PROJECT: LIFE12 ENV/IT/352 «BIONAD» - PowerPoint Presentation

Slide1

PROJECT: LIFE12 ENV/IT/352 «BIONAD»

<<

Naturalised dyes replacing commercial colorants for environmentally friendly leather dyeing and water recycle>>

EMILIA BRAMANTI

ICCOM-CNR, Pisa

12 Months Progress Meeting – SERICHIM premises, TORVISCOSA (UDINE), January 29th 2015Slide2

Actions of the last 6 months

B.1

BIOKIMICA, INESCOP, ICCOM-CNR(0-6 months)

Demonstration of the use of traditional chemical acid dyes

in

leather

dyeing

B.2

BIOKIMICA, INESCOP, (ICCOM-CNR)

(0-6

months

)

Demonstration

of the

quality

features

of

dyed

leather

with

acid

dyes

B.4

BIOKIMICA, (ICCOM-CNR)

(3-9

months

)

Demonstration

of

naturalised

dyes

in

leather

dyeing

at

laboratory

levelSlide3

DR202

DY42

DB27

Naturalised

dyes:a new chemical bridge linkingthe chromophore and lactose 

LACTOSESlide4

Commercial acid 

dyes: the chromophore and many unknown im

purities

O37

Y49

R249B113Slide5

Leather dyeing procedure

0.2 g

2 mg/mL2% (dye/leather)

Magnetic stirring

at 20°C for 1 h

Heating at 55°C400 µL

MilliQ

+

4 mg

formic acid

Magnetic stirring for 0.5 h

Washing with 4

mL

MilliQ

for 3

times and drying at room T

1. Formic acid at 55°C

B.1, B.4

0.2 g of

chrome

tanned

leather

specimen

were

put in a

plastic

tube

with a 2

mL

aqueous

solution

of

dye

at

C1

concentration

(4 mg, 2%

w

/

w

),

C2 (5%

w

/

w

), C3 (10%

w

/

w

) and C4 (15

%

w

/

w). The dyeing bath was heated at 55°C and 0.4 mL of water and 4 mg of formic acid were addedThe w/w percentage of an ADs chromophore is approximate, due to the presence of additives in commercial products [2]. Instead, NDs arechemically pure products and the percentage refers to the actual weighted amount of dye.

FTIR and TG analysisSlide6

Dyed leather characterization

Naturalised

dyes

Commercial acid dyes

2%

5%

10%

15%

B.1, B.2, B.4Slide7

Naturalised

dyes

Commercial acid dyes

Formic acid

Neutralization

B.1, B.2, B.4

Dyed leather characterization

NDs

penetrate

across

the

leather

sample

better

than

ADs

and

also

in

mild

,

laboratory

stirring

conditions

.Slide8

FT-IR CHARACTERIZATION

0

500

1000

1500

2000

2500

3000

3500

0

0.02

0.04

0.06

0.08

0.1

0.12

Wavenumbers [1/cm]

Absorbance

AMIDE I

C=O

ν

~1650 cm

-1

AMIDE II

CN

ν

, NH

δ

~1550 cm

-1

ATR spectrum

128 scans

Untreated leather

COOH

ν

~1730 cm

-1

B.1, B.2, B.4Slide9

FT-IR CHARACTERIZATION

0

500

1000

1500

2000

2500

3000

3500

0

0.02

0.04

0.06

0.08

0.1

0.12

Wavenumbers [1/cm]

Absorbance

AMIDE II

CN

ν

, NH

δ

~1550 cm

-1

ATR spectrum

128 scans

Untreated leather

COOH

ν

~1730 cm

-1

AMIDE I1

~1654 cm

-1

AMIDE I2

~1636 cm

-1

AMIDE I

C=O

ν

~1650 cm

-1

B.1, B.2, B.4Slide10

COLLAGEN CROSS-LINKING

FT-IR

~1654 cm-1

/~1690 cm-1

Collagen cross-linking type

B.1, B.2, B.4Cross-linking in dyed

leather

samples

are

due

to

the

interaction

/

reaction

with

dyes

and/or with

formic

acid

employed

in the

dyeing

procedure.Slide11

Commercial

Naturalised

In

n

aturalised dyes the cross-linking is higher

COLLAGEN CROSS-LINKING - FT-IRAbsorbance ratio (1654/1690 cm-1) from the FTIR spectra of leather samples dyed with NDs and Ads

at

C1

concentration

. The

dotted

lines

represent

the ratio

values

of the blank-1

and blank

-2

samples

.

