超分子聚合物制备新方法:超分子单体的共价聚合

超分子聚合物是超分子化学与高分子化学交叉的前沿研究领域,近年来受到了国内外研究学者的广泛关注.可控制备超分子聚合物对于研究超分子聚合物的结构与性能关系、设计合成特定功能的超分子聚合物具有重要的意义.本文将总结通过超分子单体的共价聚合反应以制备超分子聚合物的方法.不同于传统的制备超分子聚合物的方法,超分子单体的共价聚合方法将不易调控的非共价聚合转化为可控的共价聚合,为实现超分子聚合物的可控制备提供了新思路.     

界面超分子聚合

超分子聚合物诞生于高分子化学与超分子化学的交叉融合,一般是指单体间通过非共价键作用连接形成的聚合物,并在溶液或体相中表现出类似聚合物的性质。目前超分子聚合物一般通过均相溶液聚合制备得到,但溶液中的超分子聚合是一个自发的组装过程,具有浓度依赖性,组装过程不易可控。为解决此问题,研究人员可以将超分子聚合从均相溶液转移到界面,在界面上可控地制备超分子聚合物。通过界面聚合制备超分子聚合物具有一些独特的优势,如可以制备得到分子量更高的超分子聚合物,易于制备一些缺陷少、面积大、有序的二维超分子聚合物等。本文基于在液-液、气-液和固-液三种界面上制备超分子聚合物的一些代表性工作,介绍了界面超分子聚合方法和应用,并展望其未来发展。     

光响应超分子聚合物

超分子聚合物是超分子化学、高分子化学和材料化学领域的研究热点.将光响应的功能基团以非共价作用构筑到超分子聚合物体系中,得到光响应型超分子聚合物,从而能够将超分子聚合物的独特性质与光化学反应的优势有效地结合起来,从而构筑新型的光功能材料.本文总结了近年来本课题组有关光响应超分子聚合物方面的研究工作:介绍了主链型的光响应超分子聚合物的光调控组装和解离,超分子聚合物和共价聚合物的光控可逆切换和光调控组装形貌;另外还举例介绍了具有自修复和室温磷光发射等功能的侧链型光响应超分子聚合物,并对刺激-响应的超分子聚合物领域的发展做了展望.     

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.     

超分子和高分子自组装的动力学模拟研究

超分子和高分子的自组装是发展新型高性能材料的有力手段.通过自组装构筑多级有序结构,从而显著提高材料的力学、光学或电学性能,是化学和材料科学研究的前沿.然而精确调控自组装需要深入理解范德华、氢键、静电、主客体复合和π-π等相互作用以及动力学机理所扮演的角色.计算机模拟,尤其是分子动力学模拟,为研究自组装结构和演化过程提供了独一无二的手段.本文主要阐述超分子和高分子的多尺度模型和动力学模拟方法,讨论不同模拟方法的特点、适用范围和优势;进一步简述我们发展的定制模型和方法,以及同时提高模型精度和计算效率方面采取的策略.通过总结应用这些方法对超分子和高分子自组装开展的研究工作所取得的进展,为进一步发展自组装动力学模拟方法提供参考.     

基于冠醚和柱芳烃主客体识别的超分子聚合物材料

超分子聚合物材料是高分子科学、超分子化学和材料科学3个学科相结合的产物.通过精妙的设计,我们不仅可以赋予它传统高分子材料所拥有的光学、电学以及力学等性能,同时还可以使其具有超分子材料的动态可逆性和刺激响应性.已用于构筑超分子聚合物材料的主客体识别体系有很多,从识别体系中的主体来说,包括基于冠醚、环糊精、杯芳烃、葫芦脲、柱芳烃等大环的主客体体系.其中,冠醚作为第一代大环主体,它的模板合成直接开辟了超分子化学这一领域,而柱芳烃是最近发展起来的一类新的大环主体,它具有刚性的骨架,并且制备简单,容易功能化,同样也受到超分子化学家们的广泛关注.本文着重综述了我们课题组基于冠醚和柱芳烃主客体识别所构筑的超分子聚合物材料.在这些材料的制备中,我们利用了主客体识别的刺激响应性、可逆性和选择性,来实现对这类材料的组装结构以及功能的精确调控.     

