Abstract
A new natural nanomaterial in Saudi Arabian soil has been explored. It is green nanoclay consisting of two-dimensional nanoparticles with special properties and dimensions. These nanoparticles are called Saudi halloysite-like nanotubes (SHNTs) because they are similar to halloysite nanotubes (HNTs). SHNTs are transparent having a special cross-section in polygonal shapes, such as hexagonal, with unique dimensions in comparison to that of HNTs. Additionally, external width of SHNTs is 20-50 nm, length is 50-600 nm and can reach 10,000 nm while lumen width of SHNTs is larger than that of HNT, along with SHNTs having thinner walls; these attributes make SHNTs good as nanocontainer. Surface area of SHNTs (168 m(2)/g) is larger than surface area of HNTs (65 m(2)/g). SHNTs are bendable with a slight curvature, while HNTs are always straight. Geometry, dimensions, microstructure, chemical composition, surface area and zeta potential of SHNTs are characterized using SEM, TEM, EDX, Langmuir surface area technique, a laser particle size analyser and ZP analysis. SHNTs have many applications in industrial, medical and advanced nanocomposite production. Experimental work has been carried out on nanocomposites made of HDPE reinforced with 5% SHNTs, proving enhancements in mechanical, fracture and thermal properties of original HDPE materials.