基于聚多巴胺的表面改性方法研究现状

多巴胺具有与贻贝粘附蛋白类似的性能。它可以沉积在几乎所有物质表面对其进行改性,且能与氨基、巯基、金属离子等官能团反应,所以将多巴胺修饰在材料表面不但可以赋予材料表面依赖于聚多巴胺(PDA)的仿生特性,而且PDA的反应活性为材料表面的二次修饰提供了理想的平台。这种基于PDA的表面修饰方法不但简单、绿色且适用性非常广,可应用于化学、生物、医药、材料等多个领域。本文从多巴胺的结构以及聚合、粘附机理研究入手,对近几年在材料表面修饰PDA,且以其为平台再二次修饰的报道进行了归纳总结,进一步认识和理解了多巴胺的性能,并为设计和构建新型的、高性能化的PDA仿生功能材料提供思路,推动研究者们在此基础上将PDA应用于更多的领域,使其向着绿色化和多样化方向发展。     

多巴胺改性海藻酸多孔支架的制备与性能

生物大分子海藻酸(Alg)由于其安全、无毒、可生物降解等特性而被广泛应用于组织工程领域。 受海洋贻贝蛋白结构的启发,多巴胺(DA)具有优异的粘附性能,在碱性水溶液条件下可发生氧化自聚形成聚多巴胺(PDA)。 以Alg为基体,加入PDA纳米粒子复合,并通过冷冻干燥法制备得到Alg/PDA多孔支架材料。 结果表明,Alg/PDA多孔支架材料具有较为规整的内部结构。 改变Alg质量浓度,Alg/PDA支架材料的孔径可控制在60~120 μm之间,孔隙率可控于80%~88%。 所得的支架材料具有适宜大小的孔径和孔隙率,结果表明支架材料对细胞无毒副作用。     

功能蛋白纳米材料在环境保护中的应用

蛋白质是一类结构稳定、官能基团丰富的生物大分子。近年来基于功能蛋白纳米材料的改性制备逐渐成为环境领域的研究热点。其中多巴胺、淀粉样纤维和蛋白质杂化纳米花是最具代表性的三类功能蛋白纳米材料。受海洋生物贻贝启发,多巴胺在碱性条件下可氧化自聚成富有黏性的聚多巴胺涂层广泛用于界面改性;淀粉样纤维是功能蛋白经热处理或化学变性形成超高长径比纳米结构,进一步暴露氨基酸活性位点,进而强化对污染物净化性能;而蛋白三维结构也方便与金属磷酸盐形成杂化纳米花结构,提供较大比表面积,可协同金属磷酸盐高效净污。本文基于蛋白质的结构特性,总结了多巴胺、淀粉样纤维和蛋白质杂化纳米花三类纳米复合材料的制备、形成机理及在环境污染控制工程中的应用进展,为后续科研工作提供借鉴。     

聚多巴胺表面修饰毛细管电色谱的研究进展

毛细管电泳（CE）具有分离时间短、分离效率高、样品消耗量低等优点,在分离分析领域有着重要应用。原始的未修饰熔融石英毛细管只能提供阴极流向的电渗流和单一的电泳分离机制,分离性能有限,重复性较差,不能满足各类复杂样品体系尤其是中性和手性样品的分离需求。因此,有必要在CE中引入各类毛细管修饰策略,以拓展其实际应用潜力。贻贝仿生聚多巴胺（PDA）及其衍生材料因其简便易行的制备过程、优异的表面黏附性、良好的生物相容性、较强的二次反应活性和化学稳定性等优点,在催化、传感、水处理、样品前处理、生物医药以及CE分离等领域得到了广泛应用。PDA涂层的制备过程与物理吸附涂层一样简便,而表面黏附涂层的稳定性又可与共价键合涂层相媲美,因此非常适用于石英毛细管柱的修饰。更重要的是,PDA涂层较强的二次反应活性使其可作为反应平台进行灵活多样的二次表面修饰,便于构建多功能PDA涂层毛细管电色谱（CEC）固定相。基于这些突出优点,PDA涂层材料在CEC中的巨大应用价值逐渐得到了研究者们的广泛关注。该文首先对近3年有关PDA形成机理及PDA快速沉积表面化学的最新研究进展进行了总结,在此基础上综述了近10年PDA涂层材料在开管毛细管电色谱（OT-CEC）和毛细管电色谱整体柱中的最新应用。此外,还对PDA涂层材料在CEC中的发展方向进行了展望。     

