Tannic complexes coated nanocontainers for controlled release of corrosion inhibitors in self-healing coatings

Thermoresponsive Polymer Gating System on Mesoporous Shells of Silica Particles Serving as Smart Nanocontainers

“…It has been reported that the size and shape of MSNs can be easily tailored by varying the temperature [7,8], reactants ratio [9], pH [10], surfactant chain length [11], as well as the addition of functional organosilanes [12]. Properly tailored MSNs found applications in numerous fields such as drug delivery systems [13,14], wastewater treatment [15,16], catalysis [17,18], fabrication of nanoreactors [19,20] and nanocontainers [21,22].…”

Nanocontainer-based self-healing coatings: current progress and future perspectives

“…Novel benzotriazole-loaded nanocontainers with additional shell functionality were developed using a tannic acid-Fe(III) complex (TAC) as the shell and benzotriazole as the loaded inhibitor. 70 The deposition of TAC as a shell for BTA-loaded nanocontainers takes only 20 s. Electrochemical impedance of the blank coating presented a downward trend over 20 days. In terms of coatings with nanocontainers-BTA@TAC, the impedance modulus at 0.01 Hz increased from 4.7 Â 10 4 O cm 2 to 1.8 Â 10 5 O cm 2 .…”

Mesoporous silica nanoparticles as carriers of active agents for smart anticorrosive organic coatings: a critical review

“…Finally, BTA was loaded into the obtained system, exploiting its high capability to penetrate into PANI: 151 the peculiarity of this process is that BTA loading is performed after the obtainment of the PANI external layer. Finally, with another approach, Qian et al 152 reported a pH-responsive capping layer, based on tannic acid (TA)-Fe 3+ complexes, able to coat BTA loaded MSN and act as effective capping agents for the loaded BTA. With the proposed approach, the authors exploited the pH dependent stability of the TA-Fe 3+ complex and the affinity of the complex to the MSN substrates, without any further MSN surface functionalization, avoiding the polyelectrolyte layers deposition.…”

“…143 Alkaline ambient sensitive nanoparticles were also showed in another work, where MSN loaded with BTA and covered with PSS/PEI polyelectrolyte layers were developed. 142 BTA is widely exploited in pH-responsive nanocontainers applications, 105,119,[140][141][142]145,152 due to the repulsive electrical force induced by moving from neutral pH to acid or basic pH. 105 Therefore, BTA release is encouraged both in acid and in alkaline solutions, as reported by Borisova et al, 105 who simply loaded BTA in MSN and observed the corrosion inhibitor release rate, and Grigoriev et al, 145 who tested some pHresponsive polyelectrolyte layers, made by PEI, BYS and poly (allylamine hydrochloride) (PAH) or poly(diallyldimethylammonium chloride) (PDADMAC) and molybdate.…”