聚3-羟基烷酸酯异相成核结晶的研究

本论文以具有巨大应用前景的PHBV作为研究对象，针对PHBV结晶速率低，易产生二次结晶，从而严重影响其加工性能和力学性能的稳定性等方面的缺点，根据PHBV的分子结构和脆性的机理分析，试图采用添加成核剂的方法，提高PHBV的结晶速率和结晶度，从而缩短PHBV的加工成型周期，控制其聚集态结构，提高其制品的稳定性，改善材料的物理力学性能。并在此基础上，探讨PHBV异相成核结晶的机理，加深成核剂对聚合物有效成核机理的认识，更好的理解聚合物结晶过程。1．添加成核剂的量达到0.5wt％时，对苯二甲酸（TPA）对PHBV起到了显著的结晶成核作用。结晶起始温度提高了约20℃，结晶速率达到最大值所对应的温度T_p提高了30℃，结晶烙增加了15J/g，结晶速率提高了4.4倍。这些数据表明，TPA是一种对PHBV极为有效的成核剂。2．加入成核剂TPA的PHBV表现出典型的双熔融行为，主要原因是TPA对PHBV的结晶成核作用和PHBV的熔融再结晶。低温侧的熔融峰对应着PHBV自熔体降温过程形成的结晶，高温侧的对应着PHBV升温过程中形成的结晶。3．TPA的成核作用大大的改变了PHBV的形态结构，使PHBV的球晶尺寸明显减小，球晶数量增大。4．TPA使PHBV晶体在（110）和（020）方向上微晶尺寸变大，晶区和非晶区的电子密度差增大。5．添加0.5wt％的TPA后，PHBV的断裂伸长率从4％提高到10％。6．TPA、IPA、淀粉和山梨醇对PHBV的结晶都具有很明显的成核作用，其原因可能是化学结构上都具有极性基团。7．红外光谱研究没有能够有效的给出PHBV与TPA是否存在特殊相互作用，从而导致TPA对PHBV的结晶成核作用的证据，但是，PHBV拨基伸缩振动谱带随温度的变化却给出了TPA对PHBv的结晶成核作用始于160℃高温。

[Ru(bpy)(3)](2+)-doped silica nanoparticles within layer-by-layer biomolecular coatings and their application as a biocompatible electrochemiluminescent tag material

[Ru(bpy)(3)](2+)-doped silica (RuSi) nanoparticles were synthesized by using a water/oil microemulsion method. Stable electrochemiluminescence (ECL) was obtained when the RuSi nanoparticles were immobilized on a glassy carbon electrode by using tripropylamine (TPA) as a coreactant. Furthermore, the ECL of the RuSi nanoparticles with layer-by-layer biomolecular coatings was investigated. Squential self-assembly of the polyelectrolytes and biomolecules on the RuSi nanoparticles gave nanocomposite suspensions, the ECL of which decreased on increasing the number of bilayers.

Unique electrochemiluminescence behavior of Ru(bpy)(3)(2+) in a gold/Nafion/Ru(bpy)(3)(2+) composite

The unique electrochemiluminescence (ECL) behavior of tris(bipyridine) ruthenium(II) (Ru(bpy)(3)(2+) immobilized in a gold/Nafion/Ru(bpy)(3)(2+) composite material was investigated. In this composite, the Ru(bpy)(3)(2+) ECL was found mainly occurred at 0-0.4 V during the cathodic scan process and the ECL peak was at about 0.1 V, which was quite different to the reported Ru(bpy)(3)(2+) ECL. Similar to the generally observed Ru(bpy)(3)(2+) ECL, the present ECL also could be enhanced by tri-n-propylarnine (TPA). It is also unique that in the presence of TPA, another ECL peak at about 0.38 V occurred.

