RESPONSE TO ASCORBIC ACID ON POLYPYRROLE FILM MODIFIED BY COPPER PARTICLES

2019 ◽  
Vol 26 (05) ◽  
pp. 1850187
Author(s):  
I. CHIKOUCHE ◽  
C. DEHCHAR ◽  
A. SAHARI ◽  
N. LOUCIF
Keyword(s):  
Ascorbic Acid ◽  
Modified Electrode ◽  
Three Dimensional ◽  
Deposition Process ◽  
Nucleation And Growth ◽  
Current Time ◽  
Force Microscopy ◽  
Atomic Force ◽  
Instantaneous Nucleation ◽  
Polypyrrole Film

In this work, a modified electrode of copper-polypyrrole (Cu-PPy) is elaborated by charging the polymer matrix by Cu particles. The response to ascorbic acid (AA) of this material was tested. The results show good performances. The results indicated a sensitive oxidation peak current of AA on the modified electrode. The success of this application led us to study the nucleation mechanism of copper on the PPy surface which permits to obtain this response. Nucleation and growth of electrodeposited copper onto PPy substrate have been studied in an aqueous solution of 0.01[Formula: see text]M CuCl2 and 1[Formula: see text]M KCl by means of electrochemical methods: cyclic voltammetry, chronoamperometry, and using atomic force microscopy (AFM). The model described by Scharifker and Hills was used to analyze current-time transients. According to this model, the nucleation and growth kinetics at the initial stages of deposition process involve an instantaneous nucleation followed by three-dimensional (3D) growth mechanism.

Correlation between morphology and NGM of 3,4- ethylenedioxythiophene (EDOT) in acetonitrile

e-Polymers ◽  
2008 ◽  
Vol 8 (1) ◽  
Author(s):  
María Angélica del Valle ◽  
María Belén Camarada ◽  
Fernando Díaz ◽  
Gastón East
Keyword(s):  
Working Conditions ◽  
Electrode Materials ◽  
Three Dimensional ◽  
Current Time ◽  
Force Microscopy ◽  
Oxide Electrodes ◽  
Atomic Force ◽  
Diffusion Controlled ◽  
Instantaneous Nucleation ◽  
N Doping

AbstractThe nucleation and growth mechanism (NGM) for the electro-oxidation of 3,4-ethylenedioxythiophene (EDOT) in acetonitrile on platinum and tin(IV) oxide electrodes was determined by analyzing the potentiostatic current-time transients inferred from electrocrystallization theory. The measurements were complemented by using atomic force microscopy (AFM) and scanning electron microscopy (SEM). Preliminary studies performed to establish the working conditions for the potentiostatic technique using cyclic voltammetry (CV) demonstrated that under the working conditions employed herein the best potential scan-rate to obtain electrodeposits of poly(EDOT) was 50 mV·s-1. The prepared polymer displayed electrochromic properties and p- and n-doping, the p-doping being chemically reversible. In addition, it was observed that the electropolymerization mechanisms on both electrode materials were a combination of two contributions: progressive nucleation, followed by diffusion-controlled tridimensional growth, PN3Ddif; and instantaneous nucleation followed by three-dimensional growth under charge transfer control, IN3Dct. At shorter times, the IN3Dct contribution prevail giving rise to conical deposits, while at longer electrolysis times the polymeric deposit is made of granules, corresponding to the PN3Ddif mechanism. The electrode material has no effect at all on the global mechanism, but affects the time at which either contribution predominates. However, the morphological predictions made from the NGMs must be corroborated by other techniques before using the data to control the deposit to be prepared.

scholarly journals Acoustic subsurface-atomic force microscopy: Three-dimensional imaging at the nanoscale

2021 ◽  
Vol 129 (3) ◽  
pp. 030901
Author(s):  
Hossein J. Sharahi ◽  
Mohsen Janmaleki ◽  
Laurene Tetard ◽  
Seonghwan Kim ◽  
Hamed Sadeghian ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Three Dimensional ◽  
Three Dimensional Imaging ◽  
Force Microscopy ◽  
Atomic Force

scholarly journals Membrane fusion studied by colloidal probes

2021 ◽  
Vol 50 (2) ◽  
pp. 223-237 ◽  
Author(s):  
Hannes Witt ◽  
Filip Savić ◽  
Sarah Verbeek ◽  
Jörn Dietz ◽  
Gesa Tarantola ◽  
...  
Keyword(s):  
Membrane Fusion ◽  
Optical Tweezers ◽  
Three Dimensional ◽  
Biological Processes ◽  
Supported Membranes ◽  
Supported Bilayers ◽  
Force Microscopy ◽  
Advantages And Disadvantages ◽  
Atomic Force ◽  
Colloidal Probes

AbstractMembrane-coated colloidal probes combine the benefits of solid-supported membranes with a more complex three-dimensional geometry. This combination makes them a powerful model system that enables the visualization of dynamic biological processes with high throughput and minimal reliance on fluorescent labels. Here, we want to review recent applications of colloidal probes for the study of membrane fusion. After discussing the advantages and disadvantages of some classical vesicle-based fusion assays, we introduce an assay using optical detection of fusion between membrane-coated glass microspheres in a quasi two-dimensional assembly. Then, we discuss free energy considerations of membrane fusion between supported bilayers, and show how colloidal probes can be combined with atomic force microscopy or optical tweezers to access the fusion process with even greater detail.

scholarly journals Measuring the Autocorrelation Function of Nanoscale Three-Dimensional Density Distribution in Individual Cells Using Scanning Transmission Electron Microscopy, Atomic Force Microscopy, and a New Deconvolution Algorithm

