Weight Loss Measurements Research Articles

Real-time and non-destructive control of the freshness and viability of live mussels through portable near-infrared spectroscopy

This study introduces the application of a novel, rapid, and non-destructive method employing portable near-infrared (NIR) spectroscopy to assess the freshness and viability of live mussels throughout their shelf-life. NIR spectra ranging from 908 to 1676 nm were collected from 150 Mediterranean mussels (Mytilus galloprovincialis, L.) over a 10-day storage period. Simultaneously, measurements of weight loss, intravalvular liquid pH, and nonprotein nitrogen levels were taken. A predictive model was established by correlating the multivariate information derived from NIR spectral data with days of storage under refrigerated conditions using orthogonal partial least squares regression (OPLSR) analysis. While physical and chemical parameters (except for gradual weight loss due to water leakage) showed no distinct trends throughout storage, the fourth derivative-preprocessed NIR spectra enabled the construction of an OPLSR model that, following cross-validation, exhibited a correlation coefficient of 0.86 and, following external validation with new mussel samples, an average accuracy (root mean square error of prediction) of just 1.3 days. The predictive power of the model was primarily attributed to specific NIR wavelengths associated with key chemical features, including unsaturated fatty acids, nitrogen compounds, water content, glycerol, and ATP-related compounds that, collectively, constituted a distinctive fingerprint for forecasting mussel storage duration. The performance of the tool, along with its environmentally friendly, non-invasive, real-time, and cost-effective characteristics, align with industry control procedures and inspection needs, allowing effective freshness and viability assessment of live mussels across the food supply chain.

Tuning biodegradability, bone-bonding capacity, and wear resistance of zinc-30% magnesium intermetallic alloy for use in load-bearing bone applications

This work aimed to improve the rapid biodegradation, poor wear resistance properties, and lack of bioactivity of metallic biomaterials to be used in orthopedic applications. In this context, zinc–magnesium (Zn–Mg) alloy with successive contents of calcium silicate (CaSiO3) and silicon nitride (Si3N4) was prepared using powder metallurgy technique. After sintering, their phase composition and microstructure were investigated using the X-ray diffraction technique and scanning electron microscopy (SEM), respectively. Furthermore, their degradation behavior and ability to form hydroxyapatite (HA) layer on the sample surface after immersion in simulated body fluid (SBF) were monitored using weight loss measurements, inductively coupled plasma-atomic emission spectroscopy, and SEM. Moreover, their tribo-mechanical properties were measured. The results obtained showed that the successive contents of CaSiO3 were responsible for improving the bioactivity behavior as indicated by a good formation of the HA layer on the samples’ surface. Additionally, ceramic materials were responsible for a continuous decrease in the released ions in the SBF solution as indicated by the ICP results. The tribology properties were significantly improved even after exposure to different loads. Based on the above results, the prepared nanocomposites are promising for use in orthopedic applications.

Enhancing apple shelf life: A comparative analysis of photocatalytic activity in pure and manganese-doped ZnO nanoparticles

This paper presents the hydrothermal synthesis of pure and manganese-doped ZnO nanoparticles with varying doping concentrations (1–5 %) for the purpose of examining photocatalytic activity and extending apple's shelf life. The structural, morphological, vibrational and optical characteristics of nanoparticles were investigated with the aid of XPS, XRD, SEM, FTIR, and PL. When tested for photocatalytic activity against methylene blue (MB), it was confirmed that Mn–ZnO NPs showed improved photocatalytic performance during MB degradation. Additionally, apples treated with synthesized nanoparticles were subjected to a variety of tests to determine influence of these NPs on the shelf life of apples, including those that measured weight loss over time, moisture content, ascorbic acid, and decay process. The current study is quite interesting because it correlates photocatalytic activity with Apple's shelf life. Moreover, Mn doped ZnO showed remarkable antifungal and antibacterial properties against Rosellinia necatrix and Fusarium spp. and Escherichia coli and Staphylococcus aureus.

