Sulfamic Acid Solution Research Articles

Eupatorium adenophorum Spreng root extract as an efficient inhibitor for the corrosion of steel in sulfamic acid solution

Eupatorium adenophorum Spreng root extract (EASRE) was prepared using a reflux extraction method with 40 % ethanol (C2H5OH) as the extractant solvent. The corrosion inhibitory impact of EASRE on cold rolled steel (CRS) in 0.10 M sulfamic acid (NH2SO3H) solution was explored through gravimetric tests, potentiodynamic polarization curves, and electrochemical impedance spectroscopy (EIS) methods. Metallographic microscopy (MM), scanning electron microscopy (SEM), atomic force microscopy (AFM), and confocal laser scanning microscopy (CLSM) were employed to examine the micrographs of CRS specimens. The adsorbed chemical substances on the inhibited CRS surface were examined via X-ray photoemission spectroscopy (XPS). And the main chemical constituents of EASRE were analysed by high performance liquid chromatography-mass spectrometry (HPLC-MS). The results of the study showed that EASRE at a concentration of 500 mg L−1 in 0.10 M NH2SO3H at 30 °C for 12 h had a significant inhibitory effect on CRS, with a maximum inhibitory efficiency of 89.7 %. At all set temperatures, the adsorption of EASRE onto CRS surface adheres to Langmuir isotherm. EASRE functions as a mixed-type inhibitor through a “geometric covering effect”. EIS show that the addition of EASRE significantly improves the charge transfer resistance at the steel/sulfamic acid interface, and the charge transfer resistance increases with increasing inhibitor concentration. XPS analysis confirm the presence of a “protective film” generated by EASRE on the CRS surface, and it consists of O-H, N-H, C-O, C-H, CC, CN, CO. Microscopic graphs of MM, SEM, AFM and CLSM reveal that EASRE efficiently alleviates the corrosion on the CRS surface. The HPLC-MS suggest that the main components of EASRE are flavonoids and phenylpropanoid compounds.

Optimization and evaluation of corrosion inhibitors for N80 steel in sulfamic acid solutions

Sulfamic acid (SA) has a low acid-rock reaction rate and can be used for deep high-temperature acidizing. However, the inhibition effect of existing corrosion inhibitors at deep high temperatures is greatly reduced. Through experiments, it is found that corrosion inhibitors such as imidazoline (OAI), cinnamaldehyde (CA), C14 quaternary ammonium salt (C14-GN), and potassium iodide (KI) have good corrosion inhibition effect, the average corrosion inhibition rate can reach 99 %, and the corrosion rate is less than 2 g/m2 h. The experimental results show that the film formation of a single inhibitor is uneven and the pitting corrosion is serious. In contrast, the mixed-use of many kinds of inhibitors can effectively inhibit the pitting corrosion, and the corrosion rate is less than 1.6 g/m2 h. And it can effectively inhibit pitting corrosion. At 363 K, the corrosion inhibition rate is 99.9 % and the corrosion rate is 1.1 g/m2·h. Through the orthogonal test, it is concluded that the best inhibitor ratio is OAI: CA: C14-GN: KI = 3:3:3:2. The optimized inhibitor has the best synergistic effect, can play an important role at high temperature, make the film uniform and dense, and improve the corrosion inhibition effect of the solution of sulfamic acid with the investigated inhibitor.

Corrosion Prevention of Copper in 2.0 M Sulfamic Acid Using Novel Plant Extract: Chemical, Electrochemical, and Theoretical Studies.

