scholarly journals Deposition of Extended Ordered Ultrathin Films of Au 38 (SC 2 H 4 Ph) 24 Nanocluster using Langmuir–Blodgett Technique

Small ◽  
2021 ◽  
pp. 2005954
Author(s):  
Michal Swierczewski ◽  
Plinio Maroni ◽  
Alexis Chenneviere ◽  
Mohammad M. Dadras ◽  
Lay‐Theng Lee ◽  
...  
1995 ◽  
Vol 382 ◽  
Author(s):  
D. W. Cheong ◽  
V. Shivshankar ◽  
H. C. Wang ◽  
C. M. Sung ◽  
J. Kumar ◽  
...  

ABSTRACTNonlinear optical (NLO) ultrathin films of a preforrned asymmetric polydiacetylene have been fabricated by Z-type Langmuir-Blodgett film deposition from the air-water interface. Induced in-plane orientation of the polydiacetylene backbone on the substrates has been confirmed by UV/Vis, FT-IR dichroism, and degenerate four wave mixing (DFWM) studies. All the measurements indicate that the backbone is prefe rentially oriented along the dipping direction. Second harmonic generation study suggests that the LB multilayers form an asymmetric structure (Z-type) due to the accumulation of 2-dimensional ordered monolayer and the dominant induced second order polarization is in the plane of the film. The film morphology and molecular orientation have been investigated by atomic force microscopy (AFM).


Author(s):  
Cecilia Gonçalves Soares ◽  
Luciano Caseli ◽  
Diego Luan Bertuzzi ◽  
Fabio Santana Santos ◽  
Jarem Raul Garcia ◽  
...  

2011 ◽  
Vol 183-185 ◽  
pp. 2187-2191
Author(s):  
Dong Yan Tang ◽  
Shuai Han ◽  
Bao Zhu He

By the Langmuir-Blodgett(LB) technique, the zinc ion containing multilayer was prepared by transferring the zinc acetate, spread on the surface of subphase of ultrapure water and stearic acid-chloroform mixtures, onto a hydrophilic silicon wafer or glass plate. Then the multilayer was converted into ZnO ultrathin films after pre-heating and annealing. The optimized parameters for monolayer formation, such as concentration of subphase, barrier speed and spreading volume, were determined by the measurement of the surface pressure-surface area (Π-A) isotherms. The expended areas after deposition with zinc ions inferred the interaction of stearic acid with zinc ion during the formation of monolayer at air-water interface. The optimized parameters for multilayer deposition, such as surface pressure and lifting speed were determined by the measurement of the transfer coefficient. The X-ray diffraction(XRD) was used to investigate the crystal structures of ZnO nanoparticles and ultrathin film. The surface morphologies of the LB multilayer and ultrathin film were observed by the atomic force microscopy (AFM). A uniform and flat surface of ZnO ultrathin film within nanometer ranges(<35nm) were obtained.


2014 ◽  
Vol 2014 ◽  
pp. 1-5
Author(s):  
Monika Poonia ◽  
Anagh Pathak ◽  
V. Manjuladevi ◽  
R. K. Gupta

We have investigated the interaction of DNA with a highly ordered functional ultrathin layer of cationic surfactant, dioctadecyl ammonium bromide (DOAB). The ultrathin film of DOAB is fabricated by Langmuir-Blodgett technique onto the pretreated quartz crystal wafers. The solution of DNA in phosphate buffer saline (PBS) is injected through a flow cell in a quartz crystal microbalance (QCM) loaded with the functional ultrathin film. The QCM data indicate a slower kinetics (time constant  =  162.2 seconds) for the adsorption of DNA on DOAB layer as compared to PBS on DOAB. The surface morphology of the aggregation of DNA over the DOAB layer is investigated using atomic force microscope (AFM). The AFM image indicates the trapping of DNA over the DOAB layer. Such trapping of DNA can be potentially employed in the field of genomics.


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