Exfoliation of poly(ethylene glycol)-intercalated graphite oxide composite in water without sonication

A novel method for exfoliating graphite oxide(GrO)was implemented through the mass water absorption of a GrO–poly(ethylene glycol)(GrO–PEG)composite.The GrO–PEG composite was prepared by intercalating PEG into the lamellae of GrO,and the variation of the basal spacing was measured by X-ray diffraction analysis.The yield of graphene was measured with an ultraviolet–visible spectrophotometer,and the properties of graphene oxide(GO)were characterized by atomic force microscopy,transmission electron microscopy(TEM),Raman spectrometry,and Fourier transform infrared spectroscopy.Increasing intercalation time was found to improve the yield of GO,whereas increasing the PEG molecular weight had the opposite effect.The GO sheets produced from the intercalation–absorption–exfoliation process were found to be a four-layer structure.TEM and Raman analyses indicate that the graphitized structure and oxygen groups of GO were preserved during the exfoliation process.Most importantly,the results show that good-quality GO could be prepared via a mild method involving water absorption of a GrO–PEG composite.

Effect of poly(ethylene glycol) molecular weight on CO_2/N_2 separation performance of poly(amide-12-b-ethylene oxide)/poly(ethylene glycol) blend membranes

Membranes from block copolymer poly(amide-12-b-ethylene oxide)(Pebax1074) and its blends with different molecular weight poly(ethylene glycol)(PEG)(200, 400, 600, 1500, 4600 and 8000) were prepared. The thermal properties and structures of Pebax1074/PEG blend membranes were characterized by DSC and SEM, and the gas permeation properties of CO_2 and N_2 were also investigated at different temperatures. For Pebax1074/PEG blend membranes with low molecular weight PEG(MW≤ 600), higher gas permeabilities than Pebax1074 were achieved. The permeability increased with the increase of PEG molecular weight. The addition of low molecular weight PEG resulted in decrease in activation energy of permeation. For Pebax1074/PEG blend membranes with high molecular weight PEG(MW≥ 1500), due to the melt of PEO phase crystals, the gas permeation properties of blend membranes were temperaturedependent, which could be divided into crystalline region, transition region and amorphous region according to two different transition temperatures. PEG molecular weight and operation temperature determined different gas permeation properties of Pebax1074/PEG blend membranes in three regions. The activation energies of permeation in crystalline region were larger than those in amorphous region.

The Synthesis of Poly(ethylene oxide)-Block-Polybutylacrylate

Poly(ethylene oxide) containing azogroups(pre PEO) was prepared by reacting azoisobutyronitrile (AIBN) with poly( ethylene glycol ) (PEG). The molecular weight of pre PEO was depended on the reaction time, the ratio of PEG to AIBN and the molecular weight of PEG. Pre PEO decomposed in the presence of butylacrylate (BA) monomer to form poly ethylene oxide block butylacrylate copolymers(PEO b PBA). The molecular weights of PEO b PBA and the homopolymer of PBA were proportional to the ratio of BA to pre PEO. The purified block copolymers were charactherized using IR, 1H NMR and GPC.

Poly Ethylene Glycols (PEG) and Micelles as Efficient Catalysts for the Oxidation of Xanthine Derivatives under Conventional and Non-Conventional Conditions

Oxidation of Xanthine alkaloid have been studied with various one and two electron oxidizing agents using PEGs and micelle forming surfactants. The reaction is too sluggish in solution phase, but moderately fast in presence of PEGs and micelles. However, the reactions are dramatically enhanced under microwave irradiations. Present protocol has several advantages, such as solvent-free conditions, during work-up, fast reaction times, high yields, eco-friendly operational and experimental simplicity, readily available additives as catalysts.