Quantitative electrochemiluminescence detection of proteins: Avidin-based sensor and tris(2,2 '-bipyridine) ruthenium(II) label

Quantitative electrochemilumineseence (ECL) detection of a model protein, bovine serum albumin (BSA) was achieved via biotin-avidin interaction using an avidin-based sensor and a well-developed ECL system of tris(2,2'-bipyridine) ruthenium(II) derivative as label and tri-n-propylamine (TPA) as coreactant. To detect the protein, avidin was linked to the glassy carbon electrode through passive adsorptions and covalent interaction with carboxylate-terminated carbon nanotubes that was used as binder to immobilize avidin onto the electrode. Then, biotinylated BSA tagged with tris(2,2'-bipyridine) ruthenium(II) label was attached to the prepared avidin surface.

Electrochemiluminescence from tris(2,2 '-bipyridyl)ruthenium(II)-graphene-Nafion modified electrode

An electrochemiluminescence (ECL) sensor based on Ru(bpy)(3)(2+)-graphene-Nafion composite film was developed. The graphene sheet was produced by chemical conversion of graphite, and was characterized by atomic force microscopy (AFM), scanning electron microscopy (SEM), and Raman spectroscopy. The introduction of conductive graphene into Nafion not only greatly facilitates the electron transfer of Ru(bpy)(3)(2+), but also dramatically improves the long-term stability of the sensor by inhibiting the migration of Ru(bpy)(3)(2+) into the electrochemically inactive hydrophobic region of Nafion. The ECL sensor gives a good linear range over 1 x 10(-7) to 1 x 10(-4) M with a detection limit of 50 nM towards the determination of tripropylamine (TPA), comparable to that obtained by Nafion-CNT.

Solid-state electrochemiluminescence sensor based on the Nafion/poly(sodium 4-styrene sulfonate) composite film

An effective electrochemiluminescence (ECL) sensor based on Nafion/poly(sodium 4-styrene sulfonate) (PSS) composite film-modified ITO electrode was developed. The Nafion/PSS/Ru composite film was characterized by atomic force microscopy, UV-vis absorbance spectroscopy and electrochemical experiments. The Nafion/PSS composite film could effectively immobilize tris(2,2'-bipyridyl)ruthenium(II) (Ru(bpy)(3)(2+)) via ion-exchange and electrostatic interaction. The ECL behavior of Ru(bpy)(3)(2+) immobilized in Nafion/PSS composite film was investigated using tripropylamine (TPA) as an analyte. The detection limit (S/N = 3) for TPA at the Nafion/PSS/Ru composite-modified electrode was estimated to be 3.0 nM, which is 3 orders of magnitude lower than that obtained at the Nafion/Ru modified electrode. The Nafion/PSS/Ru composite film-modified indium tin oxide (ITO) electrode also exhibited good ECL stability. In addition, this kind of immobilization approach was simple, effective, and timesaving.

A Fully Diarylmethylene-Bridged Triphenylamine Derivative as Novel Host for Highly Efficient Green Phosphorescent OLEDs

A fully diarylmethylene-bridged triphenylamine derivative is efficiently synthesized. It has an almost planar triphenylamine (TPA) skeleton and exhibits excellent thermal and morphological stability. Devices with the novel TPA derivative as host material and Ir(ppy)(3) as triplet emitter show a maximum current efficiency of 83.5 cd/A and a maximum power efficiency of 71.4 Im/W for green electrophosphorescence.

High-density gold nanoparticles supported on a [Ru(bpy)(3)](2+)-doped silica/Fe3O4 nanocomposite: Facile preparation, magnetically induced immobilization, and applications in ECL detection

A large-scale process combined sonication with self-assembly techniques for the preparation of high-density gold nanoparticles supported on a [Ru(bpy)(3)](2+)-doped silica/Fe3O4 nanocomposite (GNRSF) is provided. The obtained hybrid nanomaterials containing Fe3O4 spheres have high saturation magnetization, which leads to their effective immobilization on the surface of an ITO electrode through simple manipulation by an external magnetic field (without the need of a special immobilization apparatus). Furthermore, this hybrid nanomaterial film exhibits a good and very stable electrochemiluminescence (ECL) behavior, which gives a linear response for tripropylamine (TPA) concentrations between 5 mu m and 0.21 mM, with a detection limit in the micromolar range. The sensitivity of this ECL sensor can be easily controlled by the amount of [Ru(bpy)(3)](2+) immobilized on the hybrid nanomaterials (that is, varying the amount of [Ru(bpy)(3)](2+) during GNRSF synthesis).

