De-emulsification of 2-ethyl-1-hexanol/water emulsion using oil-wet narrow channel combined with low-speed rotation

Low-speed rotation of disc in an internal circulation of a novel de-emulsification with rotation-dise horizental contactor (RHC-D) realized de-emulsification for O/W emulsions due to repeated coalescence in oil-wet narrow channels at a low rotation speed. For three emulsions included ethanol/water/2-ethyl-1-hexanol, ethanol/water/2-ethyl-1-hexanol/SDS (Sodium Dodecyl Sulfonate) and 2-ethyl-1-hexanol/water/SDS emulsion, deemulsification ratios of oil phase could reach 1, 1 and 0.67 respectively at 170 r·min^-1, and de-emulsification ratios increased obviously after agitating 10 min. De-emulsification experiment in the seam indicated that oil droplet sizes in O/W emulsion became larger after de-emulsification. The main de-emulsification mechanism in RHCD was the coalescence of oil droplets in oil-wet narrow channels. With increase of the rotation speed, oil droplets dispersed better in the aqueous phase. However, de-emulsification effect enhanced due to the increase of the coalescence rate at a bit higher rotation speed. In addition, internal circulation made those O/W emulsions to be broken repeatedly, consequently de-emulsification ratio increased. Repeated de-emulsification through internal circulation might make continuous extraction of ethanol come true at a low rotation speed.     

柴油生物脱硫乳状液的破乳

柴油生物脱硫(BDS)反应后往往会产生稳定的O/W型三相（柴油/发酵液/菌体）乳状液,为了满足工业应用的需要,就必须将三相乳状液进行破乳,从而获得BDS反应后的柴油.分析了几种破乳剂对BDS后三相乳状液的破乳效果及破乳机理,发现几种典型的水溶性破乳剂、醇类甚至用于BDS的红球菌自身都具有良好的破乳活性,其中具有强表面活性、强亲水性和合适的密度的乙醇与离心操作相结合的方法最适宜该乳状液的破乳,破乳后离心分离的菌体与原菌具有相近的脱硫活性,可用于再次脱硫. 同时探索了乙醇作为破乳剂的最佳条件,向三相乳状液中加入4％的工业乙醇,并借助4000 r•min^-1离心力的作用可使破乳率达到97.8％.GC-MS实验证实乙醇破乳不影响油品的热值.     

Ionic liquid as surfactant in microwave‐assisted emulsion polymerization

The aim of this work is to study the use of an ionic liquid (IL) as surfactant in emulsion polymerization reactions and to evaluate its effect when these reactions are heated under microwave irradiation. The IL 1‐n‐dodecyl‐3‐methylimidazolium chloride was chosen to replace the surfactant dodecyltrimethylammonium bromide (DTAB) in methyl methacrylate emulsion polymerizations. The conversion evolutions and the final average diameter of polymeric particles were quite similar for reactions using the surfactant DTAB or the IL, showing that the IL acted efficiently as surfactant in emulsion polymerizations. Comparing the polymerization reactions performed under microwave irradiation and conventional heating, reaction rate enhancements were obtained for both DTAB and IL. Using a pulsed scheme, under high‐power microwave irradiation, slightly higher reaction rates and molecular weights were obtained in reactions using IL, in comparison with surfactant DTAB, indicating the existence of some specific effects linked to IL–microwaves interaction. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Microwave enhanced synthesis of chitosan-graft-polyacrylamide

Chitosan-graft-polyacrylamide (Ch-g-PAM) was synthesized without any radical initiator or catalyst using microwave (MW) irradiation. Under optimal grafting conditions, 169% grafting was observed at 80% MW power in 1.16 min. Conventionally under similar conditions a maximum grafting of 82% could be achieved in 1 h using K₂S₂O₈/ascorbic acid as redox initiator coupled with Ag⁺ ions as catalyst and atmospheric oxygen as co-catalyst on a thermostatic water bath at 35±0.2 °C. The representative microwave synthesized graft copolymer was characterized by Fourier transform-infrared spectroscopy, thermo gravimetric analysis and X-ray diffraction measurement, taking chitosan as a reference. The effects of reaction variables as monomer/chitosan concentration, MW power and exposure time on the graft co-polymerization were studied. A probable free radical mechanism for grafting under microwaves has been proposed. The solubility pH for the grafted samples with different extent of grafting was monitored. The adsorption capacity of chitosan was much enhanced after grafting. The microwave synthesized Ch-g-PAM in comparison to that prepared conventionally was found to have much more adsorption ability for Ca²⁺ and Zn²⁺ ions in aqueous solution.     

