有机HTDIOO分子LB膜结构的AFM研究

利用原子力显微镜（ＡＦＭ）对有机分子ＨＴＤＩＯＯ单层和多层ＬＢ膜结构进行了观察。实验结果表明，针尖与ＬＢ膜表面分子间的相互作用力会对成像的膜结构有影响。当悬臂针尖与ＬＢ膜表面分子的相互作用力较大时，针尖会扰动ＨＴＤＩＯＯ分子在单层ＬＢ膜中的有序排列。ＨＴＤＩＯＯ单层ＬＢ膜具有有序结构；而在多层ＬＢ膜中，ＨＴＤＩＯＯ分子则聚集在一起形成了一定的畴结构。     

2-烷基-苯并咪唑在硝酸银亚相上的Langmuir膜及LB膜

对不同链长的2-烷基-苯并咪唑衍生物（BzCn,烷基链长从C5到C15）在硝酸银亚相上的成膜行为及形成的LB膜的结构进行了研究.表面压－面积曲线的结果表明，短链(C5～C9)的2-烷基-苯并咪唑可在银离子亚相上形成稳定的单分子膜，而长链(C13和C15)衍生物则形成多层膜.利用LB技术可将上述Langmuir膜转移到固体基板上形成LB膜，其吸收光谱的结果说明了苯并咪唑和银离子配位.利用AFM、XRD及FT-IR等技术研究了烷基链长对LB膜结构的影响.实验结果表明,除了BzC15，其余的衍生物都可形成规整的层状结构.短链衍生物的单层LB膜具有均一、平整的形貌；而对于BzC15，观察到多层结构.     

分子沉积膜的纳米摩擦特性

利用原子力显微镜研究了金衬底、沉积单层和多层分子沉积膜的金表面以及非活性端基修饰的沉积单层和多层分子沉积膜金的表面的纳米摩擦特性．结果表明,金表面沉积分子沉积膜以及对分子沉积膜的非活性端基修饰对金衬底均有一定的减摩作用;当针尖与试样表面趋于原子级摩擦时,摩擦的作用主要取决于试样表面分子的端基结构,而与分子的链长、骨架及分子沉积膜的层数等无关;分子沉积膜的活性端基使其纳米摩擦特性不稳定,而非活性端基修饰可以使其纳米摩擦特性稳定,并且可以降低摩擦力;空气的相对湿度对摩擦力有显著的影响,相对湿度越大,摩擦力越小．     

锇—聚乙烯吡啶复合物与辣根过氧化物酶分子多层膜的制备及其电化学性质研究

基于分子间静电相互作用力，将锇－聚乙烯吡啶复合物（PVP－OS）与辣根过氧化物酶（HRP）交替沉积于固体基质表面，制得了包含生物成分的分子多层膜，膜层间的聚合物分子起到了粘接与导电的双重作用，用紫外－可见光谱法跟踪了石英基片上的组装过程，研究了多层膜电极对过氧化氢的电催化还原性能，并描述了多层膜电化学行为。     

鞘氨醇／胆固醇单层分子膜的热力学特性及表面形态的AFM观测

脂筏是近年来在生物膜研究中发现的一种富含鞘脂、胆固醇和特殊蛋白质的动态微区结构,其结构和功能的改变,会引发多种疾病．本文利用LB膜技术模拟脂筏的动态微区结构,通过测量表面压力与平均分子面积（π-A）曲线数据,计算出鞘氨醇／胆固醇LB单层膜的过量分子面积（△A（ex））、表面过量吉布斯自由能（△G（ex））、活度系数（f1和f2）以及弹性模量（Cs^-1）,系统的研究了二元组份混合单层膜的热力学特性,并用原子力显微镜对鞘氨醇与胆固醇混合膜的形态进行观察．热力学分析表明过量分子面积和过量吉布斯自由能相对理想状态都具有负偏差作用,这说明分子间相互作用表现为吸引力,且单层膜的稳定性、弹性模量和活度系数的数值明显的依赖于胆固醇与鞘氨醇的比例．AFM观察结果表明,纯鞘氨醇单分子膜表现为小的颗粒体结构;当鞘氨醇与胆固醇按不同摩尔比混合时,随着胆固醇摩尔比例的增加,混合膜呈现出从链状结构向较大的片层与网状共存结构的转化．最终纯胆固醇形成高度紧密的膜结构．AFM实验有力的支持了理论分析的结果．     

