Characterization of Flame Retardancy and Oil-Water Separation Capacity of Superhydrophobic Silylated Melamine Sponges

A silylated melamine sponge(SMS)was prepared by two simple steps,namely,immersion and dehydration of a melamine sponge coated with methyltrichlorosilane.The silylated structure of SMS was characterized by FT-IR(Fourier-transform infrared)spectroscopy,SEM(Scanning electron microscopy)and in terms of water contact angles.Its oil-water absorption and separation capacities were measured by FT-IR and UV-visible spectrophoto-metry.The experimental results have shown that oligomeric silanol covalently bonds by Si-N onto the surface of melamine sponge skeletons.SMS has shown superhydrophobicity with a water contact angle exceeding 150°±1°,a better separation efficiency with regard to diesel oil(by 99.31%(wt/wt%)in oil-water mixture and even up to 99.99%(wt/wt%)for diesel oil in its saturated aqueous solution.Moreover,SMS inherited the intrinsicflame retardancy of the melamine sponge.In general,SMS has shown superhydrophobicity,high porosity,excellent selectivity,remarkable recyclability,and better absorption capacity for various oils and organic solvents,and a high separation efficiency for oil in saturated aqueous solutions.

Preparation of Silica Nanosphere with Vertical Pore and Its Application in Oil-water Separation

Uniform monodispersed mesoporous silica nanospheres with vertical pores were successfully synthesized using chiral amphiphilic small molecule L-16Ala5PyClO4and solvents as dual templates via solgel transcription.The morphologies and pore sizes of silicas are adjustable by changing the type and amount of solvents in the reaction systems.With the increase of the organic solvent content,the morphologies of the obtained silica changed from nanospheres with vertical pore structures to nanosheets structures.When 1 mL of benzene,cyclohexane or toluene were used as solvents,only silica nanospheres were obtained,the BET surface areas of silica nanospheres reached 600.7,669.5,and 560.8 m^(2)/g,respectively.The pore sizes were 3.51,3.54,and 3.46 nm,respectively.Significantly,these ordered silica nanospheres/poly(vinyl alcohol-co-ethylene)(PVAco-PE)nanofiber membranes have high separation efficiencies(>99%)for n-hexane/water mixtures.

Preparation of Hydrophobic Fly Ash by Surface Modification and Oil-water Separation Devices

A simple and effective superhydrophobic mesh was designed and made to separate oil-water mixture. Alkali-activated fly ash reacted with 1-bromooctadecane to prepare superhydrophobic modified fly ash (MFA) with low surface energy through Williamson ether synthesis. The MFA powder was then coated uniformly on a stainless steel mesh (SSM) along with the epoxy resin E44 and curing agent T31 to give the superhydrophobic MFA-modified stainless steel mesh (MFA-SSM). The MFA-SSM has a high static water contact angle (CA) of 150.1°and can separate various oil or organic solvent from water with>95%separation efficiency. The oil-water separation efficiency remained high after 30 runs of petroleum ether/water separation.The developed superhydrophobic stainless steel mesh is expected to have wider use in oil-water separation.

Robust,fluorine-free and superhydrophobic composite melamine sponge modified with dual silanized SiO_(2) microspheres for oil-water separation

Massive oily wastewater discharged from industrial production and human daily life have been an urgent environmental and ecological challenge.Superhydrophobic materials have attracted tremendous attention due to their unique properties and potential applications in the treatment of wastewater.In this study,a novel superhydrophobic/superoleophilic composite melamine sponge modified with dual silanized SiO_(2) microspheres was fabricated simply by a two-step sol-gel method using vinyltriethoxysilane and hexadecyltrimethoxysilane as functional agent,which exhibited a water contact angle of 153.2°and a water sliding contact angle of 4.8°.Furthermore,the composite sponge showed the excellent oil adsorption performance and the compressive elasticity reaching up to 130 g·g^(-1) of dichloromethane and 33.1 kPa of compressive stress.It was worth noting that the composite sponge presented the excellent separation efficiency(up to 99.5%)in the processes of continuous oil/water separation.The robust superhydrophobic composite melamine sponge provided the possibility with the practical application for oil-water separation.

