共查询到20条相似文献,搜索用时 15 毫秒
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Maria Zaharescu Maria Crisan I. MuŠeviČ 《Journal of Sol-Gel Science and Technology》1998,13(1-3):769-773
Atomic Force Microscopy (AFM) was used to study the influence of thermal treatments on the structural and textural properties of the sol-gel TiO2 films obtained from Ti(OC3H7i)4. X-ray diffraction (XRD), ellipsometric and porosity measurements have also been made.The TiO2 sol-gel films were homogeneous, transparent and amorphous. Heat treatments in the 400–600°C range indicate that the films have a strong tendency to crystallization. The high initial homogeneity of the TiO2 films was preserved during the crystallization process. AFM shows that the thermally treated films exhibit uniform, monodispersed crystals. 相似文献
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采用非去污剂在OptiPrep梯度中漂浮超声处理质膜的方法, 从鼠肺中分离质膜微囊, 在原子力显微镜下以不同条件进行了观察. 该非去污剂法能分离出完整的质膜微囊, 在去离子水稀释500倍的条件下得到了清晰的质膜微囊的原子力显微镜图片, 建立了一种新的快速分离完整质膜微囊的方法和用原子力显微镜观测质膜微囊结构的新方法. 相似文献
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Surface Assembly of DNA Origami on a Lipid Bilayer Observed Using High-Speed Atomic Force Microscopy
Masayuki Endo 《Molecules (Basel, Switzerland)》2022,27(13)
The micrometer-scale assembly of various DNA nanostructures is one of the major challenges for further progress in DNA nanotechnology. Programmed patterns of 1D and 2D DNA origami assembly using specific DNA strands and micrometer-sized lattice assembly using cross-shaped DNA origami were performed on a lipid bilayer surface. During the diffusion of DNA origami on the membrane surface, the formation of lattices and their rearrangement in real-time were observed using high-speed atomic force microscopy (HS-AFM). The formed lattices were used to further assemble DNA origami tiles into their cavities. Various patterns of lattice–tile complexes were created by changing the interactions between the lattice and tiles. For the control of the nanostructure formation, the photo-controlled assembly and disassembly of DNA origami were performed reversibly, and dynamic assembly and disassembly were observed on a lipid bilayer surface using HS-AFM. Using a lipid bilayer for DNA origami assembly, it is possible to perform a hierarchical assembly of multiple DNA origami nanostructures, such as the integration of functional components into a frame architecture. 相似文献
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M. Rinaudo F. Quemeneur F. Dubreuil A. Fery 《International Journal of Polymer Analysis and Characterization》2013,18(8):617-626
This article reports the main results obtained for the stabilization of DOPC liposomes by coating with chitosan. We investigated the compression between two planes of isolated GUV, combining force spectroscopy measurements with scanning probe microscopy (SPM) and epifluorescence microscopy observations. We obtained reproducible and reversible force-deformation curves for individual vesicles in the range of small deformation (relative deformation up to 0.3). Force-deformation curves were analyzed using a simple elastic model, which well describes the observed radius-dependency of the force response and allows determining the stretching modulus for bare vesicle and effective bending and stretching moduli for chitosan-coated membranes. Results first show that chitosan coating increases the effective stretching modulus of the lipid membranes, second, confirm that chitosan is adsorbed flat on the membrane, and finally lead us to assume that the chitosan coating structure can be regarded as a physical network of connected chitosan patches. 相似文献
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原子力显微镜与透射电镜对比研究嵌段共聚物微相分离形态 总被引:3,自引:0,他引:3
嵌段共聚物微观相分离形态结构由于其理论与应用中的重要性一直是人们研究的热点 [1] .本文研究的聚苯乙烯 -聚乙烯 /聚丁烯 -聚苯乙烯三嵌段共聚物 (SEBS)为聚苯乙烯 -聚丁二烯 -聚苯乙烯 (SBS)饱和加氢后的产物 .由于中间嵌段中的双键大多已加氢饱和 ,过去一直没有合适的染色剂进行染色 ,所以在 2 0世纪 80年代中期以前 ,SEBS形态结构未见文献报道 [1] .近年来 ,由于新型染色剂 Ru O4 的应用 ,使得用透射电镜 (TEM)观察其微相分离形态成为可能 . 随着对嵌段共聚物形态结构认识程度深入 ,人们迫切希望能有新的手段提供更加丰富的… 相似文献
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原子力显微镜研究APS化单晶硅衬底及单层MD膜表面张希,高芒来,王力彦,沈家骢(吉林大学化学系,长春,130023)关键词原子力显微镜,APS修饰表面,分子沉积膜以静电相互作用为成膜推动力的各种功能体系分子沉积(MD)超薄膜已有报道[1 ̄4].对MD... 相似文献