一种具有“浮萍”结构的单分子膜与Langmuir—Blodgett多层膜

本文以St-DVB微凝胶/甲基丙烯酸两性接枝共聚物制成了一种新型“浮萍”结构的单分子膜,并转移制备了LB多层膜,对其单分子膜的性质、LB多层膜的二维有序结构及膜的热稳定性进行了较深入的研究。     

DOPC/DPPC单层膜中分子间的相互作用及形态特征

利用Langmuir-Blodgett(LB)技术制备了不同表面压力下的1,2-二油酸-甘油-3-磷脂酰胆碱(DOPC)/1,2-二棕榈酸甘油-3-磷脂酰胆碱(DPPC)(摩尔比为1:1)和DOPC/DPPC/Chol(摩尔比为2:2:1)单层膜, 对单层膜内分子间的相互作用进行了热力学分析, 并用荧光显微镜和原子力显微镜对其形态进行了观测.热力学分析表明, DOPC与DPPC分子在单层膜结构中相互作用为排斥力, 诱导单层膜出现相变; DOPC, DPPC与胆固醇(Chol)间的相互作用均为吸引力, 当表面压力(π)大于18 mN/m时, DPPC与胆固醇的作用力大于DOPC.荧光显微镜观测表明, DOPC/DPPC单层膜出现明显相分离现象, 富含DPPC微区成“花形”结构, 且随着表面压力的升高微区逐渐增大, “花瓣”增多; 当胆固醇加入到DOPC/DPPC体系时, 单层膜相态由液相与凝胶相共存转变为液态无序相与液态有序相共存结构, 富含DPPC的微区形状从“花形”转变成“圆形”.原子力显微镜对单层膜的表征验证了荧光显微镜的观测结果, 表明胆固醇加入到DOPC/DPPC体系中对单层膜排列具有明显的影响, 压力和溶液状态等是影响脂膜结构的重要因素.     

锇-聚乙烯吡啶复合物与辣根过氧化物酶分子多层膜的制备及电化学性质研究

基于分子间静电相互作用力,将锇-聚乙烯吡啶复合物(PVP-Os)与辣根过氧化物酶(HRP)交替沉积于固体基质表面,制得了包含生物成分的分子多层膜.膜层间的聚合物分子起到了粘接与导电的双重作用.用紫外-可见光谱法跟踪了石英基片上的组装过程,研究了多层膜电极对过氧化氢的电催化还原性能,并描述了多层膜电化学行为.     

新型LB成膜材料—两亲性侧链取代酞菁锌的合成

本文合成了一种新型的两亲性硬脂酸侧链取代的酞菁化合物。利用LB膜技术制备了致菁化合物与正十六烷混合的单层和多层LB膜,LB膜内酞菁分子大环与基片大体平行,表明该分子具有良好的成膜性能。     

新型LB成膜材料-两亲性侧链取代酞菁锌的合成

本文合成了一种新型的两亲性硬脂酸侧链取代的酞菁化合物, 利用LB膜技术制备了酞菁化合物与正十六烷混合的单层和多层LB膜, LB膜内酞菁分子大环与基片大体平行, 表明该分子具有良好的成膜性能。     

Electron transfer studies on cholesterol LB films assembled on thiophenol and 2-naphthalenethiol self-assembled monolayers

