H3PO4 Solution Research Articles

IMPROVEMENT OF AN ANALYTICAL METHOD BASED ON HPLC WITH REFRACTIVE INDEX DETECTION FOR THE ANALYSIS OF GLYCEROL OXIDATION PRODUCTS

The optimized analytical methodology described herein is based on an ion exchange column and an H3PO4 solution (pH 2.24) as the mobile phase, with a flow rate of 0.4 mL min-1 and refractive index detection (RID). On applying the methodology, it was possible to identify 7 products obtained from the oxidation of glycerol with an analysis time of 27 min. The developed method was validated through the evaluation of a series of analytical parameters. The results obtained were evaluated considering the peak area and peak height. The analytical curves showed a correlation coefficient of ≥ 0.986. The coefficient of variation values obtained were ≤ 3.60% for instrumental precision, ≤ 19.36% for intermediate precision in LOQ (1.25 µg mL-1) and ≤ 17.93% for repeatability in LOQ (1.25 µg mL-1) and different days. The limit of quantification established for all compounds was 1.25 µg mL-1 obtained through the parameters of the analytical curve. The accuracy of the method showed recovery values of 85.6 to 112.3% for real fortified sample at 3 concentration levels. Two different samples of glycerol oxidation products were applied to the validated methodology; one obtained from AuNP/SiO2 as catalyst (conversion of 62.42%), and other using AuNP/MWCNT (conversion of 89.5%).

Improving Surface Quality and Machining Efficiency of Microgrooves by WECMM in H3PO4-C2H5OH Solution

Microgrooves used in microelectromechanical systems (MEMS) are small, precise and usually made of hard-to-machine material, whose surface roughness significantly affects their performance and service life. Wire electrochemical micromachining (WECMM) has been used to machine them. Sometimes, it takes extra time to polish the microgrooves produced by WECMM when they couldn't meet the requirement of some special products in terms of surface quality. In this study, a new method is proposed to produce high quality surface efficiently that simultaneously implements electrochemical cutting and polishing in phosphoric acid (H3PO4). Ethanol, which has a lower density than water, was added to the electrolyte to improve mass transport and the flatness of the microgrooves. The polarization curves were measured to explain the principle of WECMM in H3PO4 solution. The effects of the composition of the electrolyte and machining parameters on curvature and surface roughness were studied theoretically and experimentally. In optimal conditions, a microgroove with a surface roughness of Sa = 0.039μm and Ra = 0.033μm was obtained.

Microstructural characterization and film-forming mechanism of a phosphate chemical conversion ceramic coating prepared on the surface of 2A12 aluminum alloy.

Phosphate chemical conversion (PCC) ceramic coatings on the surface of 2A12 aluminum alloy substrate have been fabricated by a simple and inexpensive chemical conversion process in CrO3–NaF–H3PO4 solution. Microstructure characterization showed that the average diameter of micro-pores and the thickness of the PCC ceramic coating were about 50 nm and 4 μm, respectively, and the ceramic coating was compact and uniform when the conversion time was 60 min. Meanwhile, we found that the PCC ceramic coating mainly consisted of AlPO4, AlOOH, AlF3, and a few amorphous phases (CrPO4 and CrOOH) via EDS, XRD, XPS analyses. TG-DSC results indicated that the PCC ceramic coatings had excellent thermal stability. Significantly, the adhesion strength (178.55 N) between the PCC ceramic coatings and 2A12 Al substrate was remarkably improved owing to the strong chemical bond between the PCC ceramic coating and 2A12 Al substrate and the increase of surface roughness. Furthermore, a lower corrosion current density (1.382 × 10−7 A cm−2) and a higher corrosion inhibition efficiency (99.91%) confirmed that PCC ceramic coatings had fantastic corrosion resistance because of the presence of crystalline AlPO4/AlF3/AlOOH and amorphous CrPO4/CrOOH as a barrier layer. Additionally, a possible film-forming mechanism of the PCC ceramic coating was proposed during the chemical conversion process, which could be divided into four stages: dissolution of 2A12 aluminum substrate and hydrogen evolution; crystallization of insoluble phosphates and formation of an amorphous phase; growth of insoluble phosphates and dissolution of PCC ceramic coatings; growth and dissolution of PCC coatings to dynamic equilibrium.

