两种荧光LB膜的制备和光谱性能

制取了４－二氰基亚甲基－２－甲基－６－对二甲胺基苯乙烯基－４Ｈ－吡喃（ＤＣＭ）和１，２－双（５－甲基苯并恶唑）基乙烯（ＤＴ）两种荧光分子的ＬＢ膜以及两者的混合膜，以吸收光谱和荧光光谱探讨了膜中分子的构型，微环境，发光性能等特征，发现在ＬＢ膜的缀密排布环境中ＤＣＭ顺式构型的含量较之在溶液中大为增加。     

稀土螯合物发光体LB膜的研究(I)

稀土有机配合物的发光研究近年来取得了可喜的近展.铕(Ⅲ)、铽(Ⅲ)、钐(Ⅲ)与β-二酮(β-dik),三正辛基氧化膦(TOPO)所形成的螯合物,以及它们的硝酸盐与邻菲咯啉(Phen)所形成的螯合物都是高光效的发光体,有广阔的应用前景,在某些方面已获得应用.如能把这些具有发光功能的稀土螯合物组装成有序的分子组合体,则很可能在分子光学技术,光电子技术等领域发挥重要作用.如何组装?本文用LB 膜技术,通过交替成膜或混     

稀土Eu(Ⅲ)双酞菁衍生物LB膜的荧光性

合成了八－４－（四氢糠氧基）酞菁铕（Ⅲ）,通过元素分析、红外光谱、质谱和紫外－可见光谱加以确认。测定了配合物的ＩＩ－Ａ曲线,证明它有很好的成膜性,Ｚ型沉积形成的ＬＢ膜材料有很强的荧光响应,随着ＬＢ膜厚度的增加,荧光性增强。掺杂邻菲咯啉形成的混合ＬＢ膜,其荧光性比纯膜强。但不是邻菲咯啉加入的量越多荧光性越强。配合物：邻菲咯啉＝１：１０时（摩尔比）,有最好的荧光行为。用电子光谱对ＬＢ膜的结构进行了表征     

Modulated Fluorescence in LB Films Based on DADQs—A Potential Sensing Surface?

Novel fluorescent Langmuir-Blodgett (LB) films have been constructed from three different amphiphilic dicynaoquinodimethanes (DADQs). The DADQs varied in functional group structure, which had an impact on the LB film structure and the fluorescence properties. As the fluorescence of DADQs competes with non-radiative decay (conformational change), the packing and/or free volume in the LB film will influence the average fluorescence lifetime and integrated intensity. The pristine (blank) LB films were then exposed to a selection of non-fluorescent target analytes (some with environmental relevance) and the fluorescence was measured and analyzed relative to the pristine LB film. Exposure of the LB films to selected target analytes results in a modulation of the fluorescence, both with respect to average fluorescence lifetime and integrated intensity. The modulation of the fluorescence is different for different DADQ LB films and can be attributed to restricted non-radiative decays or charge transfer reactions between target analyte and DADQ LB film. The response from the DADQ LB films shows that these systems can be developed into sensing surfaces based on fluorescence measurements.     

花生酸LB膜周期结构的环境稳定性

花生酸ＬＢ膜周期结构的环境稳定性何平笙，管水云，李春娥（中国科学技术大学材料科学与工程系，合肥，２３００２６）关键词Ｌａｎｇｍｕｉｒ－Ｂｌｏｄｇｅｔｔ膜，Ｘ射线衍射，氨和ＨＣｌ溶液蒸汽处理，花生酸铅、镉、钡Ｌａｎｇｍｕｉｒ－Ｂｌｏｄｇｅｔｔ膜（ＬＢ膜...     

8-羟基喹啉两亲配合物的LB膜及其电致发光器件研究

制备了两亲配体N-十六烷基-8-羟基-2-喹啉甲酰胺(HL)十个配合物的LB膜。采用π-A等温线和小角X射线衍射等方法研究了这些LB膜的性质和结构。两亲配合物的单分子占有面积为(1.25±0.06)nm^2和(0.75±0.06)nm^2,分别对应于两亲分子中两个喹啉环平躺和环与环之间以一定的角度倾斜于气/水界面。LB膜内分子排列是二维有序的超晶格结构,双层高度(5.0±0.1)nm;LB膜具有导电各向异性,其平面和垂直直流电导率分别为10^-^5S.m^-^1和10^-^9S.m^-^1;LB膜的高荧光性质使之可以用作为电致发光器件的发光材料。以LaL~2(H~2O)~4Cl的LB膜为发光层的单层电致发光器件的驱动电压为9V,发光亮度330cd/m^2,为黄绿色发光。     