磁性分子印迹聚合物核壳微球的制备及应用*

分子印迹技术是综合高分子化学、生物化学等学科发展起来的一门边缘学科。通过分子印迹技术制备的聚合物具有吸附选择性好、色谱效率高、便于功能设计等优点,在色谱分离、固相萃取、传感器、药物控释等领域得到了广泛的应用。磁性聚合物微球是近年发展起来的一种新型多功能材料,已广泛应用于生物分离、药物控释、疾病诊断等领域。在磁性粒子表面进行分子印迹制备的磁性分子印迹聚合物核壳微球,兼有良好的超顺磁性和高选择吸附性两大优点,具有广阔的应用前景。本文重点综述了磁性分子印迹聚合物核壳微球的制备方法以及在化学分析、生物分离和药物控释方面应用的研究进展,并指出了该领域工作存在的问题及今后的发展方向。     

中国超分子聚合物的研究与动态

超分子聚合物是高分子科学与超分子科学交叉的研究方向.超分子聚合物的研究在中国引起了学术界的广泛兴趣,中国的学者们对推动此研究领域的发展做出了贡献,并在新的超分子聚合方法、可控超分子聚合以及功能超分子聚合物等方面取得了一系列重要的创新成果.本文总结和评述了中国超分子聚合物的研究与动态,并展望了超分子聚合物化学、超分子聚合物物理、超分子聚合物表征及功能超分子聚合物的未来发展.     

分子印迹聚合物微球的制备及表征技术

分子印迹聚合物微球作为一种具有分子识别能力的新型高分子材料,以其吸附选择性好、色谱效率高、便于功能设计等优点在固相萃取、药物手性分离等领域取得了应用.本文介绍了分子印迹聚合物微球的主要制备方法,比较了不同的聚合物微球制备方法用于分子印迹技术中的特点,同时针对不同聚合方法对分子印迹聚合物微球性能的影响作了相应评述,此外对其结构与性能的表征方法也作了较为详细的介绍,在此基础上分析了存在的问题及今后的发展方向.     

分子印迹聚合物传感器研究

分子印迹聚合物(molecular imprinting polymers,MIPs)是利用分子印迹技术合成的一种交联高聚物.分子印迹技术(molecular imprinting technique,MIT)是在近十几年来才发展起来的一门边缘科学技术.它结合了高分子化学、生物化学等学科,是模拟抗体-抗原相互作用的一种新技术,具有选择性识别位点的性质,作为传感器的理想敏感材料的制备方法日益受到研究者们的重视.本文综述了分子印迹技术的原理和分子印迹聚合物的制备方法,及其应用于传感器敏感材料的研究现状,并展望了其发展前景.     

Studies on Novel Polymer Materials Prepared through Intermacromolecular Complexation

The basic feature of polymers is their multi-order structure. Structure change at each level offers a possibility tomodify polymer properties and to develop new polymer materials. Therefore,novel polymer materials can be developed by tailoring their chain structure through chemical bonding among atoms, i.e., via the traditional molecular chemistry methods, e.g., polymerization of new monomer, controlling chain length (molecular weight and molecular weight distribution) and stereoregularity, copolymerization of different kinds of monomers, controlling sequence distribution,block of graft length of copolymer, etc., which have been the focus of polymer chemistry for several decades, as well as by tailoring specific supramolecular architecture using molecules as building block through intermolecular interactions, i.e., via supramolecular science methods, e.g., molecular self-assembly, intermacromolecular complexation, etc., which is a modern and fast-developing academic research field.This paper reports novel polymer materials prepared through intermacromolecular complexation,e.g., a new polymer solid electrolyte poly(metyl methacrylate-methacrylic acid)[P(MMA-MAA)]/poly(ethylene oxide) (PEO)/A2-LiClO4 developed by intermacromolecular complexation through hydrogen bonding, which has enhanced ambient ionic conductivity and fairly good mechanical and film-forming properties, a new polymer microcomposite poly(acrylonitrile-acrylamide-acrylic acid) [P(AN-AM-AA)]/poly(vinyl alcohol) (PVA) reinforced by the twin molecular chain microfibrils formed through intermacromolecular complexation of P(AN-AM-AA) with PVA through hydrogen bonding, which exhibits much better mechanical properties than its constituents and could be used to manufacture PVA based complexed fibers with higher modulus and better dyeability, a new polymer flooding agent poly(acrylamide-acrylic acid)[P(AM-AA)]/poly(acrylamide- dimethyldiallylammonium chloride) [P(AM-DMDAAC)] developed by intermacromolecular complexation of the oppositely charged polyions through Coulomb forces,which shows much higher viscosity and better resistance to temperature, shear rate and salt than its constituents, and has potential application in enhanced oil recovery.     

