The reductive deposition of quaternary pyridinium corrosion inhibitor multilayers on glassy carbon electrodes

2004 ◽  
Vol 82 (10) ◽  
pp. 1536-1544 ◽  
Author(s):  
Rick PC Wong ◽  
Jennifer E Wong ◽  
Viola I Birss
Keyword(s):  
Glassy Carbon ◽  
Corrosion Inhibitors ◽  
Film Deposition ◽  
Soluble Form ◽  
Original Solution ◽  
Pyridinium Bromide ◽  
Glassy Carbon Electrodes ◽  
Force Microscopy ◽  
Atomic Force ◽  
Neutral Product

The redox behaviour of several quaternary pyridinium corrosion inhibitors ("Quats") at glassy carbon (GC) electrodes has been investigated in neutral aqueous solutions. The primary emphasis is on n-butyl-3-(N-octyl carbamyl)pyridinium bromide, one of the Quats determined to have very good corrosion inhibition properties based on parallel weight loss experiments. It is demonstrated that the reduction of the Quats, which occurs in a two-electron reaction at potentials negative of –1.0 V vs. SSCE, results in the formation of a neutral product. This forms a porous film on the electrode surface, with clusters that expand and thicken as more Quat deposits, as confirmed by atomic force microscopy. The film charge density reaches a maximum of ~4 mC/cm2, equivalent to more than 100 monolayers of Quat, after which no further Quat can be deposited, suggesting full surface coverage by a nonconducting product. The Quat multilayer can then be redissolved at potentials positive of ~ –0.2 V, during its oxidation back to its original solution-soluble form. Key words: quaternarized pyridinium compounds, reductive film deposition, glassy carbon, multilayer, corrosion inhibitors, cyclic voltammetry, AFM.

ELECTROCHEMICAL INVESTIGATION OF 2-THIOHYDANTOIN DERIVATIVES AS CORROSION INHIBITORS FOR MILD STEEL IN ACIDIC MEDIUM

2021 ◽  
Author(s):  
Petar Stanić ◽  
◽  
Nataša Vukićević ◽  
Vesna Cvetković ◽  
Miroslav Pavlović ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Mild Steel ◽  
Acidic Medium ◽  
Corrosion Inhibitors ◽  
Electrochemical Impedance ◽  
Electrochemical Investigation ◽  
Force Microscopy ◽  
Atomic Force ◽  
Hcl Solution ◽  
Scanning Electron

Four 2-thiohydantoin derivatives were synthesized and their corrosion inhibition properties on mild steel (MS) in 0.5M HCl solution was evaluated using usual gravimetric and electrochemical methods (weight loss, potentiodynamic polarization, electrochemical impedance spectroscopy (EIS). Morphology of the metal surface was characterized by scanning electron microscopy (SEM) and atomic force microscopy (AFM). The study has shown that these compounds provide good protection for mild steel against corrosion in the acidic medium.

Characterization of Asymmetric Polydiacetylene Ultrathin Films

1995 ◽  
Vol 382 ◽  
Author(s):  
D. W. Cheong ◽  
V. Shivshankar ◽  
H. C. Wang ◽  
C. M. Sung ◽  
J. Kumar ◽  
...  
Keyword(s):  
Ultrathin Films ◽  
Second Harmonic ◽  
Film Deposition ◽  
Asymmetric Structure ◽  
Blodgett Film ◽  
Force Microscopy ◽  
Langmuir Blodgett ◽  
Atomic Force ◽  
Ft Ir

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).

Efficient approach for optical and morphologic characterization of hybrid perovskite films based on reflectance and transmittance measurements

2021 ◽  
Author(s):  
Jorge Caram ◽  
Maximiliano Senno ◽  
Luisa Cencha ◽  
Silvia Tinte ◽  
Raul Urteaga ◽  
...  
Keyword(s):  
Low Cost ◽  
Normal Incidence ◽  
Film Deposition ◽  
Morphological Properties ◽  
Efficient Procedure ◽  
Force Microscopy ◽  
Atomic Force ◽  
Hybrid Perovskite

Abstract Organo-inorganic perovskites have been intensively studied due to its potential application in low cost and great efficient energy conversion in solar cells. Despite the great improvement in the quality of organo-inorganic perovskite films, a wide dispersion into the same batch of perovskite-based devices keep being an obstacle to obtaining highly reproducible results. For that reason new and efficient strategies for testing deposition results is imperative for the next step. Here we present a simple and efficient procedure for characterizing the optical and morphological properties based on the simultaneous reflectance and transmittance measurements under normal incidence over a MAPbI3 film. The proposed method provides qualitative and quantitative morphological information associated with the film roughness as well as information about the position of the optical gap and possible contributions to the optical dispersion in the structure that can be used as a simple diagnostic tool to optimize the film deposition. Results are contrasted and validated with electronic and atomic force microscopy, as well as first-principles calculations.