Simultaneously spray-assisted assembling reversible superwetting coatings for oil-water separation

Here,superhydrophobic cuprous oxide(Cu2O)with hierarchical micro/nanosized structures was synthesized via sprayassisted layer by layer assembling.The asprepared superhydrophobic meshes with high contact angle(159.6°)and low sliding angle(1°)are covered with Cu_(2)O "coral reef"like micro/nanosized structures.Interestingly,the superhydrophobic mesh surfaces became superhydrophilic again due to the oxidization of Cu_(2)O to CuO by annealing at a higher temperature(300℃).And the superhydrophobic properties would be recovered by heating at 120℃.Furthermore,the superwetting meshes were applied to design a miniature device to separate light or heavy oil from the wateroil mixtures with excellent separation efficiency.These superwetting surfaces by simultaneously sprayassisted layer by layer assembling technique show the potential application in universal oilwater separation.

Magnetic Wood-based Superhydrophobic Aerogel for Efficient Oil-Water Separation

The fabrication of directionally driven oil-water separation materials has great significance for the removal of oil spills and organic pollutants.In this study,an oil-water separation aerogel capable of directionally adsorbing oil was designed using an anisotropic wood aerogel with a layered structure and a top-down fabrication strategy.Specifically,a magnetic wood-based superhydrophobic aerogel(methyltrimethoxysilane(MTMS)/Fe_(3)O_(4) wood aerogel)was developed through the in situ coprecipitation of Fe_(3)O_(4) nanoparticles and chemical vapor deposition.Owing to its highly porous structure,lipophilicity,hydrophobicity(water contact angle of 160°),and high compressibility,the MTMS/Fe_(3)O_(4) wood aerogel exhibits excellent oil-water separation performance and compression cycle stability.Additionally,the Fe_(3)O_(4) endows the material with excellent magnetic and photothermal conversion capabilities.These excellent properties make MTMS/Fe_(3)O_(4) wood aerogel a promising recyclable and sustainable oil-water separation material.

Electrospinning Nanofiber Membrane Reinforced PVA Composite Hydrogel with Preferable Mechanical Performance for Oil-Water Separation

Nowadays hydrogels have been attracting the massive interest in oil-water separation due to their robust hydrophilicity and fantastic underwater oiliness features.However,the weak toughness and tensile strength shortcomings of hydrogels have thus inhibited their actual applicability.For this reason,we successfully fabricated the electrospun nanofiber membrane-reinforced PVA composite hydrogels.The PVA-PAN composite hydrogel has exhibited the excellent tensile strength and friction performance,separately enhancing 174.2%of the tensile strength,and reducing 20.7%of the friction coefficient and 58.7%of wear volume relative to the neat PVA hydrogel.Furthermore,the pull-out experiments indicated that the PAN nanofiber membrane exerted a stronger interface bonding effect with PVA hydrogel.The oil-water separation evaluation test showed that the separation efficiency reached up to 97.6%for treating the SA-100 lubricating oil/water system.

NIR-responsive Collagen-based Sponge Coated with Polydimethylsiloxane/Candle Soot for Oil-Water Separation

To fabricate an oil-water separation material that is rich in source,eco-friendly,and responsive,in this study,we successfully developed a collagen-based sponge for application to oil-water separation based on a green and facile strategy.In this design,widely-available collagen(COL)was used as the substrate:it was immersed in polydimethylsiloxane(PDMS)suspension with candle soot(CS)nanoparticles,followed by hot curing.The resultant sponge(CS/PDMS-COL)possessed good hydrophobicity with a water contact angle of 148.3°under a low PDMS concentration of 2%.The results from field emission scanning electron microscope,Fourier transform infrared spectrometer,X-ray photoelectron spectrometer,and X-ray diffractometry demonstrated the successful coating of CS and PDMS on the surface of COL substrate.The CS/PDMS-COL can adsorb eight oils,with the adsorption capacity for trichloromethane reaching 95 g/g.With benzene as the target adsorbent,the separation efficiency was maintained at no less than 95%even after recycling 20 times.CS/PDMS-COL was also used to separate oil-in-water emulsion.Moreover,the sponge killed bacteria effectively due to its excellent near-infrared photothermal responsiveness.This study provides new insight into the preparation of facile oil-water separation materials based on naturally occurring biomaterials effortlessly.

