基于聚乙烯醇聚合物点制备荧光纳米复合材料

近年来, 由于聚合物点(PDs)具有良好的荧光性质和光收集能力, 受到了人们广泛的关注, 应用在生物成像和检测等领域. 然而, 目前报道的聚合物点大多数是指共轭聚合物经过组装、固定形成的, 因此聚合物点保持着形成之前的共轭聚合物的相关性质, 且具有更好的稳定性和进一步功能化的能力. 本文中我们研究的聚合物点是指从非共轭线性聚合物为原料而制备的聚合物点, 这类聚合物包括聚环氧乙烯, 多糖等. 聚合物点不仅包含使其具有荧光的碳化中心, 还具有外围的聚合物链结构. 因此, 可以拓展应用聚合物点的聚合物特性. 我们利用PDs的荧光中心和外围的聚合物链双功能性质, 详细研究了基于PDs制备功能性纳米复合材料体系. 首先, 我们原位制备了聚乙烯醇/PDs纳米复合膜材料(PDs是直接通过聚乙烯醇可控碳化而产生的). 复合材料不仅保持了PDs的荧光特性, 还保持了聚乙烯醇易加工的特性, 如可以制备成纳米复合膜材料, PDs含量可以根据需要调控: 0, 20%, 40%, 60%, 80%, 100%. 纳米复合膜材料在不同激发光下具有多颜色发光性质. 进一步的, 我们验证了PDs水溶液可以和很多其他水溶性聚合物, 石墨烯量子点或半导体量子点实现共混, 从而制备双功能性纳米复合材料.     

聚合物改性中纳米复合新技术

聚合物改性的研究近年来十分活跃,纳米复合技术的问世为聚合物改性开辟了崭新的途径,并且对于推动高分子材料的功能和高性能化具有重要意义。本文介绍了近年来纳米技术的发展,并综述了纳米复合材料的特性和制备方法,论述了纳米材料在聚合物改性中的应用。     

聚合物/纳米碳酸钙复合材料的制备

提出了一种制备聚合物/碳酸钙复合材料的技术.即先将纳米碳酸钙粒子在温和条件下分散到水溶液中,再在较弱的外场作用下混合分散到聚合物熔体中,使用此方法制备的4种典型聚合物(聚乙烯、聚丙烯、聚碳酸酯和聚脂)的纳米复合材料,通过扫描电镜观察纳米粒子以纳米尺寸均匀分布于树脂基体中.聚碳酸酯复合材料的相对分子质量变化不大,而且复合材料的某些力学性能有所提高,证明此种方法可用于极性与非极性聚合物制备纳米复合材料.     

用于聚合物纳米复合材料的化学改性POSS

综述了多面齐聚倍半硅氧烷(POSS)与聚合物的相容性、用于使POSS化学改性的有机反应以及改性POSS作为聚合物纳米复合材料的添加型及反应型纳米填料的实例.     

无机纳米粒子填充聚合物的研究进展

对纳米粒子的历史、结构及特性作了简要介绍，着重介绍了纳米粒子的表面处理及其在填充了聚合物方面的应用开发。     

碳纳米管/聚合物纳米复合材料研究进展

碳纳米管/聚合物纳米复合材料是近几年发展起来的一个新的研究方向。本文从增强和功能性两个方面评述了碳纳米管/聚合物纳米复合材料的发展过程以及最新进展，详细讨论了碳纳米管在聚合物中的分散、取向和胃面相互作用对复合材料力学性能的影响，介绍了碳纳米管的加入赋予聚合物的一些新的光电性能，并对今后的研究方向进行了展望。     

聚氨酯/纳米复合材料的制备方法的研究进展

综述了近年来国内外聚氨酯/纳米复合材料的制备方法,主要介绍了共混法、原位聚合法、插层聚合法、溶胶一凝胶法等几种常用的纳米材料改性聚氨酯的方法;简述了一些纳米材料表面改性的方法;并指出了聚氨酯/纳米复合材料未来的研究方向:纳米颗粒的分散工艺仍需进一步研究和完善;对少见报道的纳米金刚石,纳米SiC等新型超硬纳米材料有待于更...     