Atomic force microscopy studies of ZnS films grown on (100) GaAs by the successive ionic layer adsorption and reaction method

1998 ◽  
Vol 13 (6) ◽  
pp. 1688-1692 ◽  
Author(s):  
Mika P. Valkonen ◽  
Seppo Lindroos ◽  
Tapio Kanniainen ◽  
Markku Leskelä ◽  
Roland Resch ◽  
...  
Keyword(s):  
Thin Films ◽  
Atomic Force Microscopy ◽  
Thin Film Deposition ◽  
Film Deposition ◽  
Force Microscopy ◽  
Atomic Force ◽  
Layer Adsorption ◽  
Silar Technique ◽  
Ionic Layer

In this study zinc sulfide thin films were grown by the successive ionic layer adsorption and reaction (SILAR) technique on (100) GaAs substrates from aqueous precursor solutions. The atomic force microscopy (AFM) method was used to study the growth of the films up to a thickness of 180 nm. The ZnS thin films on (100) GaAs were smooth with an rms roughness of 0.2–1.9 nm depending on the film thickness. After the GaAs surface was covered with ZnS, the growth appeared to be nearly layerwise. In addition, in situ AFM studies were carried out to analyze the dissolution of (100) GaAs in water, which is a process competing with the thin film deposition by the SILAR.

scholarly journals Phosphate Modified Screen Printed Electrodes by LIFT Treatment for Glucose Detection

Biosensors ◽  
2018 ◽  
Vol 8 (4) ◽  
pp. 91 ◽  
Author(s):  
Francesco Milano ◽  
Livia Giotta ◽  
Daniela Chirizzi ◽  
Simos Papazoglou ◽  
Christina Kryou ◽  
...  
Keyword(s):  
Glassy Carbon ◽  
Glucose Sensor ◽  
Adsorbed Layer ◽  
Target Surface ◽  
Force Microscopy ◽  
Atomic Force ◽  
Screen Printed Electrodes ◽  
Forward Transfer ◽  
Glucose Electrooxidation ◽  
Screen Printed

The design of new materials as active layers is important for electrochemical sensor and biosensor development. Among the techniques for the modification and functionalization of electrodes, the laser induced forward transfer (LIFT) has emerged as a powerful physisorption method for the deposition of various materials (even labile materials like enzymes) that results in intimate and stable contact with target surface. In this work, Pt, Au, and glassy carbon screen printed electrodes (SPEs) treated by LIFT with phosphate buffer have been characterized by scanning electron microscopy and atomic force microscopy to reveal a flattening effect of all surfaces. The electrochemical characterization by cyclic voltammetry shows significant differences depending on the electrode material. The electroactivity of Au is reduced while that of glassy carbon and Pt is greatly enhanced. In particular, the electrochemical behavior of a phosphate LIFT treated Pt showed a marked enrichment of hydrogen adsorbed layer, suggesting an elevated electrocatalytic activity towards glucose oxidation. When Pt electrodes modified in this way were used as an effective glucose sensor, a 1–10 mM linear response and a 10 µM detection limit were obtained. A possible role of phosphate that was securely immobilized on a Pt surface, as evidenced by XPS analysis, enhancing the glucose electrooxidation is discussed.

Amorphous SIC-N Coatings: Its Properties and Applications

1994 ◽  
Vol 356 ◽  
Author(s):  
Andrew L. Yee ◽  
Hockchun Ong ◽  
Fulin Xiong ◽  
R. P. H. Chang
Keyword(s):  
Optical Properties ◽  
Film Deposition ◽  
Film Stress ◽  
Force Microscopy ◽  
Wave Measurements ◽  
Substrate Adhesion ◽  
Atomic Force ◽  
Film Substrate ◽  
Pull Testing ◽  
Amorphous Sic

AbstractLaser ablation has been used to deposit a:SiC-N films from a CVD SiC target. Depositions were carried out either in vacuum or in a nitrogen ambient ranging from 10 to 100 mT. The mechanical properties of the films versus nitrogen background pressure were assessed using nanoindentation and surface acoustic wave measurements. Deflected optical beam testing, pull testing and atomic force microscopy were used to determine film stress, film-substrate adhesion and film roughness, respectively. The optical properties were also characterized as a function of nitrogen back pressure using spectroscopic ellipsometry which determined refractive indices and predicted film compositions. Fourier transform infrared spectroscopy determined the bonding structures in the films, and finally Rutherford backscattering spectroscopy measurements were also performed. Based on the best mechanical and optical properties, the optimum film deposition conditions were obtained. It was observed that with an increase in nitrogen background pressure, oxygen content in the film, in the form of SiOx, increased significantly affecting the overall properties of the a:SiC-N films.

Electron-Beam-Induced Carbon Contamination on Silicon: Characterization Using Raman Spectroscopy and Atomic Force Microscopy

2009 ◽  
Vol 16 (1) ◽  
pp. 13-20 ◽  
Author(s):  
Deborah Lau ◽  
Anthony E. Hughes ◽  
Tim H. Muster ◽  
Timothy J. Davis ◽  
A. Matthew Glenn
Keyword(s):  
Raman Spectroscopy ◽  
Atomic Force Microscopy ◽  
Electron Beam ◽  
Prolonged Exposure ◽  
Carbon Film ◽  
Field Enhancement ◽  
Film Deposition ◽  
Cross Sectional ◽  
Force Microscopy ◽  
Atomic Force

AbstractElectron-beam-induced carbon film deposition has long been recognized as a side effect of scanning electron microscopy. To characterize the nature of this type of contamination, silicon wafers were subjected to prolonged exposure to 15 kV electron beam energy with a probe current of ∼300 pA. Using Raman spectroscopy, the deposited coating was identified as an amorphous carbon film with an estimated crystallite size of 125 Å. Using atomic force microscopy, the cross-sectional profile of the coating was found to be raised and textured, indicative of the beam raster pattern. A map of the Raman intensity across the coating showed increased intensity along the edges and at the corner of the film. The intensity profile was in excess of that which could be explained by thickness alone. The enhancement was found to correspond with a modeled local field enhancement induced by the coating boundary and showed that the deposited carbon coating generated a localized disturbance in the opto-electrical properties of the substrate, which is compared and contrasted with Raman edge enhancement that is produced by surface structure in silicon.

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