1M HCl Research Articles

Enhancement of low carbon steel corrosion resistance in acidic and saline media using superhydrophobic nanocomposite

Superhydrophobic anticorrosion layers of various thicknesses were deposited onto low carbon steel. The layer is comprised of MnO2/Polystyrene nanocomposite with a hierarchical structure. AFM imaging of the nanocomposite illustrated a very rough surface with rms roughness of 109 nm. A polarization method was applied to measure the corrosion potential and corrosion current by using a potentiostat device. Two corrosive solutions were utilized in this study (NaCl & HCl). Strong concentrations of 1M HCl and 5000ppm NaCl were used in this work. The results revealed that the nanocomposite exhibits better corrosion inhibition after 24h immersion time in NaCl compared to HCl, where the corrosion current density is 0.56 μA/cm2 in NaCl against 24.3 μA/cm2 in HCl. The uncoated sample presented a higher corrosion current density after 24h immersion time with values of 14.4 μA/cm2 and 83.6 μA/cm2 in NaCl and HCl, respectively. Moreover, the ultrathin layers of the nanocomposite demonstrated better corrosion inhibition than the relatively thicker layers. This result was elucidated by the peeling effect of the thick samples. Immersion time was also considered in this study by leaving the samples over a course of 30 days in the solution and performing the measurements for every 10 days’ span. The activation energy of the surface was determined using Arrhenius method by varying the solution temperature during measurements. Corrosion protection efficiency showed excellent results with up to 96.1% in NaCl solution. Pitting potential was also determined in this work.

Corrosion inhibition of mild steel by N, N’-(5,5- dimethylcyclohexane-1,3-diylidene)dianiline in acid media: Gravimetric and electrochemical evaluations

The corrosion inhibition efficiency of the Schiff base N,N’-(5,5-dimethylcyclohexane-1,3-diylidene)dianiline (DmChDa) on mild steel in 1M HCl and 0.5M H2SO4 was evaluated using gravimetric, electrochemical impedance spectroscopy, potentiodynamic polarization and electrochemical noise measurement. Experimental results established that DmChDa possess relatively high corrosion inhibition capacity. Langmuir and El-Awady adsorption isotherms were obeyed by the Schiff base in 1M HCl and 0.5M H2SO4 respectively. SEM analysis showed that DmChDa was adsorbed on the steel surface during corrosion inhibition. The variation of metal dissolution with temperature was also examined using gravimetric study.

Single and Sequential Extraction of Copper by Different Extractants from Different Peat Soil Samples of Bangladesh

A comprehensive in vitro study on single and sequential extraction methods for Cu exraction by different extractants of distinct chemical nature from some peat soils of Bangladesh was conducted to assess the pattern of metal-extractability in drying and wetting sequences. Samples were collected from peat basins of two different districts of Bangladesh (Gopalgonj and Bagerhat) and an incubation study was designed and conducted in which soils were incubated to three alternate drying and wetting cycles for 21 days. Single and sequentially extracted Cu ions in all three cycles and by all three selective extractants were compared. Maximum amount of Cu was extracted in drying days and 1M HCl extracted the largest proportion of Cu from all the soils in each incubation time. Conversely, 1M NH4Cl was the least effective extractant for extracting Cu by both single and sequential process in either day of incubation. Considerable amount of Cu was extracted by 0.005 M DTPA in dry periods. In general, single extraction was found to be more effective in extracting Cu in the alternate drying and wetting cycles from the peat soil samples except for 1M HCl in initial drying days.

Green inhibitor from Thaumatococcus daniellii Benn for corrosion mitigation of mild steel in 1M HCl