Weak

chrome

tanned

leather

W

eak

-chrome

tanned

leather

specimen

processed

with the

dyeing

procedure

in the

absence

of

colorantsSlide12

The

Amide

I peak fitting of FTIR spectra:

collagen conformational

analysisThe interaction of NDs

and ADs with leather proteins and the spectral differences observed in the 1654/1690 cm-1 ratio of Amide I band of FTIR spectrum, were studied more in detail applying a peak fitting

analysis

to the

vibrational

C=O stretching

frequencies

associated

to the amide

ISlide13

The

Amide

I peak fitting of FTIR spectra:

collagen conformational

analysis2%

NDsADs>5% NDs

Higher

helix

percentages

(48%)

Higher

1660

/1690 cm-1

ratio

values

Higher

cross-

linking

Lower

helix

percentages

(38%)

Lower 1660

/1690 cm-1

ratio

values

lower

cross-

linking

Two

phenomena

may

contribute

to high cross-

linking

and

higher

helix

percentage

:

the

treatment with

formic

acid

The

presence

of

the

lactose

unit in the dye structure. which may favor the hydrogen bonding within the amino acid residues of collagen, contributing to the stabilization of helix structure and to the increase of cross-linkingStacking interactions between chromophore rings in excess [46] that surround collagen fibers avoid the intermolecular covalent crosslinking and stretch the protein structure because of their steric hindranceSlide14

Characterization using Thermo Gravimetric Analysis (TGA)

Gas: N

2

200 mL

/minHeating: 30-700°C, 10 °C/minSlide15

TGA: same trend



B.1, B.2, B.4

Naturalised

2%

Commercial2%Naturalised15%The correlation between the thermal stability of the samples analysed and the higher

values

of

the 1660

/1690 cm-1 ratio

found

in the FTIR

study

supports

the

correlation

of

this

ratio with

crosslinked

structures

, in

agreement

with the

literature

data [32-34].

Higher

cross-

linking

=

higher

thermal

stabilitySlide16

Conclusions

NDs

may be competitive with the traditional AD

because of their

eco-friendly propertiesbetter penetrating capacity

at low concentrations (about 2%) give more cross-linked structures (better quality features to the leather in terms of resistance and flexibility

?)

Improved

biodegradability

properties

in the

presence

of common

bacteria

strains

(e.g., Escherichia coli).

This

would

offer

the

opportunity

to

treat

dyeing

effluents

in an eco-

friendly

manner

, re

-use the water for

further

dyeing

cycles

,

cutting

the

costs

associated

to water management.Slide17

Action C1.

Environmental impact of acid dyes within leather

manufacture

Determination of

metals in traditional (metalized) dyes which are employed in the dyeing process in leather industry. The aim is the assessment of the

concentration

of

metal

ions

in the

final

process

solution

for the

evaluation

of the

environmental

impact of

wastes

resulting

from

the

dyeing

process

.

The

determination

of

metals

has

been

performed

on the

solid

chemical

products

and on the

waste

solutions

at

the end of the dyeing

process.Slide18

Chemicals

and

procedures

Four

acid dyes have been selected for testing

experiments:‐ ACID YELLOW 194‐ ACID ORANGE 142‐ ACID RED 357‐ ACID BLUE 158The acid dyes have been tested in both the dyeing of sheep hide and calf hide samples. The

dyeing

solutions

(

calf

hide

: 20

g/

L;

sheep

hide

: 32

g/L).

The single

dyes

solutions

have

been

employed

and

also

in

combination

among

them

.

Metal

analysis

and

quantification

have

been

performed

by

atomic

spectrometry

(FAAS), ICP-OES.Slide19

Action C1.

Environmental impact of acid dyes within leather

Manufacture.

Determination of metals in solid dyes

Co and Cr were the principal metal components in the dyes (>> 1%).All the other metals were

present

at

trace

level

,Slide20

Action C1.

Environmental impact of acid dyes within leather

Manufacture.

Determination of Cr and Co dyeing waste solution of Sheep

HideResidual Co in waste solution: 2.1 ± 0.34 %Residual Cr inwaste solution:

11.2

± 3.7

%.Slide21

Action C1.

Environmental impact of acid dyes within leather

Manufacture.

Determination of Cr and Co dyeing waste solution of Calf

HideResidual Co in waste solution: 23 ± 11 %Residual Cr inwaste solution

: 59.6

±

21 %.Slide22

FUTURE

ACTIONS for ICCOM

C.3

Monitoring

of quality improvement for leather dyed with naturalised dyesC.6

Monitoring of quality assessment for leather dyed with naturalised dyes