Songqing Hu

To address the severe acidic corrosion of metals and the environmental concerns associated with conventional corrosion inhibitors in oilfield acidizing operations, three betaine-type zwitterionic chitosan derivatives with different molecular weights (CS 1K, CS 30K, and CS 200K) were synthesized from natural chitosan via modification with 1,3-propanesultone. For the first time, the relationship between molecular weight and corrosion inhibition performance of the zwitterionic chitosan derivatives is systematically investigated. The inhibition efficiency increases with increasing molecular weight, reaching 87.3% for CS 200K at 300 mg/L. When compounded with propynol ethoxylate (PA), the system exhibits a pronounced synergistic effect, with the inhibition efficiency further enhances to 98.0% and the corrosion rate reduces to 0.377 mm/a. The adsorption of the inhibitors follows the Langmuir isotherm model. Various surface analyses reveal that the composite system forms a dense protective film on the steel surface through combined electrostatic attraction and weak coordination interactions. DFT calculations further confirm that zwitterionic modification enhances the molecular reactivity and adsorption capability. This study provides a sustainable and efficient strategy for developing green corrosion inhibitors for oilfield acidizing applications.

To address the severe acidic corrosion of metals and the environmental concerns associated with conventional corrosion inhibitors in oilfield acidizing operations, three betaine-type zwitterionic chitosan derivatives with different molecular weights (CS 1K, CS 30K, and CS 200K) were synthesized from natural chitosan via modification with 1,3-propanesultone. For the first time, the relationship between molecular weight and corrosion inhibition performance of the zwitterionic chitosan derivatives is systematically investigated. The inhibition efficiency increases with increasing molecular weight, reaching 87.3% for CS 200K at 300 mg/L. When compounded with propynol ethoxylate (PA), the system exhibits a pronounced synergistic effect, with the inhibition efficiency further enhances to 98.0% and the corrosion rate reduces to 0.377 mm/a. The adsorption of the inhibitors follows the Langmuir isotherm model. Various surface analyses reveal that the composite system forms a dense protective film on the steel surface through combined electrostatic attraction and weak coordination interactions. DFT calculations further confirm that zwitterionic modification enhances the molecular reactivity and adsorption capability. This study provides a sustainable and efficient strategy for developing green corrosion inhibitors for oilfield acidizing applications.

Self‐healing dual‐phobic anticorrosive coatings can simultaneously enhance the liquid repellency and service life of materials, which is of great significance for long‐term protection of metal surfaces. Since coating damage easily destroys the barrier layer and micro‐nano structures, the liquid‐repellent performance cannot be fully restored. The preparation of coatings that possess both dual repellency, self‐repair, and long‐lasting corrosion resistance still faces challenges. This paper prepares MS‐GO microspheres via acid reflux etching and hydrothermal method, grafts KH560 and fluor silane to produce hierarchical rough, low‐surface‐energy PF‐KMS‐GO fillers; synthesizes epoxy resin matrix containing dynamic disulfide bonds using bisphenol disulfide. The coating exhibits the best overall performance with a filler content of 10 wt.%, with water and oil contact angles of 116° and 109°, respectively; scratches can be healed and the dual‐phobic properties restored after heating at 80°C for 25 min, and it still maintains stable barrier and excellent corrosion resistance after long‐term immersion in 3.5% NaCl solution. This study offers a new design idea for making highly durable, self‐healing dual‐phobic anti‐corrosion coatings by combining low surface energy fillers, 2D barrier phases, and dynamic cross‐linked networks. It is expected to expand its applications in marine equipment, metal components, and other corrosion conditions.

Design of intelligent materials that simultaneously provide efficient corrosion protection, real-time corrosion monitoring, and selective heavy metal sensing remains a significant challenge. Herein, we report a novel multifunctional carbon dot (PEG-CD) synthesized for the first time from citric acid and propargyl-PEG2-amine via a one-step hydrothermal method. The introduction of amide, ether, and propargyl groups dramatically enhances the thermal stability and dispersibility of carbon dots, enabling PEG-CD to achieve an exceptional corrosion inhibition efficiency of >99% for N80 steel in 1 M HCl at both 303 and 363 K, substantially outperforming conventional carbon dots. Mechanistic studies reveal that PEG-CD forms a dense protective film on metal surface through synergistic coordination bonding (amide, carboxyl, carbonyl groups with Fe atoms) and electrostatic interactions. Leveraging its intrinsic fluorescence properties, PEG-CD enables in-situ, real-time monitoring of metal corrosion via static quenching-induced fluorescence attenuation upon Fe3+ release. Furthermore, PEG-CD functions as a highly selective fluorescent chemosensor for Fe3+, Fe2+, and Cr2O72- in industrial wastewater, with detection limits of 0.0887mmol/L, 0.421 mmol/L, and 0.1 mmol/L, respectively. By consolidating corrosion inhibition, damage reporting, and heavy-metal detection into a single, facilely synthesized platform, this work bypasses the substantial reagent and energy inputs typical of traditional multistep routes-providing a valuable reference for next-generation smart materials with maximal resource efficiency and strong alignment with circular economy goals.