聚合物基无机纳米复合材料的制备方法Ⅱ.直接分散法和同时形成法

聚合物基无机纳米复合材料制备的关键问题是无机纳米粒子在聚合物基体中保持其纳米尺度的分散,本文主要讨论直接分散法、同时形成法制备聚合物基无机纳米材料的基本原理和技术要点。     

聚合物/层状硅酸盐纳米复合材料的性能

取合物／层状硅酸盐纳米复合材料是近十年发展起来的一类新型材料，即使硅酸盐纳米填料的含量很低，一般在5％（wt）以下，就使该类材料具有许多优良的性能，如杨氏模量，储能模量，热稳定性，气体阻隔性及阻燃性等均有较大的提高。本文综述了该类材料的性能。     

纳米ZnO/聚合物器件的制备及应用

近年来,氧化锌(ZnO)由于依赖于尺寸、形状的光电特性而备受关注。纳米ZnO尺寸较小、表面能高,易团聚,使其在光电、生物等方面的应用受到限制。将其与聚合物复合或组装,不但能稳定纳米ZnO,而且可以使纳米ZnO/聚合物复合材料具有优良性能。本文综述了近年来纳米ZnO/聚合物复合材料的制备方法(聚合物辅助、表面接枝、转移分散等法)及纳米ZnO/聚合物器件在电致发光、光伏电池、荧光成像等方面的应用,并对纳米ZnO/聚合物复合材料的发展做了展望。     

Molecularly Imprinted Polymer Coated Quantum Dots for Multiplexed Cell Targeting and Imaging

Advanced tools for cell imaging are of great interest for the detection, localization, and quantification of molecular biomarkers of cancer or infection. We describe a novel photopolymerization method to coat quantum dots (QDs) with polymer shells, in particular, molecularly imprinted polymers (MIPs), by using the visible light emitted from QDs excited by UV light. Fluorescent core–shell particles specifically recognizing glucuronic acid (GlcA) or N‐acetylneuraminic acid (NANA) were prepared. Simultaneous multiplexed labeling of human keratinocytes with green QDs conjugated with MIP‐GlcA and red QDs conjugated with MIP‐NANA was demonstrated by fluorescence imaging. The specificity of binding was verified with a non‐imprinted control polymer and by enzymatic cleavage of the terminal GlcA and NANA moieties. The coating strategy is potentially a generic method for the functionalization of QDs to address a much wider range of biocompatibility and biorecognition issues.     

Role of the Polymer Matrix on the Photoluminescence of Embedded CdSe Quantum Dots

The photoluminescence (PL) of CdSe quantum dots (QDs) that form stable nanocomposites with polymer liquid crystals (LCs) as smectic C hydrogen‐bonded homopolymers from a family of poly[4‐(n‐acryloyloxyalkyloxy)benzoic acids] is reported. The matrix that results from the combination of these units with methoxyphenyl benzoate and cholesterol‐containing units has a cholesteric structure. The exciton PL band of QDs in the smectic matrix is redshifted with respect to QDs in solution, whereas a blueshift is observed with the cholesteric matrix. The PL lifetimes and quantum yield in cholesteric nanocomposites are higher than those in smectic ones. This is interpreted in terms of a higher order of the smectic matrix in comparison to the cholesteric one. CdSe QDs in the ordered smectic matrix demonstrate a splitting of the exciton PL band and an enhancement of the photoinduced differential transmission. These results reveal the effects of the structure of polymer LC matrices on the optical properties of embedded QDs, which offer new possibilities for photonic applications of QD–LC polymer nanocomposites.     

氮掺杂石墨烯量子点/钯纳米复合材料的研究

铂基催化剂因具有高催化活性、高稳定性而成为极其重要的能源转化催化剂。本文采用水热法合成氮掺杂石墨烯量子点支撑的钯纳米复合材料(Pd@N-GQDs),并将其用于碱性介质中甲醇的电催化氧化反应。实验结果表明,相比同类型材料钯负载于石墨烯纳米片(Pd@GS)、钯负载于石墨烯量子点(Pd@GQDs)和商业钯黑催化剂(Pd@C),Pd@N-GQDs纳米材料具有很高的催化活性和稳定性,并可减少催化剂材料中贵金属的使用量。     

Monochelic Versus Telechelic Poly(Methyl Methacrylate) as a Matrix for Photoluminescent Nanocomposites with Quantum Dots

Nanocomposites based on CdSe or CdSe/ZnS quantum dots (QDs) and poly(methyl methacrylate) (PMMA) of different molecular weights and functionality were synthesized by ligand exchange of oleic acid with RAFT-based PMMA. The successful ligand exchange was confirmed by dynamic light scattering in combination with the approach “macromolecules—ghosts” and transmission electron microscopy. Comparative study of mono- and telechelics of PMMA revealed the similarities and differences in their behavior in formation of complexes with QDs and the optical properties of the corresponding nanocomposites. Telechelics exhibited higher efficiency in the complex formation and seemed to be promising candidates for the construction of devices based on QDs and polymer matrix for optical applications.     