Influences of water treatment agents on oil-water interfacial properties of oilfield produced water

The emulsion stability of oilfield produced water is related to the oil-water interfacial film strength and the zeta potential of the oil droplets. We investigated the effects of water treatment agents （corrosion inhibitor SL-2, scale inhibitor HEDP, germicide 1227, and flocculant polyaluminium chloride PAC） on the stability of oilfield produced water. The influence of these treatment agents on oil-water interfacial properties and the mechanism of these agents acting on the oilfield produced water were studied by measuring the interfacial shear viscosity, interfacial tension and zeta electric potential. The results indicated that the scale inhibitor HEDP could increase the oil-water interfacial film strength, and it could also increase the absolute value of the zeta potential of oil droplets. HEDP played an important role in the stability of the emulsion. Polyaluminum chloride （PAC） reduced the stability of the emulsion by considerably decreasing the absolute value of the zeta potential of oil droplets. Corrosion inhibitor SL-2 and germicide 1227 could decrease the oil-water interfacial tension, whereas they had little influence on oil-water interfacial shear viscosity and oil-water interfacial electricity properties.

Superhydrophobic magnetic Fe_(3)O_(4) polyurethane sponges for oil-water separation and oil-spill recovery

The effective and affordable separation of oil and water,a crucial process in the safe han dling of environmental disasters such as crude oil spills and recovery of valuable resources is a highly sought-after yet challenging task.Herein,superhydrophobic PU sponge was fab ricated for the fast and cost-effective adsorptive separation of oil and different organic sol vents from water.Octadecyltrichlorosilane(OTS)-functionalized Fe_(3)O_(4)@SiO_(2)core-shell mi crospheres were dip-coated on the surface of porous materials via a dip-coating process thereby endowing them with superhydrophobicity.Owing to the hydrophobic interaction between OTS molecules and oil and increased capillary force in the micropores,the result ing superhydrophobic sponge served as a selective oil-sorbent scaffold for absorbing oil from oil-water mixtures,including oil-water suspensions and emulsions.Remarkably,after the recovery of the adsorbed oil via mechanical extrusion,these superhydrophobic materials could be reused multiple times and maintain their oil-water separation efficacy even afte 10 oil-water separation cycles.

Simple and Ultrahigh Efficient Superhydrophilic Polydopamine-coated TiO_(2) Cotton for Oil-water Separation

Oil–water mixing has brought many problems to a society, and it is of great significance to develop a simple, convenient, efficient, and durable separation material to solve the problem of oil–water mixing. In this paper, modified cottons were successfully prepared using polydopamine as the in situ mineralization site of TiO_(2) nanoparticles combined with synergistic crosslinking with KH550. A large number of hydrophilic groups endowed the cotton with superhydrophilic ability, which greatly shortened its water spreading time. The prepared modified cotton could be successfully separated from oil and water, and still had a separation efficiency of 99.999% after 50 cycles. In addition, after 24 h immersion in 1 M HCl, NaOH, and NaCl solutions and 50 abrasion experiments, the modified cotton showed excellent oil–water separation ability, and the separation efficiency was above 99.990%. Successfully provided a simple preparation method to prepare high-efficiency and clean cottons for oil–water separation.

