title: Enlargement of halloysite clay nanotube lumen by selective etching of aluminum oxide.
abstract: Halloysite clay tubes have 50 nm diameter and chemically different inner and outer walls (inner surface of aluminum oxide and outer surface of silica). Due to this different chemistry, the selective etching of alumina from inside the tube was realized, while preserving their external diameter (lumen diameter changed from 15 to 25 nm). This increases 2-3 times the tube lumen capacity for loading and further sustained release of active chemical agents such as metals, corrosion inhibitors, and drugs. In particular, halloysite loading efficiency for the benzotriazole increased 4 times by selective etching of 60% alumina within the tubes' lumens. Specific surface area of the tubes increased over 6 times, from 40 to 250 m(2)/g, upon acid treatment.
authors: Institute for Micromanufacturing, Louisiana Tech University, 911 Hergot Avenue, Ruston, Louisiana 71272, USA.
authors: Elshad
authors: E
authors: Abdullayev
authors: Anupam
authors: A
authors: Joshi
authors: Wenbo
authors: W
authors: Wei
authors: Yafei
authors: Y
authors: Zhao
authors: Yuri
authors: Y
authors: Lvov
mesh_terms: D000537:Aluminum Oxide / Q000737:chemistry*; D000538:Aluminum Silicates / Q000737:chemistry*; D000077215:Clay; D003460:Crystallization / Q000379:methods*; D046911:Macromolecular Substances / Q000737:chemistry; D008422:Materials Testing; D008968:Molecular Conformation; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure*; D010316:Particle Size; D016062:Porosity; D013499:Surface Properties
chemical_list: D000538:Aluminum Silicates; D046911:Macromolecular Substances; D000537:Aluminum Oxide; D000077215:Clay