生物分子响应性高分子材料

在智能高分子材料中,生物分子响应性高分子能够在糖类、多肽和酶等生物分子的刺激下发生宏观性质(如:体积、表面浸润性和硬度等)的大幅转变。生物分子响应性聚合物材料包括水凝胶、共聚物膜等类型,一般通过与生物分子间的氢键、分子间作用力等弱相互作用实现响应过程,在组织工程、功能材料、生物传感、药物可控释放等领域有广泛应用前景,吸引了大量科研人员的关注。与传统外源性刺激(温度、pH、光等)相比,生物分子作为刺激源的智能高分子材料具有更好的靶向性和生物相容性,能满足生物医用材料在人体内的应用,可以作为开发新一代精准药物的靶向释放平台。本文分别对糖类、蛋白、酶和DNA四类生物分子响应性高分子材料的结构设计、响应机制及相关应用进行概述,并对生物分子响应性高分子的发展方向作了展望。     

交联型温度/pH双敏水凝胶的设计与制备

刺激响应型水凝胶是其结构和性能随环境条件的变化而发生改变的一类智能高分子材料。由于温度和pH值是生物和化学系统的两个重要因素,也是人体的重要生理指标,因此温度/pH双重响应型水凝胶的制备及其在医药领域的应用研究具有重要的理论和现实意义。论文综述了近年来国内外温度/pH双敏水凝胶的设计与制备方法,并对其制备与应用的发展方向进行展望。     

环糊精相关的超分子自组装最新进展

对基于环糊精的超分子自组装的最新研究进展作了综述.详细介绍了环糊精为轮、高分子为轴的聚轮烷的制备及其修饰的方法,同时还介绍了无高分子参与的环糊精的超分子自组装高分子化合物的制备.并且对这些超分子在智能材料、生物医药和聚合催化等方面的应用进行了介绍.     

高分子基环境响应性肥料的研究进展

随着农业现代化进程的不断推进和高分子材料的不断发展,环境响应性肥料作为一种新型的功能化肥料正受到越来越多研究者的关注.环境响应性肥料是指能够根据温度和土壤环境中特定的刺激响应信号来改变吸水、保水和养分释放等行为,从而达到智能调控土壤中水分和养分的新型多功能肥料.本文首先简要介绍了肥料的发展阶段,然后根据外界刺激信号的不同和肥料实际的应用效果,将环境响应性肥料分为温度响应性肥料、pH响应性肥料和盐敏感性肥料,并对其制备方法、刺激响应行为和应用领域进行了综述.可以预期,天然高分子基环境响应性肥料、多重响应性智能肥料和生物响应性肥料的制备及其应用研究将会成为今后肥料科学的发展趋势.     

环境响应性聚合物刷的制备与应用

聚合物在材料表面通过物理吸附或化学接枝所形成的刷子状单分子层被称为聚合物刷,环境响应性聚合物刷能够根据环境微小变化可逆改变自身的物理化学性质,高分子链构象呈现伸展或塌缩状态等,显示了潜在的应用价值。本文综述了环境响应性聚合物刷的研究进展,讨论了温度响应性、pH值响应性、光响应性聚合物刷的结构特征和环境响应性机制,以及聚合物刷的各种制备方法,并着重介绍了其在智能膜、药物控释、催化、自组装、分子器件等领域的应用。     

分子印迹技术研究进展

分子印迹技术是制备对特定目标分子具有特异性识别能力的高分子材料的技术,所制备的高分子材料被称为分子印迹聚合物.分子印迹聚合物因具有预定性、识别性和实用性三大优点已广泛应用于分离、模拟抗体与受体、催化剂以及仿生传感器等方面和领域,显示出了广泛的应用前景.作者对分子印迹技术的发展历史、基本原理、分类、应用现状以及一些新的研究热点进行了综述.     

超分子凝胶可视化选择性识别有机小分子的研究进展

近年来,超分子凝胶作为一类非常重要的软物质材料而受到广泛关注,当前研究面临的最大问题之一是智能响应性,而智能响应性凝胶材料发展的一个重要研究方向是可视化选择性识别有机小分子。本文从有机小分子的类型(手性分子、位置异构体和氨基酸等)出发,较系统地综述了可视化选择性识别有机小分子的超分子凝胶的研究进展情况,并对该研究领域作了简单展望。     