基于钙镁复合膨胀的无收缩混凝土技术研究与应用

避免管内混凝土收缩脱空是保障钢管混凝土拱桥施工质量且进一步增加跨径的关键措施之一。试验研究了掺入不同配合比的钙镁复合膨胀剂管内混凝土,在恒温和变温条件下的体积变形与力学性能。结果表明:总掺量不变的情况下,20℃恒温时管内混凝土膨胀率随CaO掺量增加而明显增大,模拟实际工程的典型变温条件下,复合膨胀剂中MgO掺量为50%时,管内混凝土最终可残余约22με的膨胀变形,可实现钢管混凝土结构无收缩。外约束作用可提高掺入膨胀剂的管内混凝土抗压强度,不同龄期较自由状态提高了4.5%~7.7%。

无线传感器网络Agent数据分流策略

移动Agent(mobile agents,简称MA)技术在无线传感器网络的异常事件监测中广泛应用.基于异常事件的性质,数据中心(即sink点)派出实现特定功能的MA到异常目标位置附近收集传感器节点(数据源节点)的感应监测数据.与传统的客户端-服务器传输模型不同,MA技术往往能够对收集到的感应数据进行压缩和融合,从而大大减少了在网络中传播的数据流量,降低了数据传输的能量消耗.通常情况下,MA经过的源节点越多,其收集的数据量越大.通过对目前已有的MA行程规划算法进行研究,提出了实现Agent数据分流的传输技术.该技术基于分流规则,决定是否提前把MA已收集到的数据传回sink,而不携带数据的MA继续访问余下的传感器节点.该Agent数据分流技术解决了由于MA携带大量数据访问源节点而造成的源节点能量消耗过快的问题,适用性强.大多数目前常用的MA行程规划算法都可以采用该技术来提高性能.Agent数据分流的最终目标是减少源节点传输的数据量,尽可能地延长源节点的工作寿命,从而更长时间地实现对异常目标的监控.

无线传感器网络Agent数据分流策略

移动Agent(mobile agents,简称MA)技术在无线传感器网络的异常事件监测中广泛应用.基于异常事件的性质,数据中心(即sink点)派出实现特定功能的MA到异常目标位置附近收集传感器节点(数据源节点)的感应监测数据.与传统的客户端-服务器传输模型不同,MA技术往往能够对收集到的感应数据进行压缩和融合,从而大大减少了在网络中传播的数据流量,降低了数据传输的能量消耗.通常情况下,MA经过的源节点越多,其收集的数据量越大.通过对目前已有的MA行程规划算法进行研究,提出了实现Agent数据分流的传输技术.该技术基于分流规则,决定是否提前把MA已收集到的数据传回sink,而不携带数据的MA继续访问余下的传感器节点.该Agent数据分流技术解决了由于MA携带大量数据访问源节点而造成的源节点能量消耗过快的问题,适用性强.大多数目前常用的MA行程规划算法都可以采用该技术来提高性能.Agent数据分流的最终目标是减少源节点传输的数据量,尽可能地延长源节点的工作寿命,从而更长时间地实现对异常目标的监控.

还原剂及脱磷剂对高磷鲕状赤铁矿直接还原-磁选影响的研究进展

这是一篇矿业工程领域的文章。综述了还原剂及脱磷剂对高磷鲕状赤铁矿直接还原的影响,从煤和其他还原剂两个方面归纳了还原剂对高磷鲕状赤铁矿还原影响的研究现状,从单一脱磷剂和组合脱磷剂两种使用方式总结了脱磷剂的研究进展。指出了高磷鲕状赤铁矿直接还原-磁选工艺存在的问题,根据目前存在问题提出了未来针对高磷鲕状赤铁矿直接还原-磁选研究方向的建议。