Fluorescence Resonance Energy Transfer between organic dyes adsorbed onto nano-clay and Langmuir–Blodgett (LB) films

In this communication we investigate two dyes N,N′-dioctadecyl thiacyanine perchlorate (NK) and octadecyl rhodamine B chloride (RhB) in Langmuir and Langmuir–Blodgett (LB) films with or with out a synthetic clay laponite. Observed changes in isotherms of RhB in absence and presence of nano-clay platelets indicate the incorporation of clay platelets onto RhB-clay hybrid films. AFM images confirm the incorporation of clay into hybrid films. FRET is observed in clay dispersion and LB films with and without clay. Efficiency of energy transfer is maximum in LB films with clay.     

Adsorption of poly(N‐ethyl‐4‐vinyl pyridinium bromide) onto langmuir‐blodgett films built up from amphiphilic polymers

The interaction of a strong cationic polyelectrolyte, poly(N‐ethyl‐4‐vinyl pyridinium bromide), with Langmuir‐Blodgett (LB) films built up from four monolayers of amphiphilic derivatives of the alternating copolymers of maleic acid and alkenes (one of the monolayers was formed by the amphiphilic copolymer containing pyrenyl groups as fluorescent labels) was examined. Transformations of absorbance spectra and quenching of fluorescence of the LB films were detected after their contact with aqueous solutions of the cationic polyelectrolyte. These changes were attributed to the adsorption of poly(N‐ethyl‐4‐vinyl pyridinium bromide) onto such films. The efficiency of this process was found to be rather sensitive to the variations in pH of the surrounding medium: adsorption of the cationic polyelectrolyte onto the LB films was pronounced in basic media while it became rather weak in acidic media.     

血红素在有序分子膜中的行为研究

本文研究了血红素(Heme)在硬脂酸(SA)单分子膜和Langmuir-B1odgett(LB)膜中的行为。Heme及其与SA的混合物均能在纯水亚相形成稳定的单分子膜。当摩尔分数x     

缺陷LB膜诱导草酸钙晶体的生长

肾结石形成与肾上皮细胞膜损伤密切相关, 但细胞膜损伤后的微结构及其与肾结石微晶粘附的分子机制仍不清楚. 本文采用经草酸钾处理后存在缺陷的二棕榈酰磷酯酰胆碱(DPPC)的LB膜为模型, 采用原子力显微镜(AFM)、荧光显微镜和扫描电子显微镜(SEM)研究了模型膜的缺陷畴区及其对一水草酸钙(COM)晶体生长的促进作用. LB膜内圆形的缺陷畴区可以诱导圆形COM晶体图形生成, 圆形晶体图形的直径从3 mm到150 mm不等. 在圆形区域内, 单个COM晶体的尺寸大都在1～3 μm, 以针状、四边形或不规则的形状存在; 而在同等条件下正常LB膜诱导的COM晶体没有圆形聚集现象, 单个COM晶体在LE/LC相边界生长, 其尺寸显著增加至5～10 mm. 不同性质LB膜促进COM成核和生长的强弱依次为: 经草酸钾处理的LB膜缺陷畴区>>正常LB膜的LC/LE边界＞正常LB膜非边界区域>>无膜诱导. 从缺陷LB膜的活性位点及其对COM晶体成核的促进作用等方面讨论了上述实验结果.     

Structural control in thin layers of poly(p-phenyleneethynylene)s: photophysical studies of Langmuir and Langmuir-Blodgett films

We present the relationship between the spatial arrangement and the photophysical properties of fluorescent polymers in thin films with controlled structures. Eight surfactant poly(p-phenyleneethynylene)s were designed and studied. These detailed studies of the behavior of the polymers at the air-water interface, and of the photophysical properties of their transferred LB films, revealed key structure-property relationships. Some of the polymers displayed pi-aggregates that are characteristic of an edge-on structure at the air-water interface. Monolayer LB films of these polymers showed greatly reduced quantum yields relative to solution values. Other polymers exhibited a highly emissive face-on structure at the air-water interface, and did not form pi-aggregates. The combination of pressure-area isotherms and the surface pressure dependent in situ UV-vis spectra of the polymers at the air-water interface revealed different behavioral details. In addition, the UV-vis spectra, fluorescence spectra, and quantum yields of the LB films provide design principles for making highly emissive films.     

