Rheological Properties of MWCNT-Doped Titanium-Oxo-Alkoxide Gel Materials for Fiber Drawing.

Tanel Tätte,Medhat Hussainov,Irina Hussainova,Alexander Vanetsev,Madis Paalo,Mahsa Amiri

doi:10.3390/ma15031186

Tanel Tätte, Medhat Hussainov + Show 4 more

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https://doi.org/10.3390/ma15031186

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Journal: Materials	Publication Date: Feb 4, 2022
Citations: 1	License type: CC BY 4.0

Affiliation: University of Tartu, Tallinn University of Technology

Abstract

A strategy of doping by multi-walled carbon nanotubes (MWCNT) to enhance mechanical strength and the electrical conductivity of ceramic fibers has nowadays attracted a great deal of attention for a wide variety of industrial applications. This study focuses on the effect of MWCNTs on rheological properties of metal alkoxide precursors used for the preparation of nanoceramic metal oxide fibers. The rheological behavior of MWCNT-loaded titanium alkoxide sol precursors has been evaluated via an extensional rheometry method. A substantial decrease in elongational viscosity and relaxation time has been observed upon an introduction of MWCNTs even of low concentrations (less than 0.1 wt.%). A high quality MWCNT/nanoceramic TiO2 composite fibers drawn from the specified precursors has been validated. The MWCNT percolation, which is mandatory for electrical conductivity (50 S/m), has been achieved at 1 wt.% MWCNT doping.

Highlights

Carbon nanotubes (CNT) of superior mechanical, electrical, and thermal properties [1,2,3,4] are frequently used in order to enhance the properties of a wide variety of materials, for example, ceramics and/or ceramic matrix composites (CMCs)
A strategy of doping by multi-walled carbon nanotubes (MWCNT) to enhance mechanical strength and the electrical conductivity of ceramic fibers has nowadays attracted a great deal of attention for a wide variety of industrial applications
This study focuses on the effect of MWCNTs on rheological properties of metal alkoxide precursors used for the preparation of nanoceramic metal oxide fibers

Summary

Introduction

Carbon nanotubes (CNT) of superior mechanical, electrical, and thermal properties [1,2,3,4] are frequently used in order to enhance the properties of a wide variety of materials, for example, ceramics and/or ceramic matrix composites (CMCs). One of the key challenges in the preparation of the reinforced composites is the uniform dispersion of CNTs in the matrix. The first approach is based on applying shear forces to distribute CNTs throughout preliminarily prepared matrix precursors, ultrasonic probes, ball milling, etc. Solid composites with a desired structure are obtained as a result of gelation of an initial sol matrix, which is typically prepared from metal alkoxides [16]. A sol-gel procedure offers a simple method for giving a final shape for the materials at a room temperature. During the sol-gel transition, the viscosity of sol-material increases until the material transforms elastic gels as a result of formation of a 3D gel network over the whole volume [17,18]

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