Copper corrosion was suppressed when a lupine extract was immersed in a 2 M sulfamic acid (H2NSO3H) solution. Numerous methods, including mass loss (ML), dynamic potential polarization (PL), and electrochemical impedance (EIS), were employed in these experiments, in addition to theoretical computations such as density functional theory (DFT), Fukui function, and Monte Carlo simulations. Fourier transform infrared (FT-IR) spectroscopy and scanning electron microscopy (SEM) were used to analyze the Cu surface's composition and determine its form. Mass loss (ML) was used to examine the inhibition rate of copper corrosion in sulfamic acid at 25 °C in the presence of lupine extract. After examining how it behaved throughout the adsorption process on copper, it was discovered that it follows the Langmuir isotherm and chemical adsorption. An analysis of the PL curves indicates that the lupine extract is a mixed-type inhibitor. It was shown that the inhibitory efficiency increased to 84.2% with increasing lupine concentration. Additionally, as the data show, the efficiency of inhibitors is diminished by increasing temperatures. Theoretical calculations and experimental data were compared using Monte Carlo simulation (MC) and density functional theory (DFT).

Characterization of PVVH/PEMA blend polymer with gold nanoparticles as corrosion inhibitors for N80 carbon steel in a 5% sulfamic acid solutions

Characterization of PVVH/PEMA blend polymer with gold nanoparticles as corrosion inhibitors for N80 carbon steel in a 5% sulfamic acid solutions

Attenuation of Mild Steel-Acid Corrosion Using Exfoliated Graphite Oxide-Polymer Composite: Synthesis, Characterization, Electrochemical, and Response Surface Method Approach

This work deals with the study of the anticorrosion behavior of a biopolymer, namely Guar Gum (GG) and its composite on mild steel (MS) in sulfamic acid (SA) solution using electrochemical techniques. GG was found to be a potential inhibitor relatively at its higher concentration and showed maximum inhibition efficiency (IE) of 74% at 3 g/L (3000 ppm). To improve its IE, exfoliated graphite oxide (xGO)/GG polymer composite was prepared, and its inhibition property was assessed in 1 M SA solution at different temperatures by weight loss method (WL). The chemical structure of xGO/GG polymer composite was examined by FT-IR, and the morphology was inspected by optical microscopy, scanning electron microscopy study, and energy dispersive spectroscopy technique. xGO/GG polymer composite emerged as an efficient corrosion inhibitor for MS as marked from the outcomes of the electrochemical investigations and showed improved IE of 93% at 0.6 g/L (600 ppm) when compared to GG. Experimental results found by WL measurements are used to evaluate the thermodynamic parameters at various temperatures. Further, a Box-Behnken composite design with three factors and three levels has been used to minimize the experimental conditions. The IE was enhanced with the increase in the inhibitor concentration as observed from the main effect plot. The maximum IE of 84.21% was projected by the response surface method (RSM) with temperature (A = 30 °C), inhibitor concentration (B = 600 ppm), and time (C = 1 h).

Electrochemical dissolution behavior of Narloy-Z in sulfuric acid and sulfamic acid solutions

Electrochemical dissolution behavior of Narloy-Z in sulfuric acid and sulfamic acid solutions

Investigation of Solupred as a pharmaceutical drug as a corrosion inhibitor for copper corrosion in 1.0 M sulfamic acid solution

Investigation of Solupred as a pharmaceutical drug as a corrosion inhibitor for copper corrosion in 1.0 M sulfamic acid solution

Sulfamic acid is an environment-friendly alternative electrolyte for industrial acid cleaning and corrosion inhibition: a mini review

Abstract Sulfamic acid (H3NSO3), which is also known as amino sulfuric acid, sulfamidic acid, amidosulfonic acid, and aminosulfonic acid, is an industrially useful water-soluble colorless crystalline solid. Sulfamic acid solutions of different concentrations are widely used for the removal of scales and metal oxides deposits from the surface of metals and ceramics. Sulfamic acid solutions (5–10%) serve as alternative electrolytes for the removal of rusts and lime scales to replace relatively more irritating and volatile hydrochloric and sulfuric acid-based electrolytes. Sulfamic acid solutions can be regarded as relatively more environmentally friendly and less toxic electrolytes for the cleaning of metallic surfaces. However, similar to the popular acidic solutions, sulfamic acid based electrolytes are corrosive to metal and metallic structures. Therefore, organic compounds based corrosion inhibitors of natural and synthetic origin are widely used to prevent corrosive damage of metallic surfaces in such electrolytes. These compounds become effective by adsorbing on the metallic surface following through the Langmuir adsorption isotherm model. Using electrochemical analyses it was observed that organic corrosion inhibitors in sulfamic acid based electrolytes behave as mixed- and interface-type corrosion inhibitors and they become effective by adsorbing at the metal/electrolyte interfaces. The adsorption of most of the corrosion inhibitors mostly follows physiochemisorption mechanism.