Preparation and properties of nanosized fluorescent solid films based on a polyelectrolyte-surfactant complex with organic dyes

A procedure for preparing an organosoluble stoichiometric complex based on a cationic polyelectrolyte and an anionic surfactant is described. A method is proposed for forming monolayers at the water-air interface, along with conditions for preparing fluorescent nanosized solid films based on polyelectrolyte complex and organic dyes using the Langmuir-Blodgett (LB) method. The spectral and luminescent properties of the obtained films are investigated. It is established from the absorption and fluorescence spectra of LB films that electrostatic interaction between the molecules of polyelectrolyte complex and oxazine dyes results in dimer formation.     

Deposition and photopolymerization of phase-separated perfluorotetradecanoic acid-10,12-pentacosadiynoic acid Langmuir-Blodgett monolayer films

Mixed monolayer surfactant films of perfluorotetradecanoic acid and the photopolymerizable diacetylene molecule 10,12-pentacosadiynoic acid were prepared at the air-water interface and transferred onto solid supports via Langmuir-Blodgett (LB) deposition. The addition of the perfluoroacid to the diacetylene surfactant results in enhanced stabilization of the monolayer in comparison with the pure diacetylene alone, allowing film transfer onto a solid substrate without resorting to addition of cations in the subphase or photopolymerization prior to deposition. The resulting LB films consisted of well-defined phase-separated domains of the two film components, and the films were characterized by a combination of atomic force microscope (AFM) imaging and fluorescence emission microscopy both before and after photopolymerization into the highly emissive "red form" of the polydiacetylene. Photopolymerization of the monolayer films resulted in the formation of diacetylene bilayers, which were highly fluorescent, with the apparent rate of photopolymerization and the fluorescence emission of the films being largely unaffected by the presence of the perfluoroacid.     

Formation of langmuir-blodgett films containing two-dimensional monoatomic arrays of rare-earth cations

The work is focused on the preparation and characterisation of rare-earth containing stearic acid Langmuir-Blodgett (LB) films. Stearic acid monolayer behavior on the rare-earth containing aqueous subphase have been analyzed by thermodynamic measurements. The compression isotherm shape changed substantially under varying the anion type at the constant rare-earth cation content in aqueous subphase. The structure of formed multilayer rare-earth containing LB films was studied using small angle X-rays diffraction. The considerable structural defects in multilayer films were found when rare-earth chloride solution was exploited as aqueous subphase, caused presumably by electrostatic interactions at the monolayer surface under high binding of rare-earth cations. The use of monodentate complexones like acetic acid was proposed to form bulk phase quasi-neutral rare-earth complexes. The electroneutral ligand exchange reactions of such complexes with stearic acid monolayer allowed to neutralise monolayer surface under rare-earth cations binding and to form condenced monolayer below the triple-point temperature. The compression of such monolayer to the state of minimal compressibility and subsequent monolayer deposition resulted in the formation of high ordered LB films with high content of adsorbed multivalent rare-earth cations arranged in two-dimensional monoatomic arrays.     

长链香豆素LB膜对n-Si/Ni液结上的光致电荷转移的影响

本文研究了由硬脂酸香豆素制得的LB膜对n-Si/Ni电极性能的修饰作用.该LB膜沉积方式是Z型的,成膜之后吸收蓝移(由343nm移至325nm).在60mW·cm^-2溴钨灯光照下,n-Si/Ni/3LB/Fe(CN) /Pt电池的光电转换效率增大了一倍,稳定性亦有明显改善.交流阻抗测量表明,光照使n-Si/Ni/3LB电极的电解电阻大大减小,实验结果表明,硬脂酸香豆素LB膜对n-Si/Ni电极上的光致电荷传递过程的修饰作用是良好的.     

