Commercial Inhibitors Research Articles

How do termite baits work? implication of subterranean termite colony demography on the successful implementation of baits.

In 1995, the launch of the first commercial chitin synthesis inhibitor (CSI) bait led to the transformation of the subterranean termite control industry around the world. Their slow mode of action, which relies on both their ability to be transferred among nestmates and termite molting biology, has made them cost-effective solutions for subterranean termite colony elimination while minimizing the introduction of pesticides into the soil toward an environmentally sustainable strategy. However, despite successful commercial implementations, the acceptance of their use varies within the pest control industry around the world. Notably, the nuanced complexity of how CSI baits lead to colony elimination upon feeding by termite foragers has, in part, remained elusive for the past 3 decades, allowing for long-lasting misconceptions to persist. A recent series of studies has since provided complementary elements of understanding how CSI baits utilize termites' inherent colony demography, behavior, and physiology to trigger colony elimination after a characteristic succession of events within the colony collapse process. I here provide a synthetic overview of subterranean termite colony characteristics when exposed to CSI baits using Coptotermes (Wasmann) (Blattodea: Heterotermitidae) as a primary model system. The changes in colony demography through the colony collapse reflect how the mode of action of CSI baits makes them a prime solution for sustainable subterranean termite pest management. Following decades of innovation, ongoing interactions among termite researchers, bait product manufacturers, and pest management providers must continue to bring solutions to existing and emerging termite pest problems around the world.

Synthesis and Antifungal Activities of Glucosamine Aromatic Derivatives Against Four Phytopathogenic Fungi of Crops.

A series of diversified glucosamine derivatives (3a-3y) was synthesized and their antifungal activity was examined against four kinds of phytopathogens, Fusarium graminearum (F. graminearum), Fusarium moniliforme (F. moniliforme), Curvularia. lunata (C. lunata), and Rhizoctonia solani (R. solani) which cause seriously economic losses worldwide by affecting crops. The compound 3o showed remarkable antifungal activity against F. graminearum with EC50 value of 3.96 μg/mL, compared to the standard drug triadimefon (10.1 μg/mL). 3D-QSAR model with the statistically recommended values (r2=0.915, q2=0.872) showed that positive charge group or bulky group in the benzyl ring was favorable for the antifungal activity. Enzyme activity assays confirmed that 3o had a moderate inhibition of trehalase with inhibition rate of 51.4 % at 5 μg/mL, which is comparable to those of commercial inhibitor validamycin A with inhibition rate of 83.3 %. Molecular docking analysis revealed that 3o also had a hydrogen bond interaction with key amino acid residue compared to validoxylamine.

Antihypertensive Activity of Peptides Derived from Toman Fish Albumin (Channa micropeltes): In-silico Angiotensin-Converting Enzyme Inhibitory Study.

The peptides from protein hydrolysis can be as bioactive peptides. Currently, the process of protein hydrolysis can be done in-silico technique, an alternative to bioactive peptide identification more effectively and efficiently. This study aims to predict bioactive peptides in-silico technique of albumin hydrolysis from Toman Fish (Channa micropeltes), which had the potential as an antihypertensive drug. Toman fish albumin sequence (A0A191TFW5) was obtained from the UniProt database. The identification of bioactive peptides was performed by simulating enzymatic hydrolysis with three human digestive enzymes: trypsin, chymotrypsin, and pepsin. The hydrolysis simulation of albumin was conducted using the ExPASy PeptideCutter program. The generated peptides’ potential activities, solubility, and ADMET (absorption, distribution, metabolism, excretion, and toxicity) properties were predicted using various online prediction tools. Molecular docking was performed on the bioactive peptides to determine the Gibbs free energy (∆G) and to illustrate the interaction between the bioactive peptides and the active site of the Angiotensin Converting Enzyme (ACE) as a comparison was used captopril which was a commercial ACE inhibitor. The results showed that bioactive peptide candidates were AI, VL and LVP. These peptides were potentially a candidate for alternative antihypertensive drugs.