We have formed the cholesterol monolayer and multilayer LB films on the self-assembled monolayers of 2-naphthalenethiol (2-NT) and thiophenol (TP) and studied the electrochemical barrier properties of these composite films using cyclic voltammetry and electrochemical impedance spectroscopy. We have also characterized the cholesterol monolayer film using grazing angle FTIR, scanning tunneling microscopy (STM) and atomic force microscopy (AFM). Cholesterol has a long hydrophobic steroid chain, which makes it a suitable candidate to assemble on the hydrophobic surfaces. We find that the highly hydrophobic surface formed by the self-assembled monolayers (SAM) of 2-NT and TP act as effective platforms for the fabrication of cholesterol monolayer and multilayer films. The STM studies show that the cholesterol monolayer films on 2-NT form striped patterns with a separation of 1.0 nm between them. The area per cholesterol molecule is observed to be 0.64 nm2 with a tilt angle of about 28.96 degrees from the surface normal. The electrochemical studies show a large increase in charge transfer resistance and lowering of interfacial capacitance due to the formation of the LB film of cholesterol. We have compared the behavior of this system with that of cholesterol monolayer and multilayers formed on the self-assembled monolayer of thiophenol.     

Effect of water and air-water interface on the structural modification of Ni-arachidate Langmuir-Blodgett films

Nickel arachidate (NiA) Langmuir-Blodgett (LB) films have been deposited on hydrophilic Si(0 0 1) substrates by three (up-down-up) and five (up-down-up-down-up) strokes. During deposition, substrates were kept inside the water subphase for different times after each down stroke. Structural information of all the LB films have been obtained from X-ray reflectivity (XRR) studies. One and two symmetric monolayer (SML) was deposited on top of the asymmetric monolayer (AML) in three and five stokes respectively. All the preformed LB films were then used to go through the air-water interface with the same speed that was used at the time of film deposition. Structural information obtained from the XRR studies show that mainly the top layer density decreases after passing through the air-water interface but the layered structure remains the same. Information obtained from both the XRR and atomic force microscopy (AFM) studies suggest that molecules peeled from the top SML layer do not reincorporate with the LB film through tail-tail hydrophobic interaction. Our study shows that NiA LB film has better stability compared with cadmium arachidate LB film inside the water subphase without forming any out-of-plane molecular reorganization.     

LB技术制备FePt纳米粒子单层膜

FePt纳米粒子由于具有高的矫顽力而成为高密度垂直磁记录材料的研究热点之一,均匀有序排布的FePt纳米粒子薄膜将有利于提高磁记录介质的记录密度,因此,如何使FePt纳米颗粒均匀有序地排布是当前需要解决的关键问题之一,很多研究小组利用磁控溅射、自组装和电沉积等方法对FePt纳米颗粒的均匀分布进行了详细的研究,     

Pure and mixed films of a nitrostilbene derivative at the air-water interface, Langmuir-Blodgett multilayer fabrication, and optical characterization

This paper reports the preparation and characterization of pure Langmuir and Langmuir-Blodgett (LB) films of a stilbene derivative containing two alkyl chains, namely 4-dioctadecylamino-4'-nitrostilbene. Mixed films incorporating docosanoic acid and the stilbene derivative are also studied. Brewster angle microscopy (BAM) analysis has revealed the existence of randomly oriented three-dimensional (3D) aggregates, spontaneously formed immediately after the spreading process of the stilbene derivative onto the water surface. These 3D aggregates coexist with a Langmuir film that shows the typical gas, liquid, and solid-like phases in the surface pressure and surface potential vs area per molecule isotherms, indicative of an average preferential orientation of the stilbene compound at the air-water interface, and a gradual molecular arrangement into a defined structure upon compression. A blue shift of 55 nm of the reflection spectrum of the Langmuir film with respect to the spectrum of a chloroform solution of the nitrostilbene indicates that two-dimensional (2D) H-aggregates are formed at the air-water interface. The monolayers are transferred undisturbed onto solid substrates with atomic force microscopy (AFM) revealing that the one layer LB films are constituted by a monolayer of the stilbene derivative together with some 3D aggregates. When the nitrostilbene compound is blended with docosanoic acid, the 3D aggregation is avoided in the Langmuir and Langmuir-Blodgett films, but does not limit the formation of 2D H-aggregates, desirable for second-order nonlinear optical response in the blue domain. The AFM images of the mixed LB films show that they are formed by a docosanoic acid monolayer and, on the top of it, a bilayer of the stilbene derivative.     

