磁性石墨烯复合材料制备与应用研究进展

石墨烯具备多种优异的性能,但容易通过π-π堆积和范德华力作用产生聚集,重新堆叠成石墨。为了改善石墨烯的堆叠问题,提高石墨烯材料的应用性,越来越多的研究者将石墨烯及其衍生物和磁性纳米粒子复合,制备综合性能更优的新型材料。本文结合近年来国内外研究报道,总结了磁性石墨烯纳米复合材料的制备方法（水热/溶剂热、化学接枝法、微波辅助法等）,概述了磁性石墨烯复合材料在环境样品分离富集、催化、涂层耐腐蚀性、吸波材料及能源等方面的应用,指出了目前磁性石墨烯复合材料研究中存在的一些问题,例如磁性颗粒容易发生团聚、生物安全性有待验证、氧化石墨烯的还原导致其表面吸附位点减少等。目前（氧化）石墨烯的制备工艺正在得到改善,而未来最重要的发展方向是加强对磁性石墨烯的表面改性,从而可使其表面具有更丰富的吸附位点,同时也可使石墨烯表面的磁性纳米粒子的形态及分布更均匀,更有利于稳定发挥磁性石墨烯的功能性。     

石墨烯及衍生除油材料的研究进展

原油采油过程或海上石油泄漏将产生大量的含油污水,给环境带来了巨大的威胁。石墨烯及衍生材料具有较大的比表面积、特殊的孔结构等特性,在含油废水除油领域引起人们的广泛关注。综述了三维石墨烯和石墨烯复合膜等石墨烯衍生除油材料在处理含油废水领域的研究进展。对三维石墨烯除油材料的研究旨在优化微孔结构和表面润湿性,提高机械性能和使用寿命;石墨烯复合膜油水分离材料主要提高膜的通量、抗污能力和稳定性。目前石墨烯及衍生除油材料合成工艺较繁琐且稳定性较差,未来对石墨烯及衍生除油材料的研究将着眼于降低成本、提高稳定性和适用性。     

离子液体-氧化石墨烯膜材料在CO2分离领域的研究进展

离子液体是一种饱和蒸汽压低、结构可设计、稳定性强、液态温度范围宽的绿色溶剂,同时对CO2又有较高的溶解度,因此成为当前CO2分离领域的研究热点材料。将离子液体和二维纳米材料结合得到的分离膜材料兼具离子液体和二维纳米材料的优势,在气体分离方面展现了良好的应用前景。其中,离子液体和氧化石墨烯的结合备受关注。针对这一热点问题,本工作综述了国内外通过氧化石墨烯、离子液体及离子液体?氧化石墨烯膜材料在CO2分离方面的研究和进展。相关研究表明,离子液体?氧化石墨烯膜材料具有较好的CO2选择性能、渗透性能和稳定性能,是一种非常有潜力的CO2分离材料。最后,提出了利用离子液体、氧化石墨烯及离子液体?氧化石墨烯膜材料进行CO2捕集分离的未来研究挑战和展望。     

基于纳米材料的静态吸附脱硫进展

综述了近年来新型纳米吸附剂静态吸附脱除燃料油中二苯并噻吩（DBT）的作用机理及最新研究进展。重点分析了金属骨架材料（MOFs）、分子印迹聚合物（MIPs）、石墨烯基材料、活性炭基材料（AC）、介孔微孔材料等不同吸附剂的研究现状,从脱硫机理角度探讨不同改性方法对吸附脱硫效果的影响。通过比较这些吸附脱硫材料的优缺点,展望未来吸附脱硫材料的发展趋势和前景,为开发更优良的吸附剂用于吸附脱除DBT提供一些研究思路。文章指出吸附脱除燃料油中的DBT目前的主要问题是吸附剂的重复利用、与燃料油接触容易产生污染和吸附剂与燃料油分离过程中造成的损耗,这些短板也是吸附脱硫法大规模工业应用的主要障碍,因此吸附材料的选择、改性方法以及机理研究是吸附脱除DBT的主要研究方向。     