Performance Assessment of Biomass-derived Urea-Furfuraldehyde Resins as Oilfield Scale Inhibitors

Oilfield-scale formation is a persistent challenge in the oil industry. While numerous scale inhibitors have been in use for decades, there is a significant research gap in discovering renewable, cost-effective, ecologically friendly, and efficient inhibitors. This study sets out to fill this gap by investigating the potential of scale inhibitors (SIs) made from bio-resin derivatives of red onion skin; ROF and ROFU, in reducing CaCO3 and CaSO4 scales. The scale inhibition performance of ROF and ROFU was rigorously evaluated using the NACE standard static bottle test method. The data revealed that increasing scale-inhibitor contact time, concentration, and temperature enhances inhibitor efficacy, with the best inhibition efficiencies found for ROF and ROFU on the CaSO4 scale compared to the CaCO3 scale across all studied parameters. A comparison of the prepared SIs with a commercial scale inhibitor (CSI) showed a high inhibition rate of over 90% at minimal dosage of 60ppm in both scales studied. Despite having a lower inhibition rate (IE) than CSI, ROF and ROFU demonstrate significant potential as green oilfield SIs. This sustainable technique, which transforms agro-waste into a valuable oilfield chemical via a one-pot chemical process, could have profound economic and societal benefits, offering hope for a more sustainable future in the oil industry.

Improving shale hydration inhibition with hydrophobically modified graphene oxide in water-based drilling fluids

Frequent wellbore instability issues caused by shale hydration and dispersion are encountered in water-based drilling fluids. In order to mitigate shale hydration, a hydrophobic graphene oxide (HGO) was prepared as a new shale inhibitor and characterized. The effectiveness of HGO in inhibiting shale hydration was evaluated through hydration expansion, hydration dispersion, and bentonite sheets immersion tests. The expansion height of bentonite in HGO (3.87 mm) was lower than that of commercial shale inhibitors potassium chloride (KCl, 4.64 mm) and polyether amine (PA, 4.33 mm). The shale recovery rate in HGO at 80 °C was 86.25 %, which was superior to KCl (46.60 %) and PA (78.25 %). Furthermore, the morphology of bentonite sheet remained more intact after immersion in HGO. Additionally, the inhibitory mechanism of HGO was studied in-depth, employing zeta potential, particle size, surface tension, wettability, capillary rise height, and scanning electron microscopy (SEM) tests. By virtue of electrostatic attraction, HGO could tightly adsorb to the shale surface, resulting in a hydrophobic blocking membrane, thereby greatly reducing water infiltration. Following interaction with shale at a concentration as low as 0.5 %, the water contact angle exhibited a notable enhancement, rising from 22.49° to 86.69°. And it could also decrease the capillary self-suction capacity of shale, further reducing water adsorption. Consequently, HGO exhibited significant potential for inhibiting hydration in shale drilling.

Discovery of Novel (5-Mercapto-4-phenyl-4H-1,2,4-triazol-3-yl)methyl Phenyl Carbamate as a Potent Phytoene Desaturase Inhibitor through Scaffold Hopping and Linker Modification.

Phytoene desaturase (PDS) is a key rate-limiting enzyme in the carotenoid biosynthesis pathway. Although commercial PDS inhibitors have been developed for decades, it remains necessary to develop novel PDS inhibitors with higher bioactivity. In this work, we used the scaffold hopping and linker modification approaches to design and synthesize a series of compounds (7a-7o, 8a-8l, and 14a-14d). The postemergence application assay demonstrated that 8e and 7e separately showed the best herbicidal activity at 750 g a.i./ha and lower doses (187.5 g, 375g a.i./ha) without no significant toxicity to maize and wheat. The surface plasmon resonance revealed strong binding affinity between 7e and Synechococcus PDS (SynPDS). The HPLC analysis confirmed that 8e at 750 g a.i./ha caused significant phytoene accumulation in Arabidopsis seedlings. This work demonstrates the efficacy of structure-guided optimization through scaffold hopping and linker modification to design potent PDS inhibitors with enhanced bioactivity and crop safety.

Kinetic Gas Hydrate Inhibition by Alternating Dipeptoids with Optimal Size and Shape N-Substituents.