Synthesis, characterization and electrochemical behavior for API 5L X70 carbon steel in 5% sulfamic acid medium using PVVH/PEMA blend filled with gold nanoparticles

In the present work, we synthesized the polymer blend of Poly (vinyl chloride-co-vinyl acetate-co-2-hydroxypropyl acrylate), and Poly (ethyl methacrylate) (PEMA) by solution casting method and then filled it with different concentrations of gold nanoparticles (Au-NPs). The present composite was employed as corrosion inhibitors for API 5L X70 carbon steel in 5% sulfamic acid solution by electrochemical methods such as potentiodynamic polarization (PP) and electrochemical impedance spectroscopy (EIS) techniques. The quantum chemical computations utilized by DFT process produced an acceptable theoretical interpretation for the adsorption and inhibition performance of the composite on the carbon steel surface. PP plots demonstrated that the examined samples act as a miscellaneous type inhibitor. With raising its concentrations, the inhibition productivity rises up to 91.3% in case of blend/ 3% Au-NPs as observed from the EIS results. The inhibition mechanism follows Langmuir adsorption isotherm. It was discussed as concerns the nanocomposite investigated adsorption on steel metal surface and confirmed using SEM. Bode plots exposed that, the total impedance elevated with raising examined polymer concentration and the constant addition to the phase angle move was clearly associated with the increasing of the examined polymer concentration adsorbed on carbon steel species. A significant agreement was attained among the quantum chemical variables (DFT and Mulliken atomic charges) and the experimental computations, indicating the efficiency of the nanocomposite to act as effective corrosion inhibitor.

Impact of phosphonium-based ionic liquid on the corrosion control of aluminum alloy AA5052 in MED desalination plants during acid cleaning process

Aluminum alloy AA5052 has recently been chosen to replace titanium tubes in desalination plants' multiple effect distillation (MED) units. The high corrosion rate of AA5052 during the acid cleaning process to remove the scale layer, on the other hand, remains a significant challenge. In this paper, we describe for the first time the use of an ionic liquid, tributyl(ethyl)phosphonium diethyl phosphate (Ph-IL), as a corrosion inhibitor for aluminum alloy AA5052 during the acid cleaning process with a 4% sulfamic acid solution. Remarkably, the addition of ionic liquid Ph-IL to sulfamic acid results in enhanced corrosion resistance of AA5052 with the efficiency reached to 93.0%. Through the adsorption of both the cationic and anionic parts of the ionic liquid, Ph-IL molecules can cover the anodic and cathodic sites. Furthermore, the Ph-IL forms a significant activation energy barrier against the corrosion process. In addition, SEM-EDX analysis confirms the formation of protective layers of Ph-IL molecules on the surface of AA5052. This finding may be helped in the expansion of the use of many ionic liquids with their new properties in the field of desalination.

A technique for uranium and plutonium determination using coulometric potentiostatic facility UPK-19 for analysis of mixed-oxide fuel