Co-electrolysis of ethylene glycol and carbon dioxide for formate synthesis

Co-electrolysis of waste plastics and carbon dioxide(CO_(2)) into value-added chemicals or fuels is a promising pathway for a sustainable society, but efficient and selective conversion remains a challenge. Herein, a gold-mediated nickel hydroxide(Au/Ni(OH)_(2)) is developed to oxidize waste plastic-derived ethylene glycol(EG) into formate. In-situ electrochemical experiments and theoretical results reveal that the introduction of Au favors the redox properties and EG adsorption behavior of Ni(OH)_(2). The Au/Ni(OH)_(2) catalyst shows an excellent formate selectivity of >90% at high current densities of above 100 m A cm^(-2). When coupled with sputtered bismuth(Bi) cathode for CO_(2) reduction, a high formate Faradic efficiency(FE) of 188.2% at 200 m A cm^(-2)and a good formate productivity of 7.33 mmol m^(-2)s^(-1)at 10 A are obtained in a flow cell and a zero-gap membrane electrode assembly(MEA) cell, respectively. This work demonstrates a promising strategy to convert waste plastics and CO_(2) into valuable products.

One-Stage Technology for Production of Concentrated Ethylene Glycol-Water Solutions （Automotive Antifreeze）

The reactor unit for one-stage technology for production of concentrated ethylene glycol-water solutions is described.Such solutions could be useful for production of automotive antifreezes. The technology is based on the highly selective hydration ofethylene oxide in the presence of heterogeneous catalyst-anion-exchange resin in HCO3-/CO/3/2-_form. The mathematical model of reactor allowed evaluating of economical benefit in comparison with conventional method.

Nanostructure and Formation Mechanism of Pt-WO_3/C Nanocatalyst by Ethylene Glycol Method

Pt-WO3 nanoparticles uniformly dispersed on Vulcan XC-72R carbon black were prepared by an ethylene glycol method.The morphology,composition,nanostructure,electrochemical characteristics and electrocatalytic activity were characterized,and the formation mechanism was investigated.The average particle size was 2.3 nm,the same as that of Pt/C catalyst.The W/Pt atomic ratio was 1/20,much lower than the design of 1/3.The deposition of WO3·xH2O nanoparticles on Vulcan XC-72R carbon black was found to be very difficult by TEM.From XPS and XRD,the Pt nanoparticles were formed in the colloidal solution of Na2WO4,the EG insoluble Na2WO4 resulted in the decreased relative crystallinity and increased crystalline lattice constant compared with those of Pt/C catalyst and,subsequently,the higher specific electrocatalytic activity as determined by CV.The Pt-mass and Pt-electrochemically-active-specific-surface-area based anodic peak current densities for ethanol oxidation were 422.2 mA·mg-1Pt and 0.43 mA·cm-2Pt,1.2 and 1.1 times higher than those of Pt/C catalyst,respectively.

Novel P-doping-tuned Pd nanoflowers/S,N-GQDs photo-electrocatalyst for high-efficient ethylene glycol oxidation

Traditional photo-electcatalyst structures of small noble metal nanoparticles assembling into large-scale photoactive semiconductors still suffer from agglomeration of noble metal nanoparticles,insufficient charge transfer,undesirable photoresponse ability that restricted the photo-electrocatalytic performance.To this end,a novel design strategy is proposed in this work,namely integrating small-scale photoactive materials(doped graphene quantum dots,S,N-GQDs)with large-sized noble metal(Pd P)nanoflowers to form novel photo-electrocatalysts for high-efficient alcohol oxidation reaction.As expected,superior electrocatalytic performance of Pd P/S,N-GQDs for ethylene glycol oxidation is acquired,thanks to the nanoflower structure with larger specific surface area and abundant active sites.Furthermore,nonmetal P are demonstrated,especially optimizing the adsorption strength,enhancing the interfacial contact,reducing metal agglomeration,ensuring uniform and efficient doping of S,N-GQDs,and ultimately significantly boost the catalytic activity of photo-electrocatalysts.