Emulsifier‐free miniemulsion polymerization of styrene using a cationic initiator

Polystyrene latex particles were synthesized using a method based on emulsifier‐free miniemulsion polymerization under ultrasonic irradiation in the presence of 2,2′ azobis (2‐amidinopropane) dihydrochloride (V‐50) as a cationic ionizable water‐soluble initiator and cetyl alcohol as costabilizer. The optimized conditions were obtained by using various parameters, such as the amounts of monomer and initiator, and the time and power of ultrasonic irradiation. In optimal conditions, the latex particles appeared to be about 250 nm in diameter through scanning electron microscopy (SEM). The SEM and gel permeation chromatography (GPC) analyses and monomer conversions of emulsifier‐free miniemulsion polymerization were compared with those of conventional emulsifier‐free emulsion polymerization using V‐50 as initiator in both cases. The results showed that in the miniemulsion polymerization, the rate of polymerization (Rp) was significantly higher, and latex particles were significantly smaller than those in the conventional emulsion polymerization. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007     

Microwave-assisted rapid fabrication of robust polyetherimide bead foam parts

Polyetherimide (PEI) is an important candidate for fabrication of high-performance polymer foams. Nevertheless, the manufacture of PEI foamed parts with specific three-dimensional geometry shape and lightweight properties remains a big challenge worldwide. Herein, a microwave (MW)-assisted foaming and selective sintering approach was proposed towards rapid fabrication of robust PEI bead foams. During the process, compressed carbon dioxide/tetrahydrofuran was used as physical co-foaming agent, and the surface-coated graphene nanoplatelets (GNPs) was used as MW absorbent. Upon MW irradiation, the GNPs selectively heated and served as solders that effectively facilitated the foaming of expandable PEI (EPEI) beads, and strongly promoted the local polymer melt and entanglement across the surface of EPEI beads. The MW irradiation power and time were considered as the important parameters to achieve fine inter-bead bonding strength between foamed beads. As a model system, we successfully fabricated a 25-mm-thickness foamed part with an apparent density of 0.32 g/cm³ and achieved excellent inter-bead bonding performance. Specifically, we also utilized the COMSOL Multiphysics simulations to study the MW selective heating mechanism. This MW-assisted fabrication strategy offers a new foaming approach toward high-performance polymer foamed parts for many advanced applications.     

Microwave effect in removal process of NO by electron beam irradiation and quantitative prediction of the removed NO

A flow process with electron beam (EB) irradiation carried out the removal of NO in air by adding microwave (MW) to improve the removal efficiency of NO. The EB irradiation combined with MW irradiation was very effective in the range of NO removal efficiency of 70–80% and reduced required doses up to more than 30%, compared to the flow process without MW. On the other hand, MW irradiation was unlikely to affect the NO removal above 90% of removal efficiency. In addition, MW effect appeared definitely in the dose ranges of 8–24 kGy, whereas the effect became minor below 8 kGy and above 24 kGy. This study found that MW irradiation can play an auxiliary role in NO removal with EB irradiation and the effect of MW on the NO removal is based on an intrinsic kinetic to the exclusion of a thermal effect. The concentrations of removed NO could be linearly correlated as ΔC=k[NO] _o +k _o . Where, k was proportional to dose and ko could be related to k _o /D ⁿ =aD+b, giving n value of 0.7 without MW irradiation and 0.4 with MW irradiation, respectively.     

Comparison of Oil‐in‐Water Emulsion between Ultrasonic Irradiation and Mechanical Stirring

To compare oil‐in‐water emulsification behaviors between ultrasonic irradiation and impeller stirring, experiments and calculation by mathematical models were performed. For ultrasonic irradiation, the peak diameter of dispersed oil droplets decreased with an increase in input power and reductions in ultrasonic frequency, ratio of dispersed volume, and interfacial tension. For mechanical stirring, it declined with higher mechanical rotation speed. The results calculated by the mathematical models approximately agreed with the experiments. Ultrasonic irradiation was better than mechanical stirring by an impeller for producing a fine emulsion at higher supplied energy rate into liquid, whereas the tendency was inverse for a rough emulsion at lower input energy rate.     

微波辅助离子液体中铜掺杂TiO2光催化剂的制备及微波强化光催化活性

在[Bmim] PF6离子液体中,用微波辐射干燥的方法制备了铜掺杂纳米二氧化钛光催化剂TiO2-Cu,测试催化剂对甲基橙溶液的微波（MW）、紫外（UV）、微波-紫外（MW-UV）条件下的降解率,考察了离子液体用量、铜掺杂量、微波干燥功率、微波干燥时间、煅烧温度、煅烧时间、微波降解功率等因素对TiO2-Cu催化剂活性的影响.结果表明,掺杂物质硝酸铜与钛酸丁酯的物质的量比为n（Cu）/n（Ti）=0.025,在功率为210 W的微波条件下干燥20 min,再在高温箱式电阻炉中于500℃下煅烧2h,所制得的TiO2-Cu催化剂具有较高的光催化活性;在MW、UV和MW-UV 3种降解条件下,对甲基橙的降解率分别为3.78％,92.98％,98.39％;并且在3种降解条件下,甲基橙降解率始终是：MW-UV＞ UV＞ MW.表明在紫外光照条件下,微波辅射具有强化TiO2-Cu催化剂降解甲基橙的作用.催化剂结构分析表明,TiO2中掺入铜后制得的催化剂,具有粒径均匀,比表面积、孔容、平均孔径和半孔宽均较大等特点,这也是TiO2-Cu催化剂具有较高的光催化活性的主要原因.     