Production of adsorbent from activated carbon of palm oil shells coated by Fe3O4 particle to remove crystal violet in water

This study focused on making environmentally friendly activated carbon (AC) derived from palm oil shells producing a palm-based powdered activated carbon (PPAC) coated with Fe3O4 particles (PPAC-Fe3O4) as an adsorbent to adsorb crystal violet (CV) dyes in water. Activation of carbon from oil palm shells was carried out chemically using a H3PO4 solution of 10%. The characterization results of PPAC-Fe3O4 adsorbent using X-ray diffraction, nitrogen adsorption–desorption isotherms, and scanning electron microscopy-energy dispersive-X ray (SEM-EDX) compared with PPAC show that the coating process of Fe3O4 particle on PPAC has been carried out successfully to produce the adsorbent of PPAC-Fe3O4. Adsorption of CV dyes on PPAC and PPAC-Fe3O4 was optimum at pH 10 with an adsorbent dose of 2.5 g L–1, and contact time of 90 min. The CV dye adsorption kinetics model on PPAC and PPAC-Fe3O4 tends to follow the pseudo-second-order kinetic model with the rate constants (k2) for PPAC and PPAC-Fe3O4 of 0.059 and 0.088 g mg–1 min–1, respectively. In addition, the adsorption isotherm model of CV dyes on PPAC and PPAC-Fe3O4 tends to follow the Freundlich adsorption isotherm with KF values of 1.066 and 2.852 (mg g–1) (L mg–1)1/n, respectively. This indicates that the CV dye adsorption process occurs on heterogeneous surfaces with multilayer that occur through the pores of activated carbon and the magnetic properties of PPAC-Fe3O4 have increased the number of adsorbed CV dye.

Effect of ultrasound on the dissolution of Mardin-Mazıdağı (Turkey) phosphate ore in dilute H3PO4 solutions

The dissolution of phosphate ore in dilute phosphoric acid solutions was investigated in both the absence and presence of ultrasound. Acid concentration, reaction temperature and reaction time were chosen as parameters. While the conversion fractions decreased with increasing temperature in dilute phosphoric acid in absence of ultrasound, these rates increased with increasing temperature in the presence of ultrasound. In the experiments, the expected effects of ultrasound were observed, such as decrease in the thickness of the diffusion layer on the solid–liquid interfaces in the suspension, leading to increased surface area.

Porous alumina scaffolds chemically modified by calcium phosphate minerals and their application in bone grafts

AbstractThe chemical modification of porous ceramic scaffold surfaces with calcium phosphate surges as an alternative to improve the bioactivity to be used as bone grafts. The biomimetic method has been commonly used to modify surfaces of Ti alloys but surges as alternative to modify ceramic biomaterials. Herein, we modified the surface of Al2O3 scaffolds with calcium phosphate minerals and strontium using the biomimetic method. The scaffolds were chemically treated using H3PO4 solution and then immersed in simulated body fluid 5× solution for 14 days. For the incorporation of strontium, they were immersed in an aqueous solution of 100 ppm analytical‐grade Sr(NO3)2 under magnetic stirring. The samples were characterized by scanning electron microscopy, X‐ray microtomography, X‐ray diffraction, near‐infrared spectroscopy, inductively coupled plasma emission spectroscopy, and energy‐dispersive X‐ray spectroscopy. The biocompatibility and ability to differentiate osteoblasts in vitro were evaluated using human cells. The incorporation of strontium into the phosphate structure was verified. Scaffolds were obtained with high porosity, three‐dimensional structures, and the preferential adhesion and maturation of osteoblastic cells, which are essential to promote bone regeneration in vivo.

Bioinspired Mineralization of Type I Collagen Fibrils with Apatite in Presence of Citrate and Europium Ions

Synthetic nanostructured hybrid composites based on collagen and nanocrystalline apatites are interesting materials for the generation of scaffolds for bone tissue engineering. In this work, mineralized collagen fibrils were prepared in the presence of citrate and Eu3+. Citrate is an indispensable and essential structural/functional component of bone. Eu3+ endows the mineralized fibrils of the necessary luminescent features to be potentially employed as a diagnostic tool in biomedical applications. The assembly and mineralization of collagen were performed by the neutralization method, which consists in adding dropwise a Ca(OH)2 solution to a H3PO4 solution containing the dispersed type I collagen until neutralization. In the absence of citrate, the resultant collagen fibrils were mineralized with nanocrystalline apatites. When citrate was added in the titrant solution in a Citrate/Ca molar ratio of 2 or 1, it acted as an inhibitor of the transformation of amorphous calcium phosphate (ACP) to nanocrystalline apatite. The addition of Eu3+ and citrate in the same titrant solution lead to the formation of Eu3+–doped citrate–coated ACP/collagen fibrils. Interestingly, the relative luminescent intensity and luminescence lifetime of this latter composite were superior to those of Eu3+–doped apatite/collagen prepared in absence of citrate. The cytocompatibility tests, evaluated by the 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) (MTT) colorimetric assay in a dose–dependent manner on GTL–16 human gastric carcinoma cells, on MG–63 human osteosarcoma cells and on the m17.ASC, a spontaneously immortalized mouse mesenchymal stem cell clone from subcutaneous adipose tissue, show that, in general, all samples are highly cytocompatible.