Fabrication of 3D hollow acorn-shell-like PtBi intermetallics via a surfactant-free pathway for efficient ethylene glycol electrooxidation

The synthesis of atomically ordered Pt-based intermetallic electrocatalysts for the direct alcohol fuel cells generally requires the addition of surfactants or the high-temperature annealing.However,some residual surfactants on the surface of the assynthesized catalysts would prevent the exposure of catalytic active sites,the high-temperature annealing process is easy to accelerate the sintering of the metal,which both lead to the decline of electrocatalytic performance.Herein,we construct the atomically ordered bimetallic PtBi intermetallics with clean surfaces and unique three-dimensional hollow acorn-shell-like structure(3D PtBi HASL)by a simple,low-temperature,surfactant-free one-pot synthetic approach.Benefiting from the special hollow structures,the obtained 3D PtBi HASL intermetallics expose abundant accessible active sites.Moreover,the introduction of oxophilic metal Bi can enhance adsorption of OHads,thereby significantly facilitating removal of poisoned intermediates.Density functional theory(DFT)simulations further indicate that formation of the PtBi intermetallic phase with the downshift of the Pt d-band center endows 3D Pt49.4Bi50.6 HASL intermetallics with significantly attenuated COads and enhanced OHads adsorption,bringing about the boosting electrocatalytic property.The mass activity of the 3D Pt49.4Bi50.6 HASL intermetallics for ethylene glycol oxidation reaction is as high as 24.67 A·mgPt^(−1),which is 12.98 times higher than that of commercial Pt/C(1.90 A·mgPt^(−1)).This work may inspire the design of Pt-based intermetallics as high-efficiency anode electrocatalysts for fuel cell applications.

Controlled synthesis of MOF-derived hollow and yolk–shell nanocages for improved water oxidation and selective ethylene glycol reformation

Delicately designed metal–organic framework(MOF)-derived nanostructured electrocatalysts are essential for improving the reaction kinetics of the oxygen evolution reaction and tuning the selectivity of small organic molecule oxidation reactions.Herein,novel oxalate-modified hollow CoFe-based layered double hydroxide nanocages(h-CoFe-LDH NCs)and yolk–shell ZIF@CoFe-LDH nanocages(ys-ZIF@CoFe-LDH NCs)are developed through an etching–doping reconstruction strategy from a Co-based MOF precursor(ZIF-67).The distinctive nanostructures,along with the incorporation of the secondary metal element and intercalated oxalate groups,enable h-CoFe-LDH NCs and ys-ZIF@CoFe-LDH NCs to expose more active sites with high intrinsic activity.The resultant h-CoFe-LDH NCs exhibit outstanding OER activity with an overpotential of only 278 mV to deliver a current density of 50 mA cm^(-2).Additionally,controlling the reconstruction degree enables the formation of ys-ZIF@CoFe-LDH NCs with a yolk–shell nanocage nanostructure,which show outstanding electrocatalytic performance for the selective ethylene glycol oxidation reaction(EGOR)toward formate,with a Faradaic efficiency of up to 91%.Consequently,a hybrid water electrolysis system integrating the EGOR and the hydrogen evolution reaction using Pt/C||ys-ZIF@CoFe-LDH NCs is explored for energy-saving hydrogen production,requiring a cell voltage 127 mV lower than water electrolysis to achieve a current density of 50 mA cm^(-2).This work demonstrates a feasible way to design advanced MOF-derived electrocatalysts toward enhanced electrocatalytic reactions.

PdPbBi nanoalloys anchored reduced graphene-wrapped metal-organic framework-derived catalyst for enhancing ethylene glycol electrooxidation

For future clean energy demand,it is essential to develop highly efficient and durable materials for use in renewable energy conversion devices.Herein,we report an electrocatalyst loaded with Pd-Pb-Bi nanoalloys on reduced graphene(rGO)-wrapped In_(2)O_(3)(PdPbBi@rGO/In_(2)O_(3))prepared by a hydrothermal method.PdPbBi@rGO/In_(2)O_(3)exhibits higher forward current density(229.12 mA·cm^(-2)),larger electrochemical active surface area(ECSA)(85.87 m^(2)·g^(-1)Pd),smaller impedance(12.68Ω)and lower E_(onset)(-0.56 V)than commercial Pd/C.Specifically,the current density and ECS A are 8.46 and3.38 times higher than those of commercial Pd/C(27.07 mA·cm^(-2),25.41 m^(2)·g^(-1)Pd),respectively.Furthermore,the oxidation mechanism of ethylene glycol and the removal of carbon monoxide[CO]_(ads)from the surface of Pd are also discussed in detail.The columnar support structure wrapped by rGO provides a huge active surface area for catalysis.Moreover,the electronic effect of Pd-PbBi nanoalloys can accelerate the removal of CO intermediate species,obtain more Pd active sites and improve the electrocatalytic performance.Our first synthesis of this highly electrocatalyst offers promising value for commercial application in direct fuel cells.