超疏水三维多孔材料在乳化液油水分离中的应用研究进展

超疏水三维多孔材料基于润湿性和毛细作用可有效吸附回收水中浮油,近年来在乳化液的油水分离中也得到应用。本文重点从超疏水三维多孔材料的设计制备、对乳化液的油水分离效果、油滴在材料中的分离机制3个方面展开分析与评价。文中指出：材料设计制备方面,以海绵为主的多孔材料主要通过修饰低表面能物质和构建粗糙结构获得超亲油疏水性,疏水改性后的材料具备较高的油吸附容量（31～131g/g）。乳化液油水分离评价方面,超疏水三维多孔材料处理的对象多为O/W模型乳化液,油浓度低、表面活性剂浓度低、液滴粒径为微米级,少见对实际乳化液的处理;应用方式包括基于吸附作用的浸泡处理和吸附协同拦截作用的过滤处理两类;分析发现影响油水分离效果的关键是材料的孔径、表面疏水性和带电性。作用机制方面,疏水多孔材料吸附乳化油的作用过程仍停留在理论推测层面,主要观点为材料通过笼状孔道结构和疏水表面高效捕集和吸附油滴,油滴聚并破乳形成油层而被分离。虽然超疏水三维多孔材料在乳化液油水分离应用研究中取得了一定进展,但仍需探究其对实际废乳化液的适用性,设计开发连续分离设备以实现工程应用;结合原位观测、数值模拟、力学解析等方法解析油滴在多孔材料...     

聚合物基氧化石墨烯纳米复合材料研究进展

氧化石墨烯作为石墨烯的重要衍生物,原料来源广泛,制备过程简单,成本低廉,具有优异力学性能、耐磨性能以及吸附性能等,其还原产物具有优良的导电性能和导热性能等,是聚合物基纳米复合材料的理想填料。近年来,随着复合材料制备方法的不断革新,聚合物基氧化石墨烯纳米复合材料得到了快速发展,并在储能、阻燃等领域实现了规模化应用,有助于引领聚合物基氧化石墨烯纳米复合材料相关产品的进一步开发和应用。本文系统介绍了氧化石墨烯的改性方法,综述了聚合物基氧化石墨烯纳米复合材料的研究进展,展望了聚合物基氧化石墨烯纳米复合材料的发展前景。     

石墨烯/陶瓷基复合材料研究进展

2004年以来,石墨烯以其优异的力学、电学、热学和光学性能以及独特的二维结构成为材料领域的研究热点。本文结合作者所在课题组的相关工作,综述了石墨烯应用于陶瓷基复合材料的国内外研究进展,重点介绍了石墨烯/陶瓷复合粉体的制备、石墨烯/陶瓷基复合材料的烧结工艺以及性能,探讨了石墨烯/陶瓷基复合材料的研究发展方向及应用前景。     

Recent developments in graphene-based polymer composite membranes: Preparation,mass transfer mechanism,and applications

The shortage of water resources is a problem concerned by all countries in the world. In order to solve this problem of human survival, membrane separation technology promotes the development of water treatment field by virtue of its own advantages of high efficiency and low consumption. Membrane separation technology combined with nanomaterials has brought surprises to researchers. Graphene has unique structure and properties, making graphene and its derivatives have very good potential in water treatment and selective separation. Graphene-based materials combined with traditional polymer materials have great potential in the field of membrane separation technology. In this article, we first introduce the preparation methods and transport mechanism of graphene-based membranes, and then summarize the recent applications of graphene oxide/polymer composite membranes in water purification, gas separation, self-cleaning, and oil–water separation. It is expected to become the next generation of functional composite membranes. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47761.     

Recent progress and future prospects of oil-absorbing materials

Oil and organic solvent contamination, derived from oil spills and organic solvent leakage, has been recognized as one of the major environmental issues imposing a serious threat to both human and ecosystem health. Among the various presented technologies applied for oil/water separation, oil absorption process has been explored widely and offers satisfactory results especially with surface modified oil-absorbing material and/or hybrid absorbents. In this review, we summarize the recent research activities involved in the designing strategies of oil-absorbing absorbents and their application in oil absorption. Then, an extensive list of various oil-absorbing materials from literature, including polymer materials, porous inorganic materials and biomass materials, has been compiled and the oil adsorption capacities toward various types of oils and organic solvents as available in the literature are presented along with highlighting and discussing the various factors involved in the designing of oil-absorbing absorbents tested so far for oil/water separation. Finally, some future trends and perspectives in oil-absorbing material are outlined.     

油气回收吸附剂研究现状

简单介绍了吸收法、冷凝法、膜分离法等油气回收技术,重点论述了吸附法油气回收技术的研究现状,对油气回收用活性炭吸附剂的研究开发进行了分析,综述了活性炭不同指标对油气吸附的影响。分析表明,开发高性能活性炭用于油气回收很有意义。     

超疏水-超亲油材料在油水分离中的研究进展

综述了超疏水-超亲油油水分离材料的研究进展及其在油水分离中的应用。首先介绍了油水分离材料的特殊润湿性的基本理论和设计理念,主要包括Young方程、Wenzel模型、Cassie模型以及制备油水分离材料的两种途径。然后全面介绍了金属网膜类、纺织品类、合成膜类等二维结构的油水分离材料,以及海绵、泡沫、气凝胶等三维网络状类油水分离材料和智能型油水分离材料。最后总结了目前在油水分离这一领域存在的一些问题,主要是油水分离的基本机制和理论研究不够完善,并指出开发和研究能够分离特殊油品的材料以及智能响应性可控的油水分离材料仍然是一大挑战。     