聚多巴胺对材料表面功能化的研究及应用进展

蚌类蛋白质结构中起黏附作用的为多巴(DOPA)分子,其衍生物——聚多巴胺(PDA)常作为黑色素类似物被广泛应用于各领域。虽然目前PDA的形成机理仍很难被明确阐述,但这并不阻碍其在各个领域发挥强大的功效。由于PDA既具有强黏附性又富含各种官能团,其可在不同材质表面进一步反应形成功能层,从而实现对材料表面的功能化改性。鉴于科研工作者对PDA的浓厚兴趣,本文综述了其发现、形成机理的发展过程以及PDA功能化纳米粒子的研究,包括PDA功能化金属纳米材料、还原石墨烯材料、磁性纳米粒子和PDA纳米材料,展望了其发展前景。     

仿贻贝粘性高分子的应用进展

海洋贻贝类生物的足丝分泌蛋白几乎能够在所有基底材料上实现高强度、高韧性的粘附,且不受水或者潮湿环境影响。这种环境友好、条件温和的高效生物粘附剂引起了研究人员的兴趣,尤其在粘附机理和应用前景方面更是研究人员关注的重点。大量研究表明,贻贝超强的粘附能力与其分泌的粘附蛋白中高含量的3,4-二羟基苯丙氨酸(多巴,DOPA)单元相关。受贻贝粘附蛋白的启发,人们研究发现,多巴胺(DA)分子具有与之相似的官能团,聚合后有相似分子结构,使用聚多巴胺替代聚多巴,可以在基体表面达到相似的粘附性能。本文简单介绍了仿贻贝粘性物质中的代表多巴胺自聚合形成聚多巴胺(PDA)与粘附机理,并重点介绍了近年来DOPA衍生物在表面改性、催化、生物防污及生物医学领域的应用和前景。     

聚多巴胺表面改性技术在分离科学领域中的应用

聚多巴胺作为新型仿生材料,具有制备过程简单、环保和适用面广（可用于各种类型基质表面改性）等优点,已被广泛应用于化学、生物医学、药学、传感器和电池制造等领域。在分离科学领域,聚多巴胺不仅可用于制备色谱固定相,也可用于制备新型的富集材料。该文对聚多巴胺的形成机理研究现状进行了简单介绍,主要综述了近年来聚多巴胺在色谱分离和富集领域的应用,包括毛细管电泳/电色谱、液相色谱、分子印迹固相萃取、分散固相微萃取和固相微萃取等技术领域。     

仿贻贝粘附蛋白聚合物的研究及动态

贻贝粘附蛋白以其对不同基材表面及在水下都具备高强的粘附能力而闻名。根据仿生学原理,通过将贻贝粘附蛋白功能元即邻苯二酚基团与合成高分子相结合制备仿贻贝粘附蛋白聚合物,达到复制重现甚至超越天然贻贝粘附蛋白粘附效力的目的,是目前贻贝仿生领域研究热点之一。本文综述了近年来国内外仿贻贝粘附蛋白聚合物的研究进展。我们按照主链结构的种类进行了分类,对仿贻贝粘附蛋白聚合物材料的发展过程、材料的设计思路以及应用领域进行了系统的归纳总结。通过研究分子结构与仿生材料功能特性之间的相互关系,希望为以后设计合成新型的功能化的贻贝仿生材料提供有益的借鉴和参考。     

生物/化学同步聚合法制备纤维蛋白纳米复合物及传感研究

本文以有效提高生物分子包埋率为目的,基于生物/化学同步聚合的新方法制备了一种新型纤维蛋白聚合物基纳米复合物,并研究了该复合物修饰电极的传感性能。该方法在凝血仿生聚合的同时,采用NaAuCl4作为氧化剂化学氧化聚合生成聚多巴胺(PDA),在PDA膜内原位合成纳米金(AuNPs),同时在PDA-纤维蛋白凝胶生长时包埋葡萄糖氧化酶(GOx)。生物/化学同步聚合法操作简单,条件温和。该纳米复合物引入了AuNPs的优异性质,有效提升了GOx的包埋量,所制电化学生物传感器对葡萄糖的检测灵敏度高达117μA/(cm2·mmol/L),检测限为57nmol/L。     