Achieving robust corrosion protection under harsh high-temperature acidic conditions and effective lubrication and friction reduction remains a formidable challenge. Here, we report a rationally designed dodecyl bispyridylimine (C-PyD-BSB) that serves as a dual-functional agent for N80 steel in HCl solutions (1 M and 15 %) at 363 K. C-PyD-BSB alone yields inhibition efficiencies of 92.91% and 93.26%, respectively, which are synergistically boosted to 99.18% and 98.90% upon combination with propargyl alcohol ethoxylate (PE). Moreover, the same molecule exhibits outstanding water-based lubrication performance, reducing the friction coefficient from 0.39 to 0.17, wear volume from 23.6×106 to 6.1×106 μm3, and wear rate from 39.6 to 10.4 mm3/(N·m). Comprehensive experimental and theoretical (DFT, MD) analyses reveal that the long alkyl chain enhances hydrophobicity and steric stabilization, while pyridinic N atoms anchor to the Fe surface via strong coordination, forming a compact chemisorbed film. PE co-adsorbs to fill voids and further densify the protective layer. Under shear, amphiphilic C-PyD-BSB self‑assembles into micelles that migrate to the interface, generating a tribochemical film comprising Fe-N coordination bonds and carbon chains, which drastically reduces friction and wear. This work demonstrates a universal interfacial design strategy for integrating high-temperature corrosion inhibition and lubrication into a single molecular platform, offering a promising pathway for durable metallic materials in aggressive environments.

Designing intelligent anticorrosion systems that couple robust protection with real-time corrosion visualization remains a formidable challenge in industrial safety and infrastructure longevity. Here, a one-step hydrothermal condensation of 2-aminothiazole and citric acid yields a multifunctional carbon dot (CD) whose surface is densely terminated with N-, O-, and S-bearing functionalities. These heteroatom-rich groups furnish abundant coordination anchors for metal substrates. Electrochemical assays and gravimetric measurements reveal that the CD delivers a corrosion inhibition efficiency of 95.18% for N80 steel in 1 M HCl at a dosage of 200 mg/L. Adsorption conforms to the Langmuir isotherm with a Gibbs free energy of −31.66 kJ/mol, indicating a spontaneous mixed physical-chemical adsorption mechanism dominated by chemisorptive interactions from Fe–N, C–S, and S═O linkages. Surface analyses confirm a compact, adherent protective film that strongly retards both anodic dissolution and cathodic hydrogen evolution. Capitalizing on the intrinsic blue fluorescence of the CD, the system additionally accomplishes in situ reporting of corrosion progression: fluorescence quenching occurs synchronously with Fe3+/Fe2+ release as the film degrades. This work establishes a single-component “protect-and-report” platform, offering an effective and conceptually innovative strategy for next-generation corrosion management.

Industrial oily wastewater poses a major treatment challenge due to the coexistence of emulsified oils, organic pollutants, and heavy metal ions, alongside concerns over the environmental impact of spent treatment materials. Here, we report a multifunctional semiconductor-hydrogel composite membrane that achieves complete remediation of oily wastewater while exhibiting eco-compatible degradation. Hydroxylated carbon nanotubes (H-CNTs) regulate surface energy to promote demulsification and tune the ZnO band structure for broad-spectrum light absorption. As a result, the membrane achieves a separation efficiency of 99.97% ± 0.02% with a flux of 1433.12 ± 25 L·m-2·h-1, degrades organic pollutants up to 95.81% ± 0.14%, and removes heavy metal ions with 85.79% ± 0.21% efficiency. Moreover, the membrane also maintains superior treatment performance when tested with real oily wastewater from oilfields, further confirming its practical applicability. In addition, spent hydrogel membranes exhibit soil biodegradability, producing byproducts that enhance plant root vitality and growth. Transcriptome analysis reveals activation of ATPase activity, ammonium transport, and cell division-related gene expression, while microbiome studies show enrichment of beneficial soil bacteria. This study establishes a sustainable paradigm for oily wastewater treatment by integrating high-efficiency separation, photocatalytic purification, and heavy metal removal, while achieving a closed-loop system through environmentally beneficial end-of-life degradation.

