Ordered molecular layer structure of lubricating oil adsorbed films

1　ＩＮＴＲＯＤＵＣＴＩＯＮＢｏｕｎｄａｒｙｌｕｂｒｉｃａｔｉｏｎａｎｄｔｈｉｎ ｆｉｌｍｌｕｂｒｉｃａｔｉｏｎａｒｅｔｗｏｌｕｂｒｉｃａｔｉｎｇｓｔａｔｅｓｗｉｄｅｌｙｅｘｉｓｔｉｎｇｉｎｍｅｔａｌｐｌａｓｔｉｃｗｏｒｋｉｎｇｐｒｏｃｅｓｓ .Ｉｎ 1919Ｈａｒｄｙｅｔａｌ[1] ｆｉｒｓｔａｄｖａｎｃｅｄｔｈｅｃｏｎｃｅｐｔｏｆｂｏｕｎｄａｒｙｌｕｂｒｉｃａｔｉｏｎ ,ｉｎ192 9Ｔｏｍｌｉｎｓｏｎ[2 ] ｄｉｓｃｌｏｓｅｄｔｈｅｉｎｔｅｒｍｏｌｅｃｕｌａｒｅｆｆｅｃｔｏｆｂｏｕｎｄａｒｙｌｕｂｒｉｃａｔｉｏ…     

Computer experiment on propagation of solitons in crystals

Molecular dynamics computer simulation was carried out for homogeneous one-dimensional crystals and Langmuir–Blogett chain crystals. A mass-spring model was used, and the anharmonic interatomic potential up to the fourth order was taken into account. The total number of atoms was 120, and an end of the crystal was free to move and the other end fixed. An input pulse was applied to a couple of free end atoms, and the displacements and kinetic energies of all atoms in the crystal were computed. Solitons and phonons were produced, propagated and reflected at the ends of the crystal. Long-period propagation of stable solitons was observed in homogeneous crystals and in one-layer LB chain crystals.     

卟啉与花生酸混合LB膜研究

研究了具有四条长脂链的卟啉与花生酸混合物在气液界面的成膜性及ＬＢ膜．结果表明,卟啉与花生酸混合可形成稳定的单层膜,在混合ＬＢ膜中卟啉形成Ｂ带劈裂聚集体,花生酸的掺入对卟啉分子的有序排列和聚集作用没有影响．利用偏振紫外可见吸收光谱测量了膜中卟啉环的取向．     

Langmuir-Blodgett deposition and second-order non-linear optics of several azobenzene dye polymers

The Langmuir-Blodgett (LB) film-forming properties of a number of novel azobenzene dye polymers are reported. The linear and second-order non-linear optical properties of the films have been studied using ellipsometry, visible spectroscopy and Pockels effect measurements. As monolayers, the effective electro-optic r-coefficients ranged from 1 to 8.7 pm V.⁻¹ When one of the polymers was combined in an alternate layer film (230 layers in total), an r₁₃-coefficient of 13 pm V⁻¹ was achieved. This is one of the highest values reported for a ‘thick’ LB film.     

5,10,15,20-四-(4-N,N,N-二甲基十六烷基氨基苯基)卟啉LB膜结构的研究

研究了两亲性卟啉５,１０,１５,２０－四－（４－Ｎ,Ｎ,Ｎ－二甲基十六烷基氨基苯基）卟啉（ＴＤＭＣ１６ＰＰ）在气／液界面上的成膜性能,制备了其多层ＬＢ膜．用ＵＶ－Ｖｉｓ吸收光谱、荧光光谱、偏振ＵＶ－Ｖｉｓ吸收光谱和小角Ｘ射线衍射对ＬＢ膜进行了测试表征．结果表明：两亲性卟啉ＴＤＭＣ１６ＰＰ具有良好的成膜性能,其ＬＢ膜性质稳定,有较好的结构均匀性和周期性．在ＬＢ膜内,脂肪链并不是直立的,卟啉大环平面与基片平面成４２．５°排列．     

Ultrathin Films from Fluorine Containing Polymers: Fabrication and Characterization