Mild steel is widely used for automobile and structural applications, however, mild steel greatly rusts in acidic environment. Applications of corrosion inhibitors and protective coatings as well as cathodic protection are some of the techniques by which corrosion of mild steel is controlled and minimised. Hence, corrosion inhibitory ability of the acetone extract of Thaumatococcus daniellii Benn on mild steel was investigated in acid-induced (1.0 ​M HCl) medium using electrochemical and gravimetric techniques. Surface characteristics of the extract and mild steel were evaluated using Scanning Electron Microscopy (SEM) and Fourier Transform Infrared (FTIR) spectroscopy. The acetone extract sufficiently inhibited the acid-induced corrosion of mild steel. The T. daniellii extract gave inhibition efficiencies of 82% and 50% by potentiodynamic polarisation and weight loss measurements, respectively, at 298 ​K, 3 ​h and 10 ​× ​103 ​ppm of the inhibitor. The inhibition efficiencies obtained from weight loss method increased to 68% at 323 ​K (3 ​h) and 89% at 96 ​h (298 ​K). The inhibitive effects were verified by four adsorption isotherm models (Langmuir, Freundlich, Temkin and El-Awady) and the Freundlich model was the best isotherm model. The SEM micrographs clearly showed the coverage of the metal surface by the extract, thereby reducing corrosion of the metal in acidic medium. The FTIR spectra showed important functional groups present in the corrosion inhibitor. The adsorption of the green inhibitor to the metal surface was found to be physical in nature and the green inhibitor was effective in minimising corrosion of mild steel in 1.0 ​M HCl.

Effect of 1,2,3- triazole derivative on the dissolution performance of mild steel in 1M HCl medium

The corrosion mitigation behaviour of 1-benzyl-4-(naphthalen-2-yl)-1H-1,2,3-triazole (BNT) has been explored on mild steel in 1M HCl medium employing chemical and electrochemical techniques. The observed results illustrate that the hindered efficacy was increased as increasing concentration of BNT and with rising temperatures. The electrochemical studies point out that the inspected BNT is a mixed kind inhibitor and the adsorption isotherm discussions proposed the inhibition mechanism obeyed Langmuir isotherm. The kinetic and thermodynamical parameters exposed that the adsorption process is endothermic, spontaneous and the mechanism is both physical and chemical adsorption. Further, the morphological investigations have been carried out by SEM, EDS and AFM techniques. The highest efficiency perceived for BNT is found to be 91.35% and behaved as a proficient inhibitor against mild steel corrosion in the 1M HCl environment.

Experimental and Theoretical Studies of Taxus Baccata Alkaloid Extract as Eco-Friendly Anticorrosion for Carbon Steel in Acidic Solution

The effect of the alkaloid extract of Taxus baccata (AETB) as a green inhibitor of carbon steel in 1M HCl solution, were assessed. It was found that the inhibition efficiency increased with the extract concentration and decreased with rising of temperature. The polarization curves revealed that the (AETB) acted as mixed type inhibitor. The extract was physisorbed on steel surface and obeys Langmuir’s model. Quantum chemical calculations and molecular dynamics simulation of the majority’s components existing in (AETB) were performed in order to correlate the electronic properties with their adsorption and inhibition behavior.

Evaluation of Inhibitive Corrosion Potential of Some Symmetrical Hydrazine Derivatives Containing Nitrophenyl Moiety In Molar Hydrochloric Acid for C38 Steel Metal: Experimental, Chemical Quantum and Molecular Dynamics Studies

The exploitation of cost-effective, sustainable, green and efficient compounds is a renewed science and a demanding mission for today’s chemists and technologists. In this view, the inhibitive corrosion properties of some hydrazine derivatives named (1E,2E) -bis(1-(2-nitrophenyl)ethylidene)hydrazine ( SSBO ), (1E,2E) -bis(1-(3-nitrophenyl)ethylidene)hydrazine ( SSBM ) and (1E,2E) -bis(1-(4-nitrophenyl)ethylidene)hydrazine ( SSBP ) on the C38 steel corrosion in 1M HCl media has been evaluated by different techniques like electrochemical impedance spectroscopy (EIS), potentiodynamic polarization (PDP), scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy. The EIS results showed that SSBM is the greatest inhibitor (η>93%) among the three tested compounds. The SSBM gives considerable inhibition efficiency against corrosion of steel compared to the previous studies. The PDP curves indicated that the studied inhibitors were a mixed-type inhibitor with a predominantly cathodic control. Quantum calculations of some descriptors derived from the density functional theory (DFT), the transition state theory (TST), the quantum theory of atoms in molecules (QTAIM) and molecular dynamics simulation have delivered helpful information regarding electron transfer and mechanism during adsorption of inhibitors on C38 steel surface.