A novel sensitive solid-state electrochemiluminescence sensor material: Ru(bpy)(2+)(3) doped SiO2@MWNTs coaxial nanocable

A simple, large scale, and one-step process for the preparation of tris(2,2'-bipyridyl)ruthenium(I) (Ru(bpy)(3)(2+)) doped SiO2@carbon nanotubes (MVNTs) coaxial nanocable used for an ultrasensitive electrochemiluminescence (ECL) is presented for the first time. More importantly, a directly coated as-formed functional material on ITO electrode surface exhibits excellent ECL behavior, good stability, and high sensitivity in the presence of tripropylamine (TPA). This novel functional material will find potential applications in biosensor, electrophoresis and electroanalysis.

有序介孔材料SBA-15吸附Ru(bpy)_3~(2+)修饰电极的电化学发光研究

制备了具有高比表面积且二维六方高度有序的介孔分子筛SBA-15,并采用TEM和氮气吸附实验对其结构性质进行了表征.利用静电作用将三联吡啶钌[Ru(bpy)32+]固定到表面带负电荷的SBA-15上,并将吸附有Ru(bpy)32+的SBA-15修饰到玻碳电极表面,研究了该固定化的Ru(bpy)32+的电化学发光行为.结果表明,随着三丙胺(TPA)的加入,氧化电流增加而还原电流减小,表明TPA对三价吡啶钌有催化作用,同时TPA的加入显著增强了发光强度.随着扫描速率的增加,发光强度逐渐降低.SBA-15较大的孔径和开放交联的孔结构体系促进了电极表面膜内的物质扩散和电子运动扩散.该修饰电极在5.0×10-5~1.0×10-2mol/LTPA浓度范围内,发光强度与浓度具有良好的线性关系,线性方程为y=71.7+41.2x,检出限为9.5×10-6mol/L.该电极在连续扫描下具有较好的稳定性.

Bifunctional nanostructure of magnetic core luminescent shell and its application as solid-state electrochemiluminescence sensor material

Bifunctional nanoarchitecture has been developed by combining the magnetic iron oxide and the luminescent Ru(bpy)(3)(2+) encapsulated in silica. First, the iron oxide nanoparticles were synthesized and coated with silica, which was used to isolate the magnetic nanoparticles from the outer-shell encapsulated Ru(bpy)(3)(2+) to prevent luminescence quenching. Then onto this core an outer shell of silica containing encapsulated Ru(bpy)(3)(2+) was grown through the Stober method. Highly luminescent Ru(bpy)(3)(2+) serves as a luminescent marker, while magnetic Fe3O4 nanoparticles allow external manipulation by a magnetic field. Since Ru(bpy)(3)(2+) is a typical electrochemiluminescence (ECL) reagent and it could still maintain such property when encapsulated in the bifunctional nanoparticle, we explored the feasibility of applying the as-prepared nanostructure to fabricating an ECL sensor; such method is simple and effective. We applied the prepared ECL sensor not only to the typical Ru(bpy)(3)(2+) co-reactant tripropylamine (TPA), but also to the practically important polyamines. Consequently, the ECL sensor shows a wide linear range, high sensitivity, and good stability.

Electrochemistry and electrogenerated chemiluminescence of SiO2 nanoparticles/tris(2,2 '-bipyridyl)ruthenium(II) multilayer films on indium tin oxide electrodes

In this paper, a simple method of preparing {SiO2/Ru-(bPY)(3)(2+)}(n) multilayer films was described. Positively charged tris(2,2'-bipyridyl)ruthenium(II) (Ru(bpy)(3)(2+)) and negatively charged SiO2 nanoparticles were assembled on ITO electrodes by a layer-by-layer method. Electrochemical and electrogenerated chemiluminescence (ECL) behaviors of the {SiO2/Ru(bpy)(3)(2+)}(n) multilayer film-modified electrodes were studied. Cyclic voltammetry, UV-visible spectroscopy, quartz crystal microbalance, and ECL were adopted to monitor the regular growth of the multilayer films. The multilayer films containing Ru(bpy)(3)(2+) was used for ECL determination of TPA, and the sensitivity was more than 1 order of magnitude higher than that observed for previous reported immobilization methods for the determination of TPA. The multilayer films also showed better stability for one month at least. The high sensitivity and stability mainly resulted from the high surface area and special structure of the silica nanoparticles.