Current commercial kinetic hydrate inhibitors (KHIs) are all based on water-soluble polymers with amphiphilic alkylamide or lactam groups. The size and shape of the hydrophobic moiety are known to be critical for optimum KHI performance. Proteins and peptides represent an environmentally friendly alternative, especially as bioengineering could be used to manufacture a product predetermined to have optimum KHI performance. Here, we explore a new series of polymers that are alternating dipeptoids where one of the peptide links originates from glycine. The dipeptoids contain n-propyl groups on the nitrogen atom and varying size and shape alkyl side chains on the neighboring carbon atom. Experiments were carried out in high-pressure steel rocking cells using the slow constant cooling (SCC) test method (1 °C/h) and a synthetic natural gas mixture. All the dipeptoids showed good KHI performance with the best result being for that with a glycine-N-propylleucine repeating unit (Poly iC4-Pr), which has pendant iso-butyl groups on the carbon atom. It exhibited the same KHI performance as poly(N-vinyl caprolactam). Dipeptoids with smaller or longer alkyl groups than iso-butyl gave worse performance. It is conjectured that the iso-butyl group is the optimal carbon length for this polymer class. In addition, the end-branching maximizes the van der Waals interaction with open cavities on growing hydrate particles, which must occur without loss of hydrogen-bonding from the neighboring peptide linkage for optimum KHI performance. Thus, the study provides further evidence for the premise that good KHI molecules must contain multiple amphiphilic groups (often as polymers) with optimal size and shape hydrophobic groups adjacent to strong hydrogen bonding groups. The solvent, n-butyl glycol ether, was shown to be a synergist for Poly iC4-Pr, lowering the onset temperature of hydrate formation in SSC tests relative to the polymer alone.

3-((2-(4-Chloro-5-ethoxy-2-nitrophenoxy)acetamido)methyl)phenyl-dimethylcarbamate

In this study, we report the synthesis of 3-((2-(4-chloro-5-ethoxy-2-nitrophenoxy)acetamido)methyl)phenyl-dimethylcarbamate, designed on the basis of the structures of the commercial acetylcholinesterase inhibitor drug rivastigmine and a substituted aryloxyacetic acid, aiming at a multi-target approach to the therapy of Alzheimer’s disease. The hybrid was obtained thanks to a synthesized intermediate by-product. The compound was fully characterized by using 1H and 13C NMR, FT-IR and HRMS.

A Novel AHAS-Inhibiting Herbicide Candidate for Controlling Leptochloa chinensis: A Devastating Weedy Grass in Rice Fields.

Given the prevalence of the malignant weed Chinese Sprangletop (Leptochloa chinensis (L.) Nees) in rice fields, the development of novel herbicides against this weed has aroused wide interest. Here, we report a novel diphenyl ether-pyrimidine hybrid, DEP-5, serving as a systematic pre/postemergence herbicide candidate for broad-spectrum weed control in rice fields, specifically for L. chinensis. Notably, DEP-5 exhibits over 80% herbicidal activity against the resistant biotypes even at 37.5 g a.i./ha under greenhouse conditions and has complete control of L. chinensis at 150 g a.i./ha in the rice fields. We uncover that DEP-5 acts as a noncompetitive inhibitor of acetohydroxyacid synthase (AHAS) with an inhibition constant (Ki) of 39.4 μM. We propose that DEP-5 binds to AHAS in two hydrophobic-driven binding modes that differ from commercial AHAS inhibitors. Overall, these findings demonstrate that DEP-5 has great potential to be developed into a herbicide for L. chinensis control and inspire fresh concepts for novel AHAS-inhibiting herbicide design.

Anti-tumor withanolides as signal transducers and activators of transcription 3 (STAT3)-inhibition from Withania obtusifolia

The Solanaceae family and the Withania genus specifically are rich sources of medicinal plants. Liquid chromatography coupled to high-resolution mass spectrometry (LC-HRMS/MS) revealed a predominance of withanolides from an organic extract of Withania obtusifolia. A constructed molecular network uncovered the presence of potentially novel withanolides. A series of withanolides were then isolated and structurally characterized from the extract including two new withanolides (withafolia A and withafolia B) and seven previously reported metabolites. Of the isolated compounds, cytotoxicity of withanolide J, physaperuvin G, and a commercial STAT3 inhibitor (S3I-201) were assessed against a human leukemia HL-60 cell line resulting in IC50 values of 26, 29, and 120 μM, respectively. In silico molecular docking simulations indicate that withanolide J and physaperuvin G can bind as an inhibitor in the active site of STAT3 with docking scores comparable to the selective STAT3 inhibitor, S3I-201.

Epigenetic-based differentiation therapy for Acute Myeloid Leukemia

Despite the development of novel therapies for acute myeloid leukemia, outcomes remain poor for most patients, and therapeutic improvements are an urgent unmet need. Although treatment regimens promoting differentiation have succeeded in the treatment of acute promyelocytic leukemia, their role in other acute myeloid leukemia subtypes needs to be explored. Here we identify and characterize two lysine deacetylase inhibitors, CM-444 and CM-1758, exhibiting the capacity to promote myeloid differentiation in all acute myeloid leukemia subtypes at low non-cytotoxic doses, unlike other commercial histone deacetylase inhibitors. Analyzing the acetylome after CM-444 and CM-1758 treatment reveals modulation of non-histone proteins involved in the enhancer–promoter chromatin regulatory complex, including bromodomain proteins. This acetylation is essential for enhancing the expression of key transcription factors directly involved in the differentiation therapy induced by CM-444/CM-1758 in acute myeloid leukemia. In summary, these compounds may represent effective differentiation-based therapeutic agents across acute myeloid leukemia subtypes with a potential mechanism for the treatment of acute myeloid leukemia.