Non-linear modeling of kinetic and equilibrium data for the adsorption of hexavalent chromium by carbon nanomaterials:Dimension and functionalization

The adsorption capacities for the removal of hexavalent chromium from aqueous solutions by six carbon nanomaterials have been evaluated. Single-walled and multi-walled carbon nanotubes as received and after oxidation treatment, graphene oxide and reduced graphene oxide are the materials with different dimension and functionalization compared in this research. Carbon nanotubes have been modified using hydrogen peroxide as oxidizing agent under microwave radiation. The oxidation treatment on carbon nanotubes has a positive effect increasing the adsorbent–adsorbate interaction. Rate-controlling mechanisms and equilibrium data are analyzed using non-linear models. Non-linear method is proposed as the most suitable method for determining the kinetic and equilibrium parameters. The values of adsorption energy(E) obtained from the Dubinin–Radushkevich isotherm,have been found around 0.371 and 0.870 k J·mol~(-1), indicating physical adsorption. Therefore, the pseudo-second order model represents better the kinetic experimental data. The results show that the Langmuir isotherm provides a slightly better fit to the experimental data compared with the Freundlich isotherm, indicating homogeneous distribution of active sites on carbon nanomaterials and monolayer adsorption. The separation factors RLare found in the range of 0–1, suggesting that the adsorption process is suitable for all adsorbents. The mechanisms for hexavalent chromium removal have been proposed as electrostatic interactions and hydrogen bonding.     

Adsorptive interaction of bisphenol A with mesoporous titanosilicate/reduced graphene oxide nanocomposite materials: FT-IR and Raman analyses

Nanocomposite materials containing graphene oxide have attracted tremendous interest as catalysts and adsorbents for water purification. In this study, mesoporous titanosilicate/reduced graphene oxide composite materials with different Ti contents were employed as adsorbents for removing bisphenol A (BPA) from water systems. The adsorptive interaction between BPA and adsorption sites on the composite materials was investigated by Fourier transform infrared (FT-IR) and Raman spectroscopy. Adsorption capacities of BPA at equilibrium, q _e (mg/g), decreased with increasing Ti contents, proportional to the surface area of the composite materials. FT-IR observations for fresh and spent adsorbents indicated that BPA adsorbed onto the composite materials by the electrostatic interaction between OH functional groups contained in BPA and on the adsorbents. The electrostatic adsorption sites on the adsorbents were categorized into three hydroxyl groups: Si-OH, Ti-OH, and graphene-OH. In Raman spectra, the intensity ratios of D to G band were decreased after the adsorption of BPA, implying adsorptive interaction of benzene rings of BPA with the sp² hybrid structure of the reduced graphene oxide.     

In vitro and in vivo properties of graphene-incorporated scaffolds for bone defect repair

The employment of graphene and its derivatives, graphene oxide and reduced graphene oxide, is extending from bioimaging and fabrications of biosensors to drug delivery and tissue engineering in the biomedical area. Graphene family-incorporated scaffolds, used in bone tissue engineering and bone regenerative medicine, profit superior properties of these materials, such as enhanced mechanical properties, large surface area, and the existence of functional groups. At the same time, problems related to cytotoxicity and adverse immune response of graphene family are solved when they are applied to produce 3-dimensional scaffolds. The objective of this review is to focus on in vitro properties of scaffolds consisting of graphene or its derivatives, especially osteogenic and antibacterial properties, as well as the influence of graphene and its derivatives on in vivo performances of implanted bone scaffolds. The positive effect of graphene and its two derivatives on attachment, and cell proliferation, as well as in vitro osteogenic differentiation of different cells was undeniable. Besides, the synergetic outcome of using graphene family on the antibacterial feature of scaffolds, especially incorporation with the silver element, was effective. Moreover, successful treatment of critical-sized bone defects was reported during in vivo preclinical tests when graphene or its derivatives-incorporated scaffolds were used. However, the limited number of in vivo studies should be considered as one of the main shortcomings to use graphene as a promising candidate for treating bone defects. It is anticipated that the increased number of well-designed preclinical studies could improve the applications of graphene incorporated scaffolds in bone tissue engineering/regeneration, and find out explanations and appropriate solutions to possible long-term toxicity and nonbiodegradability of these materials.     