1,2,4-triazole-5-thione derivative for inhibiting carbon steel corrosion in 1M HCl: Synthesis, electrochemical, SEM/EDX, DFT, and MD investigations

In the current research, the corrosion inhibition efficiency of a novel synthesized 1,2,4-triazole-5-thione derivative, named 1,8bis(5-mercapto-3-(4‑chloro)-phenyl-1,2,4-triazolyl)-triethyleneglycol (3) for carbon steel in 1 M HCl medium is assessed employing conventional weight-loss measurements as well as electrochemical methods, including electrochemical impedance spectroscopy and potentiodynamic polarization. The findings highlighted that the presence of the tested inhibitor led to a decrease in the corrosion rate and enhancement of the inhibitory efficacy with a maximum value of around 93 % obtained at a concentration of 10–3 M. This might be associated with the creation of a protective adsorption film on the metal surface. Electrochemical measurements disclosed the mixed-type inhibition effect of 3. The inhibitor adsorption mechanism followed the Langmuir adsorption isotherm. Despite that, a thorough examination of the carbon steel surfaces, both in their uninhibited and inhibited states, was conducted through scanning electron microscopy (SEM) coupled with energy-dispersive X-ray (EDX) analysis. The experimental findings were supported by computational chemistry calculations using density function theory (DFT) and Molecular Dynamic (MD) simulations.

Corrosion Effect of Biodiesel-Diesel Blend on Different Metals/Alloy as Automotive Components Materials

Biodiesel has emerged as a progressively widespread and significant alternative to traditional diesel fuel within the transportation sector. Despite its growing popularity, the issue of corrosive tendencies upon interaction with both moving and static components of diesel engines and fuel systems poses a serious concern. This research endeavors to assess the corrosion characteristics of materials commonly found in automotive fuel systems when exposed to various blends of rapeseed oil biodiesel and diesel. The study involved static immersion tests, lasting 3360 h at room temperature, using B0, B20, B40, B60, B80, and B100 fuels. Copper, brass, aluminum, zinc, and stainless steel plate samples were subjected to these tests. The evaluation at the conclusion of the study included weight loss measurements, corrosion rate calculations, and observation of changes in the exposed metal surfaces. Surface morphology was scrutinized using a Bresser LCD MICRO 5MP digital microscope. Additionally, the total acid number (TAN) was employed to assess alterations in fuel acidity before and after the immersion tests.

Performance of a new pyrazole derivative in 1 M HCl on the corrosion of carbon steel: experimental, quantum chemical and molecular dynamics simulation studies

The present research demonstrates an innovative investigation of a new pyrazol derivative (2-benzoyl-4-nitro-N-[(1H-pyrazol-1-yl)methyl]aniline (BNPMA)) as an inhibitor of carbon steel corrosion in molar hydrochloric acid. A variety of methods and techniques were used in our research to assess corrosion inhibition, including weight loss measurements (WL), electrochemical trials like potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS), surface analysis methods such a scanning electron microscope coupled with Energy-Dispersive X-ray Spectroscopy (SEM/EDX), UV-Visible analysis, as well as computational evaluation of BNPMA. The organic compound was confirmed to be a good anticorrosive product with a maximal inhibition efficiency (IE%) of 93.2% at 10−3 M. According to the PDP results, the inhibitor BNPMA acts as a mixed-type inhibitor. The Langmuir model seems to be followed during BNPMA's adsorption on the CS surface. According to UV-visible and scanning electron microscopy, a barrier coating was formed which prevented corrosive ions from reaching the CS surface. The outcomes of experimental approaches (WL, PDP, and EIS) have been supported by theoretical investigations.

