Ciencia y Tecnología del Color
Seminario 2009
Viability of Dyeing of Natural and
Synthetic Fibers with Nanopigments in
Supercritical CO2
Bàrbara Micó, Verónica Marchante,
Francisco Martínez-Verdú, Eduardo Gilabert
ÍNDEX

Introduction

Supercritical CO2
Dyeing in supercritical CO2

Nanopigments and nanoclays



Objectives
State of the art







Colorant selection
Fibres
Process variables
Challenges
Solutions / Future perspectives
Advantages of using Nanopigments
References / Acknowledgements
INTRODUCTION


Supercritical CO2 : Solvent
Properties
 Low
cost
 Non-Toxic
 Density: liquid
 Viscosity: Gas
 Recycling up to 90%
 Inert
 Non-explosive
 Low critical point
 Pressure: 73.858 ± 0.005 bar
 Temperature: 31.05 ± 0.05 ºC
DYEING IN SUPERCRITICAL CARBON DIOXIDE

ADVANTAGES
 No waste water
(problem in textile
industry)
 No require additives
 No final drying
 Recycling
 Solvent
 Colorants
 Environmental
friendly

DRAWBACKS
 Investment
 Solve colorants
 Time of process
NANOPIGMETS

NANONATERIALS: since 90’s
 Hybrid materials consisting of organic dyes and
layered silicate nanoparticles
 Nanoclay: particle size < 20nm
 Ionic-exchange reaction: Colorant + Nanoclay
(H+)
 Nanoclays: Smectite group
Montmollonite: laminar
 Sepiolite: acicular

Scheme of nanopigments’ synthesis at laboratory
Stage 1
Nanoclay
H2O deionized
Sieving
Dispersion
+
Stage 2
Colorant solution
Ionic Exchange
Washing and Filtering
Drying
APLICATIONS:
- Coloration of Plastics
- Printing Inks
- Functional materials
Schematic representation of clay sheet, dye
molecule (methylene blue) and blue Nanopigment.
e arcilla
3
3
CH
metileno
e arcilla
S
CH
CH
3
3
N
3
CH
3
CH
3
CH
CH
S
CH
N
3
CH
3
S
CH
N
3
N
3
CH
CH
CH
3
3
S
H3
CH
N
C
3
CH
3
S
CH
N
C
S CH
3
N
N
3
N
N
3
C
H3
N
3
CH
N
N
CH
3
CH
N
N
CH
3
CH S
3
S
3
CH
3S
CH
N
3
CH
S CH3
CH
N
3
CH
3
CH
3
3
CH
CH
H3
3
CH
N
N
CH
N
N
S CH3
3
CH S
3
N
3
CH
H3
3
CH
N
N
CH
3
N
3
CH
3
CH
N
N
S CH3
3
CH
N
N
3
CH
N
N
C
S C H3
3
CH
CH
3
3
N
N
3
CH
N
N
C
3
N
3
CH
S
H3
CH
N
N
3
CH
N
N
3
CH
CH
N
N
3
N
3
CH
N
CH
3
N
CH
3
S
N
OBJECTIVES: PROJECT AITEX-AINIA-UA
2. SELECTION /MATERIAL DEVELOPMENT
2.2. COLORANTS
2.3. ANTIBACTERIAL
AGENTS
3. DISSOLUTION OF MATERIALS IN
SC CO2
4. POLYMER IMPREGNATION IN
SC-CO2
6. REENGINIEERING
7. VIABILITY / ECONOMIC
5. CHARACTERIZE
TREATED
MATERIAL
WITH SC-CO2
8. RESULTS AND DOFUSION
1.STATE OF THE ART
2.1. POLIMERS
STATE OF THE ART
Colorants that can be solved in scCO2
 Textile dyes classification:

 Directs
 Reactive
 Acids/Basics
 Sulphur
NOT DISSOLVED
IN SC- CO2
 Vat
 Mordant
 Disperse
 Pigments
DISSOLVED IN
SC-CO2
COLORANT SELECTION
DISPERSE DYES
 Azoic [ N N ]
 The
most important disperse dyes
 Cheaper and easy manufacture
 From non polar fibers

