Hexagonal TiO2 Nanotube Synthesis via Anodic Oxidation

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Solution Overview

Problem

Existing methods for producing hexagonal TiO2 nanotubes on titanium substrates lack the ability to effectively adjust the diameter and height of the nanotubes through process conditions, often resulting in heterogeneous layers and requiring multi-step processes.

Innovation Solution

A single-step anodic oxidation process using a two-electrode system with ultrasound and a chelating agent, where the anodising voltage, time, ethylene glycol concentration, and fluoride ion concentration are controlled to produce hexagonal TiO2 nanotubes with adjustable diameter and height, utilizing a 99.7% pure titanium foil and 99.95% pure platinum foil electrodes in an electrolyte containing ethylene glycol, ammonium fluoride, and disodium edetate.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If conventional anodisation methods are used to form TiO2 nanotubes, then nanotubes can be produced on titanium substrate, but the diameter and height of nanotubes cannot be effectively adjusted through process conditions

Engineering Contradiction:
Improveadjustability of nanotube diameter and heightVSAvoidprocess condition control range
Core Design Contradiction:
Manufacturing precisionVSAdaptability or versatility

Solution Approach 1:

The invention changes multiple process parameters including anodisation voltage (10-100V), electrolyte composition (ethylene glycol, ammonium fluoride, disodium edetate), temperature, and time to achieve effective control over nanotube diameter and height. This systematic parameter optimization enables precise adjustment of nanotube structural properties that conventional methods cannot achieve.

Inventive Principle:
Principle #35Parameter changes

2Manufacturing precision

If multi-step anodisation processes are used to produce hexagonal nanotubes, then nanotube formation can be achieved, but fabrication time is increased

Engineering Contradiction:
Improvehexagonal nanotube structure qualityVSAvoidfabrication time
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The invention merges multiple anodisation steps into a single-step process by optimizing the electrolyte composition (ethylene glycol-based with ammonium fluoride and disodium edetate) and process conditions. This single-step method simultaneously achieves hexagonal nanotube structure formation with controlled diameter and height, eliminating the need for sequential treatment steps and significantly reducing fabrication time.

Inventive Principle:
Principle #5Merging (Combining)

3Ease of manufacture

If conventional electrolyte compositions are used in anodisation, then nanotube formation occurs, but the resulting layer is highly heterogeneous

Engineering Contradiction:
Improvenanotube layer formationVSAvoidnanotube layer homogeneity
Core Design Contradiction:
Ease of manufactureVSStability of the object's composition

Solution Approach 1:

The invention uses a specifically optimized electrolyte composition containing ethylene glycol (93-98%), ammonium fluoride (0.1-1%), and disodium edetate (0.01-0.1%), along with controlled anodisation voltage (10-100V) and temperature conditions. This parameter optimization ensures uniform nanotube formation throughout the layer, achieving high homogeneity that prevents the heterogeneous structure produced by conventional electrolytes.

Inventive Principle:
Principle #35Parameter changes

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This method allows for the controlled synthesis of hexagonal TiO2 nanotubes with adjustable structural parameters, reducing fabrication time and achieving a large layer height in a short time, as demonstrated by the relationships between anodising voltage, ethylene glycol concentration, and fluoride ion concentration.

Implementation Method 1

a method for producing hexagonal TiO2 nanotubes on a titanium substrate using an anodic oxidation process

Methodology Applied
Scientific EffectAnodic oxidation: Oxidation

Implementation Method 2

in a two-electrode system, where the working electrode is a titanium foil... and the reference electrode is a platinum foil

Methodology Applied
Scientific EffectElectrolysis: Electrolysis

Implementation Method 3

in the presence of ultrasound with a frequency of 45 kHz and a power of 200 W

Methodology Applied
Scientific EffectUltrasound: Ultrasound

Implementation Method 4

The barrier layer can be removed by chemical etching to form a membrane containing nanotubes with open ends

Methodology Applied
Scientific EffectChemical etching: Ablation

Implementation Method 5

in the presence of a chelating agent... 0.09% by weight of disodium edetate Na2[H2EDTA]

Methodology Applied
Scientific EffectChelation: Solvation

Data Source

PatentEP4464826A1Method of preparation of hexagonal tio2 nanotubes on titanium substrate
Publication Date: 2024.11.20 UNIV ZIELONOGORSKI
  • EP4464826A1 patent drawingFigure 1~2
  • EP4464826A1 patent drawingFigure 3~4
  • EP4464826A1 patent drawingFigure 5~6

AI summary

The present invention relates to a method for producing hexagonal TiO2 nanotubes on a titanium substrate using an anodic oxidation process in the presence of a chelating agent and ultrasound, wherein the anodic oxidation process is carried out: in a two-electrode system, where the working electrode is a titanium foil, preferably 99.7% pure and 0.25 mm thick, and the reference electrode is a platinum foil, preferably 99.95% pure and 0.05 mm thick; in a single step at a constant anodising voltage in the range 10 to 100 V, preferably 20 to 80 V; in the presence of ultrasound with a frequency of 45 kHz and a power of 200 W; in an electrolyte containing: 90-97.5% ethylene glycol, 2.5-10% deionised water, 0.1-0.5% by weight of ammonium fluoride, and 0.09% by weight of disodium edetate Na2[H2EDTA]; between 10 and 180 minutes, preferably between 40 and 90 minutes.