Adsorptive and Inhibitive Potential of Halide Ions and Plant Extracts from <i>Cucurbita Maxima</i> as Stainless Steel Inhibitors

By utilizing weight loss measurements and electrochemical technique, the corrosion inhibition efficiency of Cucurbita maxima peel and seed extracts on Grade 304 austenitic stainless steel in 1 M sulphuric acid solution was examined. The efficacy of C. maxima extracts' inhibition increased with concentration while decreasing with temperature. At 0.7 g/L extract concentration for 3 hours of immersion, the inhibitor's greatest efficiency was 95.21% for PCM and 94.26% for SCM. Stainless steel corrosion was successfully inhibited by C. maxima peel and seed extracts, according to the results, and it was discovered that the presence of halide ions enhanced the efficacy of the inhibition. The synergistic effect of halide ions was found to follow the order: KI > KCl. According to the polarization curve, C. maxima functions as a mixed-type inhibitor. Due to the extract components' adsorption on the stainless steel surface, peel and seed extracts exhibit an inhibitory effect. The activation energy of the corrosion reaction increases by the presence of both extracts. The physical adsorption is shown by the negative values of ΔGads, which range from -12 kJ/mol to -18 kJ/mol. These values show the spontaneity of the adsorption process. Adsorption is a physical process that adheres to Langmuir adsorption isotherms. The results of a study using scanning electron microscopy to examine the surface morphology of stainless steel in inhibited and uninhibited acid solutions revealed that the presence of extract and halide inhibitors remarkably lowers the corrosion rate. This is as a result of the extract and halide inhibitor molecules adhering to the surface and forming a barrier that prevents an acid attack.

Investigation of phosphorus-based ionic liquid with long alkyl chain as high-performance corrosion inhibitor with ultralow concentration for mild steel in 1 M HCl solution

The ionic liquids (ILs) are regarded as the ideal candidate for the novel and high-efficiency corrosion inhibitors. While the cost problem caused by relatively large dosage limited the wide employments of conventional ILs. In the current study, we synthesized two novel phosphorus-based ionic liquids (PBILs) with different alkyl chain length (dodecyltriphenylphosphonium bromide (C12TPB) and cetyltriphenylphosphonium bromide (C16TPB)), and evaluated their anticorrosion efficiencies for mild steel (MS) in 1 M HCl aqueous solution by weight loss measurement, scanning electron microscope, X-ray photoelectron spectroscopy and electrochemical test. The results revealed that PBILs performed excellently (inhibition efficiencies > 93 %) at a very low concentration of 10 μM, which was much greater than those for traditional imidazole and pyridine ionic liquids at 500 μM. It was demonstrated that PBILs could adsorb on the metal surface to form the protective film, which should be mixed corrosion inhibitors with cathodic advantage. Then the adsorption study and molecular dynamics simulation confirmed that their special molecular structure highly promoted the intensity of the adsorption film mainly caused by the chemical adsorption. This study provided a novel approach for the structural design and development of high-performance IL corrosion inhibitors.

The Study of the Glass Fiber Surface Treatment Effect on the Base Strength Characteristics of the Composite Material

This article examines the impact of surface treatment of glass fibers on the strength of a composite material with an unsaturated polyester polymer matrix reinforced with glass fibers. The strength tests conducted include tensile, bending, and impact strength tests, as well as weight loss measurements. The research was conducted in two stages: in the first stage, the time was kept constant while the fibers were treated with varying concentrations of an alkaline NaOH solution; in the second stage, the concentration was fixed and the variable parameter was the treatment time. The results of the study indicate that surface treatment of glass fibers significantly improves their adhesion to the matrix materials, resulting in improved strength test results for the composite samples. The impact resistance, bending resistance, and tensile strength values all increased compared to the reference samples. However, certain changes in the individual parameters of fiber processing led to a slight decrease in tensile strength when it fell below the reference values. Additionally, it was observed that as the concentration of the solution and treatment time increased, the weight of the fibers decreased.

