PROJECT: LIFE12 ENV/IT/352  «BIONAD»
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PROJECT: LIFE12 ENV/IT/352 «BIONAD»

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PROJECT: LIFE12 ENV/IT/352 «BIONAD»




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Presentation on theme: "PROJECT: LIFE12 ENV/IT/352 «BIONAD»"— Presentation transcript:

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 2015

Slide2

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

level

Slide3

DR202

DY42

DB27

Naturalised

 

dyes:

a new

chemical

bridge

linkingthe chromophore and lactose 

LACTOSE

Slide4

Commercial acid dyes: the chromophore and many unknown impurities

O37

Y49

R249

B113

Slide5

Leather dyeing procedure

0.2 g

2 mg/mL2% (dye/leather)

Magnetic stirring

at 20°C for 1 h

Heating at 55°C

400 µL

MilliQ

+ 4 mg formic acidMagnetic stirring for 0.5 h

Washing with 4 mL MilliQfor 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 analysis

Slide6

Dyed leather characterization

Naturalised

dyes

Commercial acid dyes

2%

5%

10%

15%

B.1, B.2, B.4

Slide7

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.4

Slide9

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.4

Slide10

COLLAGEN CROSS-LINKINGFT-IR

~1654 cm

-1

/~1690 cm

-1

Collagen cross-linking type

B.1, B.2, B.4

C

ross

-

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-IR

Absorbance 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

colorants

Slide12

The

Amide

I

peak fitting of FTIR spectra: collagen conformational analysis

The 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 I

Slide13

The

Amide

I

peak fitting of FTIR spectra: collagen conformational analysis

2%

NDs

ADs

>5% NDs

Higher

helix

percentages (48%)Higher 1660/1690 cm-1 ratio valuesHigher cross-linking

Lower helix percentages (38%)Lower 1660/1690 cm-1 ratio valueslower cross-linking

Two phenomena may contribute to high cross-linking and higher helix percentage: the treatment with formic acidThe 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-linking

Stacking

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

hindrance

Slide14

Characterization using Thermo Gravimetric Analysis (TGA)

Gas: N

2

200

mL/minHeating: 30-700°C, 10 °C/min

Slide15

TGA: same trend

B.1, B.2, B.4

Naturalised

2%

Commercial

2%

Naturalised

15%

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 withcrosslinked structures, in agreement with the literature data [32-34].

Higher

cross-

linking

=

higher

thermal

stability

Slide16

Conclusions

NDs

may

be competitive with the

traditional

AD

because

of

their

eco

-

friendly

properties

better

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 leathermanufacture

D

etermination

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 leatherManufacture. 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 leatherManufacture. Determination of Cr and Co dyeing waste solution of Sheep Hide

R

esidual

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 leatherManufacture. Determination of Cr and Co dyeing waste solution of Calf Hide

R

esidual

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

dyes

C.6

Monitoring of quality assessment for leather dyed with naturalised dyes

Slide23

Slide24

Slide25