Anthraquinone
 It’s
more soluble [1]
 More expensive
MORE
SOLUBILITY
COLORANT: SELECTION
REACTIVE DISPERSE DYES [2]
 (mono-di-)chlorotriazine  (mono-di-)-fluorotriazine
 Dyeing
of natural fibers
 Protein or synthetic fibers
REACTIVE GROUPS CHANGE
THE COLORANT’S SOLUBILITY
N
R
N
Cl
N
Colorant
Colorante
 Dyeing
cotton
 Using different co-solvents
 Methanol improves the
solubility
+ Fibre
Fibra-OH
Fibre
O Fibra
N
R
N
N
Colorant
Colorante
COLORANT SELECTION
REACTIVE DYES



Vinylsulphone : Improve fixations [3]
Are suitable for dyeing textiles containing polyester,
nylon, silk or wool.
Fixations between 70 – 90%
Solubility : [4]
-Decrease: OH, NH2,COOR’
-Increase: HX NO2
[X=F,Cl,Br,..]
PROCESS VARIABLES

Dyeing steps
 Transport

of dye to the fibres: SOLUBILITY
Works: different cosolvents
Acetonitrile
Methanol
Water
IMPROVE THE
REACTIVE
RESULTS
GROUPS
Acetone
 Reaction
of the dye with the textile: AFFINITY
 DIFFUSSION of dye into the fibres: D coefficient.
PARTICLE SIZE
EQUIPMENTS
Gas
cylinder
Carbon
dioxide pump
Pressure
gauge
Stop
valves
Pump
head
cooler
Dyeing
vessel
Stirrer
Cosolvent
pump
Cosolvent
reservoir
Back pressure
regulator
Dyeing
beam
Heating
jacket
EQUIPMENTS: AINIA PILOT PLANT
Planta FSC500
Planta SFF-58_60
Planta PFS20
FIBRES
PET the most studied
 Changes in the structure of polymers:

 Plastics:
>Tg
 Size stability

Natural fibres [5]
 Pre-treatments:
Hydrophobic and nonpolar
Polyurethane
 DMDHEU
 Solvents: Alcohol and water

CHALLENGES

We only can use non polar colorants in scCO2:

These kind of colorant haven’t affinity of natural
fibres.

There are a lot of variables in the process: Solubility
can change with:
 Colorants
(Reactive group, Particle size…)
 Pressure
 Temperature
 Substrates:

Natural or synthetic fibers
The time of process is too long: 4h
SOLUTIONS / FUTURE PERSPECTIVES
 Pre-treated fibres:
 PET:
with UV, N,N-dimethylacrylamide
 CO: DMDHEU, PUR, acetone…

Changes in structure of colorants


[6] Novel
reactive disperse dyes has been synthesized.
Control the solubility and dye process.
 Equations

to predict the solubility.
NANOPIGMENTS
ADVANTAGES OF NANOPIGMENTS




Nanopigments are a viable and environmentalfriendly alternative to traditional pigments
because of their easy synthesis and conventional
processing.
Increase the color gamut:
 We can use a lot of conventional organic dyes.
Increase the resistance of colors: UV, O2,
Temperature
Improve substrate properties: stability, strength,
permeability…
REFERENCES
[1] S. N. Joung et all. “Solubility of Disperse Anthraquinone and Azo
Dyes in Supercritical Carbon Dioxide at 313.15 to 393.15 K and from 10
to 25 MPa” J. Chem. Eng. 43, 9-12. 1998
[2] M.V. Fernandez et all “A significant approach to dye cotton in
supercritical carbon dioxide with fluorotriazine reactive dyes” J. of
Supercritical Fluids 40 477–484. 2007
[3] M. van der Kraan et all. “Dyeing of natural and synthetic textiles in
supercritical carbon dioxide with disperse reactive dyes” J. of
Supercritical Fluids 40 470–476. 2007
[4] Gerardo A. Montero et all. “Supercritical Fluid Technology in Textile
Processing: An Overview” Ind. Eng. Chem. Res., 39, 4806-4812. 2000
[5] P. L. Beltrame, et all.“Dyeing of Cotton in Supercritical Carbon
Dioxide”. Dyes and Pigments, 39, 335-340. 1998
[6] Andreas Schmidt, Elke Bach and Eckhard Schollmeyer. “Supercritical
fluid dyeing of cotton modified with 2,4,6-trichloro-1,3,5-triazine”. Color.
Technol., 119. 2003
Acknowledgements
This work is supported by Ministry of Science and
Innovation (MICINN) with the project “Aplicación de
la tecnología de fluidos supercríticos en la
impregnación de sustratos poliméricos” ref.: CIT20000-2009-2.