A New Chemical Inhibitor to Mitigate Swelling of Sodium and Calcium Bentonite during Drilling Process

Clay swelling during drilling operations is one of the challenges faced in the oil industry. While both oil-based and syntheticbased muds have been successful at reducing clay swelling, the environmental concerns of oil-based muds and the high cost of synthetic-based muds limit their usage. Commercial water-based inhibitors like sodium chloride (NaCl), potassium chloride (KCl), cesium formate (CHCsO2), ammonium chloride (NH4Cl), and tetramethylammonium chloride (C4H12NCl-) are commonly used. However, some inhibitors have limitations, such as the toxicity of KCl, which according to the Environmental Protection Agency, cannot be used at concentrations higher than 5%. Other limitations include their impact on the rheology of drilling mud, cost (CHCsO2, C4H12NCl-), and their limited behaviour at high temperatures and pressures (NaCl). In this study, novel clay inhibitors for water-based drilling muds were characterized. A capillary suction timer (CST), a filtration time test, energy dispersive spectroscopy (EDS), and a scanning electron microscope (SEM) were used for the experiments. Testing was conducted on Na and Ca bentonite mixed with water-based drilling mud (WBDM) and commercial inhibitors, as well as novel inhibitors at 3%, 4%, and 5% concentrations.

PNSC928, a plant-derived compound, specifically disrupts CtBP2-p300 interaction and reduces inflammation in mice with acute respiratory distress syndrome

BackgroundPrior research has highlighted the involvement of a transcriptional complex comprising C-terminal binding protein 2 (CtBP2), histone acetyltransferase p300, and nuclear factor kappa B (NF-κB) in the transactivation of proinflammatory cytokine genes, contributing to inflammation in mice with acute respiratory distress syndrome (ARDS). Nonetheless, it remains uncertain whether the therapeutic targeting of the CtBP2-p300-NF-κB complex holds potential for ARDS suppression.MethodsAn ARDS mouse model was established using lipopolysaccharide (LPS) exposure. RNA-Sequencing (RNA-Seq) was performed on ARDS mice and LPS-treated cells with CtBP2, p300, and p65 knockdown. Small molecules inhibiting the CtBP2-p300 interaction were identified through AlphaScreen. Gene and protein expression levels were quantified using RT-qPCR and immunoblots. Tissue damage was assessed via histological staining.Key findingsWe elucidated the specific role of the CtBP2-p300-NF-κB complex in proinflammatory gene regulation. RNA-seq analysis in LPS-challenged ARDS mice and LPS-treated CtBP2-knockdown (CtBP2KD), p300KD, and p65KD cells revealed its significant impact on proinflammatory genes with minimal effects on other NF-κB targets. Commercial inhibitors for CtBP2, p300, or NF-κB exhibited moderate cytotoxicity in vitro and in vivo, affecting both proinflammatory genes and other targets. We identified a potent inhibitor, PNSC928, for the CtBP2-p300 interaction using AlphaScreen. PNSC928 treatment hindered the assembly of the CtBP2-p300-NF-κB complex, substantially downregulating proinflammatory cytokine gene expression without observable cytotoxicity in normal cells. In vivo administration of PNSC928 significantly reduced CtBP2-driven proinflammatory gene expression in ARDS mice, alleviating inflammation and lung injury, ultimately improving ARDS prognosis.ConclusionOur results position PNSC928 as a promising therapeutic candidate to specifically target the CtBP2-p300 interaction and mitigate inflammation in ARDS management.