Monolayers and ultrathin films of some fluorine containing polymers were prepared by the Langmuir‐Blodgett (LB) technique. The polymers were obtained using two main synthetic approaches: firstly, polyamide (PA‐1) and polyimide (PI‐1) were prepared from direct polycondensation of 4,4′‐hexafluoroisopropylidenediphthalic anhydride and 4,4′‐hexafluoroisopropylidenedianiline in N‐methyl‐2‐pyrrolidone (NMP). The thermogravimetric analysis (TGA) for PI‐1 yielded 580°C by 1% weight loss. They formed stable monolayers with a collapse pressure of 62 mN/m and a collapse area of 0.20 nm² per repeat unit (R.U.) in the case of PA‐1, for PI‐1 the collapse pressure was 60 mN/m associated with a collapse area of 0.23 nm² per R.U. Secondly, poly[(maleic acid perfluorooctylamide‐imide)‐co‐ethylene] (PAPE) with fluorinated side chains was synthesized from poly[(maleic anhydride)‐co‐ethylene]. They formed stable monolayers too. Multilayer depositions onto various substrates were possible for all the synthesized polymers. LB films were characterized by ultra‐violet/visible spectroscopy (UV‐Vis), surface plasmon resonance (SPR), dielectric spectroscopy and atomic force microscopy (AFM). Gas phase polymerization of tetrafluoropropyl methacrylate (TFPM) was carried out in the presence of macroinitiator, poly[octadecene‐co‐(maleic anhydride)] modified with tert‐butyl hydroperoxide. Film thickness could be controlled on different hydrophobic substrates varying the reaction time.     

Effect of spreading solvents on Langmuir monolayers and Langmuir–Blodgett films of PS-b-P2VP

Langmuir monolayers of polystyrene-block-poly(2-vinylpyridine) (PS-b-P2VP) diblock copolymers (with the same PS block length and different P2VP block lengths) formed at the air/water interface were characterized with the Langmuir film balance technique. Nonselective and selective solvents were used to spread the samples on the water surface and the spreading solvents showed large effect on the surface pressure–molecular area isotherms. The corresponding Langmuir–Blodgett (LB) films of the samples were characterized with atomic force microscopy. The LB films transferred from the Langmuir monolayers spread with a nonselective solvent only exhibited isolated circular micelles, while those with a selective solvent exhibited quite different morphologies including planar structure, rodlike structure, circular micelles, and labyrinth pattern. As far as we know, the labyrinth pattern appears in the LB films for the first time.     

端羟基PS—PEO嵌段共聚物LB膜的微摩擦性能

合成端闯劲基聚苯乙烯和聚环烷嵌段共聚物，并拉制ＬＢ膜，用原子力／摩擦力显微镜表征其表面微观形貌，研究其在极轻载荷下的摩擦性能。     

镀有LB膜的长周期光纤光栅的谐振波长研究

从理论上分析了长周期光纤光栅谐振波长随外界环境折射率变化而变化的光谱特性,此分析结果可以较好地解释镀有LB膜(Langmuir-Blodgett thin-film)的长周期光纤光栅的谐振波长与膜厚之间的关系。     

Structural aspects of Langmuir-Blodgett and cast films of zinc phthalocyanine and zinc hexadecafluorophthalocyanine

The processing of macrocyclic phthalocyanines (Pc) in the form of thin, nanostructured films has been usually carried out via evaporation techniques, owing to the low solubility exhibited by these compounds. The fabrication of Pc ultrathin films via the Langmuir-Blodgett technique may be advantageous from a technological point of view, since parameters such as film architecture and organization can be achieved without post-thermal treatments. In this study, a parent zinc phthalocyanine (ZnPc) and its fluorinated derivative (F₁₆ZnPc) were synthesized and manipulated in the form of LB films. The morphological and structural features of ZnPc and F₁₆ZnPc Langmuir-Blodgett films containing up to 31 layers were investigated using Fourier transform infrared spectroscopy (FTIR), micro-Raman spectroscopy and X-ray diffraction analyses and were compared to ZnPc and F₁₆ZnPc cast films. The interplanar distance obtained by X-ray specular reflection decreases from 12.64 Å for ZnPc to 12.16 Å for F₁₆ZnPc. FTIR spectra indicated absence of order in the LB films from ZnPc and F₁₆ZnPc, at least in the direction perpendicular to the substrate surface. Therefore, the order observed in the X-ray diffractograms means that the molecules might be organized in crystallites that are randomly oriented in the film.