EVALUATION OF IN-VITRO ACTIVITY OF AERIAL PART OF BARANJASIF (Achillea millefolium Linn.) EXTRACTS

Hasah al-Kulya (renal calculi) is one of the leading problems affecting kidney. Recurrence of kidney stone formation is approximately 50%, after 2-3 years of recovery. This makes the prevention of its recurrence an essential problem to address. Despite substantial progress in medical therapy, there is no drug with satisfactory effect. Furthermore, the drugs those are being used for its treatment have many side effects. Baranjasif (Achillea millefolium Linn.) is one of the drugs used in Unani Medicine that has been extensively used for the management of urolithiasis. The aim of this study is to evaluate the lithotriptic action of Baranjasif in-vitro. In this study, calcium oxalate stones were prepared experimentally followed by the preparation of semipermeable membrane by dissolving the outer shell of egg in 2M HCl overnight. Calcium oxalate stones weighing 10mg were then allowed to react with 7 extracts of A. millefolium L. viz, Pet-ether, Chloroform, Ethyl Acetate, Methanol, Acetone, Hydro-alcohol and Aqueous by packing them together in semipermeable membrane. The reaction was performed on three different concentrations of each extract i.e., 50 mg, 100 mg and 150 mg. In addition to 7 groups, two more groups were taken, i) a negative group containing only the stone of weight 10 mg and ii) standard group consisting of stone weighing 10 mg and cystone (in concentrations of 50 mg, 100 mg and 150 mg). Statistical methods like mean standard deviation, percentage dissolution, percentage inhibition, IC and Pearson's correlation were applied to understand the extent of dissolution of stones 50 in each group. The study advocates that Baranjasif reveals lithotriptic activity comparable to standard drug. The efficacy of the drug is directly proportional to its concentration. Ethyl acetate extract of the plant showed the most promising results.

Magnesium extraction of ferronickel slag processed by alkali fusion and hydrochloric acid leaching

A research using ferronickel slag, the by-product of ferronickel production, as raw material for magnesium extraction was carried out. It is essential to upgrade the value of ferronickel slag instead of used directly for reclamation materials. Moreover, the accumulation due to increasing ferronickel demand as well as the environmental contamination due to various potentially toxic elements contained in the ferronickel slag could be prevented. The general objective of this study is to utilize the ferronickel slag for magnesium materials. The specific objective is to determine the optimum conditions of magnesium extraction in the process of alkali fusion followed by hydrochloric acid leaching. A novel method for magnesium extraction from ferronickel slag was carried out through reducing silica content followed by acid leaching method. Alkali fusion of the mixture of ferronickel slag and Na2CO3 at 1000?C for 60 minutes, followed by water leaching at 100?C for 60 minutes with solid to liquid percentage of 20 % was carried out to separate the silica. The leaching residue resulted from water leaching was then leached using hydrochloric acid solution to extract magnesium. The leaching temperature and time as well as the hycrochloric acid concentration were varied in the acid leaching process. Alkali fusion process proved the sodium silicate can be generated and that it can be separated in the water leaching to the leached solution. Meanwhile, the leaching residue was leached using hydrochloric acid to extract the magnesium. The highest magnesium extraction percentage is 82.67% that resulted from an optimum acid leaching condition with temperature of 80?C for 30 minutes using 2M HCl solution. Based on the kinetics study, the activation energy (Ea) for the leaching reaction of magnesium at atmospheric pressure between 32?C to 80?C is 9.44 kJ/mol and affected by diffusion and chemical reactions.

