UV light can cause damage to polymer coatings used in transportation, oil, and agricultural industries, requiring costly repair or replacement of the coating. Herein, a self‐healing epoxy coating is developed so that UV light activates a desirable autonomous healing response to mechanical damage. The coatings contain a single type of microcapsule with a UV‐curable epoxy healing chemistry in the core and a novel UV‐protecting shell wall with embedded carbon black particles. Photo‐differential scanning calorimetry reveals that up to a 65% degree of protection is provided by the UV‐blocking shell wall after UV exposure. The addition of a polyurethane (PU) top coat provides further increase in the level of protection (≈100%). After damage with a scribe and exposure to UV, the presence of healed epoxy is confirmed by confocal Raman and fluorescent spectroscopy. The anticorrosion performance of healed coatings on steel substrates is assessed after exposure to a simulated saltwater solution. The UV‐curable, self‐healing coating exhibits significantly less corrosion than a control coating with no self‐healing ability.

The corrosion of steel substrates causes damage that is costly to repair or replace. Current protective coatings predominately rely on environmentally harmful anticorrosive agents and toxic solvents to protect the underlying substrate. The use of lawsone (2-hydroxy-1,4-napthoquinone) together with a water-based epoxy coating provides an environmentally friendly alternative for common protective coatings. Microencapsulated lawsone embedded in an epoxy coating allows the anticorrosive agent to remain dormant until released by damage and delivered directly onto the steel substrate. UV–vis analysis confirms successful encapsulation of lawsone in a polyurethane shell wall and reveals up to 8 wt % lawsone in the capsule cores. Uniform dry film thickness and inflicted damaged are verified with ultrasound and optical microscopy. Visual and electrochemical analysis demonstrates that this self-protective scheme leads to a 70% corrosion inhibition efficiency in a neutral salt water solution.

Monodisperse stimuli-responsive microcapsules are difficult to fabricate with precise control over capsule properties. The paper reports a facile technique to produce highly tunable and monodisperse emulsion-templated acid-responsive microcapsules.

Numerical models based on the Semi Analytical Finite-Element method are used to study the characteristics of guided wave modes supported by bone-like multi-layered tubular structures. The method is first validated using previous literature and experimental studies on phantoms mimicking healthy and osteoporotic conditions of cortical bone, and later used to study a trilayer marrow-bone-tissue system at varying mechanical degradation levels. The results show that bone condition strongly affects the modal properties of axially propagating guided waves and indicates that L(0,3) and F(1,6) are suitable modes for assessing the mechanical condition of the bone. The work here reports suitable modal selection and their dispersion properties which would the aid in development of a transduction mechanism for mechanical assessment of bones.

Encapsulated anticorrosion agents provide a suitable alternative to dispersion of metal-based compounds in protective polymericcoatings on metal substrates. Stimuli-responsive microcapsules enhance protection abilities by autonomously responding to corrosion-induced environmental changes, rather than relying on damage-induced mechanical stimuli. This work reports pH-responsive microcapsules with triggered release over a wide range of acidic pH values (pH < 6) and robust enough to be incorporated in commercial solvent-based epoxy coatings. The pH responsiveness is achieved by integrating acid labile ketals that undergo rapid hydrolysis within the cross-linked polyamide shell and readily release acetylenic diol or jojoba oil as the anticorrosive agent. The microcapsules are stable up to a temperature of 150 °C and provide long-term room temperature stability up to 3 months. Degradation and release kinetics of the microcapsules are quantified at various pH levels (1 ≤ pH ≤ 9) using 1 H NMR and gas chromatography, respectively. Microcapsules exhibit complete release in under 5 min at pH 1 and ≈2 hours at pH 5, respectively. Coating performance is evaluated by electrochemical corrosion tests conducted in 5 wt% salt solutions with varying pH and concentration of the microcapsules in the coating. Inhibition efficiencies up to 70% are achieved in acidic saltwater solutions.