Investigation of corrosion inhibition of C38 steel in 5.5 M H3PO4 solution using Ziziphus lotus oil extract: an application model

PurposeThis study aims to investigate the corrosion inhibition effect of extracted oil from Ziziphus lotus fruit on corrosion of C38 carbon steel in 5.5 M H3PO4 solution using potentiodynamic polarization and impedance techniques.Design/methodology/approachOil composition was determined using gas chromatography, and the results showed that oleic and palmitic acids present approximately 84.0 per cent of its total chemical content. Electrochemical impedance spectroscopy (EIS) data were analyzed by adapting it to a well-developed electric circuit model. The inhibition efficiency of Z. lotus oil was calculated and compared using Tafel polarization and EIS.FindingsAccordingly, the oil extract was found to act as an anodic type inhibitor. Furthermore, inhibition efficiency of Z. lotus oil extract increase with oil concentrations and achieve approximately 70.5 per cent at 3 g/L solution of Z. lotus oil.Originality/valueThe results obtained from different tested methods were in line, and the oil was able to reduce significantly the kinetics of the corrosion process of C38 carbon steel.

The Influence of Hexamethylenetetramine on the Corrosion Inhibition of Low Carbon Steel in Mixtures of Sulfurous and Phosphorus Acids Containing Fe(III) by IFKhAN-92 and KNCS Composition

This article studies corrosion of 08PS steel in 2 M H2SO4, 2 M H3PO4 and their mixtures (t = 20–80°C). Addition of a mixture comprised of 4.5 mM IFKhAN-92, a triazole derivant, and 0.5 mM KNCS inhibits corrosion of low carbon steel in these media. The existence of Fe(III) in the solutions worsens steel protection by this composition of inhibitors. The most stable against the impact of Fe(III) cations are the solutions of H3PO4 or its mixture with sulfurous acid with high content of H3PO4. Addition of hexamethylenetetramine (0.20 M) to these media enables protection of low carbon steels in acid mixed solutions with high content of H2SO4 (up to 60%) containing Fe(III). Upon etching of steels or acid washing of steel equipment in the case of potential accumulation of Fe(III) salts in such media accelerating metal corrosion, H2SO4 + H3PO4 solutions are recommended containing up to 60% H2SO4 and IFKhAN-92 + KNCS + hexamethylenetetramine composition, since in such a solution steel corrosion is minimized due to its interaction with Fe(III) compounds.

Effect of chemical action on the chemical mechanical polishing of β-Ga2O3(100) substrate

Chemical mechanical polishing (CMP) is an essential processing step to realize ultra-precision machining of the fragile material Ga2O3 crystal and obtain ultra-smooth and undamaged crystal surface. The chemical auxiliary polishing mechanism of Ga2O3 in the CMP process was studied considering that the chemical action directly affects the CMP result. First, H3PO4 and NaOH were used to regulate the pH of slurry. This slurry was then applied to the CMP experiment of Ga2O3, and the corrosion test of Ga2O3 was implemented in H3PO4 and NaOH solutions. Second, the influence of the slurry with different acids or bases on the polishing result was analyzed. Finally, scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) were used to evaluate the influence of the corrosive action on the chemical structure of the crystal surface. Results showed that the slurry prepared by H3PO4 was more suitable for the CMP of Ga2O3 than that prepared by NaOH. The polishing efficiency was enhanced by approximately 20% and the surface quality was improved, with surface roughness of 0.21 nm. This study provides a reference for preparing the slurry of Ga2O3.