Molten salt synthesis of TiB2 nanopowder by reduction of TiO2 with MgB2

This research work presents the preparation of TiB2 nanopowders by molten-salt synthesis (MSS) technique from TiO2 and MgB2 as starting active materials and MgCl2 as a molten salt. The pure TiB2 nanopowders were finally prepared using 2M HCl aqueous solution to leach the synthesized samples. The effects of the firing temperature, firing time and reactants to salt ratio on the TiB2 nanopowders formation were examined. The results demonstrated that the TiB2 formation was completed even with reactants to salt mass ratio of 1:2 at 1000 ?C for 4 h. The TiB2 nanopowders synthesized with 1:2, 1:5 and 1:10 reactants to salt mass ratios have different particle sizes. Thus, the average particle sizes estimated from BET surface areas were 59, 55 and 46 nm for the samples synthesized with 1:2, 1:5 and 1:10 reactants to salts mass ratios, respectively. These results illustrated that the high concentration of MgCl2 plays a key role in the particles? size reduction. The above results assured that this research study presents a new low-temperature synthesis route for nano-sized metal diboride powders.

Solvent Extraction of Scandium and Yttrium Using Carboxylic Acid

Separation of scandium (Sc) from yttrium (Y) in aqueous chloride media by solvent extraction using Versatic acid 10 was investigated. Conventional slope analysis method revealed the extraction equilibrium formulation of the metals. Sc is more strongly extracted than Y by Versatic acid 10, and the separation factor of the metals is quite high at 1.93 × 104. Complete stripping of Sc from the loaded organic solution of Versatic acid 10 was achieved by 3M HCl solution. Then Versatic acid 10 was applied to solvent impregnated resin (SIR), separation of Sc was progressed via Langmuir adsorption model.

Electrochemical and Theoretical Studies of <i>Inula viscosa</i> Extract as Green Corrosion Inhibitor for Mild Steel in Hydrochloric Acid Solution

In this employ, we deliberate the effectuality of corroding inhibition of carbon steel API 5 L Gr – B in HCl 1M solution using the n-butanolic extract taken of Inula Viscosa plant. The repressive strength was observed by the electrochemical methods, Videlicet potentiodynamic condition and impedance measurements. The results indicated that the forbiddance efficiency increases with exploding choose attention. A maximum inhibition rate of 92.37 % was recorded at 600 ppm of inhibitor denseness according to the potentiodynamic measurements. The extract seems to be a goodness corroding inhibitor of electrode writing based on the obtained results. The adsorption on the element articulator was instituted to obey to Langmuir isotherm. In expansion, the HOMO and LUMO analyzing were carried out utilizing the useful thickness hypothesis strategy (DFT / B3LYP). Since HOMO and LUMO are the foremost critical orbitals in atoms, they are exceptionally valuable for understanding certain atomic properties. In expansion, from the outcome of the DFT calculations, we obtained as follows: the total dipole moment of the molecule (μ), the absolute hardness (η), the absolute electronic negativity (χ).

Sintesis dan Karakterisasi Silika Gel dari Limbah Botol Kaca sebagai Adsorpsi Ion LOgam Berat (Pb) pada Air Pasca Tambang (Kolong) di Bangka

Glass bottle waste is inorganic waste that cannot be broken down by microorganisms. The high SiO2 content in glass bottle waste has the potential as a base material in the synthesis of silica gel. This study aims to determine the characteristics and ability of silica gel as adsorption of Pb metal ions in water under Bangka. The stages in this study were started from the extraction of silica from waste glass bottles, synthesis of silica gel, activation with HCl and testing the adsorption of Pb metal ions in under water. The results showed that the characteristics of silica gel with variations of 100 and 200 mesh, the concentration of 3M NaOH, 3M HCl using SEM EDS had an amorphous structure and the SiO2 content graph had high peaks. In the BET test, the pore radius was 1164.207 for the 100 mesh sample and 1293.102 for the 200 mesh sample. The AAS results showed that in the treatment of 100 mesh, the Pb value decreased by -0.1122, while for 200 mesh also decreased by -0.1322. The Pb value is minus because the tool can only read with a standard limit of 0.1. If it is less than 0.1, then the tool cannot read the value on Pb metal even though the value is minus but has a value. The greater the minus, the lower the Pb value. So silica from glass bottle waste can adsorb heavy metals (Pb) on the surface water underneath

KARAKTERISTIK DAN NILAI SUN PROTECTING FACTOR (SPF) KITOSAN DARI TULANG SOTONG (Sephia officinalis)