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驱油用疏水缔合聚丙烯酰胺(HAP)性能优劣由其微观结构决定,优选研究HAP微观结构的方法,方便现场准确筛选功能良好的驱油聚合物。本文通过原子力显微镜(AFM)和扫描电镜(SEM)观察了不同浓度HAP溶液的微观结构,动态光散射(DLS)与AFM分析了粒径分布。结果表明,随着聚合物浓度的增加,DLS测得粒径增大,粒径分布由单峰变为双峰;SEM观察到由无空间网络结构,到相对松散、易被盐破坏空间网络结构,再到不易被盐破坏的完整、致密的网络结构;AFM可以同时得到一定空间结构以及与DLS相符的粒径大小,三种方法综合比较发现,结合三种不同的表征手段能够较好的、较全面的表示HAP在溶液中的微观结构。 相似文献
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Franceschi E. Palazzi D. Pedemonte E. 《Journal of Thermal Analysis and Calorimetry》2001,66(1):349-358
In this paper we studied the effect of oxidation on paper stability by means of simultaneous differential thermal analysis
and thermogravimetry. In our laboratory we oxidised Whatman n. 1 chromatography grade paper and performed thermal analyses
both on non-oxidised and on 6, 21 and 96 h oxidised samples. The results showed characteristic thermal effects, particularly
performing the experiments under oxygen flow: it was noticed that the temperature of the main cellulose degradation DTA peak
gradually decreases with the paper oxidation degree. An application of this method was extended to the study of differently
oxidised parts of a 1948's book.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
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A Study of the Probe Effect on the Apparent Image of Biological Atomic Force Microscopy 总被引:1,自引:0,他引:1
Xue Mei WANG * Lei QIN Long BA Zu Hong LU The State Key Lab of Coordination Chemistry Nanjing University Nanjing National Lab of Molecular Biomolecular Electronics Southeast University Nanjing 《中国化学快报》2001,(12)
The atomic force microscopy (AFM) possesses high spatial resolution and it is compatible with liquid environments. AFM can provide possibility to study a wide range of biological problems at the molecular level and acquire topological information at nanometre resolution under physiological conditions1,2. However, a major problem for image reconstruction of biological specimens is that structures of most biological molecules are very soft and delicate, which could be easily deformed and dama… 相似文献
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Biodeterioration phenomena represent a complex of physical and chemical alteration processes in various materials, such as those constituting the objects that represent our cultural heritage. The biodegradation of paper is conditioned by several variables such as the materials from which cellulose is obtained, the manufacturing processes employed, the occurrence of other affecting substances such as lignin or metallic compounds, and by the environmental conditions in which papers are conserved. In this study, biodeterioration of paper was artificially induced in order to evaluate the role of a range of chemical and physical variables on damage caused by cellulolytic fungi. A variable pressure SEM instrument was used to characterise paper samples with different fibre origins, and alterations obtained in vitro. Two fungal strains, Aspergillus terreus Thom and Chaetomium globosum Kunze, which are cellulolytic species frequently associated with paper spoilage, were used to produce stains with characteristics close to those observable on art objects made from paper. The stains obtained on the different samples of paper were compared at both low and high magnification, in order to visualize the macro- and microscopic characteristics of paper fibres, inorganic constituents, impurities, and the deteriorating agents related to the spoiled areas. During this survey it was observed that single paper characteristics can strongly influence the intensity and the results of the fungal action. For example, the activity of a fungal strain on paper grades containing fibres of the same origin, but with different sizing, led to the formation of profoundly different stains and alterations. Moreover fungal structures, analysed by low vacuum SEM, in areas on paper corresponding to the stains appeared in different physiological states suggesting an important effect of paper constituents on fungal growth and their sporulating ability. 相似文献
