori) varieties. A decrease in filament linear density from the outer to the innermost layers was observed in all the varieties. Although the filament tenacity was found to increase in bivoltine mulberry cocoons from the outer to the inner layers, no such specific trend was observed for Daba cocoons. For oak tasar cocoons, it showed a marginal rise. A similar trend was observed for filament initial modulus also. The breaking extension of filament was constant for Daba cocoons, decreased for oak tasar cocoons and showed a rise followed by a fall for bivoltine mulberry cocoons from the first to the last layers. The residual sericin decreased marginally from the outer to the inner layer in the case of tasar cocoons. However, for mulberry cocoons it decreased rapidly initially up to the fourth layer and thereafter showed no change. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010