绿色节能的萃取精馏工艺设计与强化

萃取精馏是一种通过添加新的溶剂来分离多组分共沸物的分离技术,能够有效地提取和分离混合物中的目标物质。在传统的萃取精馏工艺存在着分离效率低、能耗高和环境污染严重等不足,急需设计节能高效的强化萃取精馏工艺的背景下,首先总结了萃取精馏工艺的设计路线,指出热力学拓扑理论在萃取精馏工艺设计中的重要地位,研究了过程强化在精馏工艺设计中的应用。介绍了萃取精馏中萃取剂的选择方法,详细说明了相对挥发度和分子模拟在其中的应用,介绍了萃取精馏工艺参数优化和设计的方法,讨论了顺序迭代优化和多目标优化的优势和劣势,可为绿色节能萃取精馏工艺的设计与强化提供新的思路和方法,为相关领域的研究和应用提供参考。

智能Agent自我的统一与分离

在以自我表示Agent精神中心思想的基础上，进一步提出在智能Agent行为与活动过程中，对外其自我表现出统一，而在其内部却常表现出分离的新观点。揭示出智能Agent自我需要和自我愿望等多重性特征，并对Agent自我分离的特点和性质进行了分析和讨论，为将智能Agent行为与其结构联系起来奠定了基础。

双重孔结构SiO_(2)的制备及其吸附生物大分子的性能

采用十六烷基三甲基溴化铵作为有序介孔模板剂和相分离诱导剂,通过相分离和溶胶-凝胶转化,合成了具有较小有序介孔和较大堆积介孔/大孔的双重孔结构SiO_(2)。结果表明,采用该双重孔结构SiO_(2)吸附模型生物大分子,其吸附量明显高于单一孔结构MCM-41型SiO_(2),显示双重孔结构SiO_(2)吸附大分子的优势。

吸附剂对多环芳烃吸附分离技术的研究

采用专用模板剂制备多环芳烃吸附剂,通过X射线衍射仪(XRD)、全自动比表面分析测试仪(BET)、程序升温化学吸附分析仪(NH_(3)-TPD)、吡啶吸附红外光谱仪(Py-IR)、扫描电镜和透射电镜测试仪(SEM/TEM)等表征方法对是否添加模板剂的吸附剂进行表征分析,并以模拟油品为原料,分别在固定床和模拟移动床吸附分离装置上,考察吸附剂的多环芳烃分离性能。结果表明,与未添加模板剂的吸附剂相比,添加模板剂的多环芳烃吸附剂平均孔径增加43.3%,微孔比表面积降低72.2%,微孔孔容降低87.5%,弱酸量提高31.2%,强酸量提高60%,多环芳烃/非芳烃相对分离度提高52.7%,多环芳烃解吸时间缩短41.4%,甲基萘饱和吸附容量提高14.6%。专用模板剂制备的多环芳烃吸附剂在模拟移动床装置上稳定运行30 d后,非芳烃产品的非芳烃质量分数>95%,多环芳烃产品的多环芳烃质量分数>95%。

分子筛吸附剂对不同类型柴油吸附分离性能的研究

采用离子交换法制备分子筛吸附剂,分析发现分子筛吸附剂的孔结构以晶内微孔为主,并含有晶间介孔,具有结晶度高、晶粒分布均匀、弱酸和强酸协同作用的特点。以不同类型柴油为吸附原料和轻型解吸剂(沸点低于柴油),利用模拟移动床分离装置,考察分子筛吸附剂对不同类型柴油的吸附分离性能。结果显示:在吸附温度为120℃、压力为1.2 MPa、吸附区回流比为0.5~1.5、精制区回流比为0.2~1.5、解吸区回流比为2.0~6.0、隔离区回流比-2~0的条件下,分子筛吸附剂在不同类型柴油吸附-脱附体系下运行稳定,芳烃产品中芳烃纯度>95%,非芳烃产品中非芳烃纯度>95%;不同类型柴油中硫氮含量、馏程轻重和芳烃含量对吸附分离效果没有影响,不同类型柴油中芳烃含量越高,解吸剂与柴油体积比越高,在模拟工业应用条件下,分子筛吸附剂稳定运行时间超过600 d,所制得的分子筛吸附剂具有芳烃选择性高、吸附容量大、运行稳定性高等特点。