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The 8-hydroxyquinoline neodymium(Ndq3) organic thin films deposited on the cleaned indium/tin oxide (ITO) at different deposition rates with the same vacuity (133.3×10-5 Pa) were revealed by atomic force microscopy (AFM). Organic devices with one layer of Ndq3 as the e-type conductive material at different deposition rates sandwiched between ITO and aluminum electrodes have been fabricated. respectively. Evidence suggests that the current-voltage (I-V) characteristics were determined by the uniformity of organic film which was controlled by the deposition conditions. 相似文献
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Atomic Force Microscopy Studies of SnO2 Thin Film Microstruc tures Deposited by Atomic Layer Epitaxy
Mikko Utriainen Hanna Lattu Heli Viirola Lauri Niinistö Roland Resch Gernot Friedbacher 《Mikrochimica acta》2000,133(1-4):119-123
ALE-grown, rutile-type SnO2 thin films and gas sensor structures based thereupon were studied by AFM with main emphasis on cross-sectional investigations
(X-AFM). On glass substrates the polycrystalline films showed a preferred orientation which depended on the film thickness
and growth temperature while on single crystal sapphire () the growth was heteroepitaxial. For the X-AFM studies various sample preparation techniques were investigated but only ion
beam etching gave satisfactory results and revealed substructures in the sensor structure consisting of Pt and SnO2 layers on a silicon substrate. 相似文献
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We have determined the important statistical quantities of the rough boundary between a GaAs single crystal and its oxide film formed by thermal oxidation. Thermal oxidation of the GaAs surfaces was performed at the temperature of 500°C. Using mathematical procedures developed for treating AFM data consisting of a family of the values of the heights of the irregularities of this roughness the values of the important statistical quantities of roughness were determined for 11 samples of the GaAs surfaces created by dissolution of the thermal oxide films originated during thermal oxidation of the smooth GaAs samples (the times of oxidation of these 11 samples were within interval of 20min–8 hours). From the AFM analysis of the roughness of GaAs surfaces it was found that the roughnening of these surfaces was the most pronounced for shorter oxidation times, i.e. for times smaller than about 2 hours. 相似文献
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Gjertrud Maurstad Andreas R. Bausch Pawel Sikorski Bjørn T. Stokke 《Macromolecular Symposia》2005,227(1):161-172
The thickness and surface morphology of electrostatically self-assembled films of chitosan and xanthan (persistence length of ∼120nm) have been studied using dual-wavelength Reflection Interference Contrast Microscopy (DW-RICM) and tapping mode Atomic Force Microscopy (AFM). The multilayers were prepared at two ionic strengths (5mM and 150mM). When the multilayers were assembled at 150 mM a network like morphology was observed after one bilayer. This structure was found to be of large influence in the further growth of the multilayers, with the same kind of network structure being observed at all number of bilayers. A lack of swelling behaviour, as well as the network structure and the poresize of the network, is suggested to originate from the high chain stiffness of xanthan. 相似文献
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LIHao-ying 《高等学校化学研究》2004,20(4):501-503
By using tapping mode atomic force microscopy (TMAFM), a polymer layer was found on the enamel surface after the exposure to xanthan gum solutions. The layer thickness is closely related to the exposure time and the concentration of xanthan gum solution. The thickness data were evaluated by a Kruskal-Wallis test and Box-Whisker Plot at a 95% confidence level (p<0. 05), and a statistically significant difference among the thickness data groups was demonstrated. After the exposure to 1000, 400, 100 mg/L xanthan gum solutions, the mean of layer thickness at the adsorption equilibrium is in the ranges of 103.5--122.06,82.4--88.94 and 45. 27--55.55 nm, respectively. This phenomenon suggests that the viscosity modifying a-gents in the beverage might be adsorbed on the enamel surface during consumption, which may form a barrier that can protect the enamel from being attacked by acid and therefore reduce dental erosion. 相似文献