共查询到20条相似文献,搜索用时 31 毫秒
1.
用AFM研究了PS纳米球在自组装有羧甲基化壳聚糖(CM-CHI)单层膜的云母基底上的吸附行为及CM-CHI自组装膜形貌对PS纳米球吸附行为的影响.重点考察了盐浓度,吸附时间和温度对PS自组装动力学的影响.在CM-CHI自组装膜制备条件一定的情况下,20℃时PS最大覆盖率对应的盐浓度为0.5mol/L,平衡吸附时间为20min,对应的覆盖率约为48.0%.CM-CHI自组装膜形貌对覆盖率的影响主要表现为PS纳米球在由不同方法制备的CM-CHI自组装膜上的覆盖率在最宜吸附盐浓度,平衡吸附时间内随吸附温度的升高而显著增大,当PS吸附温度为60℃时甚至有部分覆盖率达65.0%.此外,还讨论了有关CM-CHI自组装膜是否干燥及PS自组装循环中冲洗用水盐浓度对PS纳米球覆盖率的影响. 相似文献
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Cheung CL Camarero JA Woods BW Lin T Johnson JE De Yoreo JJ 《Journal of the American Chemical Society》2003,125(23):6848-6849
We have developed a multistep route to the fabrication of virus assembled nanostructures with chemoselective protein-to-surface linkers synthesized by an efficient solid-phase method. These linkers were used to create patterns of 30-to-50-nm-width-lines by scanning probe nanolithography. Genetically modified cow pea mosaic virus with unique cysteine residues at specific locations on their capsomers were assembled through covalent linkage on these patterns. The morphology of the assembled structures on these line patterns characterized by atomic force microscopy was found to be strongly influenced by the intervirion interactions. 相似文献
3.
Oriented assembly of Au nanorods using biorecognition system 总被引:1,自引:0,他引:1
The design and formation of a linear assembly of gold nanorods using a biomolecular recognition system are described. Anti-mouse IgG was immobilized on the {111} end faces of gold nanorods through a thioctic acid containing a terminal carboxyl group. The biofunctionalized nanorods can be assembled with the desired length using mouse IgG for biorecognition and binding. The gold nanorods can be assembled to extended nanorod chains, which can be as long as 3 microm. These assembled nanostructures may be used as the precursors for future nanodevices. 相似文献
4.
Hongchao Guo 《Tetrahedron letters》2004,45(9):2009-2012
A new strategy for generating assembled polymeric chiral titanium complexes using linked bis-BINOL ligands have been developed, and the assembled catalysts showed excellent enantioselectivity (up to 96.5% ee) for carbonyl-ene reaction under heterogeneous conditions to afford corresponding α-hydroxy esters in high yield. The linkers between two BINOL units of the ligands in the assembled catalysts were found to have significant impact on the enantioselectivity of reaction, which demonstrated the importance of the supramolecular structures of the assemblies for their catalytic behaviours. 相似文献
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Carlos Montoro‐García Jorge Camacho‐García Dr. Ana M. López‐Pérez Nerea Bilbao Sonia Romero‐Pérez Dr. María J. Mayoral Dr. David González‐Rodríguez 《Angewandte Chemie (International ed. in English)》2015,54(23):6780-6784
A hydrogen‐bonded cyclic tetramer is assembled with remarkably high effective molarities from a properly designed dinucleoside monomer. This self‐assembled species exhibits an impressive thermodynamic and kinetic stability and is formed with high fidelities within a broad concentration range. 相似文献
7.
LiFePO4 nanoparticles have been successfully obtained by a solid-phase synthesis method using nanoscaled FePO4 as starting materials. Three-electrode system using as-prepared LiFePO4 as cathode was assembled to monitor the variation of voltage and impedance in the anode or cathode. The pouch-typed cells with prepared LiFePO4 were assembled to investigate electrochemical performance at level of full-cell. The results show that the assembled pouch-typed full-cells present higher power density and favorable cycle life. 相似文献
8.
Water‐soluble porphyrin‐porphyrin and porphyrin‐CdSe nanoparticle monolayer films were self‐assembled on different substrates. The influence of substrates, types of films, and heat treatment temperature on fluorescence of different kinds of porphyrin films was investigated. The SEM images showed the formation of monolayer films on porous alumina foil. The films assembled on porous alumina foil possessed higher fluorescence intensity and thermal stability. The result of conductance measurement indicated that the interaction of trimethylamidophenylporphyrin iodide (TAPPI) molecules with hydroxyl groups on porous alumina foil was weakened after CdSe nanoparticles assembled with TAPPI. 相似文献
9.
