pH-Sensitive Polymer Conjugates for Anticorrosion and Corrosion Sensing

Area of Science:

• Materials Science
• Corrosion Engineering
• Polymer Chemistry

Background:

• Global corrosion costs exceed $2.5 trillion annually, necessitating advanced protection methods.
• Conventional corrosion inhibitors leach into the environment, reducing efficiency and causing pollution.
• Smart materials are needed to control inhibitor release and enhance corrosion protection.

Purpose of the Study:

• To design and synthesize novel smart polymer/corrosion inhibitor conjugates for controlled corrosion protection.
• To develop materials that release inhibitors specifically under acidic conditions, mimicking environmental or corrosion-induced acidity.
• To create multifunctional nanoparticles capable of simultaneous corrosion sensing and protection.

Main Methods:

• Synthesis of a polymerizable derivative of 8-hydroxyquinoline (8HQ) with acid-labile linkages.
• Copolymerization of the 8HQ derivative with ethyl acrylate to form functional polymers.
• Processing of polymers into nanoparticles and evaluation of 8HQ release kinetics under varying pH conditions.
• Encapsulation of non-conjugated 8HQ for hybrid release profiles.
• Assessment of nanoparticle fluorescence for aluminum ion detection (sensing capability).

Main Results:

• Nanoparticles demonstrated triggered release of >95% 8HQ under acidic conditions within 14 days, versus only 15% under neutral conditions.
• Encapsulated non-conjugated 8HQ exhibited rapid release (<30 min), creating a hybrid sustained-burst release profile.
• The released 8HQ showed enhanced fluorescence upon chelation with aluminum ions, indicating nanosensing capability.

Conclusions:

• Smart polymer/corrosion inhibitor nanoparticles offer a new generation of controlled corrosion protection, releasing inhibitors on demand.
• The developed materials provide a tunable release profile and dual functionality for simultaneous corrosion sensing and protection.
• This approach addresses limitations of conventional inhibitors, offering improved efficiency and environmental compatibility.