Papers by Keyword: Electro Polymerization

Abstract: We present a novel microcantilever device with nano-interdigitated electrodes (nano-IDEs) and selective functionalization of nano-IDEs for biosensing applications. The nano-IDEs play a role in precisely addressing capture molecules to a specific region on a microcantilever. This leads to a detectable surface stress due to the binding of target molecules. 70~500 nm-wide gold (Au) nano- IDEs are fabricated on a low-stress SiNx microcantilever with dimensions of 100~600 μm in length, and 15~60 μm in width, with a 0.5 μm thickness using electron beam lithography and bulk micromachining. 32~96 nm-thick streptavidin is selectively deposited on one side of nano-IDEs using cyclic voltammetry at a scan rate of 0.1 V/s with a range of -0.2~0.7 V during 1~5 cycles. The selective deposition of streptavidin is confirmed by fluorescence microscopy and atomic force microscopy (AFM).

Abstract: The present work describes the studies on corrosion of powder injection molded 316L stainless steel potentiostatically coated by poly{trans[RuCl2(vpy)4]} where vpy (4- vinylpyridine) acts as ligand. Scanning Electron Microscopy (SEM) coupled to an Energy Dispersive X-Ray Analysis (EDAX) characterized the coated electrodes. Anodic polarization tests were performed in 3% NaCl to estimate the anodic dissolution current density of the electrode coated by the polymeric material. In addition, the specimens were exposed to salt spray and acid rain simulated environment. The microestrutural analysis indicated that the films were approximately 58 μm thick. Cyclic voltammetry experiments were carried out in 0.1M HTBA/methyl isobutyl ketone solution. The results revealed a scan rate dependent wave corresponding to a Ru2+/Ru3+ redox reaction, thus confirming the presence of ruthenium as metallic center in the polymer backbone. Pitting corrosion was observed in coated specimens only after thirty days of exposure to salt spray and after two days of exposure to acid rain simulated environment.

Abstract: The use of generated coated polymeric films by electrochemistry means in the sintered metallic surfaces has been being the focus of our research aimed at the corrosion protection of small mechanical components obtained from powder metallurgy. The sintered alloys Fe- 2%Ni, Fe-5%Ni and 10%Ni with polymeric coating were tested using electrochemistry methods in corrosive solutions of NaCl 3%, KNO3 1.25M, H2SO4 0.5M, HNO3 0.5M, acetic acid 1%, oxalic acid 1% and lactic acid 1%. The electrochemistry corrosion tests were performed using two techniques, Eocp vs. Time and Potentiodynamic and they proved the efficiency of the polymeric coating on the corrosion protection of sintered alloys.

Abstract: Glassy carbon (GC) discs and platinum microcylindrical electrodes were modified with a layer of nickel(II) tetrakis 3-methoxy-4 hydroxyphenyl porphyrin (poly-TMHPP-Ni) of different loadings (Γ) between 0.6 and 10 nmol/cm2, and subsequently with a Nafion layer. The topography and in some cases the thickness of films were measured by means of contact mode AFM. SEM and optical microscopy observations were used for the comparative studies on a larger scale. The useful range of the coverage with modifying polymer was investigated. The optimal value of loading for the sensor was found to be in the range of 6-8 nmole of poly-TMHPP-Ni per cm2. We observed the Nafion layer uniformity in nanometric scale.