Nitric Oxide(NO) and Plant Stress

In depth study of NO reveals that NO is a bioactive molecule that exerts a number of roles in many physiological and pathological process.NO is produced in response to drought,salinity,temperature shock and pathogen attack.NO rapidly reacts with ROS,ABA and other hormones and directly or indirectly regulate ethylene biosynthesis.The authors review the response of between plant NO and kinds of stresses,and possible mechanism was discussed.

In situ time-resolved FTIRS study of adsorption and oxidation of ethylene glycol on Pt(100) electrode

Adsorption and oxidation of ethylene glyco(EG) on Pt(100) electrode were studied by in situ timeresolved FTIRS (TRFTIRS). The TRFTIR spectra recordedat 0.10 V illustrate that an IR band appears near 2050 cm?at t > 5 s, corresponding to linearly bonded CO formed indissociative adsorption of EG. The TRFTIR results haveconfirmed also that CO species are distributed uniformly onPt(100) surface. Another band appears near 2342 cm?1 at > 70 s, associating with IR absorption of CO2 produced inthe direct oxidation of EG. With the increase of electrodepotential, the direct oxidation of EG becomes gradually themain reaction. When the potential is above 0.40 V, the oxidation of EG occurs mainly via the reactive intermediates, i.especies containing –COOH determined by in situ TRFTIRS.

Bimetallic Au/Pd catalyzed aerobic oxidation of alcohols in the poly(ethylene glycol)/CO_(2) system

Bimetallic Au/Pd nanoparticles were prepared and used to catalyze oxidation of alcohols in the poly(ethylene glycol) (PEG)/CO_(2) biphasic system using O2 as the oxidant without adding any base.The catalytic activity of Au/Pd bimetal with different mole ratios was studied using benzyl alcohol as the substrate.It was found that bimetallic Au/Pd nanoparticles with Au:Pd=1:3.5 had higher catalytic activity than monometallic Au,Pd and the bimetallic Au/Pd nanoparticles with other molar ratios.The effect of CO_(2) pressure on the oxidation of benzyl alcohol and 1-phenylethanol in PEG/CO_(2) was investigated.It was demonstrated that CO_(2) pressure could be used to tune the conversion and selectivity of the reactions effectively.α,β-Unsaturated alcohols were also studied and found to be more reactive than benzyl alcohol and 1-phenylethanol.Recycling experiments showed that the Au/Pd/PEG/CO_(2) catalytic system could be recycled at least four times without reducing the activity.In addition,the catalytic system is clean and the products can be separated easily.

基于代理模型的环氧乙烷制乙二醇工艺优化同步热集成

在当前国家“双碳”目标下,通过优化过程参数以减少化工过程能耗是节能减排的有效手段。环氧乙烷催化水合制乙二醇过程耗能高,优化其工艺参数以降低能耗是非常必要的,但由于生产流程复杂,单纯基于流程模拟很难实现多参数的同步最优化。因此本文采用流程模拟生成数据-构建代理模型-同步优化热集成的思路解决该问题。对年产30万吨环氧乙烷制乙二醇工艺进行流程模拟,根据流程中所需公用工程位点确定代理模型输出变量,通过灵敏度分析进一步确定输入变量。由Sobol随机序列生成样本点并通过模拟得到基于机理模型的可靠数据,以数据驱动方式训练神经网络得到代理模型。最后,以总公用工程费用最小为目标,采用遗传算法与D-G模型组成的同步算法对代理模型进行优化,得到最优工艺参数,总公用工程费用较优化前降低4.89%,既证明了方法的有效性,又展示了其在解决复杂全流程同步优化热集成问题方面的应用前景。