Cuttlefish (sepia officinalis) have internal shells commonly called cuttlebones which produce more chitin than shrimp shells and crab skins. The purpose of this study was to determine the characteristics of chitosan from cuttlebone including the degree of deacetylation, water content, solubility, organoleptic test (color, odor, texture) as well as testing the value of chitosan protecting the sun protection factor. Chitosan is made in 3 stages, namely deproteination, demineralization, and deacetylation. Deproteination with 4% NaOH at 100 ° C for 60 minutes. Demineralization at room temperature using 1M HCl solution for 120 minutes. Deacetylation using 50% NaOH concentration at 100 ° C for 60 minutes. Chitosan characterization includes the degree of deacetylation, moisture content, solubility, organoleptic test (color, odor, texture). Testing the value of sun protection factor using a UV-VIS spectrophotometer read at wavelengths from 290 to 320 nm. Characteristics of chitosan produced according to chitosan standards used in industry with a deacetylation rate of 71%, yield 31%, moisture content of 0.93%, soluble in acetic acid2% solution, white odorless and powdery. Chitosan with a concentration of 3% gives the value of sun protecting factor 9 as a potential sunscreen that provides maximum protection power.

Corrosion inhibition of mild steel in 1M HCl using environmentally benign Thevetia peruviana flower extracts

The corrosion inhibition of Thevetia peruviana (Kaner) flower extract (TPFE) is evaluated for mild steel in 1M HCl solution using electrochemical, surface and computational demonstrations. Results showed that TPFE acted as a potential corrosion inhibitor and shows the highest inhibition efficiency of 91.24% at 200 mg/L concentration. Electrochemical studies suggest that TPFE acted as a mixed- and interface-type of corrosion inhibitor. The TPFE inhibits metallic corrosion through an adsorption mechanism that follows Temkin adsorption isotherm model. Adsorption mechanism of corrosion inhibition was further supported using AFM, SEM-EDX, FT-IR and UV–visible surface studies. Furthermore, the anticorrosive mechanism of major phytochemicals of the TPFE was studied using computational techniques: Density Functional Theory (DFT) and Molecular Dynamics (MD) simulations. Results showed that TPFE interacts with donor-acceptor interactions and its phytochemicals acquire the flat or horizontal orientations over the metallic surface.

Evaluation of corrosion resistance of the single-phase light refractory high entropy alloy TiCrVNb0.5Al0.5 in chloride environment

A low density refractory high entropy alloy of composition TiCrVNb0.5Al0.5 was prepared by vacuum arc melting. Due to the formation of a single-phase BCC structure with uniform element distribution and a gradient passive film with a high concentration of passivating elements, the TiCrVNb0.5Al0.5 high entropy alloy (HEA) exhibits low corrosion current density (10−7~10−8 A cm−2), high breakdown potential (1.8–1.9 VSCE) and excellent repassivation ability in 3.5 wt% NaCl and 1M HCl solutions. The properties were compared with HEAs, bulk metallic glasses (BMGs) and traditional alloys reported in literatures. The results show that TiCrVNb0.5Al0.5 possesses the most outstanding corrosion resistance in chloride environment.

Effect of Partial replacement of Portland cement with micro-silica on mechanical characteristics of concrete and corrosion behavior of mild steel in 1M HCl

Effect of Partial replacement of Portland cement with micro-silica on mechanical characteristics of concrete and corrosion behavior of mild steel in 1M HCl

Binding of Gold(III) from Solutions by Tetranuclear Lead(II) Dipropyldithiocarbamate [Pb4{S2CN(C3H7)2}8] and Chemisorption Synthesis of the Double Ionic Polymer Complex ([Au{S2CN(C3H7)2}2][PbCl3] · 0.5CH3–C6H5)n: Heteronuclear ( 13 C, 15 N) CP-MAS NMR, Structural Organization, and Construction Principles of Cationic and Anionic Polymer Chains