A novel role for KIFC1-MYH9 interaction in triple-negative breast cancer aggressiveness and racial disparity

African American (AA) women are twice as likely to develop triple-negative breast cancer (TNBC) as women of European descent. Additionally, AA women with TNBC present a much more aggressive disease course than their European American (EA) counterparts. Thus, there is an unmet clinical need to identify race-specific biomarkers and improve survival outcomes in AA patients with TNBC. The minus-end directed microtubule motor protein kinesin family member C1 (KIFC1) promotes centrosome clustering and chromosomal instability and is often overexpressed in TNBC. Previous findings suggest that KIFC1 plays a role in cell proliferation and migration in TNBC cells from AAs and that the levels of nuclear KIFC1 (nKIFC1) are particularly high in AA patients with TNBC. The nuclear localization of KIFC1 in interphase may underlie its previously unrecognized race-specific association. In this study, we found that in TNBC cells derived from AAs, nKIFC1 interacted with the tumor suppressor myosin heavy chain 9 (MYH9) over EA cells. Treatment of AA TNBC cells with commercial inhibitors of KIFC1 and MYH9 disrupted the interaction between KIFC1 and MYH9. To characterize the racial differences in the KIFC1-MYH9-MYC axis in TNBC, we established homozygous KIFC1 knockout (KO) TNBC cell lines. KIFC1 KO significantly inhibited proliferation, migration, and invasion in AA TNBC cells but not in EA TNBC cells. RNA sequencing analysis showed significant downregulation of genes involved in cell migration, invasion, and metastasis upon KIFC1 KO in TNBC cell lines from AAs compared to those from EAs. These data indicate that mechanistically, the role of nKIFC1 in driving TNBC progression and metastasis is stronger in AA patients than in EA patients, and that KIFC1 may be a critical therapeutic target for AA patients with TNBC.Graphical abstract

Sustainable Calcite Scale Inhibitors via Oxidation of Lignosulfonates.

Deposition of inorganic scales in wells, flow lines, and equipment is a major problem in the water treatment, geothermal, or upstream oil and gas industries. Deployment of scale inhibitors has been adopted worldwide for oilfield scale prevention. Commercial synthetic scale inhibitors such as polymeric carboxylates and sulfonates or nonpolymeric phosphonates offer good scale inhibition performance but often suffer from one or more limitations including biodegradability, calcium compatibility, and thermal stability. Lignin-based biomaterials such as sodium lignosulfonates are natural, sustainable, and widely available polymers that are accepted for use in environmentally sensitive areas. Here we show that, although lignosulfonates perform relatively poorly as calcite scale inhibitors in dynamic tube blocking tests, oxidized lignosulfonates show a much improved inhibition effect by a factor of 20-fold. The oxidized lignosulfonates are easy to prepare in a 1-step reaction and show excellent calcium compatibility and thermal stability, useful for downhole squeeze treatments in high temperature wells. This present study unequivocally establishes oxidized lignosulfonates as a new class of sustainable green scale inhibitors, thereby bridging the gap between materials derived directly from nature and the classic synthetic polymeric scale inhibitors.

New oxadiazol‐5‐ones derivatives and their performance as angiotensin‐converting enzyme (ACE) inhibitors

AbstractAngiotensin‐converting enzyme inhibitors are widely used in treating arterial hypertension, acting on the renin‐angiotensin‐aldosterone system and controlling blood pressure. We present a novel, greener, and faster methodology to assess the 1,2,4‐oxadiazol‐5‐one ring and perform molecular modifications to obtain angiotensin‐converting enzyme (ACE) inhibitors using this heterocyclic core. Molecular docking simulations indicate that the tested compounds exhibited an affinity for the ACE binding site, with scores comparable to the commercial inhibitor lisinopril. However, in vitro assays revealed that the compounds were ineffective in inhibiting ACE activity. The lack of inhibition may be related to the compounds' more apolar nature. These results emphasize the importance of integrating computational and experimental approaches in developing new drugs, providing valuable insights for planning future studies to optimize the activity of synthesized compounds.

Performance evaluation of glutaraldehyde-modified red onion skin extract as oilfield scale inhibitors

Scale deposition occurs due to changes during injection operations and the mixing of incompatible brines. Scale inhibitors are used to mitigate such occurrences. The inhibition efficiency of the glutaraldehyde-ROSE resin (ROG) was evaluated in synthetic brines containing CaSO4, BaSO4, and CaCO3 under static conditions according to NACE standard methods. The formulated scale inhibitor was compatible with the brine and thermally stable. The inhibition studies of ROG revealed optimal inhibition of 89% at 80 ppm and 58% at 100 ppm at 90 °C and 22 h, respectively, for BaSO4 and CaCO3 scales, while for CaSO4 scales, optimal inhibition of 67% was observed at 100 ppm, 71 °C, and 22 h. On comparison, the Commercial Scale Inhibitor (CSI) showed optimal inhibition of 97% at 100 ppm and 94% at 80 ppm at 71 °C and 22 h, respectively, for BaSO4 and CaSO4 scales, while for CaCO3 scales, optimal inhibition of 98% was observed at 80 ppm, 90 °C, and 22 h, respectively. This indicates that ROG efficiently mitigated the formation of CaSO4, BaSO4, and to some reasonable extent, CaCO3 scales, and its inhibition performance compared favorably with the CSI, thus unveiling its potential for consideration as a green oilfield scale inhibitor.