Achieving both emulsified oil demulsification and metal corrosion protection during oil recovery can greatly reduce production costs, but it is extremely challenging. Herein, we synthesized an imidazolium zwitterions compound using amino acids, formaldehyde, and glyoxal. The imidazole ring in its structure provides abundant active sites, while retained carboxyl groups (-COOH/-COO⁻) and intrinsic side chains (R) endow it with dual ionic properties and functionalities. Demulsification experiments combined with theoretical calculations demonstrate that pH-adaptive regulation via carboxyl groups neutralizes anionic emulsifiers at the oil-water interface, and R groups disrupt the interfacial layer, accelerating droplet aggregation across pH ranges, with a demulsification efficiency of up to 96.32%. Electrochemical/weight loss experiments, and theoretical calculations reveal that the closed electron transfer circuit formed between the compound and iron atoms significantly enhances its adsorption on iron surfaces, achieving a corrosion inhibition efficiency of 95.83% in 1.2 M HCl solution. Notably, the compound acts as an iron ion stabilizer and UV spectroscopy confirms its chelation with iron ions, preventing iron ion precipitation, blockage, and scaling, with a maximum Fe3+ stabilization rate of 96.37%. This research offers an effective strategy to design and prepare multifunctional agents with both corrosion-inhibiting and demulsifying properties for oilfields.

Designing intelligent anticorrosion systems that couple robust protection with real-time corrosion visualization remains a formidable challenge in industrial safety and infrastructure longevity. Here, a one-step hydrothermal condensation of 2-aminothiazole and citric acid yields a multifunctional carbon dot (CD) whose surface is densely terminated with N-, O-, and S-bearing functionalities. These heteroatom-rich groups furnish abundant coordination anchors for metal substrates. Electrochemical assays and gravimetric measurements reveal that the CD delivers a corrosion inhibition efficiency of 95.18 % for N80 steel in 1 M HCl at a dosage of 200 mg/L. Adsorption conforms to the Langmuir isotherm with a Gibbs free energy of -31.66 kJ/mol, indicating a spontaneous mixed physical-chemical adsorption mechanism dominated by chemisorptive interactions from Fe-N, C-S, and S=O linkages. Surface analyses confirm a compact, adherent protective film that strongly retards both anodic dissolution and cathodic hydrogen evolution. Capitalizing on the intrinsic blue fluorescence of the CD, the system additionally accomplishes in-situ reporting of corrosion progression: fluorescence quenching occurs synchronously with Fe3+/Fe2+ release as the film degrades. This work establishes a single-component “protect-and-report” platform, offering an effective and conceptually innovative strategy for next-generation corrosion management.

The extreme conditions and complex compositions of industrial wastewater, particularly from the printing and chemical sectors, present a dual challenge: accelerated corrosion of metallic infrastructure and persistent environmental pollution. Here, we report a conceptually innovative, dual-functional solid capsule (EP/PEI/BTA) designed to address both issues simultaneously through a single, integrated material system. Synthesized via a facile curing reaction between epoxy resin (EP) and polyethyleneimine (PEI), the capsule encapsulates the corrosion inhibitor 1H-Benzotriazole (BTA) within a robust, three-dimensional polymer network. The system’s functionality is activated by the wastewater itself: upon exposure to aqueous media, the PEI-rich network undergoes controlled swelling. This swelling precisely triggers the sustained, environment-responsive release of BTA to form a protective film on metal surfaces, while simultaneously stretching the polymer chains to expose abundant intrinsic amino groups. These sites act as potent adsorption centers, enabling efficient capture of coexisting anionic pollutants such as dyes and oxyanions. Electrochemical analysis reveals exceptional long-term corrosion inhibition, with efficiencies reaching 94.65% for N80 steel in saline, acidic high-temperature conditions over 30 days. Concurrently, the capsules exhibit remarkable adsorption capacities for methyl orange (85.22%), dichromate (97.06%), and phosphate (90.29%), driven by strong electrostatic interactions and surface complexation. The release and adsorption kinetics are systematically tunable by adjusting the EP/PEI ratio, pH, and temperature. This work establishes a paradigm-shifting ”one-agent-multiple-effects” strategy, providing a robust, scalable, and intelligent solution to the intertwined challenges of corrosion and water contamination in aggressive industrial environments.