表面修饰CdTe量子点的合成及其光学特性

在水相中合成高发光性能的CdTe量子点,研究以巯基乙酸(TGA)为稳定剂对CdTe表面进行修饰,制备在水中分散性良好的纳米晶,通过对CdTe量子点合成反应条件的摸索,掌握了其合成的反应规律.同时用紫外分光光度计、荧光分光光度计和透射电子显微镜对其进行了表征.结果表明,回流时间、n(Cd²⁺):n(HTe^-)、反应物浓度、TGA用量、反应体系pH值,对纳米晶的光学性质具有显著影响.回流2 h制得的CdTe纳米粒子直径约为5 nm,其发射峰窄且对称,表现出良好稳定的光学性质.     

量子点的聚合物表面修饰及其应用

量子点作为新型纳米发光材料备受关注,但由于光学稳定性和生物相容性的问题而在实际应用上受限。聚合物对量子点的修饰能够提供量子点合成的有效支撑基质,而且还可以改善量子点的稳定性和单分散性,进而可以拓展量子点应用于化学、物理以及生物学领域。基于聚合物修饰量子点的优势,本文简述了聚合物表面修饰量子点的方法、合成路线、步骤、特点以及发展现状。其中,双亲分子涂敷的量子点可以改善量子点的水溶性;多基配体包裹的量子点更具有稳定性和功能性;末端功能化聚合物表面修饰的量子点则可以合成更为先进功能的材料;胶封树枝状定域量子点具有单分散和优越发光特性。同时,还综述了各种表面修饰方法的最新研究进展,存在问题以及应用发展趋势。     

叶酸受体靶向CdS量子点应用于HepG2细胞成像研究

0引言量子点(quantum dots,QDs)又称半导体纳米晶体(semiconductor nanocrystal),是一种由Ⅱ-Ⅵ族或Ⅲ-Ⅴ族元素组成的尺寸在2￣20nm之间,稳定的微     

A Supramolecular Polymer Network of Graphene Quantum Dots

Graphene quantum dot (GQD)–organic hybrid compounds (GQD‐ 2 b – e ) were prepared by introducing 3,4,5‐tri(hexadecyloxy)benzyl groups (C16) and linear chains terminated with a 2‐ureido‐4‐[1H]‐pyrimidinone (UPy) moiety onto the periphery of GQD‐ 1 . GQD‐ 2 b – e formed supramolecular assemblies through hydrogen bonding between the UPy units. GPC analysis showed that GQDs with high loadings of the UPy group formed larger assemblies, and this trend was confirmed by DOSY and viscosity measurements. AFM images showed the polymeric network structures of GQD‐ 2 e on mica with flat structures (ca. 1.1 nm in height), but no such structures were observed in GQD‐ 2 a , which only carries the C16 group. GQD‐ 2 c and GQD‐ 2 d formed organogels in n‐decanol, and the gelation properties can be altered by replacing the alkyl chains in the UPy group with ethylene glycol chains (GQD‐ 3 ). GQD can thus be used as a platform for supramolecular polymers and organogelators by suitable chemical functionalization.     

A Ligand System for the Flexible Functionalization of Quantum Dots via Click Chemistry

We present a novel ligand, 5‐norbornene‐2‐nonanoic acid, which can be directly added during established quantum dot (QD) syntheses in organic solvents to generate “clickable” QDs at a few hundred nmol scale. This ligand has a carboxyl group at one terminus to bind to the surface of QDs and a norbornene group at the opposite end that enables straightforward phase transfer of QDs into aqueous solutions via efficient norbornene/tetrazine click chemistry. Our ligand system removes the traditional ligand‐exchange step and can produce water‐soluble QDs with a high quantum yield and a small hydrodynamic diameter of approximately 12 nm at an order of magnitude higher scale than previous methods. We demonstrate the effectiveness of our approach by incubating azido‐functionalized CdSe/CdS QDs with 4T1 cancer cells that are metabolically labeled with a dibenzocyclooctyne‐bearing unnatural sugar. The QDs exhibit high targeting efficiency and minimal nonspecific binding.