聚苯乙烯-聚(4-乙烯基吡啶)嵌段共聚物LB膜结构形态的研究

采用氯仿作为铺展溶剂,将嵌段共聚物聚苯乙烯-聚(4-乙烯基吡啶)(PS-b-P4VP)稀溶液铺展于空气与水界面上,利用Langmuir-Blodgett(LB)膜技术转移至固体基底.研究了不同的嵌段比、表面压和小分子1-芘丁酸(PBA)的加入对嵌段共聚物气液界面聚集组装的影响.研究发现随着亲水段(P4VP)的增加,聚集组装结构由纳米片状、带状转变成纳米条状、纳米点状结构.表面压对纯PS-b-P4VP聚集组装产生影响,表面压增大,组装体排列紧密;随着表面压的继续增大,单层聚集结构遭到破坏,发生堆叠.加入PBA小分子后,PBA与PS-b-P4VP形成氢键,形态发生明显变化,原来的片状结构转变为条状或点状结构.     

Organic vapor detection by quartz crystal microbalance modified with mixed multilayer Langmuir-Blodgett Films

Mixed chloroform solution of Polysiloxane PS-264 and stearic acid was made into multilayer Langmuir-Blodgett (LB) films on the surface of quartz crystal microbalance (QCM). The condition for forming mixed multilayer LB films is discussed in this paper. In addition, PS-264, stearic acid and their mixture (molar ratio 1:1) were coated on the surface of QCM sensors by a spin coating method. The above modified crystals were exposed to different concentrations of various organic vapors, including related chlorinated hydrocarbons and alcohol vapors. The results of frequency changes corresponding to concentration change of the above vapors were compared. The linear regression coefficients of the QCM with LB film had better values (0.9881相似文献   

Microcrystalline domains of monolayer and multilayer BDN-SA Langmuir–Blodgett films

Monolayer and multilayer BDN(Bis(4-diethyannodithiobenzil)nickel)-SA(stearyl alcohol) LB (Langmuir–Blodgett) films were prepared and the characteristics of microcrystalline domains were studied using UV–vis.–NIR and AFM. The results indicate that BDN-SA LB films consist of numerous ball-like microcrystalline domains at size scales from a few tens to a few hundreds of nm. AFM images of a multilayer LB film show that well-ordered molecular arrangements exist on the surface of domains which resemble a mosaic structure. The relationship between the mean size of the domain of a BDN-SA LB film with the thickness of the film was also shown.     

A multiscale structural study of nanoparticle films prepared by the Langmuir–Blodgett technique

Arrays of magnetic nanoparticles (NPs) represent a very interesting challenge toward the development of new devices for magnetic applications such as data storage and spintronic. The final properties of such assemblies depending essentially on the spatial arrangement of NPs, it is of first importance to investigate precisely their structure. Here, the structure of monolayer and multilayer films of magnetic iron oxide NPs assembled by the Langmuir–Blodgett (LB) technique has been studied by usual techniques such as SEM, AFM and ellipsometry and by a new and an easy to process enhanced optical technique: the Surface Enhancement Ellipsometry Contrast (SEEC) microscopy. This technique is based on the use of a new generation of microscope slides used as substrates which allow the strong enhancement of the sample contrast to a point where it becomes possible to visualize the structure of monolayer and multilayer films at the nanoscale with a conventional optical microscope. The SEEC microscopy is demonstrated to be complementary to usual characterization techniques to study the structure of NPs films, especially for films containing very small nanosized NPs which are more difficult to analyze by usual techniques. While the film structure is investigated with lateral resolution of microns, the layer thickness is analyzed at the nanoscale (with a precision of 0.3 nm) with a close fit to the experimental measurements on local (AFM) and on larger (ellipsometry) areas. This technique presents the advantage to visualize directly the topography of NPs assemblies on very large areas by extracting information such as the height profile, the film roughness and generating 3D images.