Determination of substrate diffusion in polymeric films on electrode surfaces

1987 ◽  
Vol 91 (19) ◽  
pp. 5072-5076 ◽  
Author(s):  
Otto. Haas ◽  
Brigitte. Sandmeier
2020 ◽  
Vol 19 ◽  

Cathodic protection is defined as a method for slowing down or complete elimination of corrosion processes on underground or underwater, insulated or uninsulated metal structures. Protection by cathodic protection system is achieved by polarizing protected object to more negative value, with respect to its equilibrium potential. Design of the cathodic protection system implies determination of the electric potential and current density on the electrode surfaces after installation of the cathodic protection system. Most efficient way for determination of the electric potential and current density in the cathodic protection system is by applying numerical techniques. When modeling cathodic protection systems by numerical techniques, electrochemical reactions that occur on electrode surfaces are taken into account by polarization characteristics. Because of nature of the electrochemical reactions, polarization characteristics are nonlinear and under certain conditions can be time – varying (dynamic nonlinear polarization characteristics). This paper deals with numerical modeling of the cathodic protection system with dynamic nonlinear polarization characteristics. Numerical model presented in this paper is divided in the two parts. First part, which is based on the direct boundary element method, is used for the calculation of the distribution of electric potential and current density on the electrode surfaces in the spatial domain. Second part of the model is based on the finite difference time domain method and is used for the calculation of the electric potential and current density change over time. The use of presented numerical model is demonstrated on two simple geometrically examples.


2015 ◽  
Vol 133 (1) ◽  
pp. n/a-n/a ◽  
Author(s):  
Florence Dubelley ◽  
Emilie Planes ◽  
Corine Bas ◽  
Bernard Yrieix ◽  
Lionel Flandin

1999 ◽  
Vol 08 (04) ◽  
pp. 519-525
Author(s):  
SHEN YUQUAN ◽  
LI ZHAO ◽  
ZHAO YUXIA ◽  
ZHAI JIANFENG ◽  
ZHOU JIAYUN ◽  
...  

An UV-VIS-Near-IR spectroscopic method for determination of optical loss in organic/polymeric films has been suggested. The optical losses of two polyimide polymers with push-pull azobenzene chromophore attached were examined by this method and the data were calibrated by conventional optical method.


Sensors ◽  
2019 ◽  
Vol 19 (10) ◽  
pp. 2379 ◽  
Author(s):  
P. Yáñez-Sedeño ◽  
A. González-Cortés ◽  
S. Campuzano ◽  
J. M. Pingarrón

Proper functionalization of electrode surfaces and/or nanomaterials plays a crucial role in the preparation of electrochemical (bio)sensors and their resulting performance. In this context, copper(I)-catalyzed azide-alkyne cycloaddition (CuAAC) has been demonstrated to be a powerful strategy due to the high yields achieved, absence of by-products and moderate conditions required both in aqueous medium and under physiological conditions. This particular chemistry offers great potential to functionalize a wide variety of electrode surfaces, nanomaterials, metallophthalocyanines (MPcs) and polymers, thus providing electrochemical platforms with improved electrocatalytic ability and allowing the stable, reproducible and functional integration of a wide range of nanomaterials and/or different biomolecules (enzymes, antibodies, nucleic acids and peptides). Considering the rapid progress in the field, and the potential of this technology, this review paper outlines the unique features imparted by this particular reaction in the development of electrochemical sensors through the discussion of representative examples of the methods mainly reported over the last five years. Special attention has been paid to electrochemical (bio)sensors prepared using nanomaterials and applied to the determination of relevant analytes at different molecular levels. Current challenges and future directions in this field are also briefly pointed out.


2021 ◽  
Vol 16 (3) ◽  
Author(s):  
Mohsin Ali ◽  
Jitendra Singh

Ionophore N, N’–Ethylene-bis-(Salicylideneaminato) copper (II) has been synthesized and characterized by IR and 1H NMR spectroscopy. Poly (vinyl chloride) based polymeric films of this ionophore along with cation discriminator (CTAB) and different plasticizers (dibutyl phthalate, dioctyl phthalate, 1-chloronapthalene and tri-n-butyl phosphate) were prepared and investigated as Nitrate ion sensors. Among all the different sensors fabricated, the one with membrane composition as I (7 mg): PVC (31 mg): DBP (60 mg): CTAB (2 mg) exhibited best characteristics. This sensor functions admirably over a wide concentration range 1.0×10−6–1.0×10−2 M with Nernstian compliance (59.8 mV per decade of concentration) between pH range 2.5–9.2 with a rapid response time of 13s. The sensor showed a lower detection limit 1.58×10-6 M. The selectivity coefficient values as determined by the fixed interfering method (FIM) show that the Nitrate ion has excellent selectivity over several anions. The sensor shows satisfactory time span of 2 months with great reproducibility while used continuously daily for 4 hrs. The sensor has been successfully utilized in the determination of nitrate ion concentration in different water samples.


1982 ◽  
Vol 13 (35) ◽  
Author(s):  
T. IKEDA ◽  
R. SCHMEHL ◽  
P. DENISEVICH ◽  
K. WILLMAN ◽  
R. W. MURRAY

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