The content of uranium and plutonium is the main characteristic of mixed uranium-plutonium oxide fuel, which is strictly controlled and has a very narrow range of the permissible values. We focused on developing a technique for measuring mass fractions of uranium and plutonium by controlled potential coulometry using a coulometric unit UPK-19 in set with a R-40Kh potentiostat-galvanostat. Under conditions of sealed enclosures, a special design of the support stand which minimized the effect of fluctuations in ambient conditions on the signal stability was developed. Optimal conditions for coulometric determination of plutonium and uranium mass fractions were specified. The sulfuric acid solution with a molar concentration of 0.5 mol/dm3 was used as a medium. Lead ions were introduced into the background electrolyte to decrease the minimum voltage of hydrogen reduction to –190 mV. The addition of aluminum nitride reduced the effect of fluoride ions participating as a catalyst in dissolving MOX fuel samples, and the interfering effect of nitrite ions was eliminated by introducing a sulfamic acid solution into the cell. The total content of uranium and plutonium was determined by evaluation of the amount of electricity consumed at the stage of uranium and plutonium co-oxidation. Plutonium content was measured at the potentials, at which uranium remains in the stable state, which makes it possible to subtract the contribution of plutonium oxidation current from the total oxidation current. The error characteristics of the developed measurement technique were evaluated using the standard sample method and the real MOX fuel pellets. The error limits match the requirements set out in the specifications for MOX fuel. The technique for measuring mass fractions of uranium and plutonium in uranium-plutonium oxide nuclear fuel was certified. The relative measurement error of the mass fraction of plutonium and uranium was ±0.0070 and ±0.0095, respectively. The relative error of the ratio of the plutonium mass fraction to the sum of mass fractions of uranium and plutonium was ±0.0085.

Electrochemical and Density Functional Theory Studies of Alkyl Imidazoline on the Corrosion Inhibition of Carbon Steel in Sulfamic Acid Solutions

The corrosion inhibition effects of the 2-undecyl-N-carboxymethyl-N-hydroxyethyl imidazoline on simple steels were indagated in 8 wt.% NH2SO3H media using loss of weight and electrochemical methods in conjunction with adsorption and DFT researches. The anti-corrosion effect of UHCI acquired from EIS study is great and the maximum anti-corrosion efficiency could reach 90.15%. The sorption of UHCI on simple steel conforms to the Langmuir sorption equation. The DFT studies reveal that UHCI is firmly chemisorbed upon the simple steel by the Fe…O σ-type dative bonds and isolates the contact between simple steel and NH2SO3H, thus protecting simple steel from the corrosion of NH2SO3H.

Development of a Sulfamic Acid-Based Chemical Formulation for Effective Cleaning of Modified 9Cr–1Mo Steel Steam Generator Tubes

A new sulfamic acid-based formulation is developed for the effective chemical cleaning of modified 9Cr–1Mo steel as a replacement for the conventional corrosive nitric acid (HNO3) and hydrofluoric acid (HF) mixture. The effect of sulfamic acid concentrations and inhibitor (2-mercaptobenzimidazole, MBI) on the metal loss during cleaning of modified 9Cr–1Mo steel was studied using weight loss and electrochemical impedance spectroscopic methods. The metal loss was found to increase with increase in acid concentration, but it was significantly lower with increasing inhibitor concentration, with an efficiency of > 90%. The corrosion rates of modified 9Cr–1Mo steel with 10% sulfamic acid + 2 mM MBI, 10% sulfamic acid without inhibitor and HNO3 + HF mixture were 1290, 6426, and 303,515 μm year−1 respectively. The optimal composition for efficient cleaning, with least base metal loss, was found to be 10% sulfamic acid + 2 mM MBI. Laser Raman spectroscopic (LRS) analysis of the corrosion products obtained during chemical cleaning process revealed that a protective chromium oxide film was formed during the cleaning with sulfamic acid + inhibitor as compared to iron oxide-based films with HNO3 + HF mixture and 10% sulfamic acid solutions.

