Halloysite Tubes as Nanocontainers for Anticorrosion Coating with Benzotriazole

Abstract

Halloysite clay nanotubes were investigated as a tubular container for the corrosion inhibitor benzotriazole. Halloysite is a naturally occurring cylindrical clay mineral with an internal diameter in the nanometer range and a length up to several micrometers, yielding a high-aspect-ratio hollow tube structure. Halloysite may be used as an additive in paints to produce a functional composite coating material. A maximum benzotriazole loading of 5% by weight was achieved for clay tubes of 50 nm external diameters and lumen of 15 nm. Variable release rates of the corrosion inhibitor were possible in a range between 5 and 100 h, as was demonstrated by formation of stoppers at tube openings. The anticorrosive performance of the sol-gel coating and paint loaded with 2-5% of halloysite-entrapped benzotriazole was tested on copper and on 2024-aluminum alloy by direct exposure of the metal plates to corrosive media. Kinetics of the corrosion spot formation at the coating defects was analyzed by the scanning vibrating electrode technique, and an essential damping of corrosion development was demonstrated for halloysite-loaded samples.

Development and characterization of co-loaded curcumin/triazole-halloysite systems and evaluation of their potential anticancer activity

“…According to literature (Veerabadran et al, 2007) we performed a loading procedure from an aqueous solvent containing methanol, which provided higher solubility for the drug. Loading of the p-HNT with curcumin was based on vacuum cycling of a halloysite suspension in a saturated solution containing curcumin, as described previously (Price et al, 2001;Abdullayev et al, 2009). This cycle was repeated several times in order to get the highest loading efficiency.…”

Escalating Applications of Halloysite Nanotubes

“…For the HNTs-HPC nanocomposite films an increase in the water contact angle was observed 49 . HNTs are a good candidate for self healing anticorrosion coating formulations 8,[60][61][62] . Polyurethane and acrylic paints doped with HNTs laden with benzotriazole, 2-mercaptobenzimidazole, and 2-mercaptobenzothiazole corrosion inhibitors produce self-healing nanocomposites coatings for copper 62 .…”

“…HNTs lumen can act as biomimetic nanoreactor to carry enzyme-catalyzed inorganic preparations 8 . HNTs are used as a tubular pot for benzotriazole which is a corrosion inhibitor.…”

Halloysite nanotubes loaded with peppermint essential oil as filler for functional biopolymer film

“…10-30 nm and 40-70 nm, respectively . Halloysite possesses a positive alumina inner lumen and a negative silica outer surface allowing its selective functionalization (Arcudi et al, 2014;Cavallaro, Lazzara, & Milioto, 2012), the formation of a liquid crystalline phase (Luo et al, 2013) and the encapsulation of chemically and biologically active compounds Lvov, Shchukin, Möhwald, & Price, 2008;Lvov, Wang, Zhang, & Fakhrullin, 2016;Lvov, DeVilliers, & Fakhrullin, 2016;Shutava, Fakhrullin, & Lvov, 2014;), such as drugs (Aguzzi, Cerezo, Viseras, & Caramella, 2007;Lun, Ouyang, & Yang, 2014), natural molecules (Massaro, Piana et al, 2015), marine biocides (Wei et al, 2014), cosmetics (Suh et al, 2011), and other functional agents (Abdullayev, Price, Shchukin, & Lvov, 2009). HNT are suitable as catalytic supports (Machado, de Freitas Castro, Wypych, & Nakagaki, 2008;Massaro et al, 2014;, adsorbent nanomaterials for wastewater decontamination (Szczepanik & Słomkiewicz, 2016;Zhang et al, 2016), and nanofiller for sustainable packaging (Liu, Wu, Jiao, Xiong, & Zhou, 2013;Tescione, Buonocore, Stanzione, Oliviero, & Lavorgna, 2014).…”