The University of Southampton
University of Southampton Institutional Repository

Spontaneous scrolling of kaolinite nanosheets into halloysite nanotubes in an aqueous suspension in the presence of GeO2

White, Rachel D., Bavykin, Dmitry V. and Walsh, Frank C. (2012) Spontaneous scrolling of kaolinite nanosheets into halloysite nanotubes in an aqueous suspension in the presence of GeO2 The Journal of Physical Chemistry C, 116, (15), pp. 8824-8833. (doi:10.1021/jp300068t).

Record type: Article


Despite the natural occurrence of aluminosilicate nanotubes as mineral halloysite, suitable hydrothermal methods for their preparation are still undeveloped due to their lower thermodynamic stability under hydrothermal conditions. The effect of addition of GeO2 to the reaction mixture of SiO2 and Al(OH)3 on the distribution of the morphologies of nanostructured aluminosilicates obtained under hydrothermal treatment at pH 2 and 220 ºC has been systematically studied. It was found that the formation of multilayered nanotubes of halloysite (Al2Si2O5(OH)4) occurs at 0.2 Ge/(Si+Ge) molar fraction after 7 days of hydrothermal treatment. The as-obtained halloysite nanotubes are characterized by a high degree of crystallinity, a multilayered (25-40 layers) wall structure and a typical inner diameter of 5-15 nm. A further increase in Ge/(Si+Ge) molar fraction to 0.5 results in precipitation of single walled nanotubes analogous to germanium-containing imogolite (Al2SixGe1-xO3(OH)4, x ~ 0.65) characterized with an average inner diameter of 0.9-1.2 nm. At a lower molar ratio (0.05, 0.1) partially curved, multilayer nanosheets of kaolinite are produced. The complete analysis of structure and morphology of all products was performed using TEM, EDX, SAED, FTIR and nitrogen adsorption. The mechanism governing the precipitation of Al2Si2O5(OH)4 nanotubes in the presence of Ge(IV) is discussed.

PDF 2012-Spontaneous_Scrolling_of_Kaolinite_Nanosheets_into_Halloysite_Nanotubes_in_an_Aqueous_Suspension_in_the_Presence_of_GeO2.pdf - Version of Record
Restricted to Repository staff only
Download (6MB)

More information

Published date: 2012
Keywords: halloysite, hydrothermal synthesis, germanium oxide
Organisations: Engineering Mats & Surface Engineerg Gp


Local EPrints ID: 337525
ISSN: 1932-7447
PURE UUID: 0bf912f3-698e-4ac4-b569-f41e35f5243b

Catalogue record

Date deposited: 26 Apr 2012 14:37
Last modified: 18 Jul 2017 06:02

Export record


Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton:

ePrints Soton supports OAI 2.0 with a base URL of

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.