Assessment of a Nigerian lead ore potential for industrial value additions by sulfamic acid solution

The potential of a Nigerian lead ore in form of galena and anglesite containing 72.82 wt% Pb, 19.95 wt % S, 3.07 wt% Au and 2.77 wt% As, as major elements was treated by sulfamic acid (H3NSO3) solution. The influence of acid concentration, reaction temperature, stirring speed and particle size on the extent of ore dissolution were properly determined. From the results obtained, the dissolution of lead ore increases with increasing H3NSO3 concentration, reaction temperature, stirring speed and decreasing particle size. At a set of experimental conditions (0.75 mol/L H3NSO3, − 70 + 90 µm, 320 rpm, 70 °C), 68.2% of the initial 10 g/L ore reacted within 120 min. The calculated apparent activation energy of 28.35 kJ/mol with reaction order of 0.758 confirmed and supported the proposed diffusion controlled mechanism for the dissolution process appeared to be first-order relation. The leach liquor at optimal conditions as analyzed by atomic absorption spectrophotometry were found to contain 2861 mg/L (68.2%) Pb2+, 270 mg/L (6.44%) Fe2+ and 185 mg/L (5.34%) Zn2+ as major species.

Detection of Giardia spp. with formalin/ether concentration in Brassica oleracea (cabbage) and Lactuca sativa (lettuce)

Methods to detect protozoa are needed for food safety monitoring. We evaluated protocols to recover Giardia spp. cysts in Brassica oleracea (cabbage) and Lactuca sativa (lettuce) and then detection was performed by concentrating with formalin/ether solutions and microscopy or immunofluorescence or DNA amplification via PCR. To evaluate this methodology, G. duodenalis cysts were inoculated in triplicate (10 cysts) in 35-g samples of lettuce and cabbage. The method obtaining the highest percentage of recovery in cabbage was sulfamic acid solution plus stirring with stomacher (47.7% ± 7.5). For lettuce, the best method was glycine solution plus stirring with stomacher (46.6% ± 5.3). Inter-observer agreement was of 0.99. Giardia was detected by amplifying specific sequences for the DNA coding SSU rRNA. In 27 lettuce samples and 27 cabbage samples, obtained from supermarkets and street vendors, two lettuce samples (7.4%) and one cabbage sample (3.7%) were positive for Giardia via PCR assay and were sequenced, determining that they were two of assemblage B and one of lettuce to assemblage E. This method is proposed to detect Giardia in vegetables by PCR detection, enabling public health authorities to identify genotypes circulating in food, which will help to establish measures that reduce outbreaks of parasitic diseases associated with contaminated food.

The reagent method of the hydrogeological wells regeneration

The paper presents the timeframe of the under-stream period of hydrogeological well operation. The causes of the hydrological wells flowrate reducing while long operation have been indicated. The methods of the hydrological wells and near-filters zone decolmatation have been described. The pulse-reagent well recovery has been shown to be the most widely used method. The filter colmatant composition has been given and the possible filter failure cause has been shown. Laboratory investigations have been done with a special equipment that can be seen on the drawing. A solution of sulfamic and triacetate acid, corrosion inhibitor, surfactant, sodium tripolyphosphate, adalic acid and water has been suggested as an invention. Using of these chemicals allowed to achieve the synergistic effect. A double swab-packer and a washing device for wells regeneration has been designed, its description and drawing have been given. The optimal time for the colmated filter regeneration has been indicated. Laboratory investigations results are given in the table. The chemic equipment used for chemicals transportation and keeping of the reagents has been described. The created solution for hydrogeological wells regeneration has been shown to be the optinal and its using efficiency is forty percent more than that of the known one. The created solution is recommended for hydrogeological wells regeneration in field works.

Aqueous Extract of Juniperus as a Green Corrosion Inhibitor for Mild Steel (MS) in Sulfamic Acid (NH2SO3H) Solutions

The corrosion behavior of mild steel (MS) in 5% NH2SO3H solution in the nonexistence and existence of aqueous extract of Juniperus was investigated using mass loss (ML), potentiostatic polarization (PP), AC electrochemical impedance spectroscopy (EIS), electrochemical frequency modulation (EFM) techniques. It was found that, the inhibition efficiency (P%) of this plant extract depends on its concentration and temperature. Polarization studies revealed that this extract behaved as mixed-type inhibitor. The adsorption process was found to follow Langmuir adsorption isotherm. The effect of temperature on the rate of corrosion in the nonexistence and existence of this extract was also, studied and some activation and adsorption thermodynamic parameters were computed and discussed. The inhibitive action of the investigated extract was discussed in terms of blocking the electrode surface by adsorption of its active molecules through the active centers contained in their structures.