Differential separation and label-free detection of proteins using SERS from their mixtures after a convective assembly process is reported. Binary and ternary mixtures of proteins are mixed with AgNPs and assembled into ordered structures. The spectra acquired from the assembled area indicate that the proteins are differentially distributed. 相似文献
10.
Jeon J Panchagnula V Pan J Dobrynin AV 《Langmuir : the ACS journal of surfaces and colloids》2006,22(10):4629-4637
We performed molecular dynamics simulations of multilayer assemblies of flexible polyelectrolytes and nanoparticles. The film was constructed by sequential adsorption of oppositely charged polymers and nanoparticles in layer-by-layer fashion from dilute solutions. We have studied multilayer films assembled from oppositely charged polyelectrolytes, oppositely charged nanoparticles, and mixed films containing both nanoparticles and polyelectrolytes. For all studied systems, the multilayer assembly proceeds through surface overcharging after completion of each deposition step. There is almost linear growth in the surface coverage and film thickness. The multilayer films assembled from nanoparticles show better layer stratification but at the same time have higher film roughness than those assembled from flexible polyelectrolytes. 相似文献
11.
Stoerzinger KA Hasan W Lin JY Robles A Odom TW 《The journal of physical chemistry letters》2010,1(7):1046-1050
This Letter describes how gold pyramidal nanoshells (nanopyramids) can be assembled into low- and high-order structures by varying the rate of solvent evaporation and surface wettability. Single-particle and individual-cluster dark field scattering spectra on isolated, dimers and trimers of nanopyramids were compared. We found that the short wavelength resonances blue-shifted as the particles assembled; the magnitude of this shift was greater for high-order structures. To test which assembled architecture supported a larger Raman-active volume, we compared their surface enhanced Raman scattering (SERS) response of the resonant Raman molecule methylene blue (λ(ex) = 633 nm). We discovered that high-order structures exhibited more Raman scattering compared to low-order assemblies. Finite-difference time-domain modeling of nanopyramid assemblies revealed that the highest electromagnetic field intensities were localized between adjacent particle faces, a result that was consistent with the SERS observations. Thus, the local spatial arrangement of the same number of nanoparticles in assembled clusters is an important design parameter for optimizing nanoparticle-based SERS sensors. 相似文献
12.
富勒醇与阳离子聚电解质复合薄膜的制备与表征 总被引:1,自引:0,他引:1
采用静电自组装技术制备了富勒醇与聚对亚苯亚乙烯基 (PPV)的前驱体、聚二烯丙基二甲基氯化铵(PDDA)的复合薄膜 ,利用紫外 可见光吸收光谱 (UV Vis)、原子力显微镜 (AFM )、透射电镜 (TEM)和X射线光电子能谱 (XPS)对薄膜进行了表征 .UV Vis吸收光谱显示 ,在特定波长下自组装薄膜的吸光度与薄膜的双层数成线性关系 ,组装过程具有一致性与重复性 .AFM图象显示富勒醇组装到基片表面后形成直径为几十到10 0多nm的团簇 .富勒醇溶液过滤后组装薄膜 ,薄膜具有较好的均匀性 ;富勒醇溶液不经过滤 ,直接组装薄膜 ,将在薄膜中引入C6 0 晶粒 .XPS分析结果提示C6 0 被羟基修饰并通过静电吸引机制与阳离子聚电解质组装成膜 .富勒醇与PPV的前驱体、PDDA具有很好的自组装性能 ,膜层间的结合力较强 ,所组装的薄膜具有较高的牢固度 . 相似文献
13.
由沸石纳米粒子自组装制备具有高催化活性中心和水热稳定的新型介孔分子筛材料 总被引:18,自引:0,他引:18
人们合成了一系列介孔分子筛材料,并发现它们在催化、吸附与分离以及化学组装制备先进材料和分子器件等方面具有很大的潜在应用价值.但是,介孔分子筛材料相对于微孔沸石分子筛存在着两个致命弱点:较低的水热稳定性和较不活泼的催化活性中心.这两个弱点大大地影响了介孔分子筛在催化反应中的广泛应用.本文系统地综述了最近几年利用沸石纳米粒子自组装制备具有高催化活性中心和水热稳定的介孔分子筛材料的研究进展.这包括利用硅铝沸石纳米粒子自组装制备具有强酸性和水热稳定的新型介孔硅铝分子筛材料,利用钛硅沸石纳米粒子自组装制备具有高催化氧化活性中心和水热稳定的新型钛硅介孔分子筛材料,以及利用含有不同杂原子的沸石纳米粒子自组装制备一系列水热稳定的新型介孔分子筛催化材料. 相似文献
14.