Grafting of polyacrylonitrile onto guar gum under microwave irradiation

Using microwave (MW) irradiation grafting of polyacrylonitrile (PAN) onto guar gum in water was done without using any radical initiator or catalyst within a very short reaction time. The extent of grafting could be adjusted by controlling the reaction conditions and maximum percentage grafting (%G) of about 188% was obtained under optimum conditions in 1.66 min. The average molecular weight of the grafted PAN chains and water‐retention power of the alkali hydrolyzed MW‐grafted gums were also determined and compared with those of the conventionally synthesized (cs) graft copolymer. A representative MW‐grafted copolymer, guar‐g‐polyacrylonitrile was characterized by IR, NMR, XRD, TGA, and elemental analysis. A plausible mechanism for the grafting under MW was proposed. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 1569–1575, 2004     

微波技术及其在乳液聚合中的应用

摘 要 报导了微波技术自90年代中后期以来在乳液聚合中的应用情况，微波技术应用于乳液聚合的理论基础在于其热效应，微波辐照的电磁场使得极性分子发生单向极化和转向运动，使材料内部产生热效应而实现乳液聚合反应。本文同时介绍了微波乳液聚合所用的设备。     

生物优势菌破乳剂的制备及性能研究

本文将优势菌技术应用于生物破乳剂的制备研究。从菌种采集开始,经增殖及定向培养,得到了可用于O/W型乳状液破乳的优势菌群,并对其破乳性能及影响破乳性能的主要因素进行了研究。试验结果表明,在破乳时间48h,生物优势菌破乳剂的破乳效率可达约90%。破乳菌浓度、pH值、破乳时间、菌龄等对破乳性能产生影响,而灭菌处理对破乳性能无明显影响。     

Simultaneous pentachlorophenol decomposition and granular activated carbon regeneration assisted by microwave irradiation

This paper describes an integrated granular activated carbon (GAC) adsorption/microwave (MW) irradiation process used for the treatment of high concentration pentachlorophenol (PCP) wastewater. Firstly, PCP in water was adsorbed onto GAC, then the PCP was decomposed and GAC regenerated by MW irradiation. The liquid and gas produced during irradiation were collected through condensing, and absorbed by a 0.1 mol l⁻¹ NaOH solution, respectively. The determination of the PCP concentrations in the distillate, absorption solution and GAC was accomplished by a HPLC. The results suggested that when irradiated with 850 W MW for 10 min, most of the PCP adsorbed by GAC and whatever fragments formed were decomposed to CO₂, H₂O and HCl or tightly bound to GAC, and less than 2% of PCP was transformed into intermediates in the distillate. Some dechlorination and dehydroxylation products were identified by the GC/MS analysis, and the degradation mechanism was proposed. It was also confirmed that GAC could be reused after several adsorption/MW regeneration cycles and its adsorption capacity could maintain a relatively high level, even higher than that of virgin GAC, as indicated by BET results, iodine values and PCP adsorption isotherms.     

微波助离子液体中锌掺杂纳米TiO2的制备及微波强化光催化氧化活性

在1-丁基-3-甲基咪唑六氟磷酸盐（［Bmim］PF₆）离子液体介质中,采用溶胶-凝胶法和微波干燥法制备Zn掺杂的纳米TiO₂光催化剂TiO₂-Zn。室温条件下,以甲基橙为模拟污染物,在微波超声波组合催化合成仪中,分别利用微波辐射（MW）、紫外光照（UV）和微波辐射联合紫外光照（MW-UV）降解方式,考察离子液体用量、Zn掺杂量、微波干燥功率、微波干燥时间、焙烧温度和焙烧时间等因素对TiO₂-Zn光催化活性的影响。结果表明,在离子液体用量为5.6 mL、n(Zn)∶n(Ti)=0.012 5∶1、微波干燥功率210 W、微波干燥时间17.5 min、焙烧温度600 ℃和焙烧时间2 h条件下,制得的TiO_2-Zn光催化剂具有较高的光催化活性。TiO₂-Zn光催化剂在3种降解方式中对甲基橙的降解效果为：MW-UV＞UV＞MW,表明微波辐射-紫外光照具有较好的协同作用效果。     