Solid-state 13C and 15N CP-MAS NMR data adequately reflected the presence of four nonequivalent PrDtc ligands in the tetranuclear lead(II) N,N-dipropyldithiocarbamate (PrDtc), [Pb4{S2CN(C3H7)2}8] (I); the spin–spin coupling constants 3J(15N–207Pb) for the ligands were estimated. It was shown by 13C MAS NMR that the chemisorption binding of AuCl3 from a solution in 2M HCl using lead(II) dipropyldithiocarbamate is accompanied by complete redistribution of the PrDtc ligands from Pb(II) to Au(III) coordination sphere; this gives the double complex of [Au{S2CN(C3H7)2}2][PbCl3] (II). Upon crystallization from an acetone–toluene mixture (3 : 1), this complex was isolated as the solvated form ([Au{S2CN(C3H7)2}2][PbCl3] ⋅ 1/2CH3C6H5)n (IIa), which was characterized by X-ray diffraction (CIF file CCDC no. 1978947). The cationic part of the complex is represented by non-centrosymmetric gold(III) complex ions, [Au{S2CN(C3H7)2}2]+, which are combined by pairs of nonequivalent Au···S secondary bonds, thus forming supramolecular pseudo-polymer chain ([Au{S2CN(C3H7)2}2]+)n. The 1D polymeric trichloroplumbate(II) anion, {[Pb(μ2-Cl)3]–}n, acts as the counter-ion. The C–H···Cl hydrogen bonds between the anionic and cationic chains lead to formation of channels in the crystal lattice, which are occupied by solvating toluene molecules.

Pacific white shrimp (Litopenaeus vannamei) shell chitosan and the conjugate with epigallocatechin gallate: Antioxidative and antimicrobial activities.

Chitin was isolated from Pacific white shrimp (Litopenaeus vannamei) shell by demineralization and deproteinization using 1M HCl (1:20, w/v) for 2hr and 1M NaOH (1:30 w/v) for 80min at 70ºC, respectively, with 29.96% optimum yield. Thereafter, the chitin was deacetylated at various temperatures for different times, in which the chitosan prepared at 130ºC for 4hr (CS-130-4) showed higher yield (73.11%), crystallinity index (19.75%), and 85.28% degree of deacetylation (DDA) as measured by 1 H-NMR. CS-130-4 was then conjugated to epigallocatechin gallate (EGCG) at various concentrations (2-8%, w/w of chitosan). CS-130-4 was grafted with 8% EGCG (CE-8) had the higher conjugation efficiency (92.63%) and antimicrobial/antioxidant activities as compared to other conjugates (p<.05). 1 H-NMR analysis also confirmed the successful conjugation of CE-8. All the conjugates were completely water soluble. Therefore, CE-8 may be used as the natural antimicrobial and antioxidant agents in various food products. PRACTICAL APPLICATIONS: Shrimp shells are generally considered as processing by-products of the shellfish industries and can cause environmental pollution when improperly disposed. Chitosan from shrimp shells has been widely produced but it is soluble mainly in acidic solutions, which limits its applications. However, grafting of epigallocatechin gallate (EGCG) onto chitosan yielded water-soluble conjugates with enhanced antioxidant and antimicrobial properties. Although several preservatives have been applied in foods, their health hazards have been a major concern. To mitigate this limitation, chitosan-EGCG conjugates could be employed as alternative natural preservatives or additives for shelf-life extension of various foods.

Inhibition of Aluminium Corrosion in 1M HCl by Pyridoxine Hydrochloride: Thermodynamic and Quantum Chemical Studies

Currently, research in the area of corrosion inhibition is focussed on the development of green corrosion inhibitors. It is with this in mind that pyridoxine hydrochloride, which is vitamin B6, has been tested as a corrosion inhibitor of aluminium in 1M HCl by mass loss, Density Functional Theory (DFT) and Quantitative Structure-Property Relationship (QSPR) methods. The results obtained show that the inhibition efficiency increases with concentration but decreases with increasing temperature. This vitamin is adsorbed on aluminium according to the modified Langmuir isotherm and occurs in two modes: physisorption and chemisorption. Thermodynamic adsorption and activation parameters have been determined and discussed. Finally, QSPR approach was used to find the best set of parameters in order to determine the theoretical inhibition efficiencies from the experimental data. Experimental measurements were found in good collaboration with the theoretical results.