Lishuang Yao Limei Shao Zenghui Peng Lingli Zhang Chunhong Fei Fengzhen Lv 《Liquid crystals》2013,40(6):761-765
A novel vertical alignment film for nematic liquid crystals is reported based on electrostatic self‐assembly of alkyl sulfonic salts in aqueous solution. A series of self‐assembled films with different alkyl chain lengths were prepared and used as alignment films. It was revealed that only when the number of carbon atoms in the alkyl chain approaches 11 or larger, could the self‐assembled film induce vertical alignment of liquid crystals. We also found that the homeotropic alignment of liquid crystals was related to the surface roughness of self‐assembled films. In addition, this vertical alignment film showed good electro‐optical characteristics and excellent thermal stability. 相似文献
15.
In this paper, the multilayer films of poly-L-lysine (PLL) and DNA were created on TiO2 nanotube surfaces using the layer-by-layer (LBL) self-assembly technique. Chemical compositions of the assembled multilayered films were investigated by X-ray photoelectron spectroscopy. Biological properties of the multilayered films were evaluated by the biomimetic mineralization and osteoblast cell culture experiments. The results indicated that PLL and DNA were successfully assembled onto TiO2 nanotube surfaces by electrostatic attraction. Moreover, the samples of assembled PLL or/and DNA had better bioactivity in inducing HA formation and promoting osteoblast cells adhesion, proliferation and early differentiation. 相似文献
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Tian Y He Q Cui Y Tao C Li J 《Chemistry (Weinheim an der Bergstrasse, Germany)》2006,12(18):4808-4812
Nanotubes of poly(4-vinylpyridine) (PVP) and poly(acrylic acid) (PAA) were fabricated by hydrogen bonding based on layer-by-layer (LbL) assembly. The uniform and flexible tubular structures were characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). FTIR and X-ray photoelectron spectroscopy (XPS) measurements confirm the formation of hydrogen bonds in the assembled nanotubes. PAA can be released from the assembled PAA/PVP nanotubes in a basic aqueous solution to give the walls of the tubes a porous structure. Such assembled nanotubes can be considered as carriers for catalysts or drugs, especially in aqueous solution against capillary force. 相似文献
18.
银纳米粒子在云母表面的二维组装及其表面增强拉曼效应 总被引:3,自引:0,他引:3
随着纳米技术的迅速发展 ,利用共价或非共价键作用将金属纳米粒子组装到固体基片上 ,因其方法简单、重复性好而成为研究热点 .目前 ,人们已经成功地利用带有— SH[1,2 ] ,—CN,— NH2 [3 ] 等基团的单层或多层膜作为偶联剂将 Au和 Ag等金属纳米粒子固定在玻璃、石英、硅、金等固体基片上 .但在许多情况下 ,偶联剂却成为一种干扰物质 .云母是一种重要的电子工业材料 ,并具有廉价、较易获得新鲜表面等特点 ,研究金属纳米粒子在云母表面的组装和排列无疑具有重要意义 .但是 ,迄今为止 ,在表面没有偶联剂修饰的条件下 ,以云母为基底的金属纳… 相似文献
19.
Wang X Huang J Xiang S Liu Y Zhang J Eichhöfer A Fenske D Bai S Su CY 《Chemical communications (Cambridge, England)》2011,47(13):3849-3851
Ag(6)L(6)-type coordination nanotubular structures have been assembled from 6 Ag(I) ions and 6 T-shaped ligands, 4-(3,5-bis(diphenylphosphino)phenyl)pyridine; the nanotubes represent a discrete molecular architecture of a number of polymeric structures assembled from dimeric building blocks. 相似文献
20.
Yi‐Hong Chiu Jui‐Hsiang Liu 《Journal of polymer science. Part A, Polymer chemistry》2010,48(15):3368-3374
A novel achiral monomer end‐capped with a phenyl‐[1,3,4]oxadiazolyl group and threaded through β‐cyclodextrin was synthesized to investigate the host‐guest interactions in the inclusion complex. 1H NMR studies revealed that one or two cyclodextrin molecules were threaded onto the synthesized achiral monomer, leading to the formation of a fibrous construction of self‐assembled inclusion complexes. The formation of a self‐assembled inclusion complex was identified using SEM and TEM. The highly ordered alignment of self‐assembled supramolecules was confirmed using polarized optical microscopy. We demonstrate an easy process for the fabrication of nano‐structured self‐assembled inclusion complexes in pyridine/ethanol (1 mL/10 mL) as well as the enhancement of photo‐induced fluorescence via monomers end‐capped with a phenyl‐[1,3,4]oxadiazolyl moiety threaded with β‐cyclodextrins. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 3368–3374, 2010 相似文献