Halloysite for smart nano-structured materials in sustainable applications
type: CreativeWork
description: Biohybrid nanostructured materials were prepared by the co-assembling of inorganic particles, i.e. nanoclays, with organic moieties such as biopolymers. Among clays, Halloysite Nanotubes (HNTs) were deeply investigated due to their peculiar properties: morphology, different chemistry and charges on the internal and external surfaces, high aspect ratio, no toxicity, eco-friendliness and low cost. Hence, this thesis begins with a fundamental study of the thermodynamics of water confinement within the cavity of halloysite, which is at the basis for the loading mechanism of guest molecules inside its inner volume. By using Knudsen Thermogravimetry, it was found that the confined solvent exhibits a vapor pressure larger than the bulk solvent and, consequently, a faster evaporation rate. In particular, it was found that the variation of the pressure conditions during the loading procedure is responsible for the optimization of the encapsulation efficiency within halloysite nanotubes and it also allows to target the accumulation site of the guest molecules inside/outside the nanoclay, as observed by Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM). More importantly, these insights are crucial in order to tune and control the kinetics of release of active species from the clay. After this fundamental physico-chemical studies, we worked on the selective functionalization of HNTs with oppositely charged polymers and biopolymers by exploiting the electrostatic interactions arising between the organic/inorganic counterparts, as investigated by Differential Scanning Calorimetry (DSC), Dynamic Light Scattering (DLS) and contact angle measurements. The precise tailored adsorption site allowed to generate smart stimuli-responsive nanocarriers, as resulted from UV-Vis spectroscopy. Then, gel beads based on chitosan with uniformly dispersed halloysite nanotubes were obtained by a dropping method. Alginate was used to generate a coating layer over the hybr…
abstract: Biohybrid nanostructured materials were prepared by the co-assembling of inorganic particles, i.e. nanoclays, with organic moieties such as biopolymers. Among clays, Halloysite Nanotubes (HNTs) were deeply investigated due to their peculiar properties: morphology, different chemistry and charges on the internal and external surfaces, high aspect ratio, no toxicity, eco-friendliness and low cost. Hence, this thesis begins with a fundamental study of the thermodynamics of water confinement within the cavity of halloysite, which is at the basis for the loading mechanism of guest molecules inside its inner volume. By using Knudsen Thermogravimetry, it was found that the confined solvent exhibits a vapor pressure larger than the bulk solvent and, consequently, a faster evaporation rate. In particular, it was found that the variation of the pressure conditions during the loading procedure is responsible for the optimization of the encapsulation efficiency within halloysite nanotubes and it also allows to target the accumulation site of the guest molecules inside/outside the nanoclay, as observed by Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM). More importantly, these insights are crucial in order to tune and control the kinetics of release of active species from the clay. After this fundamental physico-chemical studies, we worked on the selective functionalization of HNTs with oppositely charged polymers and biopolymers by exploiting the electrostatic interactions arising between the organic/inorganic counterparts, as investigated by Differential Scanning Calorimetry (DSC), Dynamic Light Scattering (DLS) and contact angle measurements. The precise tailored adsorption site allowed to generate smart stimuli-responsive nanocarriers, as resulted from UV-Vis spectroscopy. Then, gel beads based on chitosan with uniformly dispersed halloysite nanotubes were obtained by a dropping method. Alginate was used to generate a coating layer over the hybr…
author: LISUZZO, LORENZO
language: ita
keywords: clays,halloysite,biopolymers,hybrids
date published: 2021-01-12
date modified: 2026-07-24T01:34:49Z
provider: Università degli Studi di Catania
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: Università degli studi di Catania

PropertyValue
property ID: Handle
value: https://hdl.handle.net/20.500.11769/581177