Search results for "alloys"
showing 10 items of 1689 documents
A synergic nanoantioxidant based on covalently modified halloysite–trolox nanotubes with intra-lumen loaded quercetin
2016
We describe the preparation and properties of the first example of a synergic nanoantioxidant, obtained by different functionalizations of the external surface and the inner lumen of halloysite nanotubes (HNTs). Trolox, a mimic of natural α-tocopherol, was selectively grafted on the HNT external surface; while quercetin, a natural polyphenolic antioxidant, was loaded into the inner lumen to afford a bi-functional nanoantioxidant, HNT–Trolox/Que, which was investigated for its reactivity with transient peroxyl radicals and a persistent 1,1-diphenyl-2-picrylhydrazyl (DPPH˙) radical in comparison with the corresponding mono-functional analogues HNT–Trolox and HNT/Que. Both HNT–Trolox and HNT/Q…
Halloysite Nanotubes as Support for Metal-Based Catalysts
Halloysite nanotubes (HNTs) are a natural, biocompatible, environmental friendly and cheap double-layered aluminosilicate mineral that has a predominantly hollow tubular structure. The general stoichiometry of halloysite is Al2Si2O5·4(H2O). The layer units consist of a tetrahedral SiOH sheet stacked with an edge shared octahedral AlO6 sheet with an internal aluminol group AlOH. A water layer exists between the adjacent two layers. Thanks to their structural features, HNTs are suitable for a potential application as support for catalytic composites. Recently, we reported the synthesis of novel palladium-based catalytic systems using halloysite nanotubes modified with imidazolium or triazoliu…
Covalently Modified Halloysite Clay Nanotubes: Smart Nanomaterials for Drug Delivery Applications
2017
Halloysite nanoclays (HNTs) are promising nanomaterials because of their versatile properties, such as hollow tubular morphology and tunable surface chemistry. HNTs are biocompatible, no toxic and abundantly available at low cost. Due to these characteristics HNTs are suitable for development of hybrid sustainable materials, which are perspective for polymeric matrices reinforcement, active food packaging and drug delivery. HNTs are quite polydisperse in size with a length of ca. 1 m, while the external diameter and the lumen range between 50-80 nm and 10-15 nm, respectively. Chemically, halloysite is composed of gibbsite octahedral sheet (Al-OH) groups on the inner surface and siloxane (S…
Covalently modified halloysite clay nanotubes: synthesis, properties, biological and medical applications
2017
Halloysite (HNT) is a promising natural nanosized tubular clay mineral that has many important uses in different industrial fields. It is naturally occurring, biocompatible, and available in thousands of tons at low cost. As a consequence of a hollow cavity, HNT is mainly used as nanocontainer for the controlled release of several chemicals. Chemical modification of both surfaces (inner lumen and outer surface) is a strategy to tune the nanotube's properties. Specifically, chemical modification of HNT surfaces generates a nanoarchitecture with targeted affinity through outer surface functionalization and drug transport ability from functionalization of the nanotube lumen. The primary focus …
SYNTHESIS AND CHARACTERIZATION BY THERMOGRAVIMETRIC ANALYSIS OF A NEW DRUG DELIVERY SYSTEM BASED ON HALLOYSITE NANOTUBES
2015
Recent Researches on Halloysite Nanotubes a Smart Nanomaterials for Several Applications
2016
Halloysite clay are aluminosilicate nanomaterials (HNTs) with an unique combination of hollow tubular nanostructure, large aspect ratio, suitable mechanical strength, high perspectives in terms of functionality, biocompatibility ecocompatibility and wide availability. Moreover, their low cost makes them attractive alternative to the better known carbon nanotubes. As a consequence, in the last years, HNTs have garnered particular interest in material science. HNTs possess different inner and outer surface composition; in particular most of the aluminol groups are located in the halloysite inner surface, whereas the external portions are mainly composed of siloxanes providing a surface availa…
Halloysite Nanotubes/Perfluoroctanote: an efficient consolidant and flame retardant for paper
2014
Clay nanotubes for designing eco-compatible smart materials
2013
MICROWAVE-ASSISTED FUNCTIONALIZATION OF HALLOYSITE NANOTUBE SURFACE
2014
Halloysite, Al2Si2O5·2H2O, is a naturally occurring two-layered alluminosilicate, chemically similar to kaolin, which has a predominantly high-aspect-ratio hollow tubular structure in the submicrometer range and an internal diameter in the nanometer range. The size of halloysite nanotubes (HNTs), generally varies from 50 to 70 nm in external diameter, ca. 15 nm diameter lumen, and 0.5 to 1 μm in length. Halloysite tubes have aluminol (Al-OH) groups on the internal surface and siloxan groups (Si-O-Si) on the external surface. The very large diameter of the halloysite lumen makes it potentially suitable for the accommodation of a range of guests. In recent reports, for example, the mesoporous…