Positive Program Evaluation and Health Maintenance among Post-Metabolic and Bariatric Surgery Patients Following a 6-Week Pilot Program

PurposeDespite lifestyle changes and medication therapies, weight loss is difficult to maintain. Metabolic and bariatric surgery (MBS) is an effective route for significant weight reduction. However, post-operation there are limited opportunities to support weight loss maintenance. The following study aimed to pilot test a 6-week, 6-session nutrition and support program for post-MBS surgery patients.Materials and MethodsA 6-week post-MBS pilot nutrition and support program was developed to test feasibility and acceptability. Participants completed a baseline survey that included demographics, weight changes, success post-surgery, and self-efficacy of leading a healthy lifestyle. Weight change, percent total weight loss, self-efficacy, and program evaluation measures were assessed.ResultsParticipants (n = 18) were recruited from a local MBS clinic, predominately female (88.9%), non-Hispanic white (94.4%), received sleeve gastrectomy surgery (100%), and were 2–3 years post-operation (44.4%). Eight of the 18 participants attended the in-person sessions, serving as the intervention group. Both weight loss over and behavioral variables remained stable for both groups across the 6 weeks with no significant differences from pre to post program (p > 0.05). For program evaluation, intervention participants “agreed” or “strongly agreed” with 10 of 11 program satisfaction measures.ConclusionFollowing the program, weight loss was maintained among both intervention and control groups. Intervention feedback indicated that the program’s approach to provide nutrition education and support was successful and acceptable. Future enhancement of the intervention should include a broader multidisciplinary approach, longer intervention period, and intentional recruitment of participants with a weight regain.Graphical

3,4-Dimethoxy phenyl thiosemicarbazone as an effective corrosion inhibitor of copper under acidic solution: comprehensive experimental, characterization and theoretical investigations.

This study investigates the corrosion inhibition potential of 3,4-dimethoxy phenyl thiosemicarbazone (DMPTS) for copper in 1 M hydrochloric acid (HCl) solutions, aiming to disclose the mechanism behind its protective action. Through an integrative methodology encompassing electrochemical analyses-such as weight loss measurements, potentiodynamic polarization, and electrochemical impedance spectroscopy (EIS)-we quantitatively evaluate the corrosion protection efficacy of DMPTS. It was determined that the optimal concentration of DMPTS markedly boosts the corrosion resistance of copper, achieving an impressive inhibition efficiency of up to 89% at 400 ppm. The formation of a protective layer on the copper surface, a critical aspect of DMPTS's inhibitory action, was characterized using Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM). These techniques provided empirical evidence of surface morphology modifications and roughness changes, affirming the formation of a protective barrier against corrosion. A significant advancement in our study was the application of Attenuated Total Reflectance Fourier Transform Infrared (ATR-FTIR) spectroscopy, which identified chemical adsorption as the definitive mechanism of corrosion inhibition by DMPTS. The ATR-FTIR results explicitly demonstrated the specific interactions between DMPTS molecules and the copper surface, indicative of a robust protective adsorbed layer formation. This mechanistic insight, crucial to understanding the inhibitory process, aligns with the protective efficacy observed in electrochemical and surface analyses. Theoretical support, provided by the Quantum Theory of Atoms in Molecules (QTAIM) and quantum chemical computations, further validated the strong molecular interaction between DMPTS and copper, corroborating the experimental findings. Collectively, this research not only confirms the superior corrosion inhibition performance of DMPTS in an acidic setting but also elucidates the chemical adsorption mechanism as the foundation of its action, offering valuable insights for the development of effective corrosion inhibitors in industrial applications.

Exploring corrosion protection for mild steel in HCl solution: An experimental and theoretical analysis of an antipyrine derivative as an anticorrosion agent