刺激响应型石墨烯材料的研究新进展

石墨烯是一种具有六角型蜂巢状晶格的二维碳纳米材料,它由碳原子以sp2电子轨道杂化形成,它的高比表面积以及优良的力学、电学、光学和热学性能使它成为智能材料的基本构筑单元。利用具备特定功能的聚合物、小分子或者纳米粒子对石墨烯进行修饰或者杂化,得到具备相应刺激响应性能的石墨烯材料,与传统的刺激响应型高分子材料相比,它具备更佳的力学性能以及更好的环境稳定性,有望在致动器、传感器、自愈合材料、光热治疗以及可控药物输送等方面得到应用。本文简要概述了近年来利用对温度、pH、电、光以及有机分子等刺激响应的聚合物和小分子化合物对石墨烯进行修饰,并赋予其智能响应特性的方法以及相关应用研究,分析了现有智能响应石墨烯材料的不足,展望了其未来的应用前景以及发展方向。     

高分子气体分离膜技术研究进展

从纳米材料掺杂改性和新型制备工艺发展两方面,综述了高分子气体分离膜技术的研究进展。总结了不同纳米材料(GO、MOFs和CNTs)与高分子膜界面相容性的主要改善方法;介绍了具有超薄选择层的高分子复合膜制备工艺新进展并对高分子气体分离膜技术的研究重点和发展方向进行了展望。     

基于胆固醇的有机超分子智能凝胶

胆固醇分子具有特色的多环、多手性碳结构,因此可用于构筑有机超分子凝胶智能材料。该凝胶体系除了对温度有良好的感知响应性外,对其他的外界刺激,如光、pH、超声等也能够感知并响应。由于胆固醇分子是生命体中普遍存在的生物分子,基于胆固醇的有机超分子智能凝胶在生命现象模拟、药物输运等方面具有天然的优势。本文先根据胆固醇凝胶体系的不同种类,包括光响应型、氧化还原响应型、酸碱响应型、超声响应型,金属离子响应型以及触变响应型等,对该体系的结构与性能进行了介绍,然后介绍了对凝胶因子的修饰方法,最后结合目前的研究现状,探讨了胆固醇有机超分子凝胶的应用方向及前景。     

聚N-异丙基丙烯酰胺/β-环糊精离子聚合物的合成与表征

基于β-环糊精(β-CD)的超分子包合特性,最近几年我们对环糊精聚合物的药物控制释行为进行了广泛的探索性研究,通过分子设计合成并表征了一系列基于温度敏感性聚N-异丙基丙烯酰胺(PNIPAM)和β-CD的但却具有不同结构与性能的新型聚合物,研究发现,这些聚合物不但具有PNIPAM的热敏性,也具有β-CD的超分子包合性,并表现出独特的药物控释性能。     

Preparation of polar group derivative β-cyclodextrin bonded hydride silica chiral stationary phases and their chromatography separation performances

Three new polar group-substituted β-cyclodextrin derivatives were synthetized and they covalent bonded to hydride silica to obtain chiral stationary phases. Their separation results of 35 chiral pyrrolidine compounds were also presented and discussed.     

Thermo-responsive stick-slip behavior of advancing water contact angle on the surfaces of poly(N-isopropylacrylamide)-grafted polypropylene membranes

Wettability of a solid surface is highly important to its practical application,especially for the surface that shows thermoresponsive properties.In this paper,we describe a thermo-responsive stick-slip behavior of water droplets on the surfaces of poly(N-isopropylacrylamide)(PNIPAM)-grafted polypropylene membranes.Field emission scanning electron microscope(FESEM) images elucidate that the morphology of PNIPAM-grafted membrane surface is thermo-responsive,i.e.,the surface becomes rougher above the lower cr...     

Polyrotaxane-based triblock copolymers synthesized via ATRP of N-isopropylacrylamide initiated from the terminals of polypseudorotaxane of Br end-capped pluronic 17R4 and β-cyclodextrins

Thermo-responsive polyrotaxane (PR)-based triblock copolymers were synthesized via the atom transfer radical polymerization (ATRP) of N-isopropylacrylamide initiated with self-assemblies made from a distal 2-bromoisobutyryl end-capped Pluronic 17R4 (PPO14-PEG24-PPO14) with a varying amount of β-cyclodextrins (β-CDs) in the presence of Cu(I)Cl/PMDETA at 25 °C in aqueous solution. The molecular structure was characterized by means of H NMR, FTIR, WXRD, GPC, TGA and 1 DSC analyses. About half of β-CDs are still entrapped on the Pluronic 17R4 chain while the number of incorporated NIPAAm monomers is nearly a double feed value in the resulting copolymers. The aggregate morphologies in aqueous solution were evidenced by TEM observations. A two-step thermo-responsive transition arising from a combination of a polypseudorotaxane middle block with poly(N-isopropylacrylamide) flanking blocks was also demonstrated by turbidity measurements. Given their thermo-responsive behavior in aqueous solution, these PR-based triblock copolymers show the potential to be used as smart materials for the controlled drug delivery systems, biosensors, and the like.     