Electrogenerated chemi luminescence from Ru(BPY)(3)(2+) ion-exchanged in carbon nanotube/perfluorosulfonated ionomer composite films

The electrochemistry and electrogenerated chemiluminescence (ECL) of ruthenium(II) tris(bipyridine) (Ru(bpy)(3)(2+)) ion-exchanged in carbon nanotube (CNT)/Nafion composite films were investigated with tripropylamine (TPA) as a coreactant at a glassy carbon (GC) electrode. The major goal of this work was to investigate and develop new materials and immobilization approaches for the fabrication of ECL-based sensors with improved sensitivity, reactivity, and long-term stability. Ru(bpy)(3)(2+) could be strongly incorporated into Nafion film, but the rate of charge transfer was relative slow and its stability was also problematic. The interfusion of CNT in Nafion resulted in a high peak current of Ru(bpy)(3)(2+) and high ECL intensity. The results indicated that the composite film had more open structures and a larger surface area allowing faster diffusion of Ru(bpy)(3)(2+) and that the CNT could adsorb Ru(bpy)(3)(2+) and also acted as conducting pathways to connect Ru(bpy)(3)(2+) sites to the electrode. In the present work, the sensitivity of the ECL system at the CNT/Nafion film-modified electrodes was more than 2 orders of magnitude higher than that observed at a silica/Nafion composite film-modified electrode and 3 orders of magnitude higher than that at pure Nafion films.

Electrochemical and electrogenerated chemiluminescence of clay nanoparticles/Ru(bpy)(3)(2+) multilayer films on ITO electrodes

The electrochemical and electrogenerated chemiluminescence of Ru(bpy)(3)(2+) immobilized in {clay/Ru(bpy)(3)(2+)}(n) multilayer films by layer-by-layer assembly were investigated. The stable multilayer films of clay and Ru(bpy)(3)(2+) were assembled by alternate adsorption of negatively charged clay platelets and positively charged Ru(bpy)(3)(2+) from their aqueous dispersions. UV-vis spectroscopy, quartz crystal microbalance (QCM), cyclic voltammetry, and electrogenerated chemiluminescence (ECL) were used to monitor the immobilization of Ru( bpy)(3)(2+) and the regular growth of the {clay/Ru( bpy)(3)(2+)}(n) multilayer films. The multilayer films modified electrode was used for the ECL detection of tripropylamine ( TPA) and oxalate. The proposed novel immobilized method exhibited good stability, reproducibility and high sensitivity for the determination of TPA and oxalate, which mainly resulted from the contributing of clay nanoparticles with appreciable surface area, special structural features and unusual intercalation properties.

Highly sensitive electrogenerated chemiluminescence produced at Ru(bpy)(3)(2+) in Eastman-AQ55D-carbon nanotube composite film electrode

The electrochemistry and electrogenerated chemilurninescence (ECL) of tris(2,2-bipyridyl)ruthenium(II) ion-exchanged in Eastman-AQ-carbon nanotube (CNT) composite films were investigated at a glassy carbon (GC) electrode. Eastman-AQ55D is a poly (ester sulfonic acid) cation exchanger available in a commercial dissolved form. It is much more hydrophilic than Nafion due to its unique structure, so Ru(bpy)(3)(2+) does not diffuse into the hydrophobic region where it may lose its electroactivity as that in Nafion. The interfused CNT could act as electronic wires that connect the electrode with Ru(bpy)(3)(2+), which made the composite film much more electronically which finally led to the increasing of Ru(bpy)(3)(2+) conductive. Besides, the negatively charged CNT could also absorb some Ru(bpy)(3)(2+). Moreover, the strong electrostatic interaction between AQ and Ru(bpy)(3)(2+) made the composite films much more stable. The combination of AQ and CNT brings excellent sensitivity with the detection limit as low as 3 x 10(-11) M for TPA.