KARAKTERISTIK KARBON AKTIF DARI CANGKANG BUAH KARET MENGGUNAKAN AKTIVATOR H3PO4

This research is purposed to determine the characteristic and adsorbtion ability of activated carbon which is made from rubber fruit shell with ativator phosphoric acid ( H3PO4 ). The carbonisation of activated carbon was carried out using furnace for 1 hour with temperature of 750oC. The next mashed and sieved with a size of 100 mesh. Then activated for 24 hours with H3PO4 solution with variation of concentration , 8%, 8.5%, 9%, 9.5% and 10%. As the result of characterisation, the lowest water degree wash content 10% with the value 3,25 % and lowest volatille metter from sample 10 % with the value 3,15 %. the lowest ash degree was from sample 8 % with the value 3,36 %. Maximum adsorbtion of iodine with sample 10 % with the value 947,25 mg/g . The optimum condition of activated carbon with activator phosphoric acis, which is produced in concentration 10%. Which at this concentration has moisture water degree of 3,25%, ash degree of 3,36%, volatille metter degree 3,15%, absorption iodine of 947.25 mg / g, and absorption metilene blue 98,95 mg/g.

Equilibrium Characteristics of KH2PO4 Production by Liquid, Liquid Extraction with a Trialkyl Amine-Based Solvent Mixture: A Case Study

This study evaluates the equilibrium characteristics of H3PO4 and KCl for the production of KH2PO4 by liquid, liquid extraction with organic solvent mixtures (trialkyl amine N235, isoamyl alcohol, and sulfonated kerosene). The extraction equilibrium for aqueous H3PO4 or for the reaction of H3PO4 with KCl was obtained. For the former case, the partition coefficient for extracting a standard H3PO4 solution first decreased rapidly and then slowly increased with the increase in H3PO4 content. In addition, the reaction enthalpy also showed a turning point. For the latter case, aqueous H3PO4 reacted with KCl and the organic phase separated the Cl– ions from PO43– to produce KH2PO4. The acid content presented a significant effect on the correlation between the separation performance and the molar ratio of H3PO4 to KCl. This was due to the fact that N235 dominated the partition process at low acid concentrations while the isoamyl alcohol dominated the extraction at high acid concentrations with the transition occ...

Gradual degeneration of liquid superlubricity: Transition from superlubricity to ordinary lubrication, and lubrication failure

The step-by-step evolution of the friction coefficient and substrate damage during the superlubricity degeneration of Si3N4/glass pair lubricated with H3PO4 solution was investigated. The experimental results indicate that the degeneration process experiences two stages after superlubricity failure. The superlubricity state initially degenerates to the ordinary lubrication state, gradually destabilizes, and eventually fails. Further analysis demonstrates that superlubricity degeneration is mainly attributed to serious substrate damage; however, the subsequent lubrication failure is mainly caused by the insufficient amount of lubricant. Moreover, load, not speed, plays a pivotal role in the wear behavior of substrate surface and further affects the superlubricity stability. The results may reveal the degeneration mechanism of liquid superlubricity and optimize the operation and design of superlubricant systems.

Bimetallic nanoporous Pd–Ag prepared by dealloying with polyvinylpyrrolidone and their electrocatalytic properties

Bimetallic nanoporous Pd–Ag solid solution alloys with hierarchical structure were prepared by dealloying melt-spun Al–Pd–Ag ribbons in a 10 wt% H3PO4 solution. Electrocatalytic properties of nanoporous Pd–Ag alloys were measured in comparison with the nanoporous Pd without Ag. Experimental results showed that the nanoporous Pd–Ag alloys displayed electrocatalytic properties superior to their Ag-free counterparts. In particular, the optimised composition was revealed to be Pd/Ag = 3/2 in atomic ratio in the precursor with fixed 85 at% Al alloys, which yielded in a peak current density in the nanoporous Pd–Ag alloy two times that of the pure Pd one. The electrocatalytic activity of nanoporous Pd–Ag alloy with refined microstructure was further increased up to three times of the pure Pd one by adding 1 mM polyvinylpyrrolidone (PVP) into the H3PO4 solution. The underlying mechanism of refinement was related to a restriction effect on the free diffusion of Pd and Ag under adsorption of the PVP macromolecules. The significant improvement in the electrocatalytic properties was attributed to the dual promotion by the electron transfer from PVP to Pd–Ag and by a synergistic effect between Pd and Ag.