AbstractThe corrosion of mild steel in HCl solution remains a critical issue in various industrial applications. In the quest for effective corrosion inhibitors, 4‐(2‐Hydroxy‐3‐Methoxybenzylideneamino) antipyrine (HMBA) has emerged as a promising candidate. This study investigates the inhibitory properties of HMBA on mild steel corrosion in HCl solution through weight loss measurements, electrochemical impedance spectroscopy (EIS), and potentiodynamic polarization (PDP) techniques. The experiments spanned over various time periods, including 1, 5, 10, 24, and 48 h. The results reveal that HMBA exhibits exceptional inhibition efficiency (IE), with an impressive 94.7% inhibition rate. This outstanding performance underscores its potential as a corrosion inhibitor for mild steel in aggressive HCl environments. To elucidate the adsorption behavior of HMBA on the mild steel surface, Langmuir isotherm modeling was employed, demonstrating a strong correlation between the experimental data and the Langmuir adsorption isotherm model. Furthermore, the study employs density functional theory (DFT) to gain insight into the mechanism of HMBA inhibition. DFT calculations suggest that both physisorption and chemisorption mechanisms are involved in the interaction between HMBA and the mild steel surface. The calculated Gibbs free energy of adsorption () is found to be approximately , indicating a spontaneous and energetically favorable adsorption process. In conclusion, HMBA emerges as a highly effective corrosion inhibitor for mild steel in HCl solution, offering impressive IE over various time intervals. The combination of experimental techniques, such as WL, EIS, and PDP, along with computational insights from DFT calculations, provides an understanding of the inhibitory properties of HMBA. These findings hold great promise for the development of environmentally friendly corrosion inhibitors in industrial applications.

The inhibition effect of 1, 3-diazole glyoxaline on corrosion of API 5L X52 pipeline steel in oilfield produced water under sweet corrosive conditions

Corrosion induced by aqueous environments containing carbon dioxide (CO2) is a well-documented issue in the oil and gas industries, particularly affecting transportation via steel pipelines. Operational conditions during transportation, including temperature, flow rate, and solution chemistry, significantly influence the corrosion inhibition mechanism. In this study, the corrosion inhibition behavior of API 5L X52 steel in a 3.5 wt% NaCl brine solution saturated with carbon dioxide was investigated using 1, 3-diazole glyoxaline (DG) as an organic inhibitor. Both gravimetric and electrochemical methods were employed to assess corrosion rates and inhibitor efficiency across various temperatures, inhibitor concentrations, and rotational speeds. The outcomes showed that inhibition efficiency increased with inhibitor concentration and temperature. From weight loss measurements, the maximum inhibition efficiency was 98.58 % at 3 × 10−4 M of DG and 60 °C. The polarization investigations showed a reduction in the anodic and cathodic curves in the presence of the inhibitor. This suggested a mixed-type inhibition mechanism. The electrochemical impedance spectroscopy results showed an improvement in charge transfer resistance due to the formation of a protective layer on the metal surface. In addition, AFM, SEM, contact angle, hardness, and roughness measurements proved the enhancement in surface morphology due to the presence of DG.

Green synthesis of cadmium oxide nanoparticles (CdO-NPS) using syzygium cumini: exploring industrial applications of CdO NPs as a corrosion inhibitor of mild steel in the acidic environment.

Potentiodynamic polarization (PDP), electrochemical impedance spectroscopy (EIS) and weight loss measurements were used to assess the effectiveness of CdO-NPs as a corrosion inhibitor for carbon steel in 0.5 M H2SO4. It was amply shown that as the concentration of CdO-NPs increased, the cathodic currents decreased and the active corroding sites were blocked completely. Moreover, a decrease in the mass of mild steel in an aggressive environment was reduced gradually with an increase in the concentration (ppm) of CdO-NPs inhibitor, resulting in an increase in the inhibition efficiency. The novel synthesized CdO-NPs were characterized by FT-IR, XRD and SEM-EDX spectroscopy.

Thermodynamics and adsorption studies of blended guava and mango leaves extract as inhibitors for 7075 aluminium

The petroleum industry has been very concerned about corrosion challenges. The thermodynamic and adsorption and studies on Aluminium grade 7075 using blended extract in hydrochloric acid was carried out using weight loss measurement and polarization techniques with optimization approach. The Box Behnken Design (BBD) of four variables namely; acid concentration, inhibition ratio, time of immersion and temperature were used to study the interaction of the variables. A phytochemical analysis of PGLE, MILE, and blended extract revealed that the blended extract contained more phytochemicals that prevent corrosion. The best process level observed from experimental design was at 30 °C, 80 % − 20 % inhibition volume ratio, 1.0 M acid concentration, and 9 days with 98.28 % inhibition efficiency. The result of polarization revealed that extract functioned as mixed type inhibitor. The adsorption of blended extract on Aluminium surface fitted more into Langmuir adsorption model. The result of ΔGads was from –16.73 to –22.73 kJ/mol, which indicated Spontaneity, Ea showed physisorption, −△H showed exothermic process and △S showed high disorderliness and randomness. The results of FTIR and SEM demonstrated that more effective protective film was formed on MS surface. it can be concluded that the blended extract could serve as good substitute to industrial inhibitor.