2017 ◽  
Vol 23 (3) ◽  
pp. 661-667 ◽  
Author(s):  
Yue Li ◽  
Di Zhang ◽  
Ilker Capoglu ◽  
Karl A. Hujsak ◽  
Dhwanil Damania ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Density Distribution ◽  
Scanning Transmission Electron Microscopy ◽  
Mass Density ◽  
Three Dimensional ◽  
Force Microscopy ◽  
Statistical Measures ◽  
Atomic Force ◽  
Transmission Electron ◽  
Scanning Transmission

AbstractEssentially all biological processes are highly dependent on the nanoscale architecture of the cellular components where these processes take place. Statistical measures, such as the autocorrelation function (ACF) of the three-dimensional (3D) mass–density distribution, are widely used to characterize cellular nanostructure. However, conventional methods of reconstruction of the deterministic 3D mass–density distribution, from which these statistical measures can be calculated, have been inadequate for thick biological structures, such as whole cells, due to the conflict between the need for nanoscale resolution and its inverse relationship with thickness after conventional tomographic reconstruction. To tackle the problem, we have developed a robust method to calculate the ACF of the 3D mass–density distribution without tomography. Assuming the biological mass distribution is isotropic, our method allows for accurate statistical characterization of the 3D mass–density distribution by ACF with two data sets: a single projection image by scanning transmission electron microscopy and a thickness map by atomic force microscopy. Here we present validation of the ACF reconstruction algorithm, as well as its application to calculate the statistics of the 3D distribution of mass–density in a region containing the nucleus of an entire mammalian cell. This method may provide important insights into architectural changes that accompany cellular processes.

High-resolution transmission electron microscopic investigations of molybdenum thin films on faceted α-Al2O3

2005 ◽  
Vol 38 (2) ◽  
pp. 260-265 ◽  
Author(s):  
Leonore Wiehl ◽  
Jens Oster ◽  
Michael Huth
Keyword(s):  
High Resolution ◽  
Three Dimensional ◽  
Epitaxial Relationship ◽  
Electron Microscopic ◽  
Force Microscopy ◽  
Atomic Force ◽  
Transmission Electron ◽  
High Resolution Images ◽  
Α Al2o3 ◽  
Relationship Of

Epitaxially grown Mo films on a faceted corundum (α-Al2O3)mplane were investigated by transmission electron microscopy. Low- and high-resolution images were taken from a cross-section specimen cut perpendicular to the facets. It was possible to identify unambiguously the crystallographic orientation of these facets and explain the considerable deviation (∼10°) of the experimental interfacet angle, as measured with atomic force microscopy (AFM), from the expected value. For the first time, proof is given for a smooth \{10\bar{1}1\} facet and a curvy facet with orientation near to \{10\bar{1}\bar{2}\}. Moreover, the three-dimensional epitaxial relationship of an Mo film on a faceted corundummsurface was determined.

scholarly journals Tip-Based Nanomachining on Thin Films: A Mini Review

2021 ◽  
Author(s):  
Shunyu Chang ◽  
Yanquan Geng ◽  
Yongda Yan
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Data Storage ◽  
Three Dimensional ◽  
Maintenance Cost ◽  
Two Dimensional ◽  
Force Microscopy ◽  
Atomic Force ◽  
Current State ◽  
Two Dimensional Materials

AbstractAs one of the most widely used nanofabrication methods, the atomic force microscopy (AFM) tip-based nanomachining technique offers important advantages, including nanoscale manipulation accuracy, low maintenance cost, and flexible experimental operation. This technique has been applied to one-, two-, and even three-dimensional nanomachining patterns on thin films made of polymers, metals, and two-dimensional materials. These structures are widely used in the fields of nanooptics, nanoelectronics, data storage, super lubrication, and so forth. Moreover, they are believed to have a wide application in other fields, and their possible industrialization may be realized in the future. In this work, the current state of the research into the use of the AFM tip-based nanomachining method in thin-film machining is presented. First, the state of the structures machined on thin films is reviewed according to the type of thin-film materials (i.e., polymers, metals, and two-dimensional materials). Second, the related applications of tip-based nanomachining to film machining are presented. Finally, the current situation of this area and its potential development direction are discussed. This review is expected to enrich the understanding of the research status of the use of the tip-based nanomachining method in thin-film machining and ultimately broaden its application.

scholarly journals Nucleation and Growth of Supported Metal Clusters at Defect Sites on Mgo and NaCl (001) Surfaces: The Cases of Pd and Ag

1999 ◽  
Vol 570 ◽  
Author(s):  
J. A. Venables ◽  
G. Haas ◽  
H. Brune ◽  
J.H. Harding
Keyword(s):  
Deposition Temperature ◽  
Metal Clusters ◽  
Variable Temperature ◽  
Nucleation And Growth ◽  
Force Microscopy ◽  
Atomic Force ◽  
Defect Sites ◽  
Wide Range ◽  
Adsorption Surface

ABSTRACTNucleation and growth of metal clusters at defect sites is discussed in terms of rate equation models, which are applied to the cases of Pd and Ag on MgO(001) and NaCl(001) surfaces. Pd/MgO has been studied experimentally by variable temperature atomic force microscopy (AFM). The island density of Pd on Ar-cleaved surfaces was determined in-situ by AFM for a wide range of deposition temperature and flux, and stays constant over a remarkably wide range of parameters; for a particular flux, this plateau extends from 200 K ≤ T ≤ 600 K, but at higher temperatures the density decreases. The range of energies for defect trapping, adsorption, surface diffusion and pair binding are deduced, and compared with earlier data for Ag on NaCl, and with recent calculations for these metals on both NaCl and MgO

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