Evaluation of environmentally friendly inhibitor for corrosion of mild steel in phosphoric acid solution: unconventional approach

PurposeThe purpose of this study is to investigate the corrosion inhibition of mild steel alloy in 2 M H3PO4 solution by the pomegranate peel extract as a friendly inhibitor was studied at various temperatures, inhibitor concentrations and immersion times.Design/methodology/approachA weight loss method was used to evaluate the corrosion rate. The experimental Taguchi design method was used for the distribution of experiments. The experimental design gave results which were impossible to show graphically. However, this problem was solved effectively with the aid of regression analysis.FindingsCorrosion rate increased with temperature according to Arrhenius equation. It was found that the efficiency of inhibition was increased with an increase in the concentration of inhibitor and immersion time. However, this diminishes with increased temperature. According to Langmuir isotherm, the inhibitor was adsorbed physically on steel surface. The negative sign of estimated heat of adsorption suggests a stable spontaneous inhibition process. Combination of mathematical and statistical analysis was proposed to demonstrate the results of corrosion rate with high correlation coefficients. In addition, Fourier transform infrared spectrometer examinations confirmed that the organic inhibitor consists of phenolic components as main materials.Originality/valueUsing unconventional approach for evaluation of environmentally friendly inhibitor for corrosion of mild steel in phosphoric acid solution.

Semiconducting properties assessment of passive oxide films forming on pure tungsten in 1.0 M H3PO4 solution

The current study is mainly to discuss the observed semiconducting characteristics of oxide passive films formed on pure tungsten (W) in H3PO4 solution (1.0 M). Potentiodynamic polarization (PDP) curve reveals that pure tungsten shows passive behavior in the given solution. Also, impedance spectroscopy shows that pure tungsten displays passive behavior at open-circuit potential condition in the solution. Mott–Schottky (M–S) analysis indicates that mentioned films which are formed on pure tungsten in phosphoric acid solution (1.0 M) display the semiconductors behavior of type n. The conduction of these passive films are not affected by anodic passive potential. In addition, according to M–S results, fewer defects are found in the passive film at higher anodic passive potentials. The obtained results show that corrosion resistance of pure tungsten in 1.0 M H3PO4 solution improves at higher passivation potentials due to the formation of passive films that are less defective.

The Effect of Sonication Duration on the Characteristics of Nano Hydroxyapatite-Silica (nHAp/SiO2) Composite and its Mechanical Properties

In this present study, we report the fabrication of nano-hydroxyapatite/silica (nHAp/SiO2) composite with the sonochemical method from Bojonegoro natural minerals, i.e. onyx stone and quartz sand. The nano-HAp was synthesized from Ca (OH)2 and H3PO4 solutions. The nHAp was successfully composed with silica by using sonication role. The sonication process was done in 1, 2, 3, and 4-hour variations at 20 % wt filler composition of Silica. The crystal structure properties of nHA were evaluated by X-ray diffraction (XRD). The ratio of Ca/P was evaluated by scanning electron microscopy and energy dispersive X-ray spectroscopy (SEM-EDX). The microstructural characterization of the sample was captured by scanning electron microscopy (SEM). Vickers hardness test was also conducted to identify the hardness (mechanical properties) of the sample. On the other hand, the porosity of the sample also was reported. The results of this study show that hydroxyapatite has a size of 30.57 nm and the ratio of Ca/P was 1.57. The variations of sonication affect the mechanical properties of nHA-SiO2 composite. The increasing sonication duration influences the hardness properties and porosity. The porosity of HAp (31.58 %) is still suitable to be applied for biomedical applications.

Polylaminate TaN/Ta coating modified ferritic stainless steel bipolar plate for high temperature proton exchange membrane fuel cell

A polylaminate coating with intersecting tantalum and tantalum nitride (TaN/Ta/TaN/Ta/TaN/Ta, TaN is the outermost layer) is deposited on surface of 430 stainless steel bipolar plate for high temperature proton exchange membrane fuel cell by a reactive magnetron sputtering method. Electrochemical tests including potentiodynamic, potentiostatic polarisation and electrochemical impedance spectroscopy, are carried out to evaluate the corrosion resistance and stability of the polylaminate TaN/Ta coating in simulating high temperature proton exchange membrane fuel cell environments (85% H3PO4 solution at 80 °C and 130 °C). Results show that the polylaminate TaN/Ta coating greatly improve the corrosion resistance of 430 stainless steel, which can provide almost 100% protection of the substrate in both high temperature proton exchange membrane fuel cell anode and cathode environment. Besides, the interfacial contact resistance of coated 430 stainless steel (9.03 mΩ cm2) is much lower than that of bare substrate (106.74 mΩ cm2). Furthermore, different from the highly increased interfacial contact resistance of bare specimen, the coated 430 stainless steel shows a minor increase resistance after potentiostatic tests in 85% H3PO4 solution at 130 °C.

