Composite Nanocoating Research Articles

Influence of Composite Nano-Coating of Ni-Co-SiC Obtained by Electrodeposition on the Corrosion Resistance of API 5L X80 Steel

Corrosion problems are frequent and occur in various sectors of industries, resulting consequences of economic order and serious accidents involving human lives and contaminating the environment. The electrodeposition is one of the most popular methods for preventing corrosion, where the Ni-Co metal matrix has been widely applied. The incorporation of SiC nano-particles in electrochemical baths produces nanocomposite coatings to synergistic properties with potential application in anti-corrosion protection. The objective of this work was to develop the Ni-Co-SiC nano-coating electrodeposited on API 5L X80 steel and evaluate the corrosion resistance. Open circuit potential (OCP), electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization (PP) measurements were performed in 3.5% NaCl solution. To correlate with corrosion behavior, scanning electron microscopy (SEM), energy-dispersive X-ray spectrum (EDXS) and Vickers micro-hardness tests on the nano-coating were performed.

Corrosion Behavior of Nanocomposite Al-9 wt% Si Alloy Reinforced with Carbon Nanotubes

An effort is made to study the effect of composite nanocoating using aluminum-9%wt silicon alloys reinforced with different percentage (0.5,1,2,4)wt.% of carbon nanotubes (CNTs) using plasma spraying. The effect of this composite on corrosion behavior for AA6061-T6 by extrapolation Tafel test in sea water 3.5wt% NaCl was invested. Many specimens where prepared from AA6061-T6 by the dimension (15x15x3)mm as this first set up and other steps include coating process, X-ray diffraction and SEM examination .The results show the CNTs increase the corrosion rate of the nanocomposite coatings with increasing the weight percentage of CNTs within the Al-Si matrix. Al-9wt%Si coating layer itself has less corrosion rate if compared with both nanocomposite coating and the substrate of AA6061-T6.

Features of the sol-gel synthesis of TiO2 nanolayers with calcium phosphate structures on titanium surface

A procedure for the synthesis of composite nanocoating TiO2/calcium phosphate structures on the titanium surface promising for biomedical application (bone implantation) has been proposed.

Knee Joint Ligament Implants with Composite Nanocoatings

A method for making knee joint ligament implants based on synthetic constructs manufactured from polyethylene terephthalate fibers with composite nanocoatings was developed. Coatings consisted of aqueous dispersions of multiwalled (MWNT) and single-walled (SWNT) carbon nanotubes and were applied to synthetic fibers using ultrasound and then fixed by laser evaporation. The SWNT-based composite nanocoating had a pore diameter of 10-20 nm, compared with 40-60 nm for the MWNT-based coating. In vitro studies of the proliferative activity of human fibroblasts (HFb) during colonization on the surface and between the synthetic fibers were performed. The greatest level of HFb proliferation was seen on synthetic constructs with composite nanocoatings based on MWNT with large pore size, at 55,435 cells, as compared with SWNT-based coatings (54,931 cells) and the control sample (54,715 cells), as assessed by fluorescence microscopy and the MTT test.

Mechanistic aspects of electrodeposition of Ni–Co–SiC composite nano-coating on carbon steel

The nucleation and early-stage growth mechanism and kinetics of electrodeposited Ni–Co–SiC composite coating on carbon steel was investigated by cyclic voltammetry, current–time transient measurements and atomic force microscopy characterization. The conventional Guglielmi's model for metal-inert particle co-deposition was modified to consider the effect of the bath electrolyte hydrodynamics on amount of nano-particles deposited in the coating. It is determined that the nucleation and early-stage growth of the coating depends on depositing overpotential. At low cathodic overpotentials, it is between an instantaneous and progressive mechanism; while at high overpotentials, it follows the instantaneous mechanism. Addition of SiC nano-particles in the bath electrolyte reduces the electrodepositing efficiency by inhibiting nucleation and growth of metallic coating. An empirical model is developed to estimate the amount of nano-particles contained in Ni–Co–SiC composite coating during pulse electrodeposition.

Polyimide/carbon black composite nanocoating layers as a facile surface modification strategy for high-voltage lithium ion cathode materials

Ion-conductive polyimide (PI)/electron-conductive carbon black (CB) composite nanocoating layers (referred to as “PI/CB coating layers”) are presented as a facile and scalable surface modification strategy for high-voltage lithium ion cathode materials (here, LiCoO2 (LCO) is chosen as a model system). The PI/CB coating layers exhibit a unique synergistic effect (i.e., boosted electronic conduction (from CB networks) in conjunction with suppression of unwanted interfacial side reactions between delithiated LCO and the liquid electrolyte (due to PI nanothin films)), which thus exerts a beneficial influence on the electrochemical performance and thermal stability of high-voltage cells.

Comparative Characteristics of the Morphology of Rabbit Lymph Nodes after Implantation of Porous Titanium with Composite Nanocoating and Hydroxyapatite Particles Embedded into Pores

We studied changes of microarchitectonics of lymph nodes in mature rabbits in response to introduction of bioimplants based on porous titanium with carbon-containing nanocoating or nanocoating with hydroxyapatite embedded into pores. Moderate local reactivity of the lymphoid system was observed in animals with implants coated with carbon-containing films within 30 days after surgery. In animals with nanocoated implants containing hydroxyapatite, the immune response was more pronounced. Introduction of implants led to activation of cellular and humoral mechanisms of immunity in animals of both groups.

Organic−Inorganic Composite Nanocoatings with Superhydrophobicity, Good Transparency, and Thermal Stability

Superhydrophobic, highly transparent, and stable organic-inorganic composite nanocoating is successfully prepared by a simple sol-gel dip-coating method. This method involves control of the aggregation of inorganic colloid particles by polymerization and ultrasonic vibration to create the desired micro/nanostructure in the coating. Superhydrophobicity and transparency of the coating can be controlled by adjusting the initial concentration of monomer and the size of aggregates in the sol-gel. Thus, superhydrophobicity and high transparency can be concurrently achieved in a single coating. The prepared coating also possesses good thermal stability. Its superhydrophobicity can be maintained from 20 to 90 degrees C.

Conductive paper from lignocellulose wood microfibers coated with a nanocomposite ofcarbon nanotubes and conductive polymers

Composite nanocoating of poly(3,4-ethylenedioxythiophene)–poly(styrenesulfonate)(PEDOT–PSS) and aqueous dispersion of carbon nanotubes (CNT–PSS) on lignocellulosewood microfibers has been developed to make conductive microfibers and paper sheets.To construct the multilayers on wood microfibers, cationic poly(ethyleneimine)(PEI) has been used in alternate deposition with anionic conductive PEDOT–PSSand solubilized CNT–PSS. Using a Keithley microprobe measurement system,current–voltage measurements have been carried out on single composite microfibersafter deposition of each layer to optimize the electrical properties of the coatedmicrofibers. The conductivity of the resultant wood microfibers was in the range of10−2–2 S cm−1 dependingon the architecture of the coated layer. Further, the conductivity of the coated wood microfibers increasedup to 20 S cm−1 by sandwiching multilayers of conductive co-polymer PEDOT–PSS with CNT–PSSthrough a polycation (PEI) interlayer. Moreover, paper hand sheets weremanufactured from these coated wood microfibers with conductivity ranging from 1 to20 S cm−1. A paper composite structure consisting of conductive/dielectric/conductive layers thatacts as a capacitor has also been fabricated and is reported.