Eco-friendly synthesis, biological activity and evaluation of some new pyridopyrimidinone derivatives as corrosion inhibitors for API 5L X52 carbon steel in 5% sulfamic acid medium

Some new pyridopyrimidinones derivatives (PPDs) namely (E)-2-(hexadecylthio)-8-(4-methoxybenzylidene)-5-(4-methoxyphenyl)-1,2,3,6,7,8-hexahydro-4H-cyclopenta[5,6] pyrido[2,3-d] pyrimidin 4 -one (Compound I) and (E)-8-(4-methoxybenzylidene)-5-(4-methoxyphenyl) -2-thioxo-1,2,3,6,7,8-hexahydro-4H-cyclopenta [5,6] pyrido [2,3-d] pyrimidin-4-one (Compound II) were synthesized and characterized by IR, 1H-NMR, 13C-NMR and mass spectroscopy. The inhibition behavior of these derivatives for the corrosion of API 5L X52 carbon steel in 5% sulfamic acid solutions were considered by various electrochemical methods such as potentiodynamic polarization (PP), electrochemical impedance spectroscopy (EIS) and electrochemical frequency modulation (EFM) techniques, theoretically by quantum chemical calculations by using DFT method and molecular dynamic simulation (MD). PP curves presented that the PPDs act as mixed type inhibitors. By increasing PPDs compounds concentrations, the inhibition efficiency increases. The adsorption of PPDs follows Langmuir adsorption isotherm. Excellent agreement was established between the quantum chemical parameters and the experimental data.

Corrosion Protection for Cast Iron in Sulfamic Acid Solutions and Studies of the Cooperative Effect Between Cationic Surfactant and Acid Counterions

The electrochemical behavior of white cast iron in sulfamic acid was studied in the presence of hexadecyltrimethylammonium bromide as a corrosion inhibitor. The cooperative effect between counterions of sulfamic acid and CTAB was investigated as well as the impact of this phenomenon on the inhibition efficiency; for that purpose, gravimetric method, electrochemical impedance spectroscopy, potentiodynamic polarization curves and inductively coupled plasma spectrometry (ICP-OES) techniques were exploited. The CTAB molecule reveals remarkable qualities for the protection of white cast iron in sulfamic acid cleaning solutions. Sulfamate ions play a major role in this phenomenon by facilitating the attraction and adsorption of CTAB onto the surface of white cast iron. The inhibition efficiency remains almost stable (about 95%) for a concentration of 10−3 M in CTAB. The critical micelle concentration of CTAB in the H2O/NH2SO3H system was investigated by the conductimetry method. The CTAB adsorption onto the cast iron surface was studied by Langmuir adsorption isotherms. The surface characterization by RDX and SEM showed a good anticorrosion protection and a lower surface roughness in the presence of CTAB.

Structure, Morphology and Optical Properties of TiO2 Films Formed by Anodizing in a Mixed Solution of Citric Acid and Sulfamic Acid

TiO2 films of 50-180 nm thickness were formed at room temperature by anodization of titanium metal in a mixture of citric acid and sulfamic acid in the potential range of 5-30 V. The films so obtained were characterized for their crystal structure, surface morphology, chemical composition and optical properties. Grazing incidence x-ray diffraction and micro-laser Raman spectroscopy measurements of the anodic films confirmed the formation of brookite phase of TiO2 at anodizing potentials of 15, 20, 25 and 30 V and amorphous structure at 5 and 10 V. Field emission scanning electron microscopy revealed non-porous microstructure of the films. Spectroscopic ellipsometry measurements evaluated the band gap of TiO2 at around 3.3 eV, whereas the refractive index of the films was found to be in the range of 2-2.35, in the visible range of spectrum.