二氧化碳膜分离材料及其性能研究进展

CCUS是能源行业绿色发展的重要途经。与化学吸收法、变压吸附法和低温蒸馏法等传统工艺相比,膜分离方法具有低能耗、高效率、小型化、环境友好、易于与其他技术集成等优势。目前,膜材料的选择、改性以及对膜结构的重构是提高膜材料分离性能的关键。本文总结对比了有机聚合物膜、无机膜以及混合基质膜的研究进展,并对其分离机理、分离性能、改性研究以及用于制备混合基质膜的填充材料进行了综述,并进一步展望了CO₂分离膜材料性能改进的研究方向及膜分离技术所面临的挑战。     

氧化石墨烯/天然高分子复合吸附材料在水处理中的应用

近年来,氧化石墨烯(GO)复合吸附材料在水处理方面得到了广泛研究.由GO和天然高分子组成的复合材料具有吸附能力强、机械稳定性好等优点,且表面改性的GO可以进一步提高其吸附稳定性和吸附能力.介绍了GO/天然高分子复合吸附材料的制备方法;总结了GO表面官能团,如巯基、氨基、羧基等对吸附材料吸附性能的影响;综述了GO与壳聚糖、纤维素、海藻酸钠、木质素等天然高分子形成的复合吸附材料对水中染料和重金属离子处理的应用;最后对GO/天然高分子复合吸附材料在实际应用中的发展方向提出了展望.     

Graphene-based membranes for pervaporation processes

Two-dimensional graphene and its derivatives exhibiting distinct physiochemical properties are intriguing building blocks for researchers from a large variety of scientific fields. Assembling graphene-based materials into membrane layers brings great potentials for high-efficiency membrane processes. Particularly, pervaporation by graphene-based membranes has been intensively studied with respect to the membrane design and preparation. This review aims to provide an overview on the graphene-based membranes for pervaporation processes ranged from fabrication to application. Physical or chemical decoration of graphene-based materials is elaborated regarding their effects on the microstructure and performance. The mass transport of pervaporation through graphene-based membranes is introduced, and relevant mechanisms are described. Furthermore, performances of state-of-the-art graphene-based membranes for different pervaporation applications are summarized. Finally, the perspectives of current challenges and future directions are presented.     

石墨烯基气凝胶的制备及油吸附性能研究进展

海上漏油的频繁发生以及采油废水、工业含油污水的大量排放造成水资源大片污染和生态系统平衡的严重破坏。目前，从水体中分离油品和有机污染物已受到越来越多的商业和学术的关注。石墨烯基气凝胶是由二维石墨烯片层组装成的三维宏观材料，因其孔隙率高、比表面积大、密度低、机械性能强等特点在油水分离领域具有广阔的应用前景，已成为当今的研究热点之一。本文结合最新研究进展系统地总结了石墨烯基气凝胶的结构设计、组装及干燥方法，归纳了近年来其在油水分离中的应用进展，并对石墨烯基气凝胶在油水分离领域的研究现状和未来研究方向做了简要评述，以期为该领域的深入探索提供新的视角。     

石墨烯的制备及其负载催化剂的应用研究进展

石墨烯是一种具有二维平面结构的新型碳纳米材料,其特殊的单原子层结构使其具有独特的理化性质。石墨烯具有多种形貌和结构,其形貌和结构与优异的物理和化学性质息息相关,因此,有关石墨烯的制备和应用研究已成为研究的前沿和热点之一。综述了石墨烯的制备方法、功能化方法以及在化学领域中的应用。重点阐述石墨烯应用于化学修饰电极、化学电源和催化剂载体以及气体传感器等方面的研究进展,并对石墨烯在相关领域的应用前景作了展望。     

Insight into the dynamic adsorption behavior of graphene oxide multichannel architecture toward contaminants

Graphene oxide (GO) channels exhibit unique mass transport behaviors due to their flexibility, controllable thinness and extraordinary physicochemical properties, enabling them to be widely used for adsorption and membrane separation. Nevertheless, the adsorption behavior of nanosized contaminants within the channels of GO membrane has not been fully discussed. In this study, we fabricated a GO membrane (PGn, where n represents the deposition cycles of GO) with multi channels via the cross-linking of GO and multibranched poly(ethyleneimine) (PEI). Phenol was used as molecularprobe to determine the correlations between dynamic adsorption behavior and structural parameters of the multilevel GO/PEI membrane. PG8 shows higher adsorption capacities and affinity, which is predominantly attributed to the multichannel structure providing a large specific surface for phenol adsorption, enhancing the accessibility of active sites for phenol molecules and the transport of phenol. Density functional theory calculations demonstrate that the adsorption mechanism of phenol within GO channel is energetically oriented by hydrogen bonds, which is dominated by oxygen-containing groups compared to amino groups. Particularly, the interfaces which facilitate strong π-π interaction and hydrogen bonds maybe the most active regions. Moreover, the as-prepared PG8 membrane showed outstanding performance for other contaminants such as methyl orange and Cr(VI). It is anticipated that this study will have implications for design of GO-related environmental materials with enhanced efficiency.