Enhancing Corrosion Resistance of Stainless Steel By Hot-Dip Aluminizing for High Temperature Solar Thermal Applications

The development of high temperature solar thermal systems (also known as concentrated/ting solar power, CSP) containing molten salts as the heat transfer fluids is direly needed to replace fossil-fuel energy with solar thermal power. Even though efficiency of the CSP systems increases on elevating the working temperature, molten salt overwhelmingly corrodes containments and pipes of the systems at high temperature. Therefore, corrosion is a significant obstacle for developing high temperature CSP. Ni-alloys show superior corrosion resistance to Fe-alloys in high temperature molten salt but their high cost makes them less preferable. One of the possible ways to enhance corrosion resistance in high temperature molten salt is to apply protective coatings on economic substrates like steels or stainless steel. In this work, hot-dip aluminized coating was formed on 310S-type stainless steel and the coating degradation behavior was evaluated in eutectic ternary alkali carbonate salt mixture at 650 °C. Hot-dip aluminized coatings were formed on 310S stainless steel coupons by immersing in Al-melt at 714 °C for 1.5 minutes and subsequently annealing at 700 °C for 40 minutes. Al-rich top layer was removed by a brief shot blasting. For enhancing the inter-diffusion resistance, these aluminized samples were further given an additional heat treatment and the details will be discussed during the meeting. All the samples were polished with SiC paper (#600 grit) to remove the outer porous layer. For diffusion and corrosion test at 650 °C, a eutectic salt mixture of 0.43 Li2CO3-0.32 Na2CO3-0.25 K2CO3 (mole fraction) was employed. To get mass loss due to corrosion, corrosion product was selectively etched in hot 2% CrO3+ 5% H3PO4 solution. For electrochemical polarization, polished flag-shaped aluminized 310S samples were employed as the working electrode (WE); flag-shaped Pt as counter and oxygen electrode as reference electrodes. Potential was scanned from stable OCP with 10 mV s-1. For EIS, two similar flag-shaped electrodes were used; and 10 mV AC voltage was applied to freely corroding electrodes. SEM, TEM, EPMA and XRD were used to study morphology and composition of the coating as well as that of corroded aluminized coating. The as-aluminized coating was degraded remarkably by the inter-diffusion when it was exposed in the molten salt at 650 °C. The additional heat pretreatment prevented the coating to be damaged by the inter-diffusion. Further, the heat pretreated coating was polished to remove upper porous layer and to quantify precisely the electrochemical properties. At the same time, removal of the top layer of the coating led to expose the inner highly alloyed coating material to the surface of the sample. Electrochemical polarization, EIS and mass loss observations concluded that the coating enhanced the corrosion resistance of the stainless steel at least by two orders of magnitude. Analytical TEM study revealed that ~50 nm thin α-LiAlO2 layer was formed due to corrosion. Role of composition of coating, formation of the passive film and resultant corrosion performance will be discussed in the meeting. Acknowledgements This work was supported by Council for Science, Technology and Innovation (CSTI), Cross-ministerial Strategic Innovation Promotion Program (SIP), “energy carrier” (Funding agency: Japan Science and Technology Agency, JST). Authors duly thank ‘Soken Tecnix Co., Ltd.’ for carrying out aluminizing of the specimens.

Inhibition Effect of Three-Dimensional (3D) Nanostructures on the Corrosion Resistance of 1-Dodecanethiol Self-Assembled Monolayer on Copper in NaCl Solution.

A novel and simple method to improve the corrosion resistance of copper by constructing a three-dimensional (3D) 1-dodecanethiol self-assembled monolayer (SAM) in 3.5% NaCl solution is reported in this study. Several drops of 1% H3PO4 solution are thinly and uniformly distributed on copper surface to form a 3D nanostructure constituted by Cu3(PO4)2 nanoflowers. The anticorrosion properties of 1-dodecanethiol SAM on copper surface and on copper surface that is treated with H3PO4 solution were evaluated. Results demonstrated that 1-dodecanethiol SAM on bare copper surface exhibits good protection capacity, whereas a copper surface that is pretreated with H3PO4 solution can substantially enhance the corrosion resistance of 1-dodecanethiol SAM.