Comparing Lifestyle and Behavior of Post-Bariatric Surgery and Participants with Obesity: A Community-Based Cross-Sectional Study.

There is a paucity of research dedicated to exploring behavioral change in patients following bariatric surgery. However, there is a need for comparison analysis of individuals with obesity who have received surgical treatment and those who have not opted for any surgical procedures for weight loss. This study is designed to scrutinize the lifestyle choices, behavioral patterns, psychological elements, and eating habits of individuals who have undergone bariatric surgery, in contrast to those with obesity who have not undergone such a procedure. This study is a secondary analysis from Sharik Diet and Health National Survey (SDHNS) dataset, which is a cross-sectional investigation covering the period from 2020 to 2022. The study focused on demographic factors like age, gender, educational attainment, and monthly earnings. Furthermore, other variables such as physical activity, leisure and workplace sitting habits, smoking patterns, strategies for managing weight, and eating and consumption behaviors were also examined. Out of the initial 15,980 participants reached, 4,069 satisfied the study's inclusion criteria. Bariatric surgery was reported by 806 participants (19.8%). Upon comparing three obesity status groups - The participants who underwent bariatric surgery with or without obesity, those with obesity who did not opt for any surgical weight loss measure, the analysis found that the three obesity status groups were significantly different in 21 variables from a total of 26. Moreover, a logistic regression analysis revealed that 11 variables influenced persistent obesity in the post-surgery phase, as opposed to those who successfully lost weight. These variables included advanced age, limited education, being female, lower income, waterpipe smoking habits, and the consumption of carbonated drinks. This study showed that inability to lose weight after bariatric surgery are linked to poor lifestyle choices and behavior compared to those who were able to lose weight after the surgery.

Synergistic inhibitive effect of a hybrid zinc oxide-benzalkonium chloride composite on the corrosion of carbon steel in a sulfuric acidic solution

Abstract Zinc oxide and quaternary ammonium-type surfactants have been separately recognized for their anti-corrosive efficiencies. Their composite, not investigated so far, could provide a synergetic anti-corrosion effect. In this respect, the aim of this study is to synthesize a composite material consisting of zinc oxide and benzalkonium chloride (ZnO-BAC) in varying mass ratios (3:1, 1:1, and 1:3). The inhibitory properties of the ZnO-BAC composite against carbon steel corrosion in a 0.5 M sulfuric acid solution were assessed under ambient conditions. First, X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy were used to examine the chemical structure of the prepared composite. Then, the corrosion inhibitive performance of the devised inhibitors was screened using electrochemical, hydrogen collection, and weight loss measurements. Further, the surface morphology was examined using a scanning electron microscope, both before and after immersion in the corrosion medium. The electrochemical measurements indicate that the prepared inhibitor exhibits a predominant cathodic inhibition behavior and the maximum inhibition efficiency, approximately 91.9%, was achieved for one-to-one mass ratio. Similar results were obtained from weight loss and hydrogen evolution measurements, which showed that the ZnO-BAC composite reduced the corrosion rate of carbon steel by 69.9% and 64.9%, respectively. Finally, molecular dynamics and an adsorption equilibrium model were used to elucidate the mechanism of corrosion inhibition by the ZnO-BAC composite, which exhibits a high adsorption energy on the iron surface.