Development of fluorescent film sensors for the detection of divalent copper

Monolayers of several peptide lipids at air-water and air-solid interfaces were prepared using Langmuir and Langmuir-Blodgett (LB) film techniques, and tested as fluorescent sensors for copper ions in aqueous phase. In one method, both the ionophore and the fluorophore were in the same molecule (lipid A), so intramolecular interaction was responsible for the fluorescence quenching of monolayers of this lipid. In the other method, ionophore and fluorophore were located on two different molecules (lipids B and C) so the intramolecular coupling does not exist; instead the fluorescence quenching was realized by a through-space interaction mechanism. Several experimental techniques, including pi-A isotherm, epifluorescence microscopy, and absorption and emission spectroscopies were used to study the different characteristics of copper ion effect on the properties of the lipid monolayers. Additionally, the fluorescence quenching properties of the Langmuir monolayers were found to be transferred to the one-layer LB films. On LB films, the fluorescence response presented a clear selectivity for copper ions in comparison with several other transition metal ions. Further, an excellent reversibility was observed: the fluorescence was switched OFF by immersing the solid substrate in copper ion solution and ON by washing with HCl solution. The intermolecular approach used here seems to be a very flexible and general method to design surface-oriented fluorescent sensors to meet different analytic purposes.     

Characterization of IgG Langmuir-Blodgett films immobilized on functionalized polymers

The bioactivity of anti-human IgG Langmuir-Blodgett (LB) films, the non-specific adsorption of protein and the topography of anti-IgG LB films have been studied for application in immunosensors. The antibody (AB) LB films were horizontally deposited on glass and functionalized polymers, such as carboxy-poly(vinyl chloride) (PVC-COOH), chloropropyl and aminopropyl sol-gel. The LB films were characterized by means of ellipsometry, atomic force microscopy (AFM) and bicinchoninic acid (BCA) protein test. The interpretation of ellipsometric data was performed using a one-layer model. Non-specifically adsorbed protein was desorbed by washing the IgG film in 0.5 M NaCl, 2 M NaCl and 1% N-cetyl-N,N,N-trimethylammoniumbromide detergent solution resulting in a 50% reduction of the film thickness. The mean thickness of an anti-IgG film on glass measured by ellipsometry, PVC-COOH and aminopropyl sol-gel was 9+/-2, 11+/-1 and 23+/-8 nm, respectively. According to the BCA test 6-8 mug antibody (AB) per slide was bound to the functionalized polymers, but only 3 mug AB per slide was adsorbed on glass. The average distance of anti-IgG granules as indicated by AFM measurements on PVC-COOH, chloropropyl and aminopropyl sol-gel was 42+/-20, 34+/-3 and 23+/-4 nm. The average distance of granular AB structures on glass, however, was 150+/-50 nm.     

CdS纳米微粒在LB膜层隙聚集形态的AFM观察

用LB技术制备纳米微粒与超薄有机膜的复合膜是近年来值得注意的研究进展＊．利用该方法所制备出的材料既具有纳米粒子所特有的量子尺度效应，又具有LB股的分子层次有序、股厚可控以及易于组装等特点．它可用来制备结构可控的有机无机交替膜．而且，通过改变LB膜成膜材料和制备条件还可改变纳米粒子的光电特性．因此它在微电子学、光电子学、非线性光学及传感器等研究领域有着十分广阔的应用前景问．纳米微粒的聚集形态及LB膜在生成纳米微粒后的结构变化对材料的特性有着很大的影响．但采用一般的电镜技术或光谱分析手段均不能在实空间和…     

聚合物的LB膜

简要介绍了聚合物LB(Langmuir -Blodgett)膜的制备装置和制备过程。同时对聚合物LB膜这一门学科最新的进展和应用前景做了较为详尽的介绍和论述。目前 ,随着对LB膜的研究深入 ,在对小分子LB膜、可聚合LB膜、聚合物LB膜的成膜研究中引入了将几种方法优点综合起来的新的成膜方法 ,并已成为研究热点     

Investigation of the Electrical and the Dielectric Properties of Various LB Films

The electrical and dielectric properties of metal-insulator-semiconductor(MIS) and metal-insulator-metal(MlM) structures of various LB films were investigated. High frequency capacitance-voltage (C-V)measurements of the MIS structures of the LB films showed the accumulation,depletion and inversion regions.The dielectric constants of various LB films were calculated. Contrast with other LB films, the microgel star-shaped amphiphile(MSA) LB film showed a potential application in electronic devices due to its higher thermal and mechanical stabilities. The breakdown voltage of the MIM structure of the MSA containing only a single monolayer is over 200 V.