Subcutaneous administration of Stattic alleviates neuropathic pain by relieving inflammation in a mouse model of postherpetic neuralgia

Stattic, a commercial inhibitor of STAT3, can drive the development of neuropathic pain. Exploring the connection between Stattic and JAK1/STAT3 signaling may facilitate the understanding of neuropathic pain caused by postherpetic neuralgia (PHN). In the current study, as crucial regulators of inflammation, STAT3 and its associated JAK1/STAT3 pathway were found to be upregulated and activated in the L4-L6 dorsal root ganglion (DRG) of mice in response to resiniferatoxin (RTX)-induced PHN, while subcutaneous administration of Stattic was found to downregulate STAT3 expression and phosphorylation in a PHN model. Stattic administration further attenuated hypersensitivity to mechanical and thermal stimuli in PHN mice, and alleviated inflammation and cell death in the L4-L6 DRG of mice. Overexpression of STAT3 via microinjection of a lentiviral-STAT3 overexpression vector reversed the abnormal decrease of STAT3 at both the mRNA and protein levels in the L4-6 DRGs of PHN mice and significantly promoted hypersensitivity to mechanical stimuli in the mice. Collectively, we found that subcutaneous static administration alleviated RTX-induced neuropathic pain by deactivating JAK1/STAT3 in mice.

Enhancing the shale inhibition performance of low-melting mixture solvents utilizing DTAB in water-based drilling fluids

Wellbore instability issue is a common occurrence in the development of clean energy sources such as shale gas. Low-melting mixture solvents (LoMMSs), as a novel and environmentally friendly liquids material, are anticipated to be utilized to address this issue. In this work, a novel shale inhibitor (LoMMSs-2) was formulated through introducing a cationic surfactant with a long hydrophobic chain, dodecyl trimethyl ammonium bromide (DTAB), into a commonly used choline chloride/glycerol LoMMSs. Inhibition assessment results indicated that the swelling height of bentonite in LoMMSs-2 solutions decreased by 53.46 %, and shale recovery rate reached as high as 89.51 %, demonstrating superior hydration inhibition compared to commercial inhibitors. The mechanism for inhibiting hydration in LoMMSs-2 was explored through tests involving zeta potential, particle size, interlayer spacing, shale wettability, and surface tension, etc. The findings revealed that choline cations and quaternary ammonium cations in LoMMSs-2 could tightly adsorb to the clay surface. The exposed long alkyl chains made the rock more hydrophobic, increasing the water contact angle from 22.49° to 65.26°. Subsequently, more interlayers water in the clay was expelled, leading to a significant reduction in adsorbed water. Additionally, the lower surface tension and stronger hydrophobicity corresponded to a smaller capillary force, further minimizing water infiltration into shale. Therefore, introducing hydrophobic groups into LoMMSs was a promising approach for developing efficient shale inhibitors to address wellbore instability issue in shale gas drilling.

Analysis of the Effectiveness of the Application of Corrosion Inhibitors to Steel Re-Bars Embedded in Concrete

Reinforced concrete is the most widely used material in the construction of building structures, being noted for its versatility and low cost. However, the durability of reinforced concrete structures can be compromised by the corrosion of steel re-bars, especially in the presence of chlorides. To address this challenge and promote sustainability, the use of corrosion inhibitors has been researched as a way to extend the lifespan of structures. This study assessed the effectiveness of using a commercial corrosion inhibitor on steel re-bars embedded in types of concrete with different chloride percentages, using electrochemical methods to measure the corrosion rate and potential. The results indicate that, in the absence of corrosion inhibitors, corrosion rates become unacceptable with chloride percentages equal to or higher than 0.8% by weight of cement. The application of inhibitors significantly reduced the corrosion rate, particularly at chloride percentages of 0.8% and 1.2%, maintaining the re-bars in a passive state or at moderate levels of corrosion. However, for chloride percentages higher than 1.6%, high levels of corrosion were observed, even in the presence of inhibitors. The findings suggest that the use of inhibitors can be an effective strategy in preventing corrosion in reinforced concrete structures, contributing to their structural integrity and long-term sustainability.