The properties of the newly formulated nanocomposite film are enhanced by solution casting varying amounts (0.2

Mild steel panels were zinc phosphated employing environmentally safe nano silica as an accelerator and a series of four cationic surfactants as additives. The four cationic surfactants chosen were decyltriethyl ammonium bromide (C(10)TEAB), dodecyltriethyl ammonium bromide (C(12)TEAB), hexadecyltriethyl ammonium bromide (C(16)TEAB), and octadecyltriethyl ammonium bromide (C(18)TEAB). The length of the alkyl chain of the surfactant compounds influenced the quality of the coatings. The corrosion resistance of the coated panels was assessed using a salt spray test. The hydrophobicity of the coatings increased as the hydrocarbon chain length of the surfactants extended from C-10 to C-18. Porosity, adhesion, and roughness tests were used to examine the surface properties of the coated panels. The coating weight and thickness of the resultant coatings on the base metal were used to quantify coating quality. The results of the tests revealed that the presence of C(16)TEAB additive outperformed all other components in terms of coating efficiency, coating thickness, and corrosion inhibition performance. The optimal quantity of C(18)TEAB deposited had a maximum coating weight of 0.0430 g/mm(2) that enhanced durability, appearance, and barrier qualities.

Abstract Almond gum and varied concentrations of nanosilica (0.2, 0.4, 0.6, 0.8, and 1.0 wt%) were introduced into the chitosan polymer matrix by solution cast method to enrich the characteristics of the bionanocomposite film. The surface topography, thermal stability, crystalline nature, and functional moieties of the synthesized bionanocomposite films were characterized by SEM, TGA, XRD, and FT-IR. The UV–Vis spectrophotometer showed a maximum absorption wavelength for the film containing the highest concentration of nanosilica. Change in properties such as increased tensile strength, elongation and reduced water solubility, and swelling properties were observed for the bionanocomposite film containing 1.0 wt% nanosilica. In addition, the films exhibited excellent inhibition effect against Escherichia coli bacteria and Candida albicans fungus, which were proven by well diffusion assay method. The carrot slices packed in the bionanocomposite film containing the highest amount of nanosilica retained their freshness for a longer period of time, suggesting the film to be an effective and excellent food packaging material.

The influence of nano silicon dioxide additive on calcium modified zinc phosphated mild steel sample is researched in this paper. This study shows that the environment friendly nano additive provides a high porous, fine-grained and compact phosphate sealing by facilitating strong adsorption to the successive protective covering of mild steel. The formed coatings were characterised by scanning electron microscopy (SEM), energy dispersive X-ray (EDX), atomic force microscopy (AFM) and atomic absorption spectroscopy (AAS). The thermal stabilities of the coatings were analysed by thermo gravimetric analysis (TGA). The coating quality on the mild steel surface was examined by coating weight, porosity and adhesion tests. The corrosion studies were done using salt spray test and electrochemical impedance spectroscopy. The good dispersibility of the additive was observed on the coating with increased safety from erosion. The lower i(corr) value of 2.6477 x 10(-5) A/cm(2) for CaZnPS when compared to 8.212 x 10(-5) A/cm(2) for CaZnP indicated that the nano additive has more shielding effect. The results reveal that the barrier and corrosion inhibition tendencies were increased with the addition of nano particles to the calcium modified zinc phosphated mild steel.

Mild steel panels were subjected to zinc phosphate conversion coating accelerated by environment friendly nano silicon dioxide using a series of cationic surfactants as additives. Four cationic surfactants have been synthesized in the absence of solvent using triethylamine and four different long chain alkyl halides. From 1 H NMR and 13 C NMR spectra the chemical structures of the synthesized surfactants were confirmed. The nano silicon dioxide accelerator provided a highly porous phosphate coating ensuring good adhesion to the consecutive top coating. The incorporation of cationic surfactants as additives led to fine-grained coatings which enhanced adherence and excellent corrosion resistance property to the phosphate coating. The performance of the surfactants as a corrosion inhibitor increases with the increase in the hydrophobicity of the side-chain length. Accelerator and additive incorporation effectively reduced the extent of zinc dissolution during phosphating and exhibited the highest polarization resistance. The good dispersability of additives and increased hydrophobicity yielded coatings with improved protection against corrosion. The corrosion inhibition performance of the coated steel has been studied by Open Circuit Potential (OCP), Potentiodynamic Polarization Curve, Electrochemical Impedance Spectroscopy (EIS) and salt spray test.

AbstractFour cationic surfactants have been synthesized in the absence of solvent using triethylamine and four different long chain alkyl halides. Using FTIR, 1H NMR spectra and elementary analysis the chemical structure of the synthesized surfactants were confirmed. The physio-chemical properties have been evaluated using standard analytical procedures. The corrosion inhibition properties of these four surfactants as additives were evaluated on zinc phosphate conversion coating on mild steel using nano silica as accelerator. The efficacy of the surfactants as corrosion inhibitor increases with increase in the side chain length and surface activity. With the help of X-ray diffraction (XRD), Atomic force microscope (AFM) and Scanning electron microscope (SEM) the surface morphology have been studied. The protective performance of the coatings was evaluated by salt spray exposure studies.

In this work, the phosphating process was accelerated by ECO-friendly nano silicon dioxide along with decyltriethylammonium bromide as an additive. Accelerator and additive incorporation effectively reduced the extent of zinc dissolution during phosphating and activated the process to achieve the coating weight faster. Also it yielded coatings with greater thickness than the normal phosphate coating. The parameters such as coating weight, surface coverage, roughness and corrosion resistance due to the presence of nano silicon dioxide and decyltriethylammonium bromide were evaluated. X-ray diffraction (XRD),Atomic force microscope (AFM) and Scanning electron microscopy (SEM) were availed to study the chemical composition, modified surface and microstructure of the phosphate coatings. XRD studies revealed the presence of Zn 3(PO 4)2.4H 2O (hopeite) and Zn 2Fe(PO 4)2.4H 2O (phosphophyllite) in the composition of the phosphate coating. The corrosion behaviour of the coated steel was assessed by open circuit potential, potentiodynamic polarization curve and electrochemical impedance spectroscopy.