Interfacial Self-Assembly in Halloysite Nanotube Composites

Abstract

A self-assembly of clay nanotubes in functional arrays for the production of organized organic/inorganic heterostructures is described. These 50-nm-diameter natural alumosilicate nanotubes are biocompatible. Halloysite allows for 10–20 wt % chemical/drug loading into the inner lumen, and it gives an extended release for days and months (anticorrosion, self-healing, flame-retardant, antifouling, and antibacterial composites). The structured surfaces of the oriented nanotube micropatterns enhance interactions with biological cells, improving their capture and inducing differentiation in stem cells. An encapsulation of the cells with halloysite enables control of their growth and proliferation. This approach was also developed for spill petroleum bioremediation as a synergistic process with Pickering oil emulsification. We produced 2–5-nm-diameter particles (Au, Ag, Pt, Co, Ru, Cu–Ni, Fe3O4, ZrO2, and CdS) selectively inside or outside the aluminosilicate clay nanotubes. The catalytic hydrogenation of benzene and phenol, hydrogen production, impacts of the metal core–shell architecture, the metal particle size, and the seeding density were optimized for high-efficiency processes, exceeding the competitive industrial formulations. These core–shell mesocatalysts are based on a safe and cheap natural clay nanomaterial and may be scaled up for industrial applications.

Facile Fabrication of Natural Polyelectrolyte-Nanoclay Composites: Halloysite Nanotubes, Nucleotides and DNA Study

“…Clay-based composite materials have found numerous applications in recent years, opening new opportunities in materials science and biomedicine [1] Tailoring various biopolymers to clay particles allows for controllable self-assembly on planar and three-dimensional surfaces and fabrication of porous clay-doped polymer composites, which can be utilised in tissue engineering [2], artificial cell shellization [3] and hair surface engineering [4]. The invention of gene therapy is one of the greatest achievements of modern medicine because of its potential of overcoming cancer and serious inherited illnesses (such as neurodegenerative diseases or blood and immune disorders) that once were believed to be incurable.…”

Ruthenium-Loaded Halloysite Nanotubes as Mesocatalysts for Fischer–Tropsch Synthesis

“…These nanotubes have different inside/outside chemistry composed of Al 2 O 3 and SiO 2 , exhibiting different chemical reactivities. This allowed for selective tube lumen loading with metal ions [16].…”

“…Halloysite is a unique mineral that is formed by rolling of kaolin sheets into multiwalled mesoporous nanotubes [16]. The halloysite lumen's surface is formed by alumina, and the outer tube's surface contains silica.…”

Manganese and Cobalt Doped Hierarchical Mesoporous Halloysite-Based Catalysts for Selective Oxidation of p-Xylene to Terephthalic Acid

“…Halloysite clays were successfully applied as carriers for the tubular Ru nanocatalysts, revealing high activity in the hydrogenations of aromatic compounds and phenols [19][20][21][22][23]. Grafting of the ordered mesoporous materials, such as MCM-41 or SBA-15, onto halloysite template allows us to obtain new hierarchical systems with stronger mechanical properties and surface area up to 650 m 2 /g ( Figure 2) [21,24,25]. La-doped MCM-41/HNT composite revealed high efficacy as a sulfur-reducing additive for FCC (fluid catalytic cracking) catalyst, resulting in decrease of sulfur content by 25% and in the yield of gasoline fraction of about 45% [24,26,27].…”