一次性使用输液器产品中2-氯乙醇和乙二醇残留量的测定方法研究

目的:建立有效测定经环氧乙烷(ethylene oxide,EO)灭菌后一次性使用输液器产品中2-氯乙醇(ethylene chlorohydrin,ECH)和乙二醇(ethylene glycol,EG)残留量的方法。方法:选用8890B气相色谱仪,采用液体进样方式,选择DB-WAX色谱柱,以乙醇作为浸提介质,按照一次性使用输液器质量与浸提介质体积比例为0.4 g/mL进行浸提,在37℃浸提10 h后对一次性使用输液器产品中的ECH和EG进行定量测定。结果:该测定方法专属性较强,ECH与EG均在1.25~100.00μg/mL范围内线性关系良好。ECH和EG的检出限分别为0.31和0.11μg/mL。ECH检测精密度的相对标准偏差为0.24%~2.03%,EG检测精密度的相对标准偏差为0.16%~0.87%。ECH检测的平均回收率为95.02%~100.58%,EG检测的平均回收率为99.15%~99.98%。结论:建立的ECH和EG残留量测定方法操作简单、专属性优良、检测准确、重现性好,可满足经EO灭菌的一次性使用输液器产品中ECH和EG残留量的检测需求。

纳米级钛硅分子筛合成及其催化乙烯制乙二醇性能

以四丙基氢氧化铵为模板剂,钛酸四丁酯为Ti源,硅酸四乙酯(TEOS)、钠型硅溶胶或铵型硅溶胶分别为Si源,通过水热晶化法制备出一系列钛硅分子筛(TS-1),利用X射线衍射仪、自动物理吸附仪、荧光光谱仪、傅里叶红外光谱仪、扫描电子显微镜、紫外可见分光光度计等仪器对合成的样品进行了表征,考察了Ti源引入温度、Si源种类、晶化时间以及硅钛比[n(Si)/n(Ti),下同]对合成TS-1的影响,并对比评价了系列TS-1催化乙烯制乙二醇(EG)的性能。结果表明:在常温下引入Ti源,选择TEOS作Si源,晶化时间为1 d,硅钛比为50的条件下所合成TE-50 N-1样品的催化性能最优,H_(2)O_(2)转化率为80.04%,EG选择性为97.19%。

我国环氧乙烷与乙二醇的市场分析

环氧乙烷与乙二醇是乙烯下游两大重要的化工品。近几年来,环氧乙烷行业产能面临扩张局面,但产能增速高于需求增速,供需矛盾加剧,盈利能力减弱,市场价格以持续低位震荡为主;乙二醇行业在炼化一体化以及煤化工的推动下也出现了产能快速增长的局面,市场竞争压力扩大,进口量持续缩减,部分老装置出现长停状态,市场价格维持宽幅震荡运行。文章就环氧乙烷与乙二醇供需情况、市场价格以及未来发展前景进行了分析。

乙醇醛合成及应用研究进展

乙醇醛作为重要的化工中间体,被广泛的应用于食品、医药卫生、化工等行业。综述了乙醇醛的合成工艺路线,包括以甲醛为原料通过氢甲酰化法,选择性醛糖反应,生物催化法;以乙二醇为原料通过化学氧化法、生物催化法等。其中近年来随着现代生物技术的发展,以乙二醇为原料经生物催化合成乙醇醛的方法具有良好的前景。

次氯酸钙氧化降解乙二醇丁醚及其机理研究

采用次氯酸钙氧化处理含乙二醇丁醚废水,研究了反应pH、反应温度、次氯酸钙用量和反应时间对乙二醇丁醚氧化降解效果的影响,并且探讨了氧化降解机理。研究结果表明最优工艺条件为:反应pH值为5、反应温度为50℃、次氯酸钙用量为2%、反应时间为180min。在该条件下出水COD可降低68.6%,TOC去除率为41.5%。出水有机成分分析表明,乙二醇丁醚逐步断链、脱碳、加氯,分解为较短碳链氯代烯烃、醇类等中间产物,最终被降解为CO_(2)和H_(2)O。