Novel fluorinated amphiphilic cyclodextrin derivatives: Synthesis of mono-, di- and heptakis-(6-deoxy-6-perfluoroalkylthio)-β-cyclodextrins

A new series of fluorinated amphiphilic β-cyclodextrin derivatives has been synthesized. The strategy is based on the modification of the C-6 position of the mono-6-deoxy-6^A-para-tolylsulfonyl, di-6^A, 6^D-deoxy-6^A, 6^D-(para-tolylsulfonyl) and heptakis-(6-deoxy-6-iodo)-β-cyclodextrin precursors. The synthesis lead to mono-perfluoroalkylthio-, di-perfluoroalkylthio- and heptakis-perfluoroalkylthio-β-cyclodextrin in excellent yields (90-99%).     

Novel calcium-alginate capsules with aqueous core and thermo-responsive membrane

Novel calcium-alginate (Ca-alginate) capsules with aqueous core and thermo-responsive membrane are successfully prepared by introducing a co-extrusion minifluidic approach, and the thermo-responsive gating characteristics of Ca-alginate capsule membranes embedded with poly(N-isopropylacrylamide) (PNIPAM) microspheres are investigated systematically. The experimental results show that the prepared Ca-alginate capsules are highly monodisperse, and the average diameter and membrane thickness of Ca-alginate capsules are about 2.96 mm and 0.11 mm respectively. The Ca-alginate capsule membranes exhibit desired thermo-responsive gating property. With increasing the content of PNIPAM microspheres embedded in the Ca-alginate capsule membranes, the thermo-responsive gating coefficient of the capsule membranes increases simply. When solute molecules diffuse through the capsule membrane, the thermo-responsive gating coefficient is significantly affected by the molecular weight of solute molecules.     

Thermo-responsive Hercosett/Poly(N-isopropylacrylamide) films: a new, fast, optically responsive coating

Poly(N-isopropylacrylamide) (PNIPAM) is a common thermo-responsive, water-soluble polymer, while Hercosett is a cationic resin commonly employed in the paper industry. In this paper, Hercosett? and poly(N-isopropylacrylamide) (PNIPAM) nanoparticles were used to prepare composite films that show thermo-responsive behavior and swelling–shrinking properties in water. First, size-controlled PNIPAM hydrogel nanoparticles were synthesized. These were then embedded within a matrix of the cationic resin Kymene 577H by film casting. The distribution of nanoparticles in the resin film was investigated. The thermo-responsive properties of the as-synthesized PNIPAM hydrogel nanoparticles and of the composite films were characterized together with the repeatability of the swelling–shrinking cycles. The presence of nanoparticles endowed the film with highly enhanced water retention (in comparison with resin-only films) and, most importantly, thermo-responsiveness. A very fast optical and morphological response was in fact observed. Due to the dual (optical and morphological) response, this new system is suitable for applications in optical or morphological actuation and gating.     

Highly branched stimuli responsive poly[(N-isopropyl acrylamide)-co-(1,2-propandiol-3-methacrylate)]s with protein binding functionality

Highly branched poly(NIPAM) have been prepared using the technique of reversible addition-fragmentation chain transfer (RAFT) polymerisation using a chain transfer agent that allows the incorporation of imidazole functionality in the polymer chain-ends. The lower critical solution temperature (LCST) of the polymers can be controlled by the amount of hydrophobe and GMA incorporated during copolymerisation procedures. These thermally responsive "smart" polymers were used to purify a His-tagged BRCA-1 protein fragment by affinity precipitation. [Diagram: see text]     

Synthesis and interfacial properties of amphiphilic β-cyclodextrins and their substitution at the O-6 position with a mono bio-recognisable galactosyl antenna

The synthesis of a mono-galactosylated amphiphilic β-cyclodextrin, in five steps from mono-6-azido-6-deoxy-β-cyclodextrin, via coupling to a N-β-d-galactopyranosylamino-antenna is described. Both characterization by electrospray mass spectrometry and NMR show the presence of only the mono-substituted product. The Langmuir isotherms of the final product and intermediates are described.     

Temperature-driven oxygenation rate control by polymeric photosensitizer

A polymeric photosensitizer, poly(NIPAM-co-BP), consisting of N-isopropylacrylamide (NIPAM) and benzophenone (BP) units, demonstrates a temperature-controlled oxygenation activity in water. The system promotes a heat-induced oxygenation enhancement at <17 degrees C and suppression at >22 degrees C. This unprecedented photo-oxygenation activity is triggered by a heat-induced phase transition of the polymer from coil to micelle, and then to globule state, cleverly controlling the stability and diffusion of singlet oxygen and the location of substrate.