渗透汽化型酯化膜反应器研究 聚合物/无机固体酸管式复合膜的膜反应性能

设计了渗透汽化型管式膜反应器,以乙酸丁酯合成反应为探针,考察了Ｚｒ（ＩＶ）／ＰＶＡ,Ｚｒ（ＩＶ）－ＰＶＡ／ＰＶＡ两类聚合物担载无机固体酸管式复合膜的膜催化反应性能。探讨了功能膜的组成,结构,反应条件等对膜反应和分离性能的影响以及同步膜分离过程对反应转化的促进作用。实验结果表明,膜催化酯化反应过程主要是依赖与料液接触侧膜表面层的催化活性,膜的催化活性是影响反应速率,特别是初期反应转化速率的主要因素,后期的超平衡转化则依赖于膜分离过程     

复杂基体中痕量多环芳烃分析测定方法的研究进展

介绍了环境样品（水和土壤）以及植物油中痕量多环芳烃的分析检测方法。对样品的预处理过程和分析方法做了评价。采用一些新的预处理方法（包括液相色谱法、固相萃取法、超临界二氧化碳萃取法）,并结合色谱-质谱在线联用分析检测方法能够获得比较理想的分析结果。引用文献52篇。     

聚乙烯醇膜耐水改性的研究进展

聚乙烯醇(PVA)作为一种广泛应用的水溶性高分子聚合物,具有较好的气体阻隔性、热稳定性、生物相容性,故以此基料的改性膜材料成为重要的研究方向。但是由于聚乙烯醇结构中含有大量的亲水性基团(—OH),导致成膜的耐水性差,这很大程度上限制了它的推广和应用。本文总结了国内外对聚乙烯醇膜耐水改性的方法,如酯化交联、羟醛缩合、复配增塑、纳米补强和共混杂化等,有利于进一步推进聚乙烯醇耐水改性的研究,为设计和制备高性能的聚乙烯醇膜提供一定的参考,并进一步拓展聚乙烯醇的应用范围。     

Preparation of novel thermoplastic poly(vinyl alcohol) with improved processability for fused deposition modeling

In this work, thermoplastic poly (vinyl alcohol) (PVA) with improved processability for fused deposition modeling (FDM) was successfully prepared via intermolecular complexation and plasticization. The glycerol and water, which were non‐toxic and have a complementary structure with PVA, were adapted to realize FDM processing of PVA, thus providing a novel biomaterial with FDM processability. The result showed that the water and glycerol could interrupt hydrogen bonding in PVA and reduce the melting point of PVA to 127.4°C. Moreover, the water fraction of the plasticizer had a significant effect on the FDM processability and usability of the final parts. When the water fraction was greater than 75%, the PVA/plasticizer was unsuitable for FDM processing. However, when the water fraction was lower than 25%, the glycerol precipitated from the modified PVA. Thus, a mixture of 50% water and 50% glycerol was most suitable for FDM processing. A 0.3 mm layer thickness with a nozzle temperature of 175°C was chosen as the optimal processing condition for FDM using thermoplastic PVA. Finally, complex PVA parts with high dimensional accuracy, good mechanical properties, and designated structures were fabricated by FDM machine.     

Dithiane- and trithiane-based photolabile scaffolds for molecular recognition

[see structure]. A modular synthetic approach to novel dithiane- and trithiane-based photolabile molecular hosts equipped with elements of molecular recognition is developed. The approach provides ready access to a family of amino-derivatized photocleavable molecular systems capable of hydrogen-bonding-based recognition of biologically relevant molecules, e.g., ureas, barbiturates etc. These systems undergo efficient photofragmentation in the presence of external (e.g., benzophenone) or internal (e.g., nitropyridine) electron-transfer sensitizers.     

Physically crosslinked poly(vinyl alcohol)-hydroxyethyl starch blend hydrogel membranes: Synthesis and characterization for biomedical applications