Study of Suregada Multiflora Leaves Extract as a Green Corrosion Inhibitor on Iron in HCl Medium

Suregada multiflora leaves extract (SMLE) was prepared and used as a new eco-friendly green inhibitor for acid induced corrosion of mild steel(MS) in 1M HCl solution. The aqueous extract of leaves of Suregada multiflora was tested by dipping MS coupons in 1M HCl with and without SMLE solution at 303 k, 313 k, 333k and 343k using gravimetric method. The data obtained by weight loss measurement revealed that the SMLE has good inhibiton effect and mitigates the rate of corrosion. The inhibition efficiency (IE) increases with an increase in inhibitor concentration and with the exposure time. The adsorption study showed that the use of SMLE obeyed the Langmuir isotherm with regression co-efficient value nearly equal to unity. A part from this, Flory-Huggins isotherm and Langmuir-Freundlich isotherm were also used to study the interaction between the inhibitors and the mild steel surface, and mechanism of electrochemical reaction. At last the free energy of adsorption and activation energy were calculated and discussed.

Impacts of pyridinium gemini surfactants on corrosion inhibition of carbon steel

Pyridinium gemini surfactants (PGS-n) are an important class of amphiphiles with antibacterial properties and hence, are usually preferred in industrial and medicinal applications. In this work, three PGS-n with different alkyl chain lengths having two amide spacers, 3,3′-(Malonylbis(azanediyl))bis(1-dodecylpyridin-1-ium) dibromide (PGS-12), 3,3′-(Malonylbis(azanediyl))bis(1-tetradecylpyridin-1-ium) dibromide (PGS-14), and 3,3′-(Malonylbis(azanediyl))bis(1-octadecylpyridin-1-ium) dibromide (PGS-18), were synthesized, characterized and tested as corrosion inhibitor on carbon steel in HCl for the first time. The corrosion inhibition efficiency was examined by weight loss measurement, electrochemical impedance spectroscopy (EIS), and potentiodynamic measurements at 30 °C. Furthermore, micellization parameters such as critical micelle concentration (cmc), degree of counter ion dissociation, and Gibb's energy of micellization of these PGS-n were determined. The inhibition efficiency of the studied PGS-n was found to be maximum near their cmc values and found to follow the order: PGS-18 > PGS-14 > PGS-12. The PGS-n with the longest alkyl chain could achieve a maximum inhibition efficiency of 99.2 %. The adsorption of PGS-n on the surface of carbon steel was found to follow the Langmuir adsorption isotherm. The results obtained from EIS measurements agreed well with those of polarization and weight loss studies. Field emission scanning electron microscopic analysis revealed that the corrosion of the carbon steel surface is not severe, especially in the presence of PGS -18. Density functional theory was employed to calculate various quantum chemical parameters of the PGS-n. The results suggest PGS-n as an effective inhibitor for corrosion inhibition of carbon steel.

Inhibitory Effect of Stachytarpheta mutabilis Extracts on the Corrosion of Mild Steel in Acidic Media

The anticorrosive potential of Stachytarpheta mutabilis leaf extract (SMLE) as a corrosion inhibitor for corrosion of mild steel (MS) in 1 M HCl was investigated using weight loss measurement as well as gasometric techniques at 30 and 60 oc. Relevant thermodynamic equations were employed to estimate the activation energy, enthalpy change and entropy change. The adsorption isotherms were used to determine the Gibbs free energy change. Results obtained showed that SMLE functioned as an excellent corrosion inhibitor for mild steel in the acidic environment. Temperature studies revealed a decrease in inhibition efficiency with increase in temperature and activation energies increased in the presence of the extract. The adsorption of SMLE on mild steel was approximated using Freundlich, Flory-Huggins, Frumkin, El-Awary’s and Temkin isotherms but Langmuir gave the best fit. Both kinetic and thermodynamic parameters governing the adsorption process were calculated and discussed. The adsorption followed a first order kinetics. As concluded from the results, the adsorption of S. mutabilis on mild steel in 1M HCl medium is feasible, spontaneous and it occurred by physical adsorption. From the experimental results obtained, it can be concluded that SMLE inhibit corrosion effectively when compared well with many reported green inhibitors for MS corrosion.