微波照射下的卤化银感光材料

研究了微波照射对卤化银感光材料照相性能的影响。微波照射下不会导致卤化银乳剂自发光解。通过量子化学计算可知 :卤化银乳剂的照相性能和整个卤化银晶体中静电势的分布有关 ;微波照射可以改变卤化银晶体中的静电势分布 ,从而使卤化银感光材料的照相性能发生变化。微波照射对于硫增感卤化银乳剂照相性能的影响大于对未经硫增感的卤化银乳剂。微波照射对于卤化银乳剂照相性能的影响有一定的“弛豫时间”。     

Thermally reversible highly cross‐linked polymeric materials based on furan/maleimide Diels‐Alder adducts

A novel thermally reversible cross‐linked polymer has been synthesized by a Diels‐Alder (DA) reaction between bis(4‐maleimido‐phenyl)fluorene (cBMI) and tetrakis‐furan monomers (4F) under microwave (MW) irradiation. The ultimate aim of this work was the preparation of a thermosetting material recyclable by a simple thermal treatment. The use of the MW irradiation was necessary because under thermal conditions the DA polymerization could lead to materials only partially cross‐linked for a not desired equilibrium between DA and retro‐DA processes induced by the high temperature. The easy thermal degradation of this cross‐linked material was ascertained by appropriate experiments. Moreover, to better study the involved reactions of formation and decomposition, a more simple model‐compound was also synthesized. The reported data confirm the recyclability of the synthesized cross‐linked polymer by simply heating with the possibility of a regeneration of the polymer network by a further MW irradiation. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42314.     

Auslegungskriterien für elektrostatische Emulsionsspaltanlagen

Design criteria for electrostatic de-emulsifiers. Electrostatic de-emulsifiers have been successfully used over many years for desalting of crude oil. The emulsions used for this application are rather unstable and break down easily. Different equipment and conditions are required for highly stable emulsions, such as are used for liquid membrane permeation. To permit use of higher field strengths without danger of short circuiting this new equipment must be fitted with insulated electrodes, with preference being given to glass-insulated liquid electrodes. An important feature is also a defined distance between the electrodes which are arranged in concentric manner to increase the de-emulsification rate. The rate of de-emulsification can also be increased by using high frequency (10 kHz) instead of the usual low frequency (50 Hz) alternating voltage.     

微波诱导活性炭催化降解水中灭多威的方法研究

建立了一种快速有效地降解水体中杀虫剂灭多威的方法。采用微波诱导活性炭(MW/AC)催化技术对水体中灭多威的降解进行了研究。考察了微波照射时间、溶液初始浓度、催化剂用量和溶液酸度对灭多威降解的影响。对总体积25 mL、质量浓度50 mg/L的灭多威溶液,加入活性炭1.6g/L时,使用功率750 W、频率2 450 MHz的微波照射3.0 min,则灭多威降解率达84.11%。适当提高活性炭加入量至2.4 g/L,降解率即可达100%。MW/AC降解灭多威这一方法具有降解效率高、降解速度快、成本低、没有中间产物生成和无二次污染等优点,适合于灭多威废水的处理。     

微波强化薯蓣皂甙水解的研究

报道了微波强化薯蓣皂甙水解的研究。实验表明微波可以明显促进薯蓣皂甙的水解。与水浴加热方法相比,微波水解可减少HCl用量50%,缩短水解时间92%,提高得率20%。采用正交实验对微波辐照时间、微波功率、[H+]浓度3个影响微波催化薯蓣皂甙水解的因素进行了研究,探讨了微波催化水解的机理。实验结果表明,微波强化薯蓣皂甙水解的最优实验条件为:微波功率700W,C[H+]=2 mol/L,水解时间20 min。     

TiO2纳米颗粒在陶瓷乳浊釉中应用研究

通过试验对比,系统制备了纳米级TiO2(锐钛矿相)和工业TiO2生料釉试样;研究了纳米级TiO2(锐钛矿相)配制的钛生料乳浊釉和用工业TiO2配制的钛生料乳浊釉的配方和一系列工艺参数;考察了试样的晶相、形貌以及乳浊效果,比较了产物的性能,分析了纳米钛釉的乳浊机理。实验表明,利用纳米锐钛矿相TiO2制备生料乳浊釉,避免生成金红石相,能促进CTS晶体大量析出,提高了乳浊度,改善了釉面性能,提高了产品档次。该釉具有烧成温度范围宽的特点。釉面白度可达86%,比普通工业TiO2的高。适宜在高档产品中使用;在较低温度下获得较佳的乳浊性能,可降低釉烧温度,节约能源;遮盖力强,可以利用劣质坯用原料,节约资源。