Poly(vinyl alcohol), PVA is a polymer of great importance because of its many appealing characteristics specifically for various pharmaceutical and biomedical applications. Physically crosslinked hydrogel membranes composed of different amounts of hydroxyethyl starch (HES) in (PVA) and ampicillin were prepared by applying freeze–thawing method. This freezing–thawing cycle was repeated for three consecutive cycles. Physicochemical properties of PVA–HES membrane gel such as gel fraction, swelling, morphology, elongation, tensile strength, and protein adsorption were investigated. Introducing HES into freeze–thawed PVA structure affected crystal size distribution of PVA; and hence physicochemical properties and morphological structure have been affected. Increased HES concentration decreased the gel fraction %, maximum strength and break elongation. Indeed it resulted into a significant incrementing of the swelling ability, amount of protein adsorption, broader pore size, and pore distribution of membrane morphological structure. Furthermore, an increase in HES concentration resulted in better and still lower thermal stability compared to virgin PVA and freeze–thawed PVA. The maximum weight loss of PVA–HES hydrogel membranes ranged between 18% and 60% according to HES content, after two days of degradation in phosphate buffer saline (PBS), which indicates they are biodegradable. Thus, PVA–HES hydrogel membranes containing ampicillin could be a novel approach for biomedical application e.g. wound dressing purposes.     

Computational studies of 1:2 complex between retinol propionate and β cyclodextrin

[M05-2X/6-31G*:PM3MM] and [B3LYP/6-31G*:PM3] ONIOM2 methods have been used to investigate the vitamin A propionate/β cyclodextrin complex with 1:2 stoichiometry. Both methods give almost the same lowest energy minimum. The minimum energy structure of the complex is found in good agreement with experimental data. In this configuration, the major structure of propionate of vitamin A (PVA) is embedded inside the two cavities of βCD while the propionate group is kept outside. However, the three methyl groups of PVA are positioned in the free space between both βCD molecules. The driving forces for complexation are dominated by Van der Waals interactions between PVA and the βCD molecules assisted with multiple hydrogen bond interactions between the two cyclodextrin molecules. These interactions were investigated using the natural bond orbital approach.     

Copolymers with Pendant Electron-Donor and Electron-Acceptor Groups

This paper is concerned with charge transfer complex properties of copolymers with pendant electron-donor and electron-acceptor groups obtained by radical copolymerization. The complexing groups were carbazolyl, anthryl, phenothiazinyl, and p-dimethyl-aminobenzyl as electron-donor groups, and picryl, dinitrophenyl, dinitrobenzoyl, and trinitrofluorenyl as electron-acceptor groups. The microstructure of such copolymers, including the tendency to alternating and coisotactic addition, together with the influence of monomer structure and reaction conditions, is discussed. Intramolecular complexation interactions are analyzed. These properties were measured by means of ¹H-NMR and electronic absorption spectra. Finally, some physical properties, e.g., color, solubility, density, and photoconductivity, are presented to illustrate the intramolecular and intermolecular complexation interactions. It is concluded that such copolymers are weak charge transfer complexes of the π-π type. They are of theoretical interest for study of the correlation between synthesis, structure, and properties, and of practical interest due to their optoelectric properties.     

Study of Cryostructuring of Polymer Systems: 25. The Influence of Surfactants on the Properties and Structure of Gas-Filled (Foamed) Poly(vinyl alcohol) Cryogels

Foamed poly(vinyl alcohol) (PVA) cryogels are studied. Such heterogeneous gel composites are formed as a result of the cryogenic treatment (freezing—storage in a frozen state—thawing) of water— PVA liquid foams in the absence and presence of surfactants. It is shown that the addition of ionic and nonionic surfactants to an aqueous PVA solution and its subsequent foaming result in the formation of liquid foam whose stability is lower than that of the foam prepared from an aqueous PVA solution in the absence of surfactant, i.e., surfactants cause a destabilizing effect on the foams containing PVA. Gas-filled PVA cryogels formed as a result of freezing—thawing of such foams contain large (up to ～180 μm) pores (air bubbles incorporated into the matrix of heterogeneous gel). Mechanical and thermal properties of cryogels depend on the nature and concentration of surfactants, as well as on the regime of cryogenic treatment. The rigidity of foamed PVA cryogels prepared in the presence of sodium dodecyl sulfate and cetyltrimethylammonium bromide ionic surfactants is lower and that in the presence of nonionic decaoxyethylene cetyl ether is higher than for equiconcentrated (by the polymer) foamed PVA cryogel containing no surfactant. Microscopic studies and the analysis of obtained images of cryogel structure demonstrate that the effect of surfactant on the morphology of freezing foam can be different, depending on the type of surfactant added to the initial system. This leads to foam-destabilizing effects such as the collapse, deformation, and coalescence of air bubbles; the failure of gel phase structure near the bubble surface; etc. However, the complete disintegration of the foamed structure is prevented by a very high viscosity of the unfrozen liquid microphase of a macroscopically solid sample and by the cryotropic PVA gelation that fixes the structure of partially destroyed foam.