聚多巴胺涂层的研究与应用进展

多巴胺在有氧化剂且弱碱性环境下会发生自聚合形成聚多巴胺,聚多巴胺能够在多种基底材料(包括贵金属、金属氧化物、无机及有机高分子材料等)表面实现黏附形成聚多巴胺涂层,基于聚多巴胺涂层中含有大量可以参与反应官能团的特点,聚多巴胺涂层表面可以进行二次修饰从而制备功能性材料表面,也可以基于多巴胺/聚多巴胺与功能性物质之间相互作用,一步法制备功能性材料表面。近些年来,基于聚多巴胺涂层发展起来的两步修饰法和多巴胺一步共混沉积法在诸多领域得到了应用。本文主要综述了聚多巴胺涂层的最新研究和应用进展。     

用流动电位法表征纳滤膜的结构及性能

利用测量流动电位的方法考察了纳滤膜的表面电学性能对纳滤膜的截留性能的影响.首先,采用不同功能层材料制备了复合纳滤(NF)膜,考察功能层的交联时间、单体结构等对表面电性能的影响,研究纳滤膜对不同无机盐的选择截留性能与表面电性能的关系.通过流动电位法测定纳滤膜的表面电学参数,如流动电位(ΔE)、zeta电位(ζ)和表面电荷密度(σd).实验表明,这些电学参数的变化与功能层交联时间和纳滤膜截留率的变化一致,在交联时间为45 s时,3种电学参数的绝对值均最大,而纳滤膜对无机盐的截留率也最大.复合纳滤膜zeta电位的绝对值(|ζ|)按照Na2SO4>MgSO4>MgCl2变化,同截留率的变化相同.带侧基单体交联后得到的纳滤膜的表面电性能参数的绝对值小于不带侧基单体的.因此,流动电位法可用于研究复合纳滤膜的截留机理和功能层结构.     

高分子纳滤膜的制备技术

纳滤膜是介入于反渗透膜和超滤膜之间的一种压力驱动的新型分离膜,已成为近年来研究的热点,由于其载留分子量范围相对较窄（200－1000）且孔径处于纳米级（10^-9m),因此膜材质的选择及制备技术成为制备出高性能纳滤膜的关键。本文介绍了高分子纳滤膜的几种主要的制备工艺,并概述了近年来国内外在高分子纳滤膜材质、制备方法以及所制膜性能及应用方面的研究进展。     

Nano/subnano-tuning of porous ceramic membranes for molecular separation

In sol–gel processing, porous ceramic membranes can be prepared by sol-coating porous substrates and drying for gelling, followed by a firing process. Ceramic membranes prepared by sol–gel processing can be categorized into amorphous materials such as silica, and crystalline materials such as alumina and titania. Amorphous silica networks, which can be prepared by the polymeric sol route, have ultra-microporous pores that allow small molecules such as helium and hydrogen to permeate. On the other hand, crystalline materials, which are mostly prepared by the colloidal sol route, have nano-sized pores in the range of one to several nanometers. In this article, sol–gel derived SiO₂ and TiO₂ membranes with controlled pore sizes in the range of sub-nano to nanometers will be reviewed with respect to membrane preparation and to their application in the separation of the gas and liquid phases. Ceramic membranes with high performance can be obtained by precise control of membrane structures (pore size, pore size distribution, thickness, pore shape, etc.) and membrane materials (SiO₂, TiO₂, composite oxide, hybrid materials, etc.). Nano/subnano-tuning of porous ceramic membranes is quite important for the improvement of membrane permeability and selectivity.     

Is click chemistry attractive for separation sciences?

Trends in LC focus on dedicated separation developments spanning different fields of applications ranging from sample preparation to miniaturization. Chromatographic performances result from the porous media, its implantation inside the “column,” and its surface functionalization. Because molecular interactions govern chromatographic phenomena, surface functionalization is still a hot research topic. Besides standard approaches for surface functionalization, the use of new surface chemistry reactions opens new perspectives. Click chemistry belongs to this new class of chemical reactions, characterized by its specificity, compatibility with aqueous media, and high reaction yields. In this frame, we review the use of click chemistry reactions in chromatographic sciences. In a first part, we present click chemistry with a specific focus on its implementation in stationary phases. The use of these new clicked materials is detailed and discussed with respect to the chromatographic mode.     

Highly stable and antifouling graphene oxide membranes prepared by bio-inspired modification for water purification

Graphene oxide (GO) membranes show great potential in molecular separation for water treatment. However, the inferior stability of GO membranes is a major bottleneck for practical applications. In this study, bio-inspired polydopamine (PDA) deposition is reported for enhancing the stability of GO membranes. Through simple and mild immersion, PDA is self-polymerized on GO membranes. The blocking of PDA chains to membrane defects improves the rejections for various molecules. Because the inherently strong adhesion and crosslinking of PDA greatly strengthen the interactions of substrates to GO layers and the binding force of GO nanosheets, the prepared PDA-GO membranes exhibit impressive long-term stability in cross-flow filtration, and maintain good nanofiltration performance at various feed pressures, tangential velocities, and even after external scratching. Moreover, because the deposited PDA layers obstruct the direct contact between GO and contaminants, the antifouling property of the PDA-GO membranes increases substantially, with recovery ratio about 98%.     

Polysulfone functionalized membranes: Properties and challenges

One of the most important polymers for membranes manufacturing is Polysulfone because of its remarkable properties, like chemical stability, mechanical and thermal properties, and also due to the possibility to obtain a wide range of polymeric membranes for different applications. Membrane functionalization is a key process to obtain high-value membrane materials. The present review paper is a guide related to the latest researches performed in the field of functionalization reactions of polysulfone membranes. It is based on both approaches – reactions performed at the surface of the membranes and also on applications. In this article, ion exchange membranes, biomedical or catalyst applications are presented and commented. Furthermore, key factors or analysis related to the main properties of functionalized membranes are also considered.     

Selective functionalization of 3-D polymer microstructures

We demonstrate the selective functionalization of 3-D polymer microstructures that were created using multiphoton absorption polymerization. By fabricating different portions of the structures with acrylic and methacrylic polymers, we are able to take advantage of the differential reactivities of these materials to perform functionalization chemistry on a single polymeric component. We demonstrate the selective deposition of metal to create structures, such as a functional microinductor. Our strategy is quite general and can be extended readily to the deposition of materials, such as metal oxides and biomolecules.     

Marrying mussel inspired chemistry with SET‐LRP: A novel strategy for surface functionalization of carbon nanotubes

Surface functionalization of carbon nanotubes (CNTs) with a thermo responsive polymer was achieved via combination of mussel inspired chemistry and surface initiated single electron transfer living radical polymerization (SET‐LRP). In this procedure, CNTs were first coated with polydopamine (PDA) through self polymerization under a rather mild condition. And then PDA functionalized CNTs bearing with amino and hydroxyl groups were further reacted with bromo isobutyryl bromide. Finally, a thermo responsive polymer poly(N‐isopropylacrylamide) (PNIPAM) was introduced on the CNTs via SET‐LRP. The successful surface modification of CNT‐PDA‐PNIPAM was evidenced by a series of characterization techniques. The resulting CNT‐PDA‐PNIPAM showed significant enhancement of dispersibility in both aqueous and organic solvents. More importantly, these CNT‐polymer nanocomposites showed obvious thermo responsive behavior due to the surface coating CNTs with PNIPAM. As compared with previous methods, this method is not required oxidation of CNTs to introduce funcitonal groups for immobilization of the polymerization initiators. More importantly, this method could also be utilized for fabricating many other polymer nanocomposites because of the strong and universal adhesive of PDA to various materials. It is therefore, the novel strategy via marrying mussel inspired chemistry with SET‐LRP should be a simple, general and effective method for surface functionalization. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015 , 53, 1872–1879     

Inorganic membranes and solid state sciences

The latest developments in inorganic membranes are closely related to recent advances in solid state science. Sol–gel processing, plasma-enhanced chemical vapor deposition and hydrothermal synthesis are methods that can be used for inorganic membrane preparation. Innovative concepts from material science (templating effect, nanophase materials, growing of continuous zeolite layers, hybrid organic–inorganic materials) have been applied by our group to the preparation of inorganic membrane materials. Sol–gel-derived nanophase ceramic membranes are presented with current applications in nanofiltration and catalytic membrane reactors. Silica membranes with an ordered porosity, due to liquid crystal phase templating effect, are described with potential application in pervaporation. Defect-free and thermally stable zeolite membranes can be obtained through an original synthesis method, in which zeolite crystals are grown inside the pores of a support. Hybrid organic–inorganic materials with permselective properties for gas separation and facilitated transport of solutes in liquid media, have been successfully adapted to membrane applications. Potential membrane developments offered by CVD deposition techniques are also illustrated through several examples related to the